Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 3161 insertions, 0 deletions

diff --git a/security/manager/ssl/osclientcerts/Cargo.toml b/security/manager/ssl/osclientcerts/Cargo.toml
new file mode 100644
index 0000000000..2e364e3218
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/Cargo.toml
@@ -0,0 +1,31 @@
+[package]
+name = "osclientcerts-static"
+version = "0.1.4"
+authors = ["Dana Keeler <dkeeler@mozilla.com>"]
+edition = "2018"
+description = "Platform-specific support for client authentication certificates in Firefox"
+repository = "https://github.com/mozkeeler/osclientcerts"
+license = "MPL-2.0"
+
+[dependencies]
+byteorder = "1.3"
+env_logger = {version = "0.10", default-features = false } # disable `regex` to reduce code size
+lazy_static = "1"
+log = "0.4"
+mozilla-central-workspace-hack = { path = "../../../../build/workspace-hack" }
+pkcs11-bindings = "0.1"
+rsclientcerts = { path = "../rsclientcerts" }
+sha2 = "0.10.2"
+
+[target."cfg(target_os = \"macos\")".dependencies.core-foundation]
+version = "0.9"
+
+[target."cfg(target_os = \"macos\")".dependencies.libloading]
+version = "0.7"
+
+[target."cfg(target_os = \"windows\")".dependencies.winapi]
+version = "0.3"
+features = ["wincrypt"]
+
+[lib]
+crate-type = ["staticlib"]
diff --git a/security/manager/ssl/osclientcerts/dynamic-library/moz.build b/security/manager/ssl/osclientcerts/dynamic-library/moz.build
new file mode 100644
index 0000000000..36c0341ca7
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/dynamic-library/moz.build
@@ -0,0 +1,33 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+USE_LIBS += ["osclientcerts-static"]
+
+UNIFIED_SOURCES += [
+    "stub.cpp",
+]
+
+if CONFIG["OS_ARCH"] == "WINNT":
+    OS_LIBS += [
+        "advapi32",
+        "crypt32",
+        "kernel32",
+        "ncrypt",
+        "userenv",
+        "ws2_32",
+        "ntdll",
+    ]
+
+if CONFIG["OS_ARCH"] == "Darwin":
+    OS_LIBS += [
+        "-framework CoreFoundation",
+        "-framework Security",
+    ]
+
+SharedLibrary("osclientcerts")
+
+NoVisibilityFlags()
+SYMBOLS_FILE = "osclientcerts.symbols"
diff --git a/security/manager/ssl/osclientcerts/dynamic-library/osclientcerts.symbols b/security/manager/ssl/osclientcerts/dynamic-library/osclientcerts.symbols
new file mode 100644
index 0000000000..562ecea21d
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/dynamic-library/osclientcerts.symbols
@@ -0,0 +1 @@
+C_GetFunctionList
diff --git a/security/manager/ssl/osclientcerts/dynamic-library/stub.cpp b/security/manager/ssl/osclientcerts/dynamic-library/stub.cpp
new file mode 100644
index 0000000000..bd20c15c4f
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/dynamic-library/stub.cpp
@@ -0,0 +1,8 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This is an intentionally empty file. It is necessary for the build system to
+// successfully convert a static rust library into a dynamic library on
+// Windows.
diff --git a/security/manager/ssl/osclientcerts/moz.build b/security/manager/ssl/osclientcerts/moz.build
new file mode 100644
index 0000000000..fa484af6a4
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/moz.build
@@ -0,0 +1,9 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += ["dynamic-library"]
+
+RustLibrary("osclientcerts-static")
diff --git a/security/manager/ssl/osclientcerts/src/backend_macos.rs b/security/manager/ssl/osclientcerts/src/backend_macos.rs
new file mode 100644
index 0000000000..34386371aa
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/src/backend_macos.rs
@@ -0,0 +1,849 @@
+/* -*- Mode: rust; rust-indent-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#![allow(non_upper_case_globals)]
+
+use core_foundation::array::*;
+use core_foundation::base::*;
+use core_foundation::boolean::*;
+use core_foundation::data::*;
+use core_foundation::dictionary::*;
+use core_foundation::error::*;
+use core_foundation::number::*;
+use core_foundation::string::*;
+use libloading::{Library, Symbol};
+use pkcs11_bindings::*;
+use rsclientcerts::error::{Error, ErrorType};
+use rsclientcerts::manager::{ClientCertsBackend, CryptokiObject, Sign, SlotType};
+use rsclientcerts::util::*;
+use sha2::{Digest, Sha256};
+use std::collections::BTreeMap;
+use std::convert::TryInto;
+use std::os::raw::c_void;
+
+// Normally we would generate this with a build script, but macos is
+// cross-compiled on linux, and we'd have to figure out e.g. include paths,
+// etc.. This is easier.
+include!("bindings_macos.rs");
+
+#[repr(C)]
+pub struct __SecIdentity(c_void);
+pub type SecIdentityRef = *const __SecIdentity;
+declare_TCFType!(SecIdentity, SecIdentityRef);
+impl_TCFType!(SecIdentity, SecIdentityRef, SecIdentityGetTypeID);
+
+#[repr(C)]
+pub struct __SecCertificate(c_void);
+pub type SecCertificateRef = *const __SecCertificate;
+declare_TCFType!(SecCertificate, SecCertificateRef);
+impl_TCFType!(SecCertificate, SecCertificateRef, SecCertificateGetTypeID);
+
+#[repr(C)]
+pub struct __SecKey(c_void);
+pub type SecKeyRef = *const __SecKey;
+declare_TCFType!(SecKey, SecKeyRef);
+impl_TCFType!(SecKey, SecKeyRef, SecKeyGetTypeID);
+
+#[repr(C)]
+pub struct __SecPolicy(c_void);
+pub type SecPolicyRef = *const __SecPolicy;
+declare_TCFType!(SecPolicy, SecPolicyRef);
+impl_TCFType!(SecPolicy, SecPolicyRef, SecPolicyGetTypeID);
+
+#[repr(C)]
+pub struct __SecTrust(c_void);
+pub type SecTrustRef = *const __SecTrust;
+declare_TCFType!(SecTrust, SecTrustRef);
+impl_TCFType!(SecTrust, SecTrustRef, SecTrustGetTypeID);
+
+type SecCertificateCopyKeyType = unsafe extern "C" fn(SecCertificateRef) -> SecKeyRef;
+type SecTrustEvaluateWithErrorType =
+    unsafe extern "C" fn(trust: SecTrustRef, error: *mut CFErrorRef) -> bool;
+
+#[derive(Ord, Eq, PartialOrd, PartialEq)]
+enum SecStringConstant {
+    // These are available in macOS 10.13
+    SecKeyAlgorithmRSASignatureDigestPSSSHA1,
+    SecKeyAlgorithmRSASignatureDigestPSSSHA256,
+    SecKeyAlgorithmRSASignatureDigestPSSSHA384,
+    SecKeyAlgorithmRSASignatureDigestPSSSHA512,
+}
+
+/// This implementation uses security framework functions and constants that
+/// are not provided by the version of the SDK we build with. To work around
+/// this, we attempt to open and dynamically load these functions and symbols
+/// at runtime. Unfortunately this does mean that if a user is not on a new
+/// enough version of macOS, they will not be able to use client certificates
+/// from their keychain in Firefox until they upgrade.
+struct SecurityFramework<'a> {
+    sec_certificate_copy_key: Symbol<'a, SecCertificateCopyKeyType>,
+    sec_trust_evaluate_with_error: Symbol<'a, SecTrustEvaluateWithErrorType>,
+    sec_string_constants: BTreeMap<SecStringConstant, String>,
+}
+
+lazy_static! {
+    static ref SECURITY_LIBRARY: Result<Library, String> = unsafe {
+        Library::new("/System/Library/Frameworks/Security.framework/Security")
+            .map_err(|e| e.to_string())
+    };
+}
+
+impl<'a> SecurityFramework<'a> {
+    fn new() -> Result<SecurityFramework<'a>, Error> {
+        let library = match &*SECURITY_LIBRARY {
+            Ok(library) => library,
+            Err(e) => return Err(error_here!(ErrorType::ExternalError, e.clone())),
+        };
+        let sec_certificate_copy_key = unsafe {
+            library
+                .get::<SecCertificateCopyKeyType>(b"SecCertificateCopyKey\0")
+                .map_err(|e| error_here!(ErrorType::ExternalError, e.to_string()))?
+        };
+        let sec_trust_evaluate_with_error = unsafe {
+            library
+                .get::<SecTrustEvaluateWithErrorType>(b"SecTrustEvaluateWithError\0")
+                .map_err(|e| error_here!(ErrorType::ExternalError, e.to_string()))?
+        };
+        let mut sec_string_constants = BTreeMap::new();
+        let strings_to_load = vec![
+            (
+                b"kSecKeyAlgorithmRSASignatureDigestPSSSHA1\0".as_ref(),
+                SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA1,
+            ),
+            (
+                b"kSecKeyAlgorithmRSASignatureDigestPSSSHA256\0".as_ref(),
+                SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA256,
+            ),
+            (
+                b"kSecKeyAlgorithmRSASignatureDigestPSSSHA384\0".as_ref(),
+                SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA384,
+            ),
+            (
+                b"kSecKeyAlgorithmRSASignatureDigestPSSSHA512\0".as_ref(),
+                SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA512,
+            ),
+        ];
+        for (symbol_name, sec_string_constant) in strings_to_load {
+            let cfstring_symbol = unsafe {
+                library
+                    .get::<*const CFStringRef>(symbol_name)
+                    .map_err(|e| error_here!(ErrorType::ExternalError, e.to_string()))?
+            };
+            let cfstring = unsafe { CFString::wrap_under_create_rule(**cfstring_symbol) };
+            sec_string_constants.insert(sec_string_constant, cfstring.to_string());
+        }
+        Ok(SecurityFramework {
+            sec_certificate_copy_key,
+            sec_trust_evaluate_with_error,
+            sec_string_constants,
+        })
+    }
+}
+
+struct SecurityFrameworkHolder<'a> {
+    framework: Result<SecurityFramework<'a>, Error>,
+}
+
+impl<'a> SecurityFrameworkHolder<'a> {
+    fn new() -> SecurityFrameworkHolder<'a> {
+        SecurityFrameworkHolder {
+            framework: SecurityFramework::new(),
+        }
+    }
+
+    /// SecCertificateCopyKey is available in macOS 10.14
+    fn sec_certificate_copy_key(&self, certificate: &SecCertificate) -> Result<SecKey, Error> {
+        match &self.framework {
+            Ok(framework) => unsafe {
+                let result =
+                    (framework.sec_certificate_copy_key)(certificate.as_concrete_TypeRef());
+                if result.is_null() {
+                    return Err(error_here!(ErrorType::ExternalError));
+                }
+                Ok(SecKey::wrap_under_create_rule(result))
+            },
+            Err(e) => Err(e.clone()),
+        }
+    }
+
+    /// SecTrustEvaluateWithError is available in macOS 10.14
+    fn sec_trust_evaluate_with_error(&self, trust: &SecTrust) -> Result<bool, Error> {
+        match &self.framework {
+            Ok(framework) => unsafe {
+                Ok((framework.sec_trust_evaluate_with_error)(
+                    trust.as_concrete_TypeRef(),
+                    std::ptr::null_mut(),
+                ))
+            },
+            Err(e) => Err(e.clone()),
+        }
+    }
+
+    fn get_sec_string_constant(
+        &self,
+        sec_string_constant: SecStringConstant,
+    ) -> Result<CFString, Error> {
+        match &self.framework {
+            Ok(framework) => match framework.sec_string_constants.get(&sec_string_constant) {
+                Some(string) => Ok(CFString::new(string)),
+                None => Err(error_here!(ErrorType::ExternalError)),
+            },
+            Err(e) => Err(e.clone()),
+        }
+    }
+}
+
+lazy_static! {
+    static ref SECURITY_FRAMEWORK: SecurityFrameworkHolder<'static> =
+        SecurityFrameworkHolder::new();
+}
+
+fn sec_key_create_signature(
+    key: &SecKey,
+    algorithm: SecKeyAlgorithm,
+    data: &CFData,
+) -> Result<CFData, Error> {
+    let mut error = std::ptr::null_mut();
+    let signature = unsafe {
+        SecKeyCreateSignature(
+            key.as_concrete_TypeRef(),
+            algorithm,
+            data.as_concrete_TypeRef(),
+            &mut error,
+        )
+    };
+    if signature.is_null() {
+        let error = unsafe { CFError::wrap_under_create_rule(error) };
+        return Err(error_here!(
+            ErrorType::ExternalError,
+            error.description().to_string()
+        ));
+    }
+    Ok(unsafe { CFData::wrap_under_create_rule(signature) })
+}
+
+fn sec_key_copy_attributes<T: TCFType>(key: &SecKey) -> CFDictionary<CFString, T> {
+    unsafe { CFDictionary::wrap_under_create_rule(SecKeyCopyAttributes(key.as_concrete_TypeRef())) }
+}
+
+fn sec_key_copy_external_representation(key: &SecKey) -> Result<CFData, Error> {
+    let mut error = std::ptr::null_mut();
+    let representation =
+        unsafe { SecKeyCopyExternalRepresentation(key.as_concrete_TypeRef(), &mut error) };
+    if representation.is_null() {
+        let error = unsafe { CFError::wrap_under_create_rule(error) };
+        return Err(error_here!(
+            ErrorType::ExternalError,
+            error.description().to_string()
+        ));
+    }
+    Ok(unsafe { CFData::wrap_under_create_rule(representation) })
+}
+
+fn sec_identity_copy_certificate(identity: &SecIdentity) -> Result<SecCertificate, Error> {
+    let mut certificate = std::ptr::null();
+    let status =
+        unsafe { SecIdentityCopyCertificate(identity.as_concrete_TypeRef(), &mut certificate) };
+    if status != errSecSuccess {
+        return Err(error_here!(ErrorType::ExternalError, status.to_string()));
+    }
+    if certificate.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(unsafe { SecCertificate::wrap_under_create_rule(certificate) })
+}
+
+fn sec_certificate_copy_subject_summary(certificate: &SecCertificate) -> Result<CFString, Error> {
+    let result = unsafe { SecCertificateCopySubjectSummary(certificate.as_concrete_TypeRef()) };
+    if result.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(unsafe { CFString::wrap_under_create_rule(result) })
+}
+
+fn sec_certificate_copy_data(certificate: &SecCertificate) -> Result<CFData, Error> {
+    let result = unsafe { SecCertificateCopyData(certificate.as_concrete_TypeRef()) };
+    if result.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(unsafe { CFData::wrap_under_create_rule(result) })
+}
+
+fn sec_identity_copy_private_key(identity: &SecIdentity) -> Result<SecKey, Error> {
+    let mut key = std::ptr::null();
+    let status = unsafe { SecIdentityCopyPrivateKey(identity.as_concrete_TypeRef(), &mut key) };
+    if status != errSecSuccess {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    if key.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(unsafe { SecKey::wrap_under_create_rule(key) })
+}
+
+pub struct Cert {
+    class: Vec<u8>,
+    token: Vec<u8>,
+    id: Vec<u8>,
+    label: Vec<u8>,
+    value: Vec<u8>,
+    issuer: Vec<u8>,
+    serial_number: Vec<u8>,
+    subject: Vec<u8>,
+}
+
+impl Cert {
+    fn new_from_identity(identity: &SecIdentity) -> Result<Cert, Error> {
+        let certificate = sec_identity_copy_certificate(identity)?;
+        Cert::new_from_certificate(&certificate)
+    }
+
+    fn new_from_certificate(certificate: &SecCertificate) -> Result<Cert, Error> {
+        let label = sec_certificate_copy_subject_summary(certificate)?;
+        let der = sec_certificate_copy_data(certificate)?;
+        let der = der.bytes().to_vec();
+        let id = Sha256::digest(&der).to_vec();
+        let (serial_number, issuer, subject) = read_encoded_certificate_identifiers(&der)?;
+        Ok(Cert {
+            class: serialize_uint(CKO_CERTIFICATE)?,
+            token: serialize_uint(CK_TRUE)?,
+            id,
+            label: label.to_string().into_bytes(),
+            value: der,
+            issuer,
+            serial_number,
+            subject,
+        })
+    }
+
+    fn class(&self) -> &[u8] {
+        &self.class
+    }
+
+    fn token(&self) -> &[u8] {
+        &self.token
+    }
+
+    fn id(&self) -> &[u8] {
+        &self.id
+    }
+
+    fn label(&self) -> &[u8] {
+        &self.label
+    }
+
+    fn value(&self) -> &[u8] {
+        &self.value
+    }
+
+    fn issuer(&self) -> &[u8] {
+        &self.issuer
+    }
+
+    fn serial_number(&self) -> &[u8] {
+        &self.serial_number
+    }
+
+    fn subject(&self) -> &[u8] {
+        &self.subject
+    }
+}
+
+impl CryptokiObject for Cert {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool {
+        // The modern/legacy slot distinction in theory enables differentiation
+        // between keys that are from modules that can use modern cryptography
+        // (namely EC keys and RSA-PSS signatures) and those that cannot.
