/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include "errno-util.h" #include "format-table.h" #include "hexdecoct.h" #include "homectl-pkcs11.h" #include "libcrypt-util.h" #include "memory-util.h" #include "openssl-util.h" #include "pkcs11-util.h" #include "random-util.h" #include "strv.h" static int add_pkcs11_encrypted_key( JsonVariant **v, const char *uri, const void *encrypted_key, size_t encrypted_key_size, const void *decrypted_key, size_t decrypted_key_size) { _cleanup_(json_variant_unrefp) JsonVariant *l = NULL, *w = NULL, *e = NULL; _cleanup_(erase_and_freep) char *base64_encoded = NULL, *hashed = NULL; ssize_t base64_encoded_size; int r; assert(v); assert(uri); assert(encrypted_key); assert(encrypted_key_size > 0); assert(decrypted_key); assert(decrypted_key_size > 0); /* Before using UNIX hashing on the supplied key we base64 encode it, since crypt_r() and friends * expect a NUL terminated string, and we use a binary key */ base64_encoded_size = base64mem(decrypted_key, decrypted_key_size, &base64_encoded); if (base64_encoded_size < 0) return log_error_errno(base64_encoded_size, "Failed to base64 encode secret key: %m"); r = hash_password(base64_encoded, &hashed); if (r < 0) return log_error_errno(errno_or_else(EINVAL), "Failed to UNIX hash secret key: %m"); r = json_build(&e, JSON_BUILD_OBJECT( JSON_BUILD_PAIR("uri", JSON_BUILD_STRING(uri)), JSON_BUILD_PAIR("data", JSON_BUILD_BASE64(encrypted_key, encrypted_key_size)), JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRING(hashed)))); if (r < 0) return log_error_errno(r, "Failed to build encrypted JSON key object: %m"); w = json_variant_ref(json_variant_by_key(*v, "privileged")); l = json_variant_ref(json_variant_by_key(w, "pkcs11EncryptedKey")); r = json_variant_append_array(&l, e); if (r < 0) return log_error_errno(r, "Failed append PKCS#11 encrypted key: %m"); r = json_variant_set_field(&w, "pkcs11EncryptedKey", l); if (r < 0) return log_error_errno(r, "Failed to set PKCS#11 encrypted key: %m"); r = json_variant_set_field(v, "privileged", w); if (r < 0) return log_error_errno(r, "Failed to update privileged field: %m"); return 0; } static int add_pkcs11_token_uri(JsonVariant **v, const char *uri) { _cleanup_(json_variant_unrefp) JsonVariant *w = NULL; _cleanup_strv_free_ char **l = NULL; int r; assert(v); assert(uri); w = json_variant_ref(json_variant_by_key(*v, "pkcs11TokenUri")); if (w) { r = json_variant_strv(w, &l); if (r < 0) return log_error_errno(r, "Failed to parse PKCS#11 token list: %m"); if (strv_contains(l, uri)) return 0; } r = strv_extend(&l, uri); if (r < 0) return log_oom(); w = json_variant_unref(w); r = json_variant_new_array_strv(&w, l); if (r < 0) return log_error_errno(r, "Failed to create PKCS#11 token URI JSON: %m"); r = json_variant_set_field(v, "pkcs11TokenUri", w); if (r < 0) return log_error_errno(r, "Failed to update PKCS#11 token URI list: %m"); return 0; } int identity_add_token_pin(JsonVariant **v, const char *pin) { _cleanup_(json_variant_unrefp) JsonVariant *w = NULL, *l = NULL; _cleanup_strv_free_erase_ char **pins = NULL; int r; assert(v); if (isempty(pin)) return 0; w = json_variant_ref(json_variant_by_key(*v, "secret")); l = json_variant_ref(json_variant_by_key(w, "tokenPin")); r = json_variant_strv(l, &pins); if (r < 0) return log_error_errno(r, "Failed to convert PIN array: %m"); if (strv_contains(pins, pin)) return 0; r = strv_extend(&pins, pin); if (r < 0) return log_oom(); strv_uniq(pins); l = json_variant_unref(l); r = json_variant_new_array_strv(&l, pins); if (r < 0) return log_error_errno(r, "Failed to allocate new PIN array JSON: %m"); json_variant_sensitive(l); r = json_variant_set_field(&w, "tokenPin", l); if (r < 0) return log_error_errno(r, "Failed to update PIN field: %m"); r = json_variant_set_field(v, "secret", w); if (r < 0) return log_error_errno(r, "Failed to update secret object: %m"); return 1; } static int acquire_pkcs11_certificate( const char *uri, const char *askpw_friendly_name, const char *askpw_icon_name, X509 **ret_cert, char **ret_pin_used) { #if HAVE_P11KIT return pkcs11_acquire_certificate(uri, askpw_friendly_name, askpw_icon_name, ret_cert, ret_pin_used); #else return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "PKCS#11 tokens not supported on this build."); #endif } int identity_add_pkcs11_key_data(JsonVariant **v, const char *uri) { _cleanup_(erase_and_freep) void *decrypted_key = NULL, *encrypted_key = NULL; _cleanup_(erase_and_freep) char *pin = NULL; size_t decrypted_key_size, encrypted_key_size; _cleanup_(X509_freep) X509 *cert = NULL; EVP_PKEY *pkey; int r; assert(v); r = acquire_pkcs11_certificate(uri, "home directory operation", "user-home", &cert, &pin); if (r < 0) return r; pkey = X509_get0_pubkey(cert); if (!pkey) return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to extract public key from X.509 certificate."); r = rsa_pkey_to_suitable_key_size(pkey, &decrypted_key_size); if (r < 0) return log_error_errno(r, "Failed to extract RSA key size from X509 certificate."); log_debug("Generating %zu bytes random key.", decrypted_key_size); decrypted_key = malloc(decrypted_key_size); if (!decrypted_key) return log_oom(); r = crypto_random_bytes(decrypted_key, decrypted_key_size); if (r < 0) return log_error_errno(r, "Failed to generate random key: %m"); r = rsa_encrypt_bytes(pkey, decrypted_key, decrypted_key_size, &encrypted_key, &encrypted_key_size); if (r < 0) return log_error_errno(r, "Failed to encrypt key: %m"); /* Add the token URI to the public part of the record. */ r = add_pkcs11_token_uri(v, uri); if (r < 0) return r; /* Include the encrypted version of the random key we just generated in the privileged part of the record */ r = add_pkcs11_encrypted_key( v, uri, encrypted_key, encrypted_key_size, decrypted_key, decrypted_key_size); if (r < 0) return r; /* If we acquired the PIN also include it in the secret section of the record, so that systemd-homed * can use it if it needs to, given that it likely needs to decrypt the key again to pass to LUKS or * fscrypt. */ r = identity_add_token_pin(v, pin); if (r < 0) return r; return 0; }