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Merge pull request #205 from libtom/pr/shake-be-fix

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SHAKE (SHA3 related) big endian fix
This commit is contained in:
karel-m 2017-05-03 17:06:27 +02:00 committed by GitHub
commit 1712c0eae1
2 changed files with 20 additions and 15 deletions
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32
src/hashes/sha3.c
View File

@ -231,6 +231,8 @@ int sha3_process(hash_state *md, const unsigned char *in, unsigned long inlen)
int sha3_done(hash_state *md, unsigned char *hash)
{
unsigned i;
LTC_ARGCHK(md != NULL);
LTC_ARGCHK(hash != NULL);
@ -238,17 +240,10 @@ int sha3_done(hash_state *md, unsigned char *hash)
md->sha3.s[SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words - 1] ^= CONST64(0x8000000000000000);
keccakf(md->sha3.s);
#ifndef ENDIAN_LITTLE
{
unsigned i;
for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
const ulong32 t1 = (ulong32)(md->sha3.s[i] & CONST64(0xFFFFFFFF));
const ulong32 t2 = (ulong32)(md->sha3.s[i] >> 32);
STORE32L(t1, md->sha3.sb + i * 8);
STORE32L(t2, md->sha3.sb + i * 8 + 4);
}
/* store sha3.s[] as little-endian bytes into sha3.sb */
for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
STORE64L(md->sha3.s[i], md->sha3.sb + i * 8);
}
#endif
XMEMCPY(hash, md->sha3.sb, md->sha3.capacity_words * 4);
return CRYPT_OK;
@ -256,8 +251,9 @@ int sha3_done(hash_state *md, unsigned char *hash)
int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
{
unsigned long i = 0;
/* sha3_shake_done can be called many times */
/* IMPORTANT NOTE: sha3_shake_done can be called many times */
unsigned long idx;
unsigned i;
if (outlen == 0) return CRYPT_OK; /* nothing to do */
LTC_ARGCHK(md != NULL);
@ -268,16 +264,24 @@ int sha3_shake_done(hash_state *md, unsigned char *out, unsigned long outlen)
md->sha3.s[md->sha3.word_index] ^= (md->sha3.saved ^ (CONST64(0x1F) << (md->sha3.byte_index * 8)));
md->sha3.s[SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words - 1] ^= CONST64(0x8000000000000000);
keccakf(md->sha3.s);
/* store sha3.s[] as little-endian bytes into sha3.sb */
for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
STORE64L(md->sha3.s[i], md->sha3.sb + i * 8);
}
md->sha3.byte_index = 0;
md->sha3.xof_flag = 1;
}
while (i < outlen) {
for (idx = 0; idx < outlen; idx++) {
if(md->sha3.byte_index >= (SHA3_KECCAK_SPONGE_WORDS - md->sha3.capacity_words) * 8) {
keccakf(md->sha3.s);
/* store sha3.s[] as little-endian bytes into sha3.sb */
for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
STORE64L(md->sha3.s[i], md->sha3.sb + i * 8);
}
md->sha3.byte_index = 0;
}
out[i++] = md->sha3.sb[md->sha3.byte_index++];
out[idx] = md->sha3.sb[md->sha3.byte_index++];
}
return CRYPT_OK;
}

3
src/headers/tomcrypt_hash.h
View File

@ -2,7 +2,8 @@
#ifdef LTC_SHA3
struct sha3_state {
ulong64 saved; /* the portion of the input message that we didn't consume yet */
union { ulong64 s[25]; unsigned char sb[25 * 8]; };
ulong64 s[25];
unsigned char sb[25 * 8]; /* used for storing `ulong64 s[25]` as little-endian bytes */
unsigned short byte_index; /* 0..7--the next byte after the set one (starts from 0; 0--none are buffered) */
unsigned short word_index; /* 0..24--the next word to integrate input (starts from 0) */
unsigned short capacity_words; /* the double size of the hash output in words (e.g. 16 for Keccak 512) */