evp/e_chacha20_poly1305.c: TLS interop fixes.

Thanks to: David Benjamin of Chromuim.

Reviewed-by: Rich Salz <rsalz@openssl.org>
This commit is contained in:
Andy Polyakov 2015-12-10 21:53:01 +01:00
parent 80b1247fe6
commit 30a5f32227

View File

@ -244,6 +244,8 @@ static int chacha20_poly1305_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
actx->key.key.d, actx->key.counter);
Poly1305_Init(POLY1305_ctx(actx), actx->key.buf);
actx->key.counter[0] = 1;
actx->key.partial_len = 0;
actx->len.aad = actx->len.text = 0;
actx->mac_inited = 1;
}
@ -426,18 +428,14 @@ static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
return 0;
{
unsigned int len;
unsigned char temp[POLY1305_BLOCK_SIZE];
unsigned char *aad = ptr, temp[POLY1305_BLOCK_SIZE];
/*
* compose padded aad
*/
memset(temp, 0, sizeof(temp));
memcpy(temp, ptr, EVP_AEAD_TLS1_AAD_LEN);
len = temp[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 |
temp[EVP_AEAD_TLS1_AAD_LEN - 1];
len = aad[EVP_AEAD_TLS1_AAD_LEN - 2] << 8 |
aad[EVP_AEAD_TLS1_AAD_LEN - 1];
if (!ctx->encrypt) {
len -= POLY1305_BLOCK_SIZE; /* discount attached tag */
memcpy(temp, aad, EVP_AEAD_TLS1_AAD_LEN - 2);
aad = temp;
temp[EVP_AEAD_TLS1_AAD_LEN - 2] = (unsigned char)(len >> 8);
temp[EVP_AEAD_TLS1_AAD_LEN - 1] = (unsigned char)len;
}
@ -448,10 +446,10 @@ static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
* draft-ietf-tls-chacha20-poly1305-03
*/
actx->key.counter[1] = actx->nonce[0];
actx->key.counter[2] = actx->nonce[1] ^ CHACHA_U8TOU32(temp);
actx->key.counter[3] = actx->nonce[2] ^ CHACHA_U8TOU32(temp+4);
actx->key.counter[2] = actx->nonce[1] ^ CHACHA_U8TOU32(aad);
actx->key.counter[3] = actx->nonce[2] ^ CHACHA_U8TOU32(aad+4);
actx->mac_inited = 0;
chacha20_poly1305_cipher(ctx, NULL, temp, POLY1305_BLOCK_SIZE);
chacha20_poly1305_cipher(ctx, NULL, aad, EVP_AEAD_TLS1_AAD_LEN);
return POLY1305_BLOCK_SIZE; /* tag length */
}