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crypto: axis - support variable AEAD tag length

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The implementation assumed that the client always wants the whole 16
byte AES-GCM tag. Now we respect the requested authentication tag size
fetched using crypto_aead_authsize().

Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Lars Persson 2019-01-23 12:59:44 +01:00 committed by Herbert Xu
parent 0d1d482416
commit 48ef0908b8
1 changed files with 25 additions and 10 deletions
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35
drivers/crypto/axis/artpec6_crypto.c
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@ -1907,7 +1907,7 @@ static int artpec6_crypto_prepare_aead(struct aead_request *areq)
/* For the decryption, cryptlen includes the tag. */
input_length = areq->cryptlen;
if (req_ctx->decrypt)
input_length -= AES_BLOCK_SIZE;
input_length -= crypto_aead_authsize(cipher);
/* Prepare the context buffer */
req_ctx->hw_ctx.aad_length_bits =
@ -1972,7 +1972,7 @@ static int artpec6_crypto_prepare_aead(struct aead_request *areq)
size_t output_len = areq->cryptlen;
if (req_ctx->decrypt)
output_len -= AES_BLOCK_SIZE;
output_len -= crypto_aead_authsize(cipher);
artpec6_crypto_walk_init(&walk, areq->dst);
@ -2001,19 +2001,32 @@ static int artpec6_crypto_prepare_aead(struct aead_request *areq)
* the output ciphertext. For decryption it is put in a context
* buffer for later compare against the input tag.
*/
count = AES_BLOCK_SIZE;
if (req_ctx->decrypt) {
ret = artpec6_crypto_setup_in_descr(common,
req_ctx->decryption_tag, count, false);
req_ctx->decryption_tag, AES_BLOCK_SIZE, false);
if (ret)
return ret;
} else {
/* For encryption the requested tag size may be smaller
* than the hardware's generated tag.
*/
size_t authsize = crypto_aead_authsize(cipher);
ret = artpec6_crypto_setup_sg_descrs_in(common, &walk,
count);
authsize);
if (ret)
return ret;
if (authsize < AES_BLOCK_SIZE) {
count = AES_BLOCK_SIZE - authsize;
ret = artpec6_crypto_setup_in_descr(common,
ac->pad_buffer,
count, false);
if (ret)
return ret;
}
}
}
@ -2174,27 +2187,29 @@ static void artpec6_crypto_complete_aead(struct crypto_async_request *req)
/* Verify GCM hashtag. */
struct aead_request *areq = container_of(req,
struct aead_request, base);
struct crypto_aead *aead = crypto_aead_reqtfm(areq);
struct artpec6_crypto_aead_req_ctx *req_ctx = aead_request_ctx(areq);
if (req_ctx->decrypt) {
u8 input_tag[AES_BLOCK_SIZE];
unsigned int authsize = crypto_aead_authsize(aead);
sg_pcopy_to_buffer(areq->src,
sg_nents(areq->src),
input_tag,
AES_BLOCK_SIZE,
authsize,
areq->assoclen + areq->cryptlen -
AES_BLOCK_SIZE);
authsize);
if (memcmp(req_ctx->decryption_tag,
input_tag,
AES_BLOCK_SIZE)) {
authsize)) {
pr_debug("***EBADMSG:\n");
print_hex_dump_debug("ref:", DUMP_PREFIX_ADDRESS, 32, 1,
input_tag, AES_BLOCK_SIZE, true);
input_tag, authsize, true);
print_hex_dump_debug("out:", DUMP_PREFIX_ADDRESS, 32, 1,
req_ctx->decryption_tag,
AES_BLOCK_SIZE, true);
authsize, true);
result = -EBADMSG;
}