| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include "openssl-util.h" |
| #include "alloc-util.h" |
| |
| #if HAVE_OPENSSL |
| int rsa_encrypt_bytes( |
| EVP_PKEY *pkey, |
| const void *decrypted_key, |
| size_t decrypted_key_size, |
| void **ret_encrypt_key, |
| size_t *ret_encrypt_key_size) { |
| |
| _cleanup_(EVP_PKEY_CTX_freep) EVP_PKEY_CTX *ctx = NULL; |
| _cleanup_free_ void *b = NULL; |
| size_t l; |
| |
| ctx = EVP_PKEY_CTX_new(pkey, NULL); |
| if (!ctx) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to allocate public key context"); |
| |
| if (EVP_PKEY_encrypt_init(ctx) <= 0) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to initialize public key context"); |
| |
| if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to configure PKCS#1 padding"); |
| |
| if (EVP_PKEY_encrypt(ctx, NULL, &l, decrypted_key, decrypted_key_size) <= 0) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to determine encrypted key size"); |
| |
| b = malloc(l); |
| if (!b) |
| return -ENOMEM; |
| |
| if (EVP_PKEY_encrypt(ctx, b, &l, decrypted_key, decrypted_key_size) <= 0) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Failed to determine encrypted key size"); |
| |
| *ret_encrypt_key = TAKE_PTR(b); |
| *ret_encrypt_key_size = l; |
| |
| return 0; |
| } |
| |
| int rsa_pkey_to_suitable_key_size( |
| EVP_PKEY *pkey, |
| size_t *ret_suitable_key_size) { |
| |
| size_t suitable_key_size; |
| int bits; |
| |
| assert_se(pkey); |
| assert_se(ret_suitable_key_size); |
| |
| /* Analyzes the specified public key and that it is RSA. If so, will return a suitable size for a |
| * disk encryption key to encrypt with RSA for use in PKCS#11 security token schemes. */ |
| |
| if (EVP_PKEY_base_id(pkey) != EVP_PKEY_RSA) |
| return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "X.509 certificate does not refer to RSA key."); |
| |
| bits = EVP_PKEY_bits(pkey); |
| log_debug("Bits in RSA key: %i", bits); |
| |
| /* We use PKCS#1 padding for the RSA cleartext, hence let's leave some extra space for it, hence only |
| * generate a random key half the size of the RSA length */ |
| suitable_key_size = bits / 8 / 2; |
| |
| if (suitable_key_size < 1) |
| return log_debug_errno(SYNTHETIC_ERRNO(EIO), "Uh, RSA key size too short?"); |
| |
| *ret_suitable_key_size = suitable_key_size; |
| return 0; |
| } |
| #endif |