int ivlen; /* IV length */
int taglen;
int iv_gen; /* It is OK to generate IVs */
+ int tls_aad_len; /* TLS AAD length */
} EVP_AES_GCM_CTX;
typedef struct
gctx->iv = c->iv;
gctx->taglen = -1;
gctx->iv_gen = 0;
+ gctx->tls_aad_len = -1;
return 1;
case EVP_CTRL_GCM_SET_IVLEN:
return 0;
if (arg)
memcpy(gctx->iv, ptr, arg);
- if (RAND_bytes(gctx->iv + arg, gctx->ivlen - arg) <= 0)
+ if (c->encrypt &&
+ RAND_bytes(gctx->iv + arg, gctx->ivlen - arg) <= 0)
return 0;
gctx->iv_gen = 1;
return 1;
if (gctx->iv_gen == 0 || gctx->key_set == 0)
return 0;
CRYPTO_gcm128_setiv(&gctx->gcm, gctx->iv, gctx->ivlen);
- memcpy(ptr, gctx->iv, gctx->ivlen);
+ if (arg <= 0 || arg > gctx->ivlen)
+ arg = gctx->ivlen;
+ memcpy(ptr, gctx->iv + gctx->ivlen - arg, arg);
/* Invocation field will be at least 8 bytes in size and
* so no need to check wrap around or increment more than
* last 8 bytes.
gctx->iv_set = 1;
return 1;
+ case EVP_CTRL_GCM_SET_IV_INV:
+ if (gctx->iv_gen == 0 || gctx->key_set == 0 || c->encrypt)
+ return 0;
+ memcpy(gctx->iv + gctx->ivlen - arg, ptr, arg);
+ CRYPTO_gcm128_setiv(&gctx->gcm, gctx->iv, gctx->ivlen);
+ gctx->iv_set = 1;
+ return 1;
+
+ case EVP_CTRL_AEAD_TLS1_AAD:
+ /* Save the AAD for later use */
+ if (arg != 13)
+ return 0;
+ memcpy(c->buf, ptr, arg);
+ gctx->tls_aad_len = arg;
+ {
+ unsigned int len=c->buf[arg-2]<<8|c->buf[arg-1];
+ /* Correct length for explicit IV */
+ len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
+ /* If decrypting correct for tag too */
+ if (!c->encrypt)
+ len -= EVP_GCM_TLS_TAG_LEN;
+ c->buf[arg-2] = len>>8;
+ c->buf[arg-1] = len & 0xff;
+ }
+ /* Extra padding: tag appended to record */
+ return EVP_GCM_TLS_TAG_LEN;
+
default:
return -1;
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 aes_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(&gctx->gcm, in, out, len))
+ goto err;
+ 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(&gctx->gcm, in, out, len))
+ 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 aes_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 aes_gcm_tls_cipher(ctx, out, in, len);
+
+ if (!gctx->iv_set)
return -1;
if (!ctx->encrypt && gctx->taglen < 0)
return -1;
| EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER \
| EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT)
-BLOCK_CIPHER_custom(NID_aes,128,1,12,gcm,GCM,EVP_CIPH_FLAG_FIPS|CUSTOM_FLAGS)
-BLOCK_CIPHER_custom(NID_aes,192,1,12,gcm,GCM,EVP_CIPH_FLAG_FIPS|CUSTOM_FLAGS)
-BLOCK_CIPHER_custom(NID_aes,256,1,12,gcm,GCM,EVP_CIPH_FLAG_FIPS|CUSTOM_FLAGS)
+BLOCK_CIPHER_custom(NID_aes,128,1,12,gcm,GCM,
+ EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS)
+BLOCK_CIPHER_custom(NID_aes,192,1,12,gcm,GCM,
+ EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS)
+BLOCK_CIPHER_custom(NID_aes,256,1,12,gcm,GCM,
+ EVP_CIPH_FLAG_FIPS|EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS)
static int aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
projects / openssl.git / blobdiff