+        // However, the function that would enable this
+        // (SecKeyIsAlgorithmSupported) causes a password dialog to appear on
+        // our test machines, so this backend pretends that everything supports
+        // modern crypto for now.
+        if slot_type != SlotType::Modern {
+            return false;
+        }
+        for (attr_type, attr_value) in attrs {
+            let comparison = match *attr_type {
+                CKA_CLASS => self.class(),
+                CKA_TOKEN => self.token(),
+                CKA_LABEL => self.label(),
+                CKA_ID => self.id(),
+                CKA_VALUE => self.value(),
+                CKA_ISSUER => self.issuer(),
+                CKA_SERIAL_NUMBER => self.serial_number(),
+                CKA_SUBJECT => self.subject(),
+                _ => return false,
+            };
+            if attr_value.as_slice() != comparison {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]> {
+        let result = match attribute {
+            CKA_CLASS => self.class(),
+            CKA_TOKEN => self.token(),
+            CKA_LABEL => self.label(),
+            CKA_ID => self.id(),
+            CKA_VALUE => self.value(),
+            CKA_ISSUER => self.issuer(),
+            CKA_SERIAL_NUMBER => self.serial_number(),
+            CKA_SUBJECT => self.subject(),
+            _ => return None,
+        };
+        Some(result)
+    }
+}
+
+#[allow(clippy::upper_case_acronyms)]
+#[derive(Clone, Copy, Debug)]
+pub enum KeyType {
+    EC(usize),
+    RSA,
+}
+
+#[allow(clippy::upper_case_acronyms)]
+enum SignParams<'a> {
+    EC(CFString, &'a [u8]),
+    RSA(CFString, &'a [u8]),
+}
+
+impl<'a> SignParams<'a> {
+    fn new(
+        key_type: KeyType,
+        data: &'a [u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<SignParams<'a>, Error> {
+        match key_type {
+            KeyType::EC(_) => SignParams::new_ec_params(data),
+            KeyType::RSA => SignParams::new_rsa_params(params, data),
+        }
+    }
+
+    fn new_ec_params(data: &'a [u8]) -> Result<SignParams<'a>, Error> {
+        let algorithm = unsafe {
+            CFString::wrap_under_get_rule(match data.len() {
+                20 => kSecKeyAlgorithmECDSASignatureDigestX962SHA1,
+                32 => kSecKeyAlgorithmECDSASignatureDigestX962SHA256,
+                48 => kSecKeyAlgorithmECDSASignatureDigestX962SHA384,
+                64 => kSecKeyAlgorithmECDSASignatureDigestX962SHA512,
+                _ => {
+                    return Err(error_here!(ErrorType::UnsupportedInput));
+                }
+            })
+        };
+        Ok(SignParams::EC(algorithm, data))
+    }
+
+    fn new_rsa_params(
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+        data: &'a [u8],
+    ) -> Result<SignParams<'a>, Error> {
+        if let Some(pss_params) = params {
+            let algorithm = {
+                let algorithm_id = match pss_params.hashAlg {
+                    CKM_SHA_1 => SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA1,
+                    CKM_SHA256 => SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA256,
+                    CKM_SHA384 => SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA384,
+                    CKM_SHA512 => SecStringConstant::SecKeyAlgorithmRSASignatureDigestPSSSHA512,
+                    _ => {
+                        return Err(error_here!(ErrorType::UnsupportedInput));
+                    }
+                };
+                SECURITY_FRAMEWORK.get_sec_string_constant(algorithm_id)?
+            };
+            return Ok(SignParams::RSA(algorithm, data));
+        }
+
+        // Handle the case where this is a TLS 1.0 MD5/SHA1 hash.
+        if data.len() == 36 {
+            let algorithm = unsafe {
+                CFString::wrap_under_get_rule(kSecKeyAlgorithmRSASignatureDigestPKCS1v15Raw)
+            };
+            return Ok(SignParams::RSA(algorithm, data));
+        }
+        // Otherwise, `data` should be a DigestInfo.
+        let (digest_oid, hash) = read_digest_info(data)?;
+        let algorithm = unsafe {
+            CFString::wrap_under_create_rule(match digest_oid {
+                OID_BYTES_SHA_256 => kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA256,
+                OID_BYTES_SHA_384 => kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA384,
+                OID_BYTES_SHA_512 => kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA512,
+                OID_BYTES_SHA_1 => kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA1,
+                _ => return Err(error_here!(ErrorType::UnsupportedInput)),
+            })
+        };
+
+        Ok(SignParams::RSA(algorithm, hash))
+    }
+
+    fn get_algorithm(&self) -> SecKeyAlgorithm {
+        match self {
+            SignParams::EC(algorithm, _) => algorithm.as_concrete_TypeRef(),
+            SignParams::RSA(algorithm, _) => algorithm.as_concrete_TypeRef(),
+        }
+    }
+
+    fn get_data_to_sign(&self) -> &'a [u8] {
+        match self {
+            SignParams::EC(_, data_to_sign) => data_to_sign,
+            SignParams::RSA(_, data_to_sign) => data_to_sign,
+        }
+    }
+}
+
+pub struct Key {
+    identity: SecIdentity,
+    class: Vec<u8>,
+    token: Vec<u8>,
+    id: Vec<u8>,
+    private: Vec<u8>,
+    key_type: Vec<u8>,
+    modulus: Option<Vec<u8>>,
+    ec_params: Option<Vec<u8>>,
+    key_type_enum: KeyType,
+    key_handle: Option<SecKey>,
+}
+
+impl Key {
+    fn new(identity: &SecIdentity) -> Result<Key, Error> {
+        let certificate = sec_identity_copy_certificate(identity)?;
+        let der = sec_certificate_copy_data(&certificate)?;
+        let id = Sha256::digest(der.bytes()).to_vec();
+        let key = SECURITY_FRAMEWORK.sec_certificate_copy_key(&certificate)?;
+        let key_type: CFString = get_key_attribute(&key, unsafe { kSecAttrKeyType })?;
+        let key_size_in_bits: CFNumber = get_key_attribute(&key, unsafe { kSecAttrKeySizeInBits })?;
+        let mut modulus = None;
+        let mut ec_params = None;
+        let sec_attr_key_type_ec =
+            unsafe { CFString::wrap_under_create_rule(kSecAttrKeyTypeECSECPrimeRandom) };
+        let (key_type_enum, key_type_attribute) =
+            if key_type.as_concrete_TypeRef() == unsafe { kSecAttrKeyTypeRSA } {
+                let public_key = sec_key_copy_external_representation(&key)?;
+                let modulus_value = read_rsa_modulus(public_key.bytes())?;
+                modulus = Some(modulus_value);
+                (KeyType::RSA, CKK_RSA)
+            } else if key_type == sec_attr_key_type_ec {
+                // Assume all EC keys are secp256r1, secp384r1, or secp521r1. This
+                // is wrong, but the API doesn't seem to give us a way to determine
+                // which curve this key is on.
+                // This might not matter in practice, because it seems all NSS uses
+                // this for is to get the signature size.
+                let key_size_in_bits = match key_size_in_bits.to_i64() {
+                    Some(value) => value,
+                    None => return Err(error_here!(ErrorType::ValueTooLarge)),
+                };
+                match key_size_in_bits {
+                    256 => ec_params = Some(ENCODED_OID_BYTES_SECP256R1.to_vec()),
+                    384 => ec_params = Some(ENCODED_OID_BYTES_SECP384R1.to_vec()),
+                    521 => ec_params = Some(ENCODED_OID_BYTES_SECP521R1.to_vec()),
+                    _ => return Err(error_here!(ErrorType::UnsupportedInput)),
+                }
+                let coordinate_width = (key_size_in_bits as usize + 7) / 8;
+                (KeyType::EC(coordinate_width), CKK_EC)
+            } else {
+                return Err(error_here!(ErrorType::LibraryFailure));
+            };
+
+        Ok(Key {
+            identity: identity.clone(),
+            class: serialize_uint(CKO_PRIVATE_KEY)?,
+            token: serialize_uint(CK_TRUE)?,
+            id,
+            private: serialize_uint(CK_TRUE)?,
+            key_type: serialize_uint(key_type_attribute)?,
+            modulus,
+            ec_params,
+            key_type_enum,
+            key_handle: None,
+        })
+    }
+
+    fn class(&self) -> &[u8] {
+        &self.class
+    }
+
+    fn token(&self) -> &[u8] {
+        &self.token
+    }
+
+    fn id(&self) -> &[u8] {
+        &self.id
+    }
+
+    fn private(&self) -> &[u8] {
+        &self.private
+    }
+
+    fn key_type(&self) -> &[u8] {
+        &self.key_type
+    }
+
+    fn modulus(&self) -> Option<&[u8]> {
+        match &self.modulus {
+            Some(modulus) => Some(modulus.as_slice()),
+            None => None,
+        }
+    }
+
+    fn ec_params(&self) -> Option<&[u8]> {
+        match &self.ec_params {
+            Some(ec_params) => Some(ec_params.as_slice()),
+            None => None,
+        }
+    }
+
+    fn sign_internal(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<Vec<u8>, Error> {
+        // If this key hasn't been used for signing yet, there won't be a cached key handle. Obtain
+        // and cache it if this is the case. Doing so can cause the underlying implementation to
+        // show an authentication or pin prompt to the user. Caching the handle can avoid causing
+        // multiple prompts to be displayed in some cases.
+        if self.key_handle.is_none() {
+            let _ = self
+                .key_handle
+                .replace(sec_identity_copy_private_key(&self.identity)?);
+        }
+        let key = match &self.key_handle {
+            Some(key) => key,
+            None => return Err(error_here!(ErrorType::LibraryFailure)),
+        };
+        let sign_params = SignParams::new(self.key_type_enum, data, params)?;
+        let signing_algorithm = sign_params.get_algorithm();
+        let data_to_sign = CFData::from_buffer(sign_params.get_data_to_sign());
+        let signature = sec_key_create_signature(key, signing_algorithm, &data_to_sign)?;
+        let signature_value = match self.key_type_enum {
+            KeyType::EC(coordinate_width) => {
+                // We need to convert the DER Ecdsa-Sig-Value to the
+                // concatenation of r and s, the coordinates of the point on
+                // the curve. r and s must be 0-padded to be coordinate_width
+                // total bytes.
+                let (r, s) = read_ec_sig_point(signature.bytes())?;
+                if r.len() > coordinate_width || s.len() > coordinate_width {
+                    return Err(error_here!(ErrorType::InvalidInput));
+                }
+                let mut signature_value = Vec::with_capacity(2 * coordinate_width);
+                let r_padding = vec![0; coordinate_width - r.len()];
+                signature_value.extend(r_padding);
+                signature_value.extend_from_slice(r);
+                let s_padding = vec![0; coordinate_width - s.len()];
+                signature_value.extend(s_padding);
+                signature_value.extend_from_slice(s);
+                signature_value
+            }
+            KeyType::RSA => signature.bytes().to_vec(),
+        };
+        Ok(signature_value)
+    }
+}
+
+impl CryptokiObject for Key {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool {
+        // The modern/legacy slot distinction in theory enables differentiation
+        // between keys that are from modules that can use modern cryptography
+        // (namely EC keys and RSA-PSS signatures) and those that cannot.
+        // However, the function that would enable this
+        // (SecKeyIsAlgorithmSupported) causes a password dialog to appear on
+        // our test machines, so this backend pretends that everything supports
+        // modern crypto for now.
