1 files changed, 186 insertions, 0 deletions
diff --git a/security/manager/ssl/KeychainSecret.cpp b/security/manager/ssl/KeychainSecret.cpp
new file mode 100644
index 0000000000..376e2f14c3
--- /dev/null
+++ b/security/manager/ssl/KeychainSecret.cpp
@@ -0,0 +1,186 @@
+/* -*- 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/. */
+
+#include "KeychainSecret.h"
+
+#include <Security/Security.h>
+
+#include "mozilla/Logging.h"
+
+// This is the implementation of KeychainSecret, an instantiation of OSKeyStore
+// for OS X. It uses the system keychain, hence the name.
+
+using namespace mozilla;
+
+LazyLogModule gKeychainSecretLog("keychainsecret");
+
+KeychainSecret::KeychainSecret() {}
+
+KeychainSecret::~KeychainSecret() {}
+
+nsresult KeychainSecret::Lock() {
+  // https://developer.apple.com/documentation/security/1402180-seckeychainlock
+  // Passing `nullptr` locks the default keychain.
+  OSStatus rv = SecKeychainLock(nullptr);
+  if (rv != errSecSuccess) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("SecKeychainLock failed: %d", rv));
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult KeychainSecret::Unlock() {
+  // https://developer.apple.com/documentation/security/1400341-seckeychainunlock
+  // This attempts to unlock the default keychain. Using `false` indicates we
+  // aren't passing in a password (if the keychain is locked, a dialog will
+  // appear for the user).
+  OSStatus rv = SecKeychainUnlock(nullptr, 0, nullptr, false);
+  if (rv != errSecSuccess) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("SecKeychainUnlock failed: %d", rv));
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+ScopedCFType<CFStringRef> MozillaStringToCFString(const nsACString& stringIn) {
+  // https://developer.apple.com/documentation/corefoundation/1543419-cfstringcreatewithbytes
+  ScopedCFType<CFStringRef> stringOut(CFStringCreateWithBytes(
+      nullptr, reinterpret_cast<const UInt8*>(stringIn.BeginReading()),
+      stringIn.Length(), kCFStringEncodingUTF8, false));
+  return stringOut;
+}
+
+nsresult KeychainSecret::StoreSecret(const nsACString& aSecret,
+                                     const nsACString& aLabel) {
+  // This creates a CFDictionary of the form:
+  // { class: generic password,
+  //   account: the given label,
+  //   value: the given secret }
+  // "account" is the way we differentiate different secrets.
+  // By default, secrets stored by the application (Firefox) in this way are not
+  // accessible to other applications, so we shouldn't need to worry about
+  // unauthorized access or namespace collisions. This will be the case as long
+  // as we never set the kSecAttrAccessGroup attribute on the CFDictionary. The
+  // platform enforces this restriction using the application-identifier
+  // entitlement that each application bundle should have. See
+  // https://developer.apple.com/documentation/security/1401659-secitemadd?language=objc#discussion
+
+  // The keychain does not overwrite secrets by default (unlike other backends
+  // like libsecret and credential manager). To be consistent, we first delete
+  // any previously-stored secrets that use the given label.
+  nsresult rv = DeleteSecret(aLabel);
+  if (NS_FAILED(rv)) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("DeleteSecret before StoreSecret failed"));
+    return rv;
+  }
+  const CFStringRef keys[] = {kSecClass, kSecAttrAccount, kSecValueData};
+  ScopedCFType<CFStringRef> label(MozillaStringToCFString(aLabel));
+  if (!label) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("MozillaStringToCFString failed"));
+    return NS_ERROR_FAILURE;
+  }
+  ScopedCFType<CFDataRef> secret(CFDataCreate(
+      nullptr, reinterpret_cast<const UInt8*>(aSecret.BeginReading()),
+      aSecret.Length()));
+  if (!secret) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug, ("CFDataCreate failed"));
+    return NS_ERROR_FAILURE;
+  }
+  const void* values[] = {kSecClassGenericPassword, label.get(), secret.get()};
+  static_assert(ArrayLength(keys) == ArrayLength(values),
+                "mismatched SecItemAdd key/value array sizes");
+  ScopedCFType<CFDictionaryRef> addDictionary(CFDictionaryCreate(
+      nullptr, (const void**)&keys, (const void**)&values, ArrayLength(keys),
+      &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
+  // https://developer.apple.com/documentation/security/1401659-secitemadd
+  OSStatus osrv = SecItemAdd(addDictionary.get(), nullptr);
+  if (osrv != errSecSuccess) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("SecItemAdd failed: %d", osrv));
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult KeychainSecret::DeleteSecret(const nsACString& aLabel) {
+  // To delete a secret, we create a CFDictionary of the form:
+  // { class: generic password,
+  //   account: the given label }
+  // and then call SecItemDelete.
