diff options
Diffstat (limited to 'crypto/xts.c')
| -rw-r--r-- | crypto/xts.c | 84 |
1 files changed, 58 insertions, 26 deletions
diff --git a/crypto/xts.c b/crypto/xts.c index bee23f8..0ad231f 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -31,6 +31,13 @@ typedef union { uint64_t u[2]; } xts_uint128; +static inline void xts_uint128_xor(xts_uint128 *D, + const xts_uint128 *S1, + const xts_uint128 *S2) +{ + D->u[0] = S1->u[0] ^ S2->u[0]; + D->u[1] = S1->u[1] ^ S2->u[1]; +} static void xts_mult_x(uint8_t *I) { @@ -60,25 +67,19 @@ static void xts_mult_x(uint8_t *I) */ static void xts_tweak_encdec(const void *ctx, xts_cipher_func *func, - const uint8_t *src, - uint8_t *dst, - uint8_t *iv) + const xts_uint128 *src, + xts_uint128 *dst, + xts_uint128 *iv) { - unsigned long x; - /* tweak encrypt block i */ - for (x = 0; x < XTS_BLOCK_SIZE; x++) { - dst[x] = src[x] ^ iv[x]; - } + xts_uint128_xor(dst, src, iv); - func(ctx, XTS_BLOCK_SIZE, dst, dst); + func(ctx, XTS_BLOCK_SIZE, dst->b, dst->b); - for (x = 0; x < XTS_BLOCK_SIZE; x++) { - dst[x] = dst[x] ^ iv[x]; - } + xts_uint128_xor(dst, dst, iv); /* LFSR the tweak */ - xts_mult_x(iv); + xts_mult_x(iv->b); } @@ -110,20 +111,34 @@ void xts_decrypt(const void *datactx, /* encrypt the iv */ encfunc(tweakctx, XTS_BLOCK_SIZE, T.b, iv); - for (i = 0; i < lim; i++) { - xts_tweak_encdec(datactx, decfunc, src, dst, T.b); - - src += XTS_BLOCK_SIZE; - dst += XTS_BLOCK_SIZE; + if (QEMU_PTR_IS_ALIGNED(src, sizeof(uint64_t)) && + QEMU_PTR_IS_ALIGNED(dst, sizeof(uint64_t))) { + xts_uint128 *S = (xts_uint128 *)src; + xts_uint128 *D = (xts_uint128 *)dst; + for (i = 0; i < lim; i++, S++, D++) { + xts_tweak_encdec(datactx, decfunc, S, D, &T); + } + } else { + xts_uint128 D; + + for (i = 0; i < lim; i++) { + memcpy(&D, src, XTS_BLOCK_SIZE); + xts_tweak_encdec(datactx, decfunc, &D, &D, &T); + memcpy(dst, &D, XTS_BLOCK_SIZE); + src += XTS_BLOCK_SIZE; + dst += XTS_BLOCK_SIZE; + } } /* if length is not a multiple of XTS_BLOCK_SIZE then */ if (mo > 0) { + xts_uint128 S, D; memcpy(&CC, &T, XTS_BLOCK_SIZE); xts_mult_x(CC.b); /* PP = tweak decrypt block m-1 */ - xts_tweak_encdec(datactx, decfunc, src, PP.b, CC.b); + memcpy(&S, src, XTS_BLOCK_SIZE); + xts_tweak_encdec(datactx, decfunc, &S, &PP, &CC); /* Pm = first length % XTS_BLOCK_SIZE bytes of PP */ for (i = 0; i < mo; i++) { @@ -135,7 +150,8 @@ void xts_decrypt(const void *datactx, } /* Pm-1 = Tweak uncrypt CC */ - xts_tweak_encdec(datactx, decfunc, CC.b, dst, T.b); + xts_tweak_encdec(datactx, decfunc, &CC, &D, &T); + memcpy(dst, &D, XTS_BLOCK_SIZE); } /* Decrypt the iv back */ @@ -171,17 +187,32 @@ void xts_encrypt(const void *datactx, /* encrypt the iv */ encfunc(tweakctx, XTS_BLOCK_SIZE, T.b, iv); - for (i = 0; i < lim; i++) { - xts_tweak_encdec(datactx, encfunc, src, dst, T.b); + if (QEMU_PTR_IS_ALIGNED(src, sizeof(uint64_t)) && + QEMU_PTR_IS_ALIGNED(dst, sizeof(uint64_t))) { + xts_uint128 *S = (xts_uint128 *)src; + xts_uint128 *D = (xts_uint128 *)dst; + for (i = 0; i < lim; i++, S++, D++) { + xts_tweak_encdec(datactx, encfunc, S, D, &T); + } + } else { + xts_uint128 D; + + for (i = 0; i < lim; i++) { + memcpy(&D, src, XTS_BLOCK_SIZE); + xts_tweak_encdec(datactx, encfunc, &D, &D, &T); + memcpy(dst, &D, XTS_BLOCK_SIZE); - dst += XTS_BLOCK_SIZE; - src += XTS_BLOCK_SIZE; + dst += XTS_BLOCK_SIZE; + src += XTS_BLOCK_SIZE; + } } /* if length is not a multiple of XTS_BLOCK_SIZE then */ if (mo > 0) { + xts_uint128 S, D; /* CC = tweak encrypt block m-1 */ - xts_tweak_encdec(datactx, encfunc, src, CC.b, T.b); + memcpy(&S, src, XTS_BLOCK_SIZE); + xts_tweak_encdec(datactx, encfunc, &S, &CC, &T); /* Cm = first length % XTS_BLOCK_SIZE bytes of CC */ for (i = 0; i < mo; i++) { @@ -194,7 +225,8 @@ void xts_encrypt(const void *datactx, } /* Cm-1 = Tweak encrypt PP */ - xts_tweak_encdec(datactx, encfunc, PP.b, dst, T.b); + xts_tweak_encdec(datactx, encfunc, &PP, &D, &T); + memcpy(dst, &D, XTS_BLOCK_SIZE); } /* Decrypt the iv back */ |