+        if slot_type != SlotType::Modern {
+            return false;
+        }
+        for (attr_type, attr_value) in attrs {
+            let comparison = match *attr_type {
+                CKA_CLASS => self.class(),
+                CKA_TOKEN => self.token(),
+                CKA_ID => self.id(),
+                CKA_PRIVATE => self.private(),
+                CKA_KEY_TYPE => self.key_type(),
+                CKA_MODULUS => {
+                    if let Some(modulus) = self.modulus() {
+                        modulus
+                    } else {
+                        return false;
+                    }
+                }
+                CKA_EC_PARAMS => {
+                    if let Some(ec_params) = self.ec_params() {
+                        ec_params
+                    } else {
+                        return false;
+                    }
+                }
+                _ => return false,
+            };
+            if attr_value.as_slice() != comparison {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]> {
+        match attribute {
+            CKA_CLASS => Some(self.class()),
+            CKA_TOKEN => Some(self.token()),
+            CKA_ID => Some(self.id()),
+            CKA_PRIVATE => Some(self.private()),
+            CKA_KEY_TYPE => Some(self.key_type()),
+            CKA_MODULUS => self.modulus(),
+            CKA_EC_PARAMS => self.ec_params(),
+            _ => None,
+        }
+    }
+}
+
+impl Sign for Key {
+    fn get_signature_length(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<usize, Error> {
+        // Unfortunately we don't have a way of getting the length of a signature without creating
+        // one.
+        let dummy_signature_bytes = self.sign(data, params)?;
+        Ok(dummy_signature_bytes.len())
+    }
+
+    // The input data is a hash. What algorithm we use depends on the size of the hash.
+    fn sign(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<Vec<u8>, Error> {
+        let result = self.sign_internal(data, params);
+        if result.is_ok() {
+            return result;
+        }
+        // Some devices appear to not work well when the key handle is held for too long or if a
+        // card is inserted/removed while Firefox is running. Try refreshing the key handle.
+        let _ = self.key_handle.take();
+        self.sign_internal(data, params)
+    }
+}
+
+fn get_key_attribute<T: TCFType + Clone>(key: &SecKey, attr: CFStringRef) -> Result<T, Error> {
+    let attributes: CFDictionary<CFString, T> = sec_key_copy_attributes(key);
+    match attributes.find(attr as *const _) {
+        Some(value) => Ok((*value).clone()),
+        None => Err(error_here!(ErrorType::ExternalError)),
+    }
+}
+
+// Given a SecIdentity, attempts to build as much of a path to a trust anchor as possible, gathers
+// the CA certificates from that path, and returns them. The purpose of this function is not to
+// validate the given certificate but to find CA certificates that gecko may need to do path
+// building when filtering client certificates according to the acceptable CA list sent by the
+// server during client authentication.
+fn get_issuers(identity: &SecIdentity) -> Result<Vec<SecCertificate>, Error> {
+    let certificate = sec_identity_copy_certificate(identity)?;
+    let policy = unsafe { SecPolicyCreateSSL(false, std::ptr::null()) };
+    if policy.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    let policy = unsafe { SecPolicy::wrap_under_create_rule(policy) };
+    let mut trust = std::ptr::null();
+    // Each of SecTrustCreateWithCertificates' input arguments can be either single items or an
+    // array of items. Since we only want to specify one of each, we directly specify the arguments.
+    let status = unsafe {
+        SecTrustCreateWithCertificates(
+            certificate.as_concrete_TypeRef(),
+            policy.as_concrete_TypeRef(),
+            &mut trust,
+        )
+    };
+    if status != errSecSuccess {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    if trust.is_null() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    let trust = unsafe { SecTrust::wrap_under_create_rule(trust) };
+    // Disable AIA fetching so that SecTrustEvaluateWithError doesn't result in network I/O.
+    let status = unsafe { SecTrustSetNetworkFetchAllowed(trust.as_concrete_TypeRef(), 0) };
+    if status != errSecSuccess {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    // We ignore the return value here because we don't care if the certificate is trusted or not -
+    // we're only doing this to build its issuer chain as much as possible.
+    let _ = SECURITY_FRAMEWORK.sec_trust_evaluate_with_error(&trust)?;
+    let certificate_count = unsafe { SecTrustGetCertificateCount(trust.as_concrete_TypeRef()) };
+    let mut certificates = Vec::with_capacity(
+        certificate_count
+            .try_into()
+            .map_err(|_| error_here!(ErrorType::ValueTooLarge))?,
+    );
+    for i in 1..certificate_count {
+        let certificate = unsafe { SecTrustGetCertificateAtIndex(trust.as_concrete_TypeRef(), i) };
+        if certificate.is_null() {
+            error!("SecTrustGetCertificateAtIndex returned null certificate?");
+            continue;
+        }
+        let certificate = unsafe { SecCertificate::wrap_under_get_rule(certificate) };
+        certificates.push(certificate);
+    }
+    Ok(certificates)
+}
+
+pub struct Backend {}
+
+impl ClientCertsBackend for Backend {
+    type Cert = Cert;
+    type Key = Key;
+
+    fn find_objects(&self) -> Result<(Vec<Cert>, Vec<Key>), Error> {
+        let mut certs = Vec::new();
+        let mut keys = Vec::new();
+        let identities = unsafe {
+            let class_key = CFString::wrap_under_get_rule(kSecClass);
+            let class_value = CFString::wrap_under_get_rule(kSecClassIdentity);
+            let return_ref_key = CFString::wrap_under_get_rule(kSecReturnRef);
+            let return_ref_value = CFBoolean::wrap_under_get_rule(kCFBooleanTrue);
+            let match_key = CFString::wrap_under_get_rule(kSecMatchLimit);
+            let match_value = CFString::wrap_under_get_rule(kSecMatchLimitAll);
+            let vals = vec![
+                (class_key.as_CFType(), class_value.as_CFType()),
+                (return_ref_key.as_CFType(), return_ref_value.as_CFType()),
+                (match_key.as_CFType(), match_value.as_CFType()),
+            ];
+            let dict = CFDictionary::from_CFType_pairs(&vals);
+            let mut result = std::ptr::null();
+            let status = SecItemCopyMatching(dict.as_CFTypeRef() as CFDictionaryRef, &mut result);
+            if status == errSecItemNotFound {
+                return Ok((certs, keys));
+            }
+            if status != errSecSuccess {
+                return Err(error_here!(ErrorType::ExternalError, status.to_string()));
+            }
+            if result.is_null() {
+                return Err(error_here!(ErrorType::ExternalError));
+            }
+            CFArray::<SecIdentityRef>::wrap_under_create_rule(result as CFArrayRef)
+        };
+        for identity in identities.get_all_values().iter() {
+            let identity = unsafe { SecIdentity::wrap_under_get_rule(*identity as SecIdentityRef) };
+            let cert = Cert::new_from_identity(&identity);
+            let key = Key::new(&identity);
+            if let (Ok(cert), Ok(key)) = (cert, key) {
+                certs.push(cert);
+                keys.push(key);
+            } else {
+                continue;
+            }
+            if let Ok(issuers) = get_issuers(&identity) {
+                for issuer in issuers {
+                    if let Ok(cert) = Cert::new_from_certificate(&issuer) {
+                        certs.push(cert);
+                    }
+                }
+            }
+        }
+        Ok((certs, keys))
+    }
+}
diff --git a/security/manager/ssl/osclientcerts/src/backend_windows.rs b/security/manager/ssl/osclientcerts/src/backend_windows.rs
new file mode 100644
index 0000000000..2a80ff8354
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/src/backend_windows.rs
@@ -0,0 +1,914 @@
+/* -*- Mode: rust; rust-indent-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#![allow(non_camel_case_types)]
+
+use pkcs11_bindings::*;
+use rsclientcerts::error::{Error, ErrorType};
+use rsclientcerts::manager::{ClientCertsBackend, CryptokiObject, Sign, SlotType};
+use rsclientcerts::util::*;
+use sha2::{Digest, Sha256};
+use std::convert::TryInto;
+use std::ffi::{c_void, CStr, CString};
+use std::ops::Deref;
+use std::slice;
+use winapi::shared::bcrypt::*;
+use winapi::shared::minwindef::{DWORD, PBYTE};
+use winapi::um::errhandlingapi::GetLastError;
+use winapi::um::ncrypt::*;
+use winapi::um::wincrypt::{HCRYPTHASH, HCRYPTPROV, *};
+
+// winapi has some support for ncrypt.h, but not for this function.
+extern "system" {
+    fn NCryptSignHash(
+        hKey: NCRYPT_KEY_HANDLE,
+        pPaddingInfo: *mut c_void,
+        pbHashValue: PBYTE,
+        cbHashValue: DWORD,
+        pbSignature: PBYTE,
+        cbSignature: DWORD,
+        pcbResult: *mut DWORD,
+        dwFlags: DWORD,
+    ) -> SECURITY_STATUS;
+}
+
+/// Given a `CERT_INFO`, tries to return the bytes of the subject distinguished name as formatted by
+/// `CertNameToStrA` using the flag `CERT_SIMPLE_NAME_STR`. This is used as the label for the
+/// certificate.
+fn get_cert_subject_dn(cert_info: &CERT_INFO) -> Result<Vec<u8>, Error> {
+    let mut cert_info_subject = cert_info.Subject;
+    let subject_dn_len = unsafe {
+        CertNameToStrA(
+            X509_ASN_ENCODING,
+            &mut cert_info_subject,
+            CERT_SIMPLE_NAME_STR,
+            std::ptr::null_mut(),
+            0,
+        )
+    };
+    // subject_dn_len includes the terminating null byte.
+    let mut subject_dn_string_bytes: Vec<u8> = vec![0; subject_dn_len as usize];
+    let subject_dn_len = unsafe {
+        CertNameToStrA(
+            X509_ASN_ENCODING,
+            &mut cert_info_subject,
+            CERT_SIMPLE_NAME_STR,
+            subject_dn_string_bytes.as_mut_ptr() as *mut i8,
+            subject_dn_string_bytes
+                .len()
+                .try_into()
+                .map_err(|_| error_here!(ErrorType::ValueTooLarge))?,
+        )
+    };
+    if subject_dn_len as usize != subject_dn_string_bytes.len() {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(subject_dn_string_bytes)
+}
+
+/// Represents a certificate for which there exists a corresponding private key.
+pub struct Cert {
+    /// PKCS #11 object class. Will be `CKO_CERTIFICATE`.
+    class: Vec<u8>,
+    /// Whether or not this is on a token. Will be `CK_TRUE`.
+    token: Vec<u8>,
+    /// An identifier unique to this certificate. Must be the same as the ID for the private key.
+    id: Vec<u8>,
+    /// The bytes of a human-readable label for this certificate. Will be the subject DN.
+    label: Vec<u8>,
+    /// The DER bytes of the certificate.
+    value: Vec<u8>,
+    /// The DER bytes of the issuer distinguished name of the certificate.
+    issuer: Vec<u8>,
+    /// The DER bytes of the serial number of the certificate.
+    serial_number: Vec<u8>,
+    /// The DER bytes of the subject distinguished name of the certificate.
+    subject: Vec<u8>,
+    /// Which slot this certificate should be exposed on.
+    slot_type: SlotType,
+}
+
+impl Cert {
+    fn new(cert_context: PCCERT_CONTEXT) -> Result<Cert, Error> {
+        let cert = unsafe { &*cert_context };
+        let cert_info = unsafe { &*cert.pCertInfo };
+        let value =
+            unsafe { slice::from_raw_parts(cert.pbCertEncoded, cert.cbCertEncoded as usize) };
+        let value = value.to_vec();
+        let id = Sha256::digest(&value).to_vec();
+        let label = get_cert_subject_dn(cert_info)?;
+        let (serial_number, issuer, subject) = read_encoded_certificate_identifiers(&value)?;
+        Ok(Cert {
+            class: serialize_uint(CKO_CERTIFICATE)?,
+            token: serialize_uint(CK_TRUE)?,
+            id,
+            label,
+            value,
+            issuer,
+            serial_number,
+            subject,
+            slot_type: SlotType::Modern,
+        })
+    }
+
+    fn class(&self) -> &[u8] {
+        &self.class
+    }
+
+    fn token(&self) -> &[u8] {
+        &self.token
+    }
+
+    fn id(&self) -> &[u8] {
+        &self.id
+    }
+
+    fn label(&self) -> &[u8] {
+        &self.label
+    }
+
+    fn value(&self) -> &[u8] {
+        &self.value
+    }
+
+    fn issuer(&self) -> &[u8] {
+        &self.issuer
+    }
+
+    fn serial_number(&self) -> &[u8] {
+        &self.serial_number
+    }
+
+    fn subject(&self) -> &[u8] {
+        &self.subject
+    }
+}
+
+impl CryptokiObject for Cert {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool {
+        if slot_type != self.slot_type {
+            return false;
+        }
+        for (attr_type, attr_value) in attrs {
+            let comparison = match *attr_type {
+                CKA_CLASS => self.class(),
+                CKA_TOKEN => self.token(),
+                CKA_LABEL => self.label(),
+                CKA_ID => self.id(),
+                CKA_VALUE => self.value(),
+                CKA_ISSUER => self.issuer(),
+                CKA_SERIAL_NUMBER => self.serial_number(),
+                CKA_SUBJECT => self.subject(),
+                _ => return false,
+            };
+            if attr_value.as_slice() != comparison {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]> {
+        let result = match attribute {
+            CKA_CLASS => self.class(),
+            CKA_TOKEN => self.token(),
+            CKA_LABEL => self.label(),
+            CKA_ID => self.id(),
+            CKA_VALUE => self.value(),
+            CKA_ISSUER => self.issuer(),
+            CKA_SERIAL_NUMBER => self.serial_number(),
+            CKA_SUBJECT => self.subject(),
+            _ => return None,
+        };
+        Some(result)
+    }
+}
+
+struct CertContext(PCCERT_CONTEXT);
+
+impl CertContext {
+    fn new(cert: PCCERT_CONTEXT) -> CertContext {
+        CertContext(unsafe { CertDuplicateCertificateContext(cert) })
+    }
+}
+
+impl Drop for CertContext {
+    fn drop(&mut self) {
+        unsafe {
+            CertFreeCertificateContext(self.0);
+        }
+    }
+}
+
+impl Deref for CertContext {
+    type Target = PCCERT_CONTEXT;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+enum KeyHandle {
+    NCrypt(NCRYPT_KEY_HANDLE),
+    CryptoAPI(HCRYPTPROV, DWORD),
+}
+
+impl KeyHandle {
+    fn from_cert(cert: &CertContext) -> Result<KeyHandle, Error> {
+        let mut key_handle = 0;
+        let mut key_spec = 0;
+        let mut must_free = 0;
+        unsafe {
+            if CryptAcquireCertificatePrivateKey(
+                **cert,
+                CRYPT_ACQUIRE_PREFER_NCRYPT_KEY_FLAG,
+                std::ptr::null_mut(),
+                &mut key_handle,
+                &mut key_spec,
+                &mut must_free,
+            ) != 1
+            {
+                return Err(error_here!(
+                    ErrorType::ExternalError,
+                    GetLastError().to_string()
+                ));
+            }
+        }
+        if must_free == 0 {
+            return Err(error_here!(ErrorType::ExternalError));
+        }
+        if key_spec == CERT_NCRYPT_KEY_SPEC {
+            Ok(KeyHandle::NCrypt(key_handle as NCRYPT_KEY_HANDLE))
+        } else {
+            Ok(KeyHandle::CryptoAPI(key_handle as HCRYPTPROV, key_spec))
+        }
+    }
+
+    fn sign(
+        &self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+        do_signature: bool,
+        key_type: KeyType,
+    ) -> Result<Vec<u8>, Error> {
+        match &self {
+            KeyHandle::NCrypt(ncrypt_handle) => {
+                sign_ncrypt(ncrypt_handle, data, params, do_signature, key_type)
+            }
+            KeyHandle::CryptoAPI(hcryptprov, key_spec) => {
+                sign_cryptoapi(hcryptprov, key_spec, data, params, do_signature)
+            }
+        }
+    }
+}
+
+impl Drop for KeyHandle {
+    fn drop(&mut self) {
+        match self {
+            KeyHandle::NCrypt(ncrypt_handle) => unsafe {
+                let _ = NCryptFreeObject(*ncrypt_handle);
+            },
+            KeyHandle::CryptoAPI(hcryptprov, _) => unsafe {
+                let _ = CryptReleaseContext(*hcryptprov, 0);
+            },
+        }
+    }
+}
+
+fn sign_ncrypt(
+    ncrypt_handle: &NCRYPT_KEY_HANDLE,
+    data: &[u8],
+    params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    do_signature: bool,
+    key_type: KeyType,
+) -> Result<Vec<u8>, Error> {
+    let mut sign_params = SignParams::new(key_type, params)?;
+    let params_ptr = sign_params.params_ptr();
+    let flags = sign_params.flags();
+    let mut data = data.to_vec();
+    let mut signature_len = 0;
+    // We call NCryptSignHash twice: the first time to get the size of the buffer we need to
+    // allocate and then again to actually sign the data, if `do_signature` is `true`.