+  const CFStringRef keys[] = {kSecClass, kSecAttrAccount};
+  ScopedCFType<CFStringRef> label(MozillaStringToCFString(aLabel));
+  if (!label) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("MozillaStringToCFString failed"));
+    return NS_ERROR_FAILURE;
+  }
+  const void* values[] = {kSecClassGenericPassword, label.get()};
+  static_assert(ArrayLength(keys) == ArrayLength(values),
+                "mismatched SecItemDelete key/value array sizes");
+  ScopedCFType<CFDictionaryRef> deleteDictionary(CFDictionaryCreate(
+      nullptr, (const void**)&keys, (const void**)&values, ArrayLength(keys),
+      &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
+  // https://developer.apple.com/documentation/security/1395547-secitemdelete
+  OSStatus rv = SecItemDelete(deleteDictionary.get());
+  if (rv != errSecSuccess && rv != errSecItemNotFound) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("SecItemDelete failed: %d", rv));
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult KeychainSecret::RetrieveSecret(const nsACString& aLabel,
+                                        /* out */ nsACString& aSecret) {
+  // To retrieve a secret, we create a CFDictionary of the form:
+  // { class: generic password,
+  //   account: the given label,
+  //   match limit: match one,
+  //   return attributes: true,
+  //   return data: true }
+  // This searches for and returns the attributes and data for the secret
+  // matching the given label. We then extract the data (i.e. the secret) and
+  // return it.
+  const CFStringRef keys[] = {kSecClass, kSecAttrAccount, kSecMatchLimit,
+                              kSecReturnAttributes, kSecReturnData};
+  ScopedCFType<CFStringRef> label(MozillaStringToCFString(aLabel));
+  if (!label) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("MozillaStringToCFString failed"));
+    return NS_ERROR_FAILURE;
+  }
+  const void* values[] = {kSecClassGenericPassword, label.get(),
+                          kSecMatchLimitOne, kCFBooleanTrue, kCFBooleanTrue};
+  static_assert(ArrayLength(keys) == ArrayLength(values),
+                "mismatched SecItemCopyMatching key/value array sizes");
+  ScopedCFType<CFDictionaryRef> searchDictionary(CFDictionaryCreate(
+      nullptr, (const void**)&keys, (const void**)&values, ArrayLength(keys),
+      &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks));
+  CFTypeRef item;
+  // https://developer.apple.com/documentation/security/1398306-secitemcopymatching
+  OSStatus rv = SecItemCopyMatching(searchDictionary.get(), &item);
+  if (rv != errSecSuccess) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("SecItemCopyMatching failed: %d", rv));
+    return NS_ERROR_FAILURE;
+  }
+  ScopedCFType<CFDictionaryRef> dictionary(
+      reinterpret_cast<CFDictionaryRef>(item));
+  CFDataRef secret = reinterpret_cast<CFDataRef>(
+      CFDictionaryGetValue(dictionary.get(), kSecValueData));
+  if (!secret) {
+    MOZ_LOG(gKeychainSecretLog, LogLevel::Debug,
+            ("CFDictionaryGetValue failed"));
+    return NS_ERROR_FAILURE;
+  }
+  aSecret.Assign(reinterpret_cast<const char*>(CFDataGetBytePtr(secret)),
+                 CFDataGetLength(secret));
+  return NS_OK;
+}