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aesni TLS GCM support

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This commit is contained in:
Dr. Stephen Henson 2011-08-11 23:06:19 +00:00
parent 19ad345739
commit ab1ec69843
1 changed files with 69 additions and 1 deletions
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70
crypto/evp/e_aes.c
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@ -305,12 +305,80 @@ static int aesni_gcm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
return 1;
}
/* Handle TLS GCM packet format. This consists of the last portion of the IV
* followed by the payload and finally the tag. On encrypt generate IV,
* encrypt payload and write the tag. On verify retrieve IV, decrypt payload
* and verify tag.
*/
static int aesni_gcm_tls_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
const unsigned char *in, size_t len)
{
EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
int rv = -1;
/* Encrypt/decrypt must be performed in place */
if (out != in)
return -1;
/* Set IV from start of buffer or generate IV and write to start
* of buffer.
*/
if (EVP_CIPHER_CTX_ctrl(ctx, ctx->encrypt ?
EVP_CTRL_GCM_IV_GEN : EVP_CTRL_GCM_SET_IV_INV,
EVP_GCM_TLS_EXPLICIT_IV_LEN, out) <= 0)
goto err;
/* Use saved AAD */
if (CRYPTO_gcm128_aad(&gctx->gcm, ctx->buf, gctx->tls_aad_len))
goto err;
/* Fix buffer and length to point to payload */
in += EVP_GCM_TLS_EXPLICIT_IV_LEN;
out += EVP_GCM_TLS_EXPLICIT_IV_LEN;
len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
if (ctx->encrypt)
{
/* Encrypt payload */
if (CRYPTO_gcm128_encrypt_ctr32(&gctx->gcm, in, out, len,
aesni_ctr32_encrypt_blocks))
out += len;
/* Finally write tag */
CRYPTO_gcm128_tag(&gctx->gcm, out, EVP_GCM_TLS_TAG_LEN);
rv = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
}
else
{
/* Decrypt */
if (CRYPTO_gcm128_decrypt_ctr32(&gctx->gcm, in, out, len,
aesni_ctr32_encrypt_blocks))
goto err;
/* Retrieve tag */
CRYPTO_gcm128_tag(&gctx->gcm, ctx->buf,
EVP_GCM_TLS_TAG_LEN);
/* If tag mismatch wipe buffer */
if (memcmp(ctx->buf, in + len, EVP_GCM_TLS_TAG_LEN))
{
OPENSSL_cleanse(out, len);
goto err;
}
rv = len;
}
err:
gctx->iv_set = 0;
gctx->tls_aad_len = -1;
return rv;
}
static int aesni_gcm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
const unsigned char *in, size_t len)
{
EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
/* If not set up, return error */
if (!gctx->iv_set && !gctx->key_set)
if (!gctx->key_set)
return -1;
if (gctx->tls_aad_len >= 0)
return aesni_gcm_tls_cipher(ctx, out, in, len);
if (!gctx->iv_set)
return -1;
if (!ctx->encrypt && gctx->taglen < 0)
return -1;