+    let status = unsafe {
+        NCryptSignHash(
+            *ncrypt_handle,
+            params_ptr,
+            data.as_mut_ptr(),
+            data.len()
+                .try_into()
+                .map_err(|_| error_here!(ErrorType::ValueTooLarge))?,
+            std::ptr::null_mut(),
+            0,
+            &mut signature_len,
+            flags,
+        )
+    };
+    // 0 is "ERROR_SUCCESS" (but "ERROR_SUCCESS" is unsigned, whereas SECURITY_STATUS is signed)
+    if status != 0 {
+        return Err(error_here!(ErrorType::ExternalError, status.to_string()));
+    }
+    let mut signature = vec![0; signature_len as usize];
+    if !do_signature {
+        return Ok(signature);
+    }
+    let mut final_signature_len = signature_len;
+    let status = unsafe {
+        NCryptSignHash(
+            *ncrypt_handle,
+            params_ptr,
+            data.as_mut_ptr(),
+            data.len()
+                .try_into()
+                .map_err(|_| error_here!(ErrorType::ValueTooLarge))?,
+            signature.as_mut_ptr(),
+            signature_len,
+            &mut final_signature_len,
+            flags,
+        )
+    };
+    if status != 0 {
+        return Err(error_here!(ErrorType::ExternalError, status.to_string()));
+    }
+    if final_signature_len != signature_len {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    Ok(signature)
+}
+
+fn sign_cryptoapi(
+    hcryptprov: &HCRYPTPROV,
+    key_spec: &DWORD,
+    data: &[u8],
+    params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    do_signature: bool,
+) -> Result<Vec<u8>, Error> {
+    if params.is_some() {
+        return Err(error_here!(ErrorType::LibraryFailure));
+    }
+    // data will be an encoded DigestInfo, which specifies the hash algorithm and bytes of the hash
+    // to sign. However, CryptoAPI requires directly specifying the bytes of the hash, so it must
+    // be extracted first.
+    let (_, hash_bytes) = read_digest_info(data)?;
+    let hash = HCryptHash::new(hcryptprov, hash_bytes)?;
+    let mut signature_len = 0;
+    if unsafe {
+        CryptSignHashW(
+            *hash,
+            *key_spec,
+            std::ptr::null_mut(),
+            0,
+            std::ptr::null_mut(),
+            &mut signature_len,
+        )
+    } != 1
+    {
+        return Err(error_here!(
+            ErrorType::ExternalError,
+            unsafe { GetLastError() }.to_string()
+        ));
+    }
+    let mut signature = vec![0; signature_len as usize];
+    if !do_signature {
+        return Ok(signature);
+    }
+    let mut final_signature_len = signature_len;
+    if unsafe {
+        CryptSignHashW(
+            *hash,
+            *key_spec,
+            std::ptr::null_mut(),
+            0,
+            signature.as_mut_ptr(),
+            &mut final_signature_len,
+        )
+    } != 1
+    {
+        return Err(error_here!(
+            ErrorType::ExternalError,
+            unsafe { GetLastError() }.to_string()
+        ));
+    }
+    if final_signature_len != signature_len {
+        return Err(error_here!(ErrorType::ExternalError));
+    }
+    // CryptoAPI returns the signature with the most significant byte last (little-endian),
+    // whereas PKCS#11 expects the most significant byte first (big-endian).
+    signature.reverse();
+    Ok(signature)
+}
+
+struct HCryptHash(HCRYPTHASH);
+
+impl HCryptHash {
+    fn new(hcryptprov: &HCRYPTPROV, hash_bytes: &[u8]) -> Result<HCryptHash, Error> {
+        let alg = match hash_bytes.len() {
+            20 => CALG_SHA1,
+            32 => CALG_SHA_256,
+            48 => CALG_SHA_384,
+            64 => CALG_SHA_512,
+            _ => {
+                return Err(error_here!(ErrorType::UnsupportedInput));
+            }
+        };
+        let mut hash: HCRYPTHASH = 0;
+        if unsafe { CryptCreateHash(*hcryptprov, alg, 0, 0, &mut hash) } != 1 {
+            return Err(error_here!(
+                ErrorType::ExternalError,
+                unsafe { GetLastError() }.to_string()
+            ));
+        }
+        if unsafe { CryptSetHashParam(hash, HP_HASHVAL, hash_bytes.as_ptr(), 0) } != 1 {
+            return Err(error_here!(
+                ErrorType::ExternalError,
+                unsafe { GetLastError() }.to_string()
+            ));
+        }
+        Ok(HCryptHash(hash))
+    }
+}
+
+impl Drop for HCryptHash {
+    fn drop(&mut self) {
+        unsafe {
+            CryptDestroyHash(self.0);
+        }
+    }
+}
+
+impl Deref for HCryptHash {
+    type Target = HCRYPTHASH;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+// In some cases, the ncrypt API takes a pointer to a null-terminated wide-character string as a way
+// of specifying an algorithm. The "right" way to do this would be to take the corresponding
+// &'static str constant provided by the winapi crate, create an OsString from it, encode it as wide
+// characters, and collect it into a Vec<u16>. However, since the implementation that provides this
+// functionality isn't constant, we would have to manage the memory this creates and uses. Since
+// rust structures generally can't be self-referrential, this memory would have to live elsewhere,
+// and the nice abstractions we've created for this implementation start to break down. It's much
+// simpler to hard-code the identifiers we support, since there are only four of them.
+// The following arrays represent the identifiers "SHA1", "SHA256", "SHA384", and "SHA512",
+// respectively.
+const SHA1_ALGORITHM_STRING: &[u16] = &[83, 72, 65, 49, 0];
+const SHA256_ALGORITHM_STRING: &[u16] = &[83, 72, 65, 50, 53, 54, 0];
+const SHA384_ALGORITHM_STRING: &[u16] = &[83, 72, 65, 51, 56, 52, 0];
+const SHA512_ALGORITHM_STRING: &[u16] = &[83, 72, 65, 53, 49, 50, 0];
+
+enum SignParams {
+    EC,
+    RSA_PKCS1(BCRYPT_PKCS1_PADDING_INFO),
+    RSA_PSS(BCRYPT_PSS_PADDING_INFO),
+}
+
+impl SignParams {
+    fn new(
+        key_type: KeyType,
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<SignParams, Error> {
+        // EC is easy, so handle that first.
+        match key_type {
+            KeyType::EC => return Ok(SignParams::EC),
+            KeyType::RSA => {}
+        }
+        // If `params` is `Some`, we're doing RSA-PSS. If it is `None`, we're doing RSA-PKCS1.
+        let pss_params = match params {
+            Some(pss_params) => pss_params,
+            None => {
+                // The hash algorithm should be encoded in the data to be signed, so we don't have to
+                // (and don't want to) specify a particular algorithm here.
+                return Ok(SignParams::RSA_PKCS1(BCRYPT_PKCS1_PADDING_INFO {
+                    pszAlgId: std::ptr::null(),
+                }));
+            }
+        };
+        let algorithm_string = match pss_params.hashAlg {
+            CKM_SHA_1 => SHA1_ALGORITHM_STRING,
+            CKM_SHA256 => SHA256_ALGORITHM_STRING,
+            CKM_SHA384 => SHA384_ALGORITHM_STRING,
+            CKM_SHA512 => SHA512_ALGORITHM_STRING,
+            _ => {
+                return Err(error_here!(ErrorType::UnsupportedInput));
+            }
+        };
+        Ok(SignParams::RSA_PSS(BCRYPT_PSS_PADDING_INFO {
+            pszAlgId: algorithm_string.as_ptr(),
+            cbSalt: pss_params.sLen,
+        }))
+    }
+
+    fn params_ptr(&mut self) -> *mut std::ffi::c_void {
+        match self {
+            SignParams::EC => std::ptr::null_mut(),
+            SignParams::RSA_PKCS1(params) => {
+                params as *mut BCRYPT_PKCS1_PADDING_INFO as *mut std::ffi::c_void
+            }
+            SignParams::RSA_PSS(params) => {
+                params as *mut BCRYPT_PSS_PADDING_INFO as *mut std::ffi::c_void
+            }
+        }
+    }
+
+    fn flags(&self) -> u32 {
+        match *self {
+            SignParams::EC => 0,
+            SignParams::RSA_PKCS1(_) => NCRYPT_PAD_PKCS1_FLAG,
+            SignParams::RSA_PSS(_) => NCRYPT_PAD_PSS_FLAG,
+        }
+    }
+}
+
+/// A helper enum to identify a private key's type. We support EC and RSA.
+#[allow(clippy::upper_case_acronyms)]
+#[derive(Clone, Copy, Debug)]
+pub enum KeyType {
+    EC,
+    RSA,
+}
+
+/// Represents a private key for which there exists a corresponding certificate.
+pub struct Key {
+    /// A handle on the OS mechanism that represents the certificate for this key.
+    cert: CertContext,
+    /// PKCS #11 object class. Will be `CKO_PRIVATE_KEY`.
+    class: Vec<u8>,
+    /// Whether or not this is on a token. Will be `CK_TRUE`.
+    token: Vec<u8>,
+    /// An identifier unique to this key. Must be the same as the ID for the certificate.
+    id: Vec<u8>,
+    /// Whether or not this key is "private" (can it be exported?). Will be CK_TRUE (it can't be
+    /// exported).
+    private: Vec<u8>,
+    /// PKCS #11 key type. Will be `CKK_EC` for EC, and `CKK_RSA` for RSA.
+    key_type: Vec<u8>,
+    /// If this is an RSA key, this is the value of the modulus as an unsigned integer.
+    modulus: Option<Vec<u8>>,
+    /// If this is an EC key, this is the DER bytes of the OID identifying the curve the key is on.
+    ec_params: Option<Vec<u8>>,
+    /// An enum identifying this key's type.
+    key_type_enum: KeyType,
+    /// Which slot this key should be exposed on.
+    slot_type: SlotType,
+    /// A handle on the OS mechanism that represents this key.
+    key_handle: Option<KeyHandle>,
+}
+
+impl Key {
+    fn new(cert_context: PCCERT_CONTEXT) -> Result<Key, Error> {
+        let cert = unsafe { *cert_context };
+        let cert_der =
+            unsafe { slice::from_raw_parts(cert.pbCertEncoded, cert.cbCertEncoded as usize) };
+        let id = Sha256::digest(cert_der).to_vec();
+        let id = id.to_vec();
+        let cert_info = unsafe { &*cert.pCertInfo };
+        let mut modulus = None;
+        let mut ec_params = None;
+        let spki = &cert_info.SubjectPublicKeyInfo;
+        let algorithm_oid = unsafe { CStr::from_ptr(spki.Algorithm.pszObjId) }
+            .to_str()
+            .map_err(|_| error_here!(ErrorType::ExternalError))?;
+        let (key_type_enum, key_type_attribute) = if algorithm_oid == szOID_RSA_RSA {
+            if spki.PublicKey.cUnusedBits != 0 {
+                return Err(error_here!(ErrorType::ExternalError));
+            }
+            let public_key_bytes = unsafe {
+                std::slice::from_raw_parts(spki.PublicKey.pbData, spki.PublicKey.cbData as usize)
+            };
+            let modulus_value = read_rsa_modulus(public_key_bytes)?;
+            modulus = Some(modulus_value);
+            (KeyType::RSA, CKK_RSA)
+        } else if algorithm_oid == szOID_ECC_PUBLIC_KEY {
+            let params = &spki.Algorithm.Parameters;
+            ec_params = Some(
+                unsafe { std::slice::from_raw_parts(params.pbData, params.cbData as usize) }
+                    .to_vec(),
+            );
+            (KeyType::EC, CKK_EC)
+        } else {
+            return Err(error_here!(ErrorType::LibraryFailure));
+        };
+        let cert = CertContext::new(cert_context);
+        Ok(Key {
+            cert,
+            class: serialize_uint(CKO_PRIVATE_KEY)?,
+            token: serialize_uint(CK_TRUE)?,
+            id,
+            private: serialize_uint(CK_TRUE)?,
+            key_type: serialize_uint(key_type_attribute)?,
+            modulus,
+            ec_params,
+            key_type_enum,
+            slot_type: SlotType::Modern,
+            key_handle: None,
+        })
+    }
+
+    fn class(&self) -> &[u8] {
+        &self.class
+    }
+
+    fn token(&self) -> &[u8] {
+        &self.token
+    }
+
+    fn id(&self) -> &[u8] {
+        &self.id
+    }
+
+    fn private(&self) -> &[u8] {
+        &self.private
+    }
+
+    fn key_type(&self) -> &[u8] {
+        &self.key_type
+    }
+
+    fn modulus(&self) -> Option<&[u8]> {
+        match &self.modulus {
+            Some(modulus) => Some(modulus.as_slice()),
+            None => None,
+        }
+    }
+
+    fn ec_params(&self) -> Option<&[u8]> {
+        match &self.ec_params {
+            Some(ec_params) => Some(ec_params.as_slice()),
+            None => None,
+        }
+    }
+
+    fn sign_with_retry(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+        do_signature: bool,
+    ) -> Result<Vec<u8>, Error> {
+        let result = self.sign_internal(data, params, do_signature);
+        if result.is_ok() {
+            return result;
+        }
+        // Some devices appear to not work well when the key handle is held for too long or if a
+        // card is inserted/removed while Firefox is running. Try refreshing the key handle.
