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crypto/builtin: Remove odd-sized AES block handling

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We verified that the data block is properly sized modulo
AES_BLOCK_SIZE within qcrypto_builtin_cipher_{en,de}crypt.
Therefore we will never have to handle odd sized blocks.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Richard Henderson 2020-08-28 10:05:17 -07:00 committed by Daniel P. Berrangé
parent e46064a4c6
commit 838e4631cb
1 changed files with 12 additions and 28 deletions
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40
crypto/cipher-builtin.c.inc
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@ -80,21 +80,13 @@ static void qcrypto_cipher_aes_ecb_encrypt(const AES_KEY *key,
{ {
const uint8_t *inptr = in; const uint8_t *inptr = in;
uint8_t *outptr = out; uint8_t *outptr = out;
/* We have already verified that len % AES_BLOCK_SIZE == 0. */
while (len) { while (len) {
if (len > AES_BLOCK_SIZE) { AES_encrypt(inptr, outptr, key);
AES_encrypt(inptr, outptr, key); inptr += AES_BLOCK_SIZE;
inptr += AES_BLOCK_SIZE; outptr += AES_BLOCK_SIZE;
outptr += AES_BLOCK_SIZE; len -= AES_BLOCK_SIZE;
len -= AES_BLOCK_SIZE;
} else {
uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
memcpy(tmp1, inptr, len);
/* Fill with 0 to avoid valgrind uninitialized reads */
memset(tmp1 + len, 0, sizeof(tmp1) - len);
AES_encrypt(tmp1, tmp2, key);
memcpy(outptr, tmp2, len);
len = 0;
}
} }
} }
@ -106,21 +98,13 @@ static void qcrypto_cipher_aes_ecb_decrypt(const AES_KEY *key,
{ {
const uint8_t *inptr = in; const uint8_t *inptr = in;
uint8_t *outptr = out; uint8_t *outptr = out;
/* We have already verified that len % AES_BLOCK_SIZE == 0. */
while (len) { while (len) {
if (len > AES_BLOCK_SIZE) { AES_decrypt(inptr, outptr, key);
AES_decrypt(inptr, outptr, key); inptr += AES_BLOCK_SIZE;
inptr += AES_BLOCK_SIZE; outptr += AES_BLOCK_SIZE;
outptr += AES_BLOCK_SIZE; len -= AES_BLOCK_SIZE;
len -= AES_BLOCK_SIZE;
} else {
uint8_t tmp1[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
memcpy(tmp1, inptr, len);
/* Fill with 0 to avoid valgrind uninitialized reads */
memset(tmp1 + len, 0, sizeof(tmp1) - len);
AES_decrypt(tmp1, tmp2, key);
memcpy(outptr, tmp2, len);
len = 0;
}
} }
} }