diff options
| -rw-r--r-- | engines/e_dasync.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/engines/e_dasync.c b/engines/e_dasync.c index 0fe1d436ee..1c2ccf0cb2 100644 --- a/engines/e_dasync.c +++ b/engines/e_dasync.c @@ -155,6 +155,14 @@ static const EVP_CIPHER *dasync_aes_128_cbc(void) /* * Holds the EVP_CIPHER object for aes_128_cbc_hmac_sha1 in this engine. Set up * once only during engine bind and can then be reused many times. + * + * This 'stitched' cipher depends on the EVP_aes_128_cbc_hmac_sha1() cipher, + * which is implemented only if the AES-NI instruction set extension is available + * (see OPENSSL_IA32CAP(3)). If that's not the case, then this cipher will not + * be available either. + * + * Note: Since it is a legacy mac-then-encrypt cipher, modern TLS peers (which + * negotiate the encrypt-then-mac extension) won't negotiate it anyway. */ static EVP_CIPHER *_hidden_aes_128_cbc_hmac_sha1 = NULL; static const EVP_CIPHER *dasync_aes_128_cbc_hmac_sha1(void) @@ -751,6 +759,10 @@ static int dasync_aes128_cbc_hmac_sha1_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *iv, int enc) { + /* + * We can safely assume that EVP_aes_128_cbc_hmac_sha1() != NULL, + * see comment before the definition of dasync_aes_128_cbc_hmac_sha1(). + */ return dasync_cipher_init_key_helper(ctx, key, iv, enc, EVP_aes_128_cbc_hmac_sha1()); } @@ -765,5 +777,9 @@ static int dasync_aes128_cbc_hmac_sha1_cipher(EVP_CIPHER_CTX *ctx, static int dasync_aes128_cbc_hmac_sha1_cleanup(EVP_CIPHER_CTX *ctx) { + /* + * We can safely assume that EVP_aes_128_cbc_hmac_sha1() != NULL, + * see comment before the definition of dasync_aes_128_cbc_hmac_sha1(). + */ return dasync_cipher_cleanup_helper(ctx, EVP_aes_128_cbc_hmac_sha1()); } |