+        debug!("sign failed: refreshing key handle");
+        let _ = self.key_handle.take();
+        self.sign_internal(data, params, do_signature)
+    }
+
+    /// data: the data to sign
+    /// do_signature: if true, actually perform the signature. Otherwise, return a `Vec<u8>` of the
+    /// length the signature would be, if performed.
+    fn sign_internal(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+        do_signature: bool,
+    ) -> Result<Vec<u8>, Error> {
+        // If this key hasn't been used for signing yet, there won't be a cached key handle. Obtain
+        // and cache it if this is the case. Doing so can cause the underlying implementation to
+        // show an authentication or pin prompt to the user. Caching the handle can avoid causing
+        // multiple prompts to be displayed in some cases.
+        if self.key_handle.is_none() {
+            let _ = self.key_handle.replace(KeyHandle::from_cert(&self.cert)?);
+        }
+        let key = match &self.key_handle {
+            Some(key) => key,
+            None => return Err(error_here!(ErrorType::LibraryFailure)),
+        };
+        key.sign(data, params, do_signature, self.key_type_enum)
+    }
+}
+
+impl CryptokiObject for Key {
+    fn matches(&self, slot_type: SlotType, attrs: &[(CK_ATTRIBUTE_TYPE, Vec<u8>)]) -> bool {
+        if slot_type != self.slot_type {
+            return false;
+        }
+        for (attr_type, attr_value) in attrs {
+            let comparison = match *attr_type {
+                CKA_CLASS => self.class(),
+                CKA_TOKEN => self.token(),
+                CKA_ID => self.id(),
+                CKA_PRIVATE => self.private(),
+                CKA_KEY_TYPE => self.key_type(),
+                CKA_MODULUS => {
+                    if let Some(modulus) = self.modulus() {
+                        modulus
+                    } else {
+                        return false;
+                    }
+                }
+                CKA_EC_PARAMS => {
+                    if let Some(ec_params) = self.ec_params() {
+                        ec_params
+                    } else {
+                        return false;
+                    }
+                }
+                _ => return false,
+            };
+            if attr_value.as_slice() != comparison {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn get_attribute(&self, attribute: CK_ATTRIBUTE_TYPE) -> Option<&[u8]> {
+        match attribute {
+            CKA_CLASS => Some(self.class()),
+            CKA_TOKEN => Some(self.token()),
+            CKA_ID => Some(self.id()),
+            CKA_PRIVATE => Some(self.private()),
+            CKA_KEY_TYPE => Some(self.key_type()),
+            CKA_MODULUS => self.modulus(),
+            CKA_EC_PARAMS => self.ec_params(),
+            _ => None,
+        }
+    }
+}
+
+impl Sign for Key {
+    fn get_signature_length(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<usize, Error> {
+        match self.sign_with_retry(data, params, false) {
+            Ok(dummy_signature_bytes) => Ok(dummy_signature_bytes.len()),
+            Err(e) => Err(e),
+        }
+    }
+
+    fn sign(
+        &mut self,
+        data: &[u8],
+        params: &Option<CK_RSA_PKCS_PSS_PARAMS>,
+    ) -> Result<Vec<u8>, Error> {
+        self.sign_with_retry(data, params, true)
+    }
+}
+
+struct CertStore {
+    handle: HCERTSTORE,
+}
+
+impl Drop for CertStore {
+    fn drop(&mut self) {
+        if !self.handle.is_null() {
+            unsafe {
+                CertCloseStore(self.handle, 0);
+            }
+        }
+    }
+}
+
+impl Deref for CertStore {
+    type Target = HCERTSTORE;
+
+    fn deref(&self) -> &Self::Target {
+        &self.handle
+    }
+}
+
+impl CertStore {
+    fn new(handle: HCERTSTORE) -> CertStore {
+        CertStore { handle }
+    }
+}
+
+// Given a pointer to a CERT_CHAIN_CONTEXT, enumerates each chain in the context and each element
+// in each chain to gather every CERT_CONTEXT pointed to by the CERT_CHAIN_CONTEXT.
+// https://docs.microsoft.com/en-us/windows/win32/api/wincrypt/ns-wincrypt-cert_chain_context says
+// that the 0th element of the 0th chain will be the end-entity certificate. This certificate (if
+// present), will be the 0th element of the returned Vec.
+fn gather_cert_contexts(cert_chain_context: *const CERT_CHAIN_CONTEXT) -> Vec<*const CERT_CONTEXT> {
+    let mut cert_contexts = Vec::new();
+    if cert_chain_context.is_null() {
+        return cert_contexts;
+    }
+    let cert_chain_context = unsafe { &*cert_chain_context };
+    let cert_chains = unsafe {
+        std::slice::from_raw_parts(
+            cert_chain_context.rgpChain,
+            cert_chain_context.cChain as usize,
+        )
+    };
+    for cert_chain in cert_chains {
+        // First dereference the borrow.
+        let cert_chain = *cert_chain;
+        if cert_chain.is_null() {
+            continue;
+        }
+        // Then dereference the pointer.
+        let cert_chain = unsafe { &*cert_chain };
+        let chain_elements = unsafe {
+            std::slice::from_raw_parts(cert_chain.rgpElement, cert_chain.cElement as usize)
+        };
+        for chain_element in chain_elements {
+            let chain_element = *chain_element; // dereference borrow
+            if chain_element.is_null() {
+                continue;
+            }
+            let chain_element = unsafe { &*chain_element }; // dereference pointer
+            cert_contexts.push(chain_element.pCertContext);
+        }
+    }
+    cert_contexts
+}
+
+pub struct Backend {}
+
+impl ClientCertsBackend for Backend {
+    type Cert = Cert;
+    type Key = Key;
+
+    /// Attempts to enumerate certificates with private keys exposed by the OS. Currently only looks in
+    /// the "My" cert store of the current user. In the future this may look in more locations.
+    fn find_objects(&self) -> Result<(Vec<Cert>, Vec<Key>), Error> {
+        let mut certs = Vec::new();
+        let mut keys = Vec::new();
+        let location_flags = CERT_SYSTEM_STORE_CURRENT_USER
+            | CERT_STORE_OPEN_EXISTING_FLAG
+            | CERT_STORE_READONLY_FLAG;
+        let store_name = match CString::new("My") {
+            Ok(store_name) => store_name,
+            Err(_) => return Err(error_here!(ErrorType::LibraryFailure)),
+        };
+        let store = CertStore::new(unsafe {
+            CertOpenStore(
+                CERT_STORE_PROV_SYSTEM_REGISTRY_A,
+                0,
+                0,
+                location_flags,
+                store_name.as_ptr() as *const winapi::ctypes::c_void,
+            )
+        });
+        if store.is_null() {
+            return Err(error_here!(ErrorType::ExternalError));
+        }
+        let find_params = CERT_CHAIN_FIND_ISSUER_PARA {
+            cbSize: std::mem::size_of::<CERT_CHAIN_FIND_ISSUER_PARA>() as u32,
+            pszUsageIdentifier: std::ptr::null(),
+            dwKeySpec: 0,
+            dwAcquirePrivateKeyFlags: 0,
+            cIssuer: 0,
+            rgIssuer: std::ptr::null_mut(),
+            pfnFindCallback: None,
+            pvFindArg: std::ptr::null_mut(),
+            pdwIssuerChainIndex: std::ptr::null_mut(),
+            pdwIssuerElementIndex: std::ptr::null_mut(),
+        };
+        let mut cert_chain_context: PCCERT_CHAIN_CONTEXT = std::ptr::null_mut();
+        loop {
+            // CertFindChainInStore finds all certificates with private keys in the store. It also
+            // attempts to build a verified certificate chain to a trust anchor for each certificate.
+            // We gather and hold onto these extra certificates so that gecko can use them when
+            // filtering potential client certificates according to the acceptable CAs list sent by
+            // servers when they request client certificates.
+            cert_chain_context = unsafe {
+                CertFindChainInStore(
+                    *store,
+                    X509_ASN_ENCODING,
+                    CERT_CHAIN_FIND_BY_ISSUER_CACHE_ONLY_FLAG
+                        | CERT_CHAIN_FIND_BY_ISSUER_CACHE_ONLY_URL_FLAG,
+                    CERT_CHAIN_FIND_BY_ISSUER,
+                    &find_params as *const CERT_CHAIN_FIND_ISSUER_PARA
+                        as *const winapi::ctypes::c_void,
+                    cert_chain_context,
+                )
+            };
+            if cert_chain_context.is_null() {
+                break;
+            }
+            let cert_contexts = gather_cert_contexts(cert_chain_context);
+            // The 0th CERT_CONTEXT is the end-entity (i.e. the certificate with the private key we're
+            // after).
+            match cert_contexts.get(0) {
+                Some(cert_context) => {
+                    let key = match Key::new(*cert_context) {
+                        Ok(key) => key,
+                        Err(_) => continue,
+                    };
+                    let cert = match Cert::new(*cert_context) {
+                        Ok(cert) => cert,
+                        Err(_) => continue,
+                    };
+                    certs.push(cert);
+                    keys.push(key);
+                }
+                None => {}
+            };
+            for cert_context in cert_contexts.iter().skip(1) {
+                if let Ok(cert) = Cert::new(*cert_context) {
+                    certs.push(cert);
+                }
+            }
+        }
+        Ok((certs, keys))
+    }
+}
diff --git a/security/manager/ssl/osclientcerts/src/bindings_macos.rs b/security/manager/ssl/osclientcerts/src/bindings_macos.rs
new file mode 100644
index 0000000000..7294bbb555
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/src/bindings_macos.rs
@@ -0,0 +1,79 @@
+/* -*- Mode: rust; rust-indent-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This was originally generated by rust-bindgen at build time. Later in
+// development it became clear that using bindgen for this library as part of
+// mozilla-central would be difficult (if not impossible). So, this was
+// converted to a static file and unused declarations were removed. Also,
+// intermediate types added by rust-bindgen were removed for clarity.
+
+pub type OSStatus = i32;
+pub const errSecSuccess: OSStatus = 0;
+pub const errSecItemNotFound: OSStatus = -25300;
+
+pub type SecKeyAlgorithm = CFStringRef;
+
+extern "C" {
+    // Available starting macOS 10.3
+    pub fn SecCertificateGetTypeID() -> CFTypeID;
+    pub fn SecTrustCreateWithCertificates(
+        certificates: SecCertificateRef,
+        policies: SecPolicyRef,
+        trust: *mut SecTrustRef,
+    ) -> OSStatus;
+    pub fn SecIdentityGetTypeID() -> CFTypeID;
+    pub fn SecIdentityCopyCertificate(
+        identityRef: SecIdentityRef,
+        certificateRef: *mut SecCertificateRef,
+    ) -> OSStatus;
+    pub fn SecIdentityCopyPrivateKey(
+        identityRef: SecIdentityRef,
+        privateKeyRef: *mut SecKeyRef,
+    ) -> OSStatus;
+    pub fn SecKeyGetTypeID() -> CFTypeID;
+    pub fn SecPolicyGetTypeID() -> CFTypeID;
+    pub fn SecTrustGetTypeID() -> CFTypeID;
+
+    // Available starting macOS 10.6
+    pub fn SecCertificateCopyData(certificate: SecCertificateRef) -> CFDataRef;
+    pub fn SecCertificateCopySubjectSummary(certificate: SecCertificateRef) -> CFStringRef;
+    pub fn SecItemCopyMatching(query: CFDictionaryRef, result: *mut CFTypeRef) -> OSStatus;
+    pub fn SecPolicyCreateSSL(server: bool, hostname: CFStringRef) -> SecPolicyRef;
+    pub static kSecClass: CFStringRef;
+    pub static kSecAttrKeyType: CFStringRef;
+    pub static kSecAttrKeySizeInBits: CFStringRef;
+    pub static kSecMatchLimit: CFStringRef;
+    pub static kSecMatchLimitAll: CFStringRef;
+    pub static kSecReturnRef: CFStringRef;
+
+    // Available starting macOS 10.7
+    pub fn SecTrustGetCertificateAtIndex(trust: SecTrustRef, ix: CFIndex) -> SecCertificateRef;
+    pub fn SecTrustGetCertificateCount(trust: SecTrustRef) -> CFIndex;
+    pub static kSecClassIdentity: CFStringRef;
+    pub static kSecAttrKeyTypeRSA: CFStringRef;
+
+    // Available starting macOS 10.9
+    pub fn SecTrustSetNetworkFetchAllowed(trust: SecTrustRef, allowFetch: Boolean) -> OSStatus;
+
+    // Available starting macOS 10.12
+    pub fn SecKeyCreateSignature(
+        key: SecKeyRef,
+        algorithm: SecKeyAlgorithm,
+        data: CFDataRef,
+        err: *mut CFErrorRef,
+    ) -> CFDataRef;
+    pub fn SecKeyCopyAttributes(key: SecKeyRef) -> CFDictionaryRef;
+    pub fn SecKeyCopyExternalRepresentation(key: SecKeyRef, err: *mut CFErrorRef) -> CFDataRef;
+    pub static kSecKeyAlgorithmECDSASignatureDigestX962SHA1: CFStringRef;
+    pub static kSecKeyAlgorithmECDSASignatureDigestX962SHA256: CFStringRef;
+    pub static kSecKeyAlgorithmECDSASignatureDigestX962SHA384: CFStringRef;
+    pub static kSecKeyAlgorithmECDSASignatureDigestX962SHA512: CFStringRef;
+    pub static kSecKeyAlgorithmRSASignatureDigestPKCS1v15Raw: CFStringRef;
+    pub static kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA256: CFStringRef;
+    pub static kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA384: CFStringRef;
+    pub static kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA512: CFStringRef;
+    pub static kSecKeyAlgorithmRSASignatureDigestPKCS1v15SHA1: CFStringRef;
+    pub static kSecAttrKeyTypeECSECPrimeRandom: CFStringRef;
+}
diff --git a/security/manager/ssl/osclientcerts/src/lib.rs b/security/manager/ssl/osclientcerts/src/lib.rs
new file mode 100644
index 0000000000..a6cc206cfa
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/src/lib.rs
@@ -0,0 +1,1235 @@
+/* -*- Mode: rust; rust-indent-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#![allow(non_snake_case)]
+
+extern crate byteorder;
+#[cfg(target_os = "macos")]
+#[macro_use]
+extern crate core_foundation;
+extern crate env_logger;
+#[cfg(target_os = "macos")]
+#[macro_use]
+extern crate lazy_static;
+#[cfg(target_os = "macos")]
+extern crate libloading;
+#[macro_use]
+extern crate log;
+extern crate pkcs11_bindings;
+#[macro_use]
+extern crate rsclientcerts;
+extern crate sha2;
+#[cfg(target_os = "windows")]
+extern crate winapi;
+
+use pkcs11_bindings::*;
+use rsclientcerts::manager::{ManagerProxy, SlotType};
+use std::ffi::CStr;
+use std::sync::Mutex;
+use std::thread;
+
+#[cfg(target_os = "macos")]
+mod backend_macos;
+#[cfg(target_os = "windows")]
+mod backend_windows;
+
+#[cfg(target_os = "macos")]
+use crate::backend_macos::Backend;
+#[cfg(target_os = "windows")]
+use crate::backend_windows::Backend;
+
+struct ModuleState {
+    manager_proxy: ManagerProxy,
+    mechanisms: Vec<CK_MECHANISM_TYPE>,
+}
+
+/// The singleton `ModuleState` that handles state with respect to PKCS #11. Only one thread
+/// may use it at a time, but there is no restriction on which threads may use it. However, as
+/// OS APIs being used are not necessarily thread-safe (e.g. they may be using
+/// thread-local-storage), the `ManagerProxy` of the `ModuleState` forwards calls from any
+/// thread to a single thread where the real `Manager` does the actual work.
