diff options
Diffstat (limited to 'crypto/xts.c')
| -rw-r--r-- | crypto/xts.c | 64 |
1 files changed, 15 insertions, 49 deletions
diff --git a/crypto/xts.c b/crypto/xts.c index 9521234..3c1a92f 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -43,20 +43,20 @@ static void xts_mult_x(uint8_t *I) /** - * xts_tweak_uncrypt: + * xts_tweak_encdec: * @param ctxt: the cipher context * @param func: the cipher function - * @src: buffer providing the cipher text of XTS_BLOCK_SIZE bytes - * @dst: buffer to output the plain text of XTS_BLOCK_SIZE bytes + * @src: buffer providing the input text of XTS_BLOCK_SIZE bytes + * @dst: buffer to output the output text of XTS_BLOCK_SIZE bytes * @iv: the initialization vector tweak of XTS_BLOCK_SIZE bytes * - * Decrypt data with a tweak + * Encrypt/decrypt data with a tweak */ -static void xts_tweak_decrypt(const void *ctx, - xts_cipher_func *func, - const uint8_t *src, - uint8_t *dst, - uint8_t *iv) +static void xts_tweak_encdec(const void *ctx, + xts_cipher_func *func, + const uint8_t *src, + uint8_t *dst, + uint8_t *iv) { unsigned long x; @@ -105,7 +105,7 @@ void xts_decrypt(const void *datactx, encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv); for (i = 0; i < lim; i++) { - xts_tweak_decrypt(datactx, decfunc, src, dst, T); + xts_tweak_encdec(datactx, decfunc, src, dst, T); src += XTS_BLOCK_SIZE; dst += XTS_BLOCK_SIZE; @@ -117,7 +117,7 @@ void xts_decrypt(const void *datactx, xts_mult_x(CC); /* PP = tweak decrypt block m-1 */ - xts_tweak_decrypt(datactx, decfunc, src, PP, CC); + xts_tweak_encdec(datactx, decfunc, src, PP, CC); /* Pm = first length % XTS_BLOCK_SIZE bytes of PP */ for (i = 0; i < mo; i++) { @@ -129,7 +129,7 @@ void xts_decrypt(const void *datactx, } /* Pm-1 = Tweak uncrypt CC */ - xts_tweak_decrypt(datactx, decfunc, CC, dst, T); + xts_tweak_encdec(datactx, decfunc, CC, dst, T); } /* Decrypt the iv back */ @@ -137,40 +137,6 @@ void xts_decrypt(const void *datactx, } -/** - * xts_tweak_crypt: - * @param ctxt: the cipher context - * @param func: the cipher function - * @src: buffer providing the plain text of XTS_BLOCK_SIZE bytes - * @dst: buffer to output the cipher text of XTS_BLOCK_SIZE bytes - * @iv: the initialization vector tweak of XTS_BLOCK_SIZE bytes - * - * Encrypt data with a tweak - */ -static void xts_tweak_encrypt(const void *ctx, - xts_cipher_func *func, - const uint8_t *src, - uint8_t *dst, - uint8_t *iv) -{ - unsigned long x; - - /* tweak encrypt block i */ - for (x = 0; x < XTS_BLOCK_SIZE; x++) { - dst[x] = src[x] ^ iv[x]; - } - - func(ctx, XTS_BLOCK_SIZE, dst, dst); - - for (x = 0; x < XTS_BLOCK_SIZE; x++) { - dst[x] = dst[x] ^ iv[x]; - } - - /* LFSR the tweak */ - xts_mult_x(iv); -} - - void xts_encrypt(const void *datactx, const void *tweakctx, xts_cipher_func *encfunc, @@ -200,7 +166,7 @@ void xts_encrypt(const void *datactx, encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv); for (i = 0; i < lim; i++) { - xts_tweak_encrypt(datactx, encfunc, src, dst, T); + xts_tweak_encdec(datactx, encfunc, src, dst, T); dst += XTS_BLOCK_SIZE; src += XTS_BLOCK_SIZE; @@ -209,7 +175,7 @@ void xts_encrypt(const void *datactx, /* if length is not a multiple of XTS_BLOCK_SIZE then */ if (mo > 0) { /* CC = tweak encrypt block m-1 */ - xts_tweak_encrypt(datactx, encfunc, src, CC, T); + xts_tweak_encdec(datactx, encfunc, src, CC, T); /* Cm = first length % XTS_BLOCK_SIZE bytes of CC */ for (i = 0; i < mo; i++) { @@ -222,7 +188,7 @@ void xts_encrypt(const void *datactx, } /* Cm-1 = Tweak encrypt PP */ - xts_tweak_encrypt(datactx, encfunc, PP, dst, T); + xts_tweak_encdec(datactx, encfunc, PP, dst, T); } /* Decrypt the iv back */ |