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AES-XTS performance enhancement

pull/1270/head
Jacob Barthelmeh 2017-12-23 13:56:42 -07:00
parent cf1575fafb
commit 22fc90006b
2 changed files with 72 additions and 1 deletions
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71
wolfcrypt/src/aes.c
View File

@ -8012,6 +8012,45 @@ int wc_AesXtsDecryptSector(XtsAes* aes, byte* out, const byte* in, word32 sz,
return wc_AesXtsDecrypt(aes, out, in, sz, (const byte*)i, AES_BLOCK_SIZE);
}
#ifdef HAVE_AES_ECB
/* helper function for encrypting / decrypting full buffer at once */
static int _AesXtsHelper(Aes* aes, byte* out, const byte* in, word32 sz, int dir)
{
word32 outSz = sz;
word32 totalSz = (sz / AES_BLOCK_SIZE) * AES_BLOCK_SIZE; /* total bytes */
byte* pt = out;
outSz -= AES_BLOCK_SIZE;
while (outSz > 0) {
word32 j;
byte carry = 0;
/* multiply by shift left and propogate carry */
for (j = 0; j < AES_BLOCK_SIZE && outSz > 0; j++, outSz--) {
byte tmpC;
tmpC = (pt[j] >> 7) & 0x01;
pt[j+AES_BLOCK_SIZE] = ((pt[j] << 1) + carry) & 0xFF;
carry = tmpC;
}
if (carry) {
pt[AES_BLOCK_SIZE] ^= GF_XTS;
}
pt += AES_BLOCK_SIZE;
}
xorbuf(out, in, totalSz);
if (dir == AES_ENCRYPTION) {
return wc_AesEcbEncrypt(aes, out, out, totalSz);
}
else {
return wc_AesEcbDecrypt(aes, out, out, totalSz);
}
}
#endif /* HAVE_AES_ECB */
/* AES with XTS mode. (XTS) XEX encryption with Tweak and cipher text Stealing.
*
@ -8051,14 +8090,30 @@ int wc_AesXtsEncrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
wc_AesEncryptDirect(tweak, tmp, i);
#ifdef HAVE_AES_ECB
/* encrypt all of buffer at once when possible */
if (in != out) { /* can not handle inline */
XMEMCPY(out, tmp, AES_BLOCK_SIZE);
if ((ret = _AesXtsHelper(aes, out, in, sz, AES_ENCRYPTION)) != 0) {
return ret;
}
}
#endif
while (blocks > 0) {
word32 j;
byte carry = 0;
byte buf[AES_BLOCK_SIZE];
#ifdef HAVE_AES_ECB
if (in == out) { /* check for if inline */
#endif
XMEMCPY(buf, in, AES_BLOCK_SIZE);
xorbuf(buf, tmp, AES_BLOCK_SIZE);
wc_AesEncryptDirect(aes, out, buf);
#ifdef HAVE_AES_ECB
}
#endif
xorbuf(out, tmp, AES_BLOCK_SIZE);
/* multiply by shift left and propogate carry */
@ -8151,12 +8206,28 @@ int wc_AesXtsDecrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
blocks--;
}
#ifdef HAVE_AES_ECB
/* decrypt all of buffer at once when possible */
if (in != out) { /* can not handle inline */
XMEMCPY(out, tmp, AES_BLOCK_SIZE);
if ((ret = _AesXtsHelper(aes, out, in, sz, AES_DECRYPTION)) != 0) {
return ret;
}
}
#endif
while (blocks > 0) {
byte buf[AES_BLOCK_SIZE];
#ifdef HAVE_AES_ECB
if (in == out) { /* check for if inline */
#endif
XMEMCPY(buf, in, AES_BLOCK_SIZE);
xorbuf(buf, tmp, AES_BLOCK_SIZE);
wc_AesDecryptDirect(aes, out, buf);
#ifdef HAVE_AES_ECB
}
#endif
xorbuf(out, tmp, AES_BLOCK_SIZE);
/* multiply by shift left and propogate carry */

2
wolfssl/wolfcrypt/settings.h
View File

@ -1197,7 +1197,7 @@ extern void uITRON4_free(void *p) ;
#undef WOLFSSL_IMX6_CAAM_BLOB
#define WOLFSSL_IMX6_CAAM_BLOB
#ifdef HAVE_AESGCM
#if defined(HAVE_AESGCM) || defined(WOLFSSL_AES_XTS)
/* large performance gain with HAVE_AES_ECB defined */
#undef HAVE_AES_ECB
#define HAVE_AES_ECB