+static MODULE_STATE: Mutex<Option<ModuleState>> = Mutex::new(None);
+
+// Obtaining a handle on the manager proxy is a two-step process. First the mutex must be locked,
+// which (if successful), results in a mutex guard object. We must then get a mutable refence to the
+// underlying manager proxy (if set - otherwise we return an error). This can't happen all in one
+// macro without dropping a reference that needs to live long enough for this to be safe. In
+// practice, this looks like:
+//   let mut module_state_guard = try_to_get_module_state_guard!();
+//   let manager = module_state_guard_to_manager!(module_state_guard);
+macro_rules! try_to_get_module_state_guard {
+    () => {
+        match MODULE_STATE.lock() {
+            Ok(maybe_module_state) => maybe_module_state,
+            Err(poison_error) => {
+                log_with_thread_id!(
+                    error,
+                    "previous thread panicked acquiring manager lock: {}",
+                    poison_error
+                );
+                return CKR_DEVICE_ERROR;
+            }
+        }
+    };
+}
+
+macro_rules! module_state_guard_to_manager {
+    ($module_state_guard:ident) => {
+        match $module_state_guard.as_mut() {
+            Some(module_state) => &mut module_state.manager_proxy,
+            None => {
+                log_with_thread_id!(error, "module state expected to be set, but it is not");
+                return CKR_DEVICE_ERROR;
+            }
+        }
+    };
+}
+
+macro_rules! module_state_guard_to_mechanisms {
+    ($module_state_guard:ident) => {
+        match $module_state_guard.as_ref() {
+            Some(module_state) => &module_state.mechanisms,
+            None => {
+                log_with_thread_id!(error, "module state expected to be set, but it is not");
+                return CKR_DEVICE_ERROR;
+            }
+        }
+    };
+}
+
+// Helper macro to prefix log messages with the current thread ID.
+macro_rules! log_with_thread_id {
+    ($log_level:ident, $($message:expr),*) => {
+        $log_level!("{:?} {}", thread::current().id(), format_args!($($message),*));
+    };
+}
+
+/// This gets called to initialize the module. For this implementation, this consists of
+/// instantiating the `ManagerProxy`.
+extern "C" fn C_Initialize(pInitArgs: CK_VOID_PTR) -> CK_RV {
+    // This will fail if this has already been called, but this isn't a problem because either way,
+    // logging has been initialized.
+    let _ = env_logger::try_init();
+
+    if pInitArgs.is_null() {
+        return CKR_DEVICE_ERROR;
+    }
+    let init_args_ptr = unsafe { (*(pInitArgs as CK_C_INITIALIZE_ARGS_PTR)).pReserved };
+    if init_args_ptr.is_null() {
+        return CKR_DEVICE_ERROR;
+    }
+    let init_args_cstr = unsafe { CStr::from_ptr(init_args_ptr as *mut std::os::raw::c_char) };
+    let init_args = match init_args_cstr.to_str() {
+        Ok(init_args) => init_args,
+        Err(_) => return CKR_DEVICE_ERROR,
+    };
+    let mechanisms = if init_args == "RSA-PSS" {
+        vec![CKM_ECDSA, CKM_RSA_PKCS, CKM_RSA_PKCS_PSS]
+    } else {
+        vec![CKM_ECDSA, CKM_RSA_PKCS]
+    };
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager_proxy = match ManagerProxy::new(Backend {}) {
+        Ok(p) => p,
+        Err(e) => {
+            log_with_thread_id!(error, "C_Initialize: ManagerProxy: {}", e);
+            return CKR_DEVICE_ERROR;
+        }
+    };
+    match module_state_guard.replace(ModuleState {
+        manager_proxy,
+        mechanisms,
+    }) {
+        Some(_unexpected_previous_module_state) => {
+            #[cfg(target_os = "macos")]
+            {
+                log_with_thread_id!(info, "C_Initialize: module state previously set (this is expected on macOS - replacing it)");
+            }
+            #[cfg(target_os = "windows")]
+            {
+                log_with_thread_id!(
+                    warn,
+                    "C_Initialize: module state unexpectedly previously set (replacing it)"
+                );
+            }
+        }
+        None => {}
+    }
+    log_with_thread_id!(debug, "C_Initialize: CKR_OK");
+    CKR_OK
+}
+
+extern "C" fn C_Finalize(_pReserved: CK_VOID_PTR) -> CK_RV {
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    match manager.stop() {
+        Ok(()) => {
+            log_with_thread_id!(debug, "C_Finalize: CKR_OK");
+            CKR_OK
+        }
+        Err(e) => {
+            log_with_thread_id!(error, "C_Finalize: CKR_DEVICE_ERROR: {}", e);
+            CKR_DEVICE_ERROR
+        }
+    }
+}
+
+// The specification mandates that these strings be padded with spaces to the appropriate length.
+// Since the length of fixed-size arrays in rust is part of the type, the compiler enforces that
+// these byte strings are of the correct length.
+const MANUFACTURER_ID_BYTES: &[u8; 32] = b"Mozilla Corporation             ";
+const LIBRARY_DESCRIPTION_BYTES: &[u8; 32] = b"OS Client Cert Module           ";
+
+/// This gets called to gather some information about the module. In particular, this implementation
+/// supports (portions of) cryptoki (PKCS #11) version 2.2.
+extern "C" fn C_GetInfo(pInfo: CK_INFO_PTR) -> CK_RV {
+    if pInfo.is_null() {
+        log_with_thread_id!(error, "C_GetInfo: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    log_with_thread_id!(debug, "C_GetInfo: CKR_OK");
+    let mut info = CK_INFO::default();
+    info.cryptokiVersion.major = 2;
+    info.cryptokiVersion.minor = 2;
+    info.manufacturerID = *MANUFACTURER_ID_BYTES;
+    info.libraryDescription = *LIBRARY_DESCRIPTION_BYTES;
+    unsafe {
+        *pInfo = info;
+    }
+    CKR_OK
+}
+
+/// This module has one slot.
+const SLOT_COUNT: CK_ULONG = 1;
+const SLOT_ID: CK_SLOT_ID = 1;
+
+/// This gets called twice: once with a null `pSlotList` to get the number of slots (returned via
+/// `pulCount`) and a second time to get the ID for each slot.
+extern "C" fn C_GetSlotList(
+    _tokenPresent: CK_BBOOL,
+    pSlotList: CK_SLOT_ID_PTR,
+    pulCount: CK_ULONG_PTR,
+) -> CK_RV {
+    if pulCount.is_null() {
+        log_with_thread_id!(error, "C_GetSlotList: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    if !pSlotList.is_null() {
+        if unsafe { *pulCount } < SLOT_COUNT {
+            log_with_thread_id!(error, "C_GetSlotList: CKR_BUFFER_TOO_SMALL");
+            return CKR_BUFFER_TOO_SMALL;
+        }
+        unsafe {
+            *pSlotList = SLOT_ID;
+        }
+    };
+    unsafe {
+        *pulCount = SLOT_COUNT;
+    }
+    log_with_thread_id!(debug, "C_GetSlotList: CKR_OK");
+    CKR_OK
+}
+
+const SLOT_DESCRIPTION_BYTES: &[u8; 64] =
+    b"OS Client Cert Slot                                             ";
+
+/// This gets called to obtain information about slots. In this implementation, the token is
+/// always present in the singular slot.
+extern "C" fn C_GetSlotInfo(slotID: CK_SLOT_ID, pInfo: CK_SLOT_INFO_PTR) -> CK_RV {
+    if slotID != SLOT_ID || pInfo.is_null() {
+        log_with_thread_id!(error, "C_GetSlotInfo: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let slot_info = CK_SLOT_INFO {
+        slotDescription: *SLOT_DESCRIPTION_BYTES,
+        manufacturerID: *MANUFACTURER_ID_BYTES,
+        flags: CKF_TOKEN_PRESENT,
+        hardwareVersion: CK_VERSION::default(),
+        firmwareVersion: CK_VERSION::default(),
+    };
+    unsafe {
+        *pInfo = slot_info;
+    }
+    log_with_thread_id!(debug, "C_GetSlotInfo: CKR_OK");
+    CKR_OK
+}
+
+const TOKEN_LABEL_BYTES: &[u8; 32] = b"OS Client Cert Token            ";
+const TOKEN_MODEL_BYTES: &[u8; 16] = b"osclientcerts   ";
+const TOKEN_SERIAL_NUMBER_BYTES: &[u8; 16] = b"0000000000000000";
+
+/// This gets called to obtain some information about tokens. This implementation has one slot,
+/// so it has one token. This information is primarily for display purposes.
+extern "C" fn C_GetTokenInfo(slotID: CK_SLOT_ID, pInfo: CK_TOKEN_INFO_PTR) -> CK_RV {
+    if slotID != SLOT_ID || pInfo.is_null() {
+        log_with_thread_id!(error, "C_GetTokenInfo: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut token_info = CK_TOKEN_INFO::default();
+    token_info.label = *TOKEN_LABEL_BYTES;
+    token_info.manufacturerID = *MANUFACTURER_ID_BYTES;
+    token_info.model = *TOKEN_MODEL_BYTES;
+    token_info.serialNumber = *TOKEN_SERIAL_NUMBER_BYTES;
+    unsafe {
+        *pInfo = token_info;
+    }
+    log_with_thread_id!(debug, "C_GetTokenInfo: CKR_OK");
+    CKR_OK
+}
+
+/// This gets called to determine what mechanisms a slot supports. The singular slot supports
+/// ECDSA and RSA PKCS1. Depending on the configuration the module was loaded with, it may also
+/// support RSA PSS.
+extern "C" fn C_GetMechanismList(
+    slotID: CK_SLOT_ID,
+    pMechanismList: CK_MECHANISM_TYPE_PTR,
+    pulCount: CK_ULONG_PTR,
+) -> CK_RV {
+    if slotID != SLOT_ID || pulCount.is_null() {
+        log_with_thread_id!(error, "C_GetMechanismList: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let module_state_guard = try_to_get_module_state_guard!();
+    let mechanisms = module_state_guard_to_mechanisms!(module_state_guard);
+    if !pMechanismList.is_null() {
+        if unsafe { *pulCount as usize } < mechanisms.len() {
+            log_with_thread_id!(error, "C_GetMechanismList: CKR_ARGUMENTS_BAD");
+            return CKR_ARGUMENTS_BAD;
+        }
+        for (i, mechanism) in mechanisms.iter().enumerate() {
+            unsafe {
+                *pMechanismList.add(i) = *mechanism;
+            }
+        }
+    }
+    unsafe {
+        *pulCount = mechanisms.len() as CK_ULONG;
+    }
+    log_with_thread_id!(debug, "C_GetMechanismList: CKR_OK");
+    CKR_OK
+}
+
+extern "C" fn C_GetMechanismInfo(
+    _slotID: CK_SLOT_ID,
+    _type: CK_MECHANISM_TYPE,
+    _pInfo: CK_MECHANISM_INFO_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GetMechanismInfo: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_InitToken(
+    _slotID: CK_SLOT_ID,
+    _pPin: CK_UTF8CHAR_PTR,
+    _ulPinLen: CK_ULONG,
+    _pLabel: CK_UTF8CHAR_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_InitToken: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_InitPIN(
+    _hSession: CK_SESSION_HANDLE,
+    _pPin: CK_UTF8CHAR_PTR,
+    _ulPinLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_InitPIN: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SetPIN(
+    _hSession: CK_SESSION_HANDLE,
+    _pOldPin: CK_UTF8CHAR_PTR,
+    _ulOldLen: CK_ULONG,
+    _pNewPin: CK_UTF8CHAR_PTR,
+    _ulNewLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SetPIN: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+/// This gets called to create a new session. This module defers to the `ManagerProxy` to implement
+/// this.
+extern "C" fn C_OpenSession(
+    slotID: CK_SLOT_ID,
+    _flags: CK_FLAGS,
+    _pApplication: CK_VOID_PTR,
+    _Notify: CK_NOTIFY,
+    phSession: CK_SESSION_HANDLE_PTR,
+) -> CK_RV {
+    if slotID != SLOT_ID || phSession.is_null() {
+        log_with_thread_id!(error, "C_OpenSession: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    // The "modern"/"legacy" slot distinction still exists in ipcclientcerts,
+    // which shares some library code with this module, to allow for a more
+    // nuanced notion of whether or not e.g. RSA-PSS is supported.
