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add non block size AesCtr support

This commit is contained in:
toddouska 2014-01-23 12:34:27 -08:00
parent 9f8dcccc61
commit 45c05ffd30
2 changed files with 34 additions and 3 deletions
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34
ctaocrypt/src/aes.c
View File

@ -1476,6 +1476,10 @@ static int AesSetKeyLocal(Aes* aes, const byte* userKey, word32 keylen,
#ifdef CYASSL_AESNI
aes->use_aesni = 0;
#endif /* CYASSL_AESNI */
#ifdef CYASSL_AES_COUNTER
aes->left = 0;
#endif /* CYASSL_AES_COUNTER */
aes->rounds = keylen/4 + 6;
XMEMCPY(rk, userKey, keylen);
@ -2129,15 +2133,39 @@ static INLINE void IncrementAesCounter(byte* inOutCtr)
void AesCtrEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
{
word32 blocks = sz / AES_BLOCK_SIZE;
byte* tmp = (byte*)aes->tmp + AES_BLOCK_SIZE - aes->left;
while (blocks--) {
/* consume any unused bytes left in aes->tmp */
while (aes->left && sz) {
*(out++) = *(in++) ^ *(tmp++);
aes->left--;
sz--;
}
/* do as many block size ops as possible */
while (sz >= AES_BLOCK_SIZE) {
AesEncrypt(aes, (byte*)aes->reg, out);
IncrementAesCounter((byte*)aes->reg);
xorbuf(out, in, AES_BLOCK_SIZE);
out += AES_BLOCK_SIZE;
in += AES_BLOCK_SIZE;
in += AES_BLOCK_SIZE;
sz -= AES_BLOCK_SIZE;
aes->left = 0;
}
/* handle non block size remaining and sotre unused byte count in left */
if (sz) {
AesEncrypt(aes, (byte*)aes->reg, (byte*)aes->tmp);
IncrementAesCounter((byte*)aes->reg);
aes->left = AES_BLOCK_SIZE;
tmp = (byte*)aes->tmp;
while (sz--) {
*(out++) = *(in++) ^ *(tmp++);
aes->left--;
}
}
}

3
cyassl/ctaocrypt/aes.h
View File

@ -92,6 +92,9 @@ typedef struct Aes {
word32 magic; /* using cavium magic */
word64 contextHandle; /* nitrox context memory handle */
#endif
#ifdef CYASSL_AES_COUNTER
word32 left; /* unsued bytes left from last call */
#endif
} Aes;