+    let session_handle = match manager.open_session(SlotType::Modern) {
+        Ok(session_handle) => session_handle,
+        Err(e) => {
+            log_with_thread_id!(error, "C_OpenSession: open_session failed: {}", e);
+            return CKR_DEVICE_ERROR;
+        }
+    };
+    unsafe {
+        *phSession = session_handle;
+    }
+    log_with_thread_id!(debug, "C_OpenSession: CKR_OK");
+    CKR_OK
+}
+
+/// This gets called to close a session. This is handled by the `ManagerProxy`.
+extern "C" fn C_CloseSession(hSession: CK_SESSION_HANDLE) -> CK_RV {
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    if manager.close_session(hSession).is_err() {
+        log_with_thread_id!(error, "C_CloseSession: CKR_SESSION_HANDLE_INVALID");
+        return CKR_SESSION_HANDLE_INVALID;
+    }
+    log_with_thread_id!(debug, "C_CloseSession: CKR_OK");
+    CKR_OK
+}
+
+/// This gets called to close all open sessions at once. This is handled by the `ManagerProxy`.
+extern "C" fn C_CloseAllSessions(slotID: CK_SLOT_ID) -> CK_RV {
+    if slotID != SLOT_ID {
+        log_with_thread_id!(error, "C_CloseAllSessions: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    match manager.close_all_sessions(SlotType::Modern) {
+        Ok(()) => {
+            log_with_thread_id!(debug, "C_CloseAllSessions: CKR_OK");
+            CKR_OK
+        }
+        Err(e) => {
+            log_with_thread_id!(
+                error,
+                "C_CloseAllSessions: close_all_sessions failed: {}",
+                e
+            );
+            CKR_DEVICE_ERROR
+        }
+    }
+}
+
+extern "C" fn C_GetSessionInfo(_hSession: CK_SESSION_HANDLE, _pInfo: CK_SESSION_INFO_PTR) -> CK_RV {
+    log_with_thread_id!(error, "C_GetSessionInfo: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GetOperationState(
+    _hSession: CK_SESSION_HANDLE,
+    _pOperationState: CK_BYTE_PTR,
+    _pulOperationStateLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GetOperationState: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SetOperationState(
+    _hSession: CK_SESSION_HANDLE,
+    _pOperationState: CK_BYTE_PTR,
+    _ulOperationStateLen: CK_ULONG,
+    _hEncryptionKey: CK_OBJECT_HANDLE,
+    _hAuthenticationKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SetOperationState: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_Login(
+    _hSession: CK_SESSION_HANDLE,
+    _userType: CK_USER_TYPE,
+    _pPin: CK_UTF8CHAR_PTR,
+    _ulPinLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_Login: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+/// This gets called to log out and drop any authenticated resources. Because this module does not
+/// hold on to authenticated resources, this module "implements" this by doing nothing and
+/// returning a success result.
+extern "C" fn C_Logout(_hSession: CK_SESSION_HANDLE) -> CK_RV {
+    log_with_thread_id!(debug, "C_Logout: CKR_OK");
+    CKR_OK
+}
+
+extern "C" fn C_CreateObject(
+    _hSession: CK_SESSION_HANDLE,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulCount: CK_ULONG,
+    _phObject: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_CreateObject: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_CopyObject(
+    _hSession: CK_SESSION_HANDLE,
+    _hObject: CK_OBJECT_HANDLE,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulCount: CK_ULONG,
+    _phNewObject: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_CopyObject: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DestroyObject(_hSession: CK_SESSION_HANDLE, _hObject: CK_OBJECT_HANDLE) -> CK_RV {
+    log_with_thread_id!(error, "C_DestroyObject: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GetObjectSize(
+    _hSession: CK_SESSION_HANDLE,
+    _hObject: CK_OBJECT_HANDLE,
+    _pulSize: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GetObjectSize: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+/// This gets called to obtain the values of a number of attributes of an object identified by the
+/// given handle. This module implements this by requesting that the `ManagerProxy` find the object
+/// and attempt to get the value of each attribute. If a specified attribute is not defined on the
+/// object, the length of that attribute is set to -1 to indicate that it is not available.
+/// This gets called twice: once to obtain the lengths of the attributes and again to get the
+/// values.
+extern "C" fn C_GetAttributeValue(
+    _hSession: CK_SESSION_HANDLE,
+    hObject: CK_OBJECT_HANDLE,
+    pTemplate: CK_ATTRIBUTE_PTR,
+    ulCount: CK_ULONG,
+) -> CK_RV {
+    if pTemplate.is_null() {
+        log_with_thread_id!(error, "C_GetAttributeValue: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut attr_types = Vec::with_capacity(ulCount as usize);
+    for i in 0..ulCount as usize {
+        let attr = unsafe { &*pTemplate.add(i) };
+        attr_types.push(attr.type_);
+    }
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    let values = match manager.get_attributes(hObject, attr_types) {
+        Ok(values) => values,
+        Err(e) => {
+            log_with_thread_id!(error, "C_GetAttributeValue: CKR_ARGUMENTS_BAD ({})", e);
+            return CKR_ARGUMENTS_BAD;
+        }
+    };
+    if values.len() != ulCount as usize {
+        log_with_thread_id!(
+            error,
+            "C_GetAttributeValue: manager.get_attributes didn't return the right number of values"
+        );
+        return CKR_DEVICE_ERROR;
+    }
+    for (i, value) in values.iter().enumerate().take(ulCount as usize) {
+        let mut attr = unsafe { &mut *pTemplate.add(i) };
+        if let Some(attr_value) = value {
+            if attr.pValue.is_null() {
+                attr.ulValueLen = attr_value.len() as CK_ULONG;
+            } else {
+                let ptr: *mut u8 = attr.pValue as *mut u8;
+                if attr_value.len() != attr.ulValueLen as usize {
+                    log_with_thread_id!(error, "C_GetAttributeValue: incorrect attr size");
+                    return CKR_ARGUMENTS_BAD;
+                }
+                unsafe {
+                    std::ptr::copy_nonoverlapping(attr_value.as_ptr(), ptr, attr_value.len());
+                }
+            }
+        } else {
+            attr.ulValueLen = (0 - 1) as CK_ULONG;
+        }
+    }
+    log_with_thread_id!(debug, "C_GetAttributeValue: CKR_OK");
+    CKR_OK
+}
+
+extern "C" fn C_SetAttributeValue(
+    _hSession: CK_SESSION_HANDLE,
+    _hObject: CK_OBJECT_HANDLE,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulCount: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SetAttributeValue: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+fn trace_attr(prefix: &str, attr: &CK_ATTRIBUTE) {
+    let typ = match unsafe_packed_field_access!(attr.type_) {
+        CKA_CLASS => "CKA_CLASS".to_string(),
+        CKA_TOKEN => "CKA_TOKEN".to_string(),
+        CKA_LABEL => "CKA_LABEL".to_string(),
+        CKA_ID => "CKA_ID".to_string(),
+        CKA_VALUE => "CKA_VALUE".to_string(),
+        CKA_ISSUER => "CKA_ISSUER".to_string(),
+        CKA_SERIAL_NUMBER => "CKA_SERIAL_NUMBER".to_string(),
+        CKA_SUBJECT => "CKA_SUBJECT".to_string(),
+        CKA_PRIVATE => "CKA_PRIVATE".to_string(),
+        CKA_KEY_TYPE => "CKA_KEY_TYPE".to_string(),
+        CKA_MODULUS => "CKA_MODULUS".to_string(),
+        CKA_EC_PARAMS => "CKA_EC_PARAMS".to_string(),
+        _ => format!("0x{:x}", unsafe_packed_field_access!(attr.type_)),
+    };
+    let value =
+        unsafe { std::slice::from_raw_parts(attr.pValue as *const u8, attr.ulValueLen as usize) };
+    log_with_thread_id!(
+        trace,
+        "{}CK_ATTRIBUTE {{ type: {}, pValue: {:?}, ulValueLen: {} }}",
+        prefix,
+        typ,
+        value,
+        unsafe_packed_field_access!(attr.ulValueLen)
+    );
+}
+
+/// This gets called to initialize a search for objects matching a given list of attributes. This
+/// module implements this by gathering the attributes and passing them to the `ManagerProxy` to
+/// start the search.
+extern "C" fn C_FindObjectsInit(
+    hSession: CK_SESSION_HANDLE,
+    pTemplate: CK_ATTRIBUTE_PTR,
+    ulCount: CK_ULONG,
+) -> CK_RV {
+    if pTemplate.is_null() {
+        log_with_thread_id!(error, "C_FindObjectsInit: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut attrs = Vec::new();
+    log_with_thread_id!(trace, "C_FindObjectsInit:");
+    for i in 0..ulCount as usize {
+        let attr = unsafe { &*pTemplate.add(i) };
+        trace_attr("  ", attr);
+        let slice = unsafe {
+            std::slice::from_raw_parts(attr.pValue as *const u8, attr.ulValueLen as usize)
+        };
+        attrs.push((attr.type_, slice.to_owned()));
+    }
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    match manager.start_search(hSession, attrs) {
+        Ok(()) => {}
+        Err(e) => {
+            log_with_thread_id!(error, "C_FindObjectsInit: CKR_ARGUMENTS_BAD: {}", e);
+            return CKR_ARGUMENTS_BAD;
+        }
+    }
+    log_with_thread_id!(debug, "C_FindObjectsInit: CKR_OK");
+    CKR_OK
+}
+
+/// This gets called after `C_FindObjectsInit` to get the results of a search. This module
+/// implements this by looking up the search in the `ManagerProxy` and copying out the matching
+/// object handles.
+extern "C" fn C_FindObjects(
+    hSession: CK_SESSION_HANDLE,
+    phObject: CK_OBJECT_HANDLE_PTR,
+    ulMaxObjectCount: CK_ULONG,
+    pulObjectCount: CK_ULONG_PTR,
+) -> CK_RV {
+    if phObject.is_null() || pulObjectCount.is_null() || ulMaxObjectCount == 0 {
+        log_with_thread_id!(error, "C_FindObjects: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    let handles = match manager.search(hSession, ulMaxObjectCount as usize) {
+        Ok(handles) => handles,
+        Err(e) => {
+            log_with_thread_id!(error, "C_FindObjects: CKR_ARGUMENTS_BAD: {}", e);
+            return CKR_ARGUMENTS_BAD;
+        }
+    };
+    log_with_thread_id!(debug, "C_FindObjects: found handles {:?}", handles);
+    if handles.len() > ulMaxObjectCount as usize {
+        log_with_thread_id!(error, "C_FindObjects: manager returned too many handles");
+        return CKR_DEVICE_ERROR;
+    }
+    unsafe {
+        *pulObjectCount = handles.len() as CK_ULONG;
+    }
+    for (index, handle) in handles.iter().enumerate() {
+        if index < ulMaxObjectCount as usize {
+            unsafe {
+                *(phObject.add(index)) = *handle;
+            }
+        }
+    }
+    log_with_thread_id!(debug, "C_FindObjects: CKR_OK");
+    CKR_OK
+}
+
+/// This gets called after `C_FindObjectsInit` and `C_FindObjects` to finish a search. The module
+/// tells the `ManagerProxy` to clear the search.
+extern "C" fn C_FindObjectsFinal(hSession: CK_SESSION_HANDLE) -> CK_RV {
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    // It would be an error if there were no search for this session, but we can be permissive here.
+    match manager.clear_search(hSession) {
+        Ok(()) => {
+            log_with_thread_id!(debug, "C_FindObjectsFinal: CKR_OK");
+            CKR_OK
+        }
+        Err(e) => {
+            log_with_thread_id!(error, "C_FindObjectsFinal: clear_search failed: {}", e);
+            CKR_DEVICE_ERROR
+        }
+    }
+}
+
+extern "C" fn C_EncryptInit(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_EncryptInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_Encrypt(
+    _hSession: CK_SESSION_HANDLE,
+    _pData: CK_BYTE_PTR,
+    _ulDataLen: CK_ULONG,
+    _pEncryptedData: CK_BYTE_PTR,
+    _pulEncryptedDataLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_Encrypt: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_EncryptUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _pulEncryptedPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_EncryptUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_EncryptFinal(
+    _hSession: CK_SESSION_HANDLE,
+    _pLastEncryptedPart: CK_BYTE_PTR,
+    _pulLastEncryptedPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_EncryptFinal: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DecryptInit(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DecryptInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_Decrypt(
+    _hSession: CK_SESSION_HANDLE,
+    _pEncryptedData: CK_BYTE_PTR,
+    _ulEncryptedDataLen: CK_ULONG,
+    _pData: CK_BYTE_PTR,
+    _pulDataLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_Decrypt: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DecryptUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _ulEncryptedPartLen: CK_ULONG,
+    _pPart: CK_BYTE_PTR,
+    _pulPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DecryptUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DecryptFinal(
+    _hSession: CK_SESSION_HANDLE,
+    _pLastPart: CK_BYTE_PTR,
+    _pulLastPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DecryptFinal: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DigestInit(_hSession: CK_SESSION_HANDLE, _pMechanism: CK_MECHANISM_PTR) -> CK_RV {
+    log_with_thread_id!(error, "C_DigestInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_Digest(
+    _hSession: CK_SESSION_HANDLE,
+    _pData: CK_BYTE_PTR,
+    _ulDataLen: CK_ULONG,
+    _pDigest: CK_BYTE_PTR,
+    _pulDigestLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_Digest: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DigestUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DigestUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DigestKey(_hSession: CK_SESSION_HANDLE, _hKey: CK_OBJECT_HANDLE) -> CK_RV {
+    log_with_thread_id!(error, "C_DigestKey: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DigestFinal(
+    _hSession: CK_SESSION_HANDLE,
+    _pDigest: CK_BYTE_PTR,
+    _pulDigestLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DigestFinal: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+/// This gets called to set up a sign operation. The module essentially defers to the
+/// `ManagerProxy`.
+extern "C" fn C_SignInit(
+    hSession: CK_SESSION_HANDLE,
+    pMechanism: CK_MECHANISM_PTR,
+    hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    if pMechanism.is_null() {
+        log_with_thread_id!(error, "C_SignInit: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    // Presumably we should validate the mechanism against hKey, but the specification doesn't
+    // actually seem to require this.
+    let mechanism = unsafe { *pMechanism };
+    log_with_thread_id!(debug, "C_SignInit: mechanism is {:?}", mechanism);
+    let mechanism_params = if mechanism.mechanism == CKM_RSA_PKCS_PSS {
+        if mechanism.ulParameterLen as usize != std::mem::size_of::<CK_RSA_PKCS_PSS_PARAMS>() {
+            log_with_thread_id!(
+                error,
+                "C_SignInit: bad ulParameterLen for CKM_RSA_PKCS_PSS: {}",
+                unsafe_packed_field_access!(mechanism.ulParameterLen)
+            );
+            return CKR_ARGUMENTS_BAD;
+        }
+        Some(unsafe { *(mechanism.pParameter as *const CK_RSA_PKCS_PSS_PARAMS) })
+    } else {
+        None
+    };
+    let mut module_state_guard = try_to_get_module_state_guard!();
+    let manager = module_state_guard_to_manager!(module_state_guard);
+    match manager.start_sign(hSession, hKey, mechanism_params) {
+        Ok(()) => {}
+        Err(e) => {
+            log_with_thread_id!(error, "C_SignInit: CKR_GENERAL_ERROR: {}", e);
+            return CKR_GENERAL_ERROR;
+        }
+    };
+    log_with_thread_id!(debug, "C_SignInit: CKR_OK");
+    CKR_OK
+}
+
+/// NSS calls this after `C_SignInit` (there are more ways in the PKCS #11 specification to sign
+/// data, but this is the only way supported by this module). The module essentially defers to the
+/// `ManagerProxy` and copies out the resulting signature.
+extern "C" fn C_Sign(
+    hSession: CK_SESSION_HANDLE,
+    pData: CK_BYTE_PTR,
+    ulDataLen: CK_ULONG,
+    pSignature: CK_BYTE_PTR,
+    pulSignatureLen: CK_ULONG_PTR,
+) -> CK_RV {
+    if pData.is_null() || pulSignatureLen.is_null() {
+        log_with_thread_id!(error, "C_Sign: CKR_ARGUMENTS_BAD");
+        return CKR_ARGUMENTS_BAD;
+    }
+    let data = unsafe { std::slice::from_raw_parts(pData, ulDataLen as usize) };
+    if pSignature.is_null() {
+        let mut module_state_guard = try_to_get_module_state_guard!();
+        let manager = module_state_guard_to_manager!(module_state_guard);
+        match manager.get_signature_length(hSession, data.to_vec()) {
+            Ok(signature_length) => unsafe {
+                *pulSignatureLen = signature_length as CK_ULONG;
+            },
+            Err(e) => {
+                log_with_thread_id!(error, "C_Sign: get_signature_length failed: {}", e);
+                log_with_thread_id!(error, "C_Sign: try setting security.osclientcerts.assume_rsa_pss_support to false and restarting");
+                return CKR_GENERAL_ERROR;
+            }
+        }
+    } else {
+        let mut module_state_guard = try_to_get_module_state_guard!();
+        let manager = module_state_guard_to_manager!(module_state_guard);
+        match manager.sign(hSession, data.to_vec()) {
+            Ok(signature) => {
+                let signature_capacity = unsafe { *pulSignatureLen } as usize;
+                if signature_capacity < signature.len() {
+                    log_with_thread_id!(error, "C_Sign: CKR_ARGUMENTS_BAD");
+                    return CKR_ARGUMENTS_BAD;
+                }
+                let ptr: *mut u8 = pSignature as *mut u8;
+                unsafe {
+                    std::ptr::copy_nonoverlapping(signature.as_ptr(), ptr, signature.len());
+                    *pulSignatureLen = signature.len() as CK_ULONG;
+                }
+            }
+            Err(e) => {
+                log_with_thread_id!(error, "C_Sign: sign failed: {}", e);
+                log_with_thread_id!(error, "C_Sign: try setting security.osclientcerts.assume_rsa_pss_support to false and restarting");
+                return CKR_GENERAL_ERROR;
+            }
+        }
+    }
+    log_with_thread_id!(debug, "C_Sign: CKR_OK");
+    CKR_OK
+}
+
+extern "C" fn C_SignUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SignUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SignFinal(
+    _hSession: CK_SESSION_HANDLE,
+    _pSignature: CK_BYTE_PTR,
+    _pulSignatureLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SignFinal: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SignRecoverInit(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SignRecoverInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SignRecover(
+    _hSession: CK_SESSION_HANDLE,
+    _pData: CK_BYTE_PTR,
+    _ulDataLen: CK_ULONG,
+    _pSignature: CK_BYTE_PTR,
+    _pulSignatureLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SignRecover: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_VerifyInit(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_VerifyInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_Verify(
+    _hSession: CK_SESSION_HANDLE,
+    _pData: CK_BYTE_PTR,
+    _ulDataLen: CK_ULONG,
+    _pSignature: CK_BYTE_PTR,
+    _ulSignatureLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_Verify: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_VerifyUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_VerifyUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_VerifyFinal(
+    _hSession: CK_SESSION_HANDLE,
+    _pSignature: CK_BYTE_PTR,
+    _ulSignatureLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_VerifyFinal: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_VerifyRecoverInit(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hKey: CK_OBJECT_HANDLE,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_VerifyRecoverInit: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_VerifyRecover(
+    _hSession: CK_SESSION_HANDLE,
+    _pSignature: CK_BYTE_PTR,
+    _ulSignatureLen: CK_ULONG,
+    _pData: CK_BYTE_PTR,
+    _pulDataLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_VerifyRecover: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DigestEncryptUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _pulEncryptedPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DigestEncryptUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DecryptDigestUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _ulEncryptedPartLen: CK_ULONG,
+    _pPart: CK_BYTE_PTR,
+    _pulPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DecryptDigestUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SignEncryptUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pPart: CK_BYTE_PTR,
+    _ulPartLen: CK_ULONG,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _pulEncryptedPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SignEncryptUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DecryptVerifyUpdate(
+    _hSession: CK_SESSION_HANDLE,
+    _pEncryptedPart: CK_BYTE_PTR,
+    _ulEncryptedPartLen: CK_ULONG,
+    _pPart: CK_BYTE_PTR,
+    _pulPartLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DecryptVerifyUpdate: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GenerateKey(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulCount: CK_ULONG,
+    _phKey: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GenerateKey: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GenerateKeyPair(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _pPublicKeyTemplate: CK_ATTRIBUTE_PTR,
+    _ulPublicKeyAttributeCount: CK_ULONG,
+    _pPrivateKeyTemplate: CK_ATTRIBUTE_PTR,
+    _ulPrivateKeyAttributeCount: CK_ULONG,
+    _phPublicKey: CK_OBJECT_HANDLE_PTR,
+    _phPrivateKey: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GenerateKeyPair: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_WrapKey(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hWrappingKey: CK_OBJECT_HANDLE,
+    _hKey: CK_OBJECT_HANDLE,
+    _pWrappedKey: CK_BYTE_PTR,
+    _pulWrappedKeyLen: CK_ULONG_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_WrapKey: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_UnwrapKey(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hUnwrappingKey: CK_OBJECT_HANDLE,
+    _pWrappedKey: CK_BYTE_PTR,
+    _ulWrappedKeyLen: CK_ULONG,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulAttributeCount: CK_ULONG,
+    _phKey: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_UnwrapKey: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_DeriveKey(
+    _hSession: CK_SESSION_HANDLE,
+    _pMechanism: CK_MECHANISM_PTR,
+    _hBaseKey: CK_OBJECT_HANDLE,
+    _pTemplate: CK_ATTRIBUTE_PTR,
+    _ulAttributeCount: CK_ULONG,
+    _phKey: CK_OBJECT_HANDLE_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_DeriveKey: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_SeedRandom(
+    _hSession: CK_SESSION_HANDLE,
+    _pSeed: CK_BYTE_PTR,
+    _ulSeedLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_SeedRandom: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GenerateRandom(
+    _hSession: CK_SESSION_HANDLE,
+    _RandomData: CK_BYTE_PTR,
+    _ulRandomLen: CK_ULONG,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_GenerateRandom: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_GetFunctionStatus(_hSession: CK_SESSION_HANDLE) -> CK_RV {
+    log_with_thread_id!(error, "C_GetFunctionStatus: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_CancelFunction(_hSession: CK_SESSION_HANDLE) -> CK_RV {
+    log_with_thread_id!(error, "C_CancelFunction: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+extern "C" fn C_WaitForSlotEvent(
+    _flags: CK_FLAGS,
+    _pSlot: CK_SLOT_ID_PTR,
+    _pRserved: CK_VOID_PTR,
+) -> CK_RV {
+    log_with_thread_id!(error, "C_WaitForSlotEvent: CKR_FUNCTION_NOT_SUPPORTED");
+    CKR_FUNCTION_NOT_SUPPORTED
+}
+
+/// To be a valid PKCS #11 module, this list of functions must be supported. At least cryptoki 2.2
+/// must be supported for this module to work in NSS.
+static mut FUNCTION_LIST: CK_FUNCTION_LIST = CK_FUNCTION_LIST {
+    version: CK_VERSION { major: 2, minor: 2 },
+    C_Initialize: Some(C_Initialize),
+    C_Finalize: Some(C_Finalize),
+    C_GetInfo: Some(C_GetInfo),
+    C_GetFunctionList: None,
+    C_GetSlotList: Some(C_GetSlotList),
+    C_GetSlotInfo: Some(C_GetSlotInfo),
+    C_GetTokenInfo: Some(C_GetTokenInfo),
+    C_GetMechanismList: Some(C_GetMechanismList),
+    C_GetMechanismInfo: Some(C_GetMechanismInfo),
+    C_InitToken: Some(C_InitToken),
+    C_InitPIN: Some(C_InitPIN),
+    C_SetPIN: Some(C_SetPIN),
+    C_OpenSession: Some(C_OpenSession),
+    C_CloseSession: Some(C_CloseSession),
+    C_CloseAllSessions: Some(C_CloseAllSessions),
+    C_GetSessionInfo: Some(C_GetSessionInfo),
+    C_GetOperationState: Some(C_GetOperationState),
+    C_SetOperationState: Some(C_SetOperationState),
+    C_Login: Some(C_Login),
+    C_Logout: Some(C_Logout),
+    C_CreateObject: Some(C_CreateObject),
+    C_CopyObject: Some(C_CopyObject),
+    C_DestroyObject: Some(C_DestroyObject),
+    C_GetObjectSize: Some(C_GetObjectSize),
+    C_GetAttributeValue: Some(C_GetAttributeValue),
+    C_SetAttributeValue: Some(C_SetAttributeValue),
+    C_FindObjectsInit: Some(C_FindObjectsInit),
+    C_FindObjects: Some(C_FindObjects),
+    C_FindObjectsFinal: Some(C_FindObjectsFinal),
+    C_EncryptInit: Some(C_EncryptInit),
+    C_Encrypt: Some(C_Encrypt),
+    C_EncryptUpdate: Some(C_EncryptUpdate),
+    C_EncryptFinal: Some(C_EncryptFinal),
+    C_DecryptInit: Some(C_DecryptInit),
+    C_Decrypt: Some(C_Decrypt),
+    C_DecryptUpdate: Some(C_DecryptUpdate),
+    C_DecryptFinal: Some(C_DecryptFinal),
+    C_DigestInit: Some(C_DigestInit),
+    C_Digest: Some(C_Digest),
+    C_DigestUpdate: Some(C_DigestUpdate),
+    C_DigestKey: Some(C_DigestKey),
+    C_DigestFinal: Some(C_DigestFinal),
+    C_SignInit: Some(C_SignInit),
+    C_Sign: Some(C_Sign),
+    C_SignUpdate: Some(C_SignUpdate),
+    C_SignFinal: Some(C_SignFinal),
+    C_SignRecoverInit: Some(C_SignRecoverInit),
+    C_SignRecover: Some(C_SignRecover),
+    C_VerifyInit: Some(C_VerifyInit),
+    C_Verify: Some(C_Verify),
+    C_VerifyUpdate: Some(C_VerifyUpdate),
+    C_VerifyFinal: Some(C_VerifyFinal),
+    C_VerifyRecoverInit: Some(C_VerifyRecoverInit),
+    C_VerifyRecover: Some(C_VerifyRecover),
+    C_DigestEncryptUpdate: Some(C_DigestEncryptUpdate),
+    C_DecryptDigestUpdate: Some(C_DecryptDigestUpdate),
+    C_SignEncryptUpdate: Some(C_SignEncryptUpdate),
+    C_DecryptVerifyUpdate: Some(C_DecryptVerifyUpdate),
+    C_GenerateKey: Some(C_GenerateKey),
+    C_GenerateKeyPair: Some(C_GenerateKeyPair),
+    C_WrapKey: Some(C_WrapKey),
+    C_UnwrapKey: Some(C_UnwrapKey),
+    C_DeriveKey: Some(C_DeriveKey),
+    C_SeedRandom: Some(C_SeedRandom),
+    C_GenerateRandom: Some(C_GenerateRandom),
+    C_GetFunctionStatus: Some(C_GetFunctionStatus),
+    C_CancelFunction: Some(C_CancelFunction),
+    C_WaitForSlotEvent: Some(C_WaitForSlotEvent),
+};
+
+/// # Safety
+///
+/// This is the only function this module exposes. NSS calls it to obtain the list of functions
+/// comprising this module.
+/// ppFunctionList must be a valid pointer.
+#[no_mangle]
+pub unsafe extern "C" fn C_GetFunctionList(ppFunctionList: CK_FUNCTION_LIST_PTR_PTR) -> CK_RV {
+    if ppFunctionList.is_null() {
+        return CKR_ARGUMENTS_BAD;
+    }
+    *ppFunctionList = &mut FUNCTION_LIST;
+    CKR_OK
+}
+
+#[cfg_attr(target_os = "macos", link(name = "Security", kind = "framework"))]
+extern "C" {}
diff --git a/security/manager/ssl/osclientcerts/test/certificate.bin b/security/manager/ssl/osclientcerts/test/certificate.bin
new file mode 100644
index 0000000000..01fbafb15c
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/test/certificate.bin
diff --git a/security/manager/ssl/osclientcerts/test/modulus.bin b/security/manager/ssl/osclientcerts/test/modulus.bin
new file mode 100644
index 0000000000..a9b09ff53e
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/test/modulus.bin
@@ -0,0 +1,2 @@
+��Q�D��A�n��6=<���5J���hWl${��%�������n��k�Zukjdqz�Z�E���$�~�C�i�8 )�� �I�۹L�kl���~�i��:�*A�p�
��f+�$��}��ay��W�=�;��H�7ӈC�'�U�fZ�~�/:{�$�l���a[���u1��ݴ����%�	��h�{/"oi㴊�a�&�%���N6�$,��/��1���I#�rQ�1���
+5�
\ No newline at end of file
diff --git a/security/manager/ssl/osclientcerts/test/rsa.bin b/security/manager/ssl/osclientcerts/test/rsa.bin
new file mode 100644
index 0000000000..93ededb827
--- /dev/null
+++ b/security/manager/ssl/osclientcerts/test/rsa.bin