/* -------------------------------------------------------------------------
* Works when compiled for either 32-bit or 64-bit targets, optimized for
* 64 bit.
*
* Canonical implementation of Init/Update/Finalize for SHA-3 byte input.
*
* SHA3-256, SHA3-384, SHA-512 are implemented. SHA-224 can easily be added.
*
* Based on code from http://keccak.noekeon.org/ .
*
* I place the code that I wrote into public domain, free to use.
*
* I would appreciate if you give credits to this work if you used it to
* write or test * your code.
*
* Aug 2015. Andrey Jivsov. crypto@brainhub.org
* ---------------------------------------------------------------------- */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "sha3.h"
#define SHA3_ASSERT( x )
#if defined(_MSC_VER)
#define SHA3_TRACE( format, ...)
#define SHA3_TRACE_BUF( format, buf, l, ...)
#else
#define SHA3_TRACE(format, args...)
#define SHA3_TRACE_BUF(format, buf, l, args...)
#endif
//#define SHA3_USE_KECCAK
/*
* Define SHA3_USE_KECCAK to run "pure" Keccak, as opposed to SHA3.
* The tests that this macro enables use the input and output from [Keccak]
* (see the reference below). The used test vectors aren't correct for SHA3,
* however, they are helpful to verify the implementation.
* SHA3_USE_KECCAK only changes one line of code in Finalize.
*/
#if defined(_MSC_VER)
#define SHA3_CONST(x) x
#else
#define SHA3_CONST(x) x##L
#endif
#ifndef SHA3_ROTL64
#define SHA3_ROTL64(x, y) \
(((x) << (y)) | ((x) >> ((sizeof(uint64_t)*8) - (y))))
#endif
static const uint64_t keccakf_rndc[24] = {
SHA3_CONST(0x0000000000000001UL), SHA3_CONST(0x0000000000008082UL),
SHA3_CONST(0x800000000000808aUL), SHA3_CONST(0x8000000080008000UL),
SHA3_CONST(0x000000000000808bUL), SHA3_CONST(0x0000000080000001UL),
SHA3_CONST(0x8000000080008081UL), SHA3_CONST(0x8000000000008009UL),
SHA3_CONST(0x000000000000008aUL), SHA3_CONST(0x0000000000000088UL),
SHA3_CONST(0x0000000080008009UL), SHA3_CONST(0x000000008000000aUL),
SHA3_CONST(0x000000008000808bUL), SHA3_CONST(0x800000000000008bUL),
SHA3_CONST(0x8000000000008089UL), SHA3_CONST(0x8000000000008003UL),
SHA3_CONST(0x8000000000008002UL), SHA3_CONST(0x8000000000000080UL),
SHA3_CONST(0x000000000000800aUL), SHA3_CONST(0x800000008000000aUL),
SHA3_CONST(0x8000000080008081UL), SHA3_CONST(0x8000000000008080UL),
SHA3_CONST(0x0000000080000001UL), SHA3_CONST(0x8000000080008008UL)
};
static const unsigned keccakf_rotc[24] = {
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 2, 14, 27, 41, 56, 8, 25, 43, 62,
18, 39, 61, 20, 44
};
static const unsigned keccakf_piln[24] = {
10, 7, 11, 17, 18, 3, 5, 16, 8, 21, 24, 4, 15, 23, 19, 13, 12, 2, 20,
14, 22, 9, 6, 1
};
/* generally called after SHA3_KECCAK_SPONGE_WORDS-ctx->capacityWords words
* are XORed into the state s
*/
static void
keccakf(uint64_t s[25])
{
int i, j, round;
uint64_t t, bc[5];
#define KECCAK_ROUNDS 24
for(round = 0; round < KECCAK_ROUNDS; round++) {
/* Theta */
for(i = 0; i < 5; i++)
bc[i] = s[i] ^ s[i + 5] ^ s[i + 10] ^ s[i + 15] ^ s[i + 20];
for(i = 0; i < 5; i++) {
t = bc[(i + 4) % 5] ^ SHA3_ROTL64(bc[(i + 1) % 5], 1);
for(j = 0; j < 25; j += 5)
s[j + i] ^= t;
}
/* Rho Pi */
t = s[1];
for(i = 0; i < 24; i++) {
j = keccakf_piln[i];
bc[0] = s[j];
s[j] = SHA3_ROTL64(t, keccakf_rotc[i]);
t = bc[0];
}
/* Chi */
for(j = 0; j < 25; j += 5) {
for(i = 0; i < 5; i++)
bc[i] = s[j + i];
for(i = 0; i < 5; i++)
s[j + i] ^= (~bc[(i + 1) % 5]) & bc[(i + 2) % 5];
}
/* Iota */
s[0] ^= keccakf_rndc[round];
}
}
/* *************************** Public Inteface ************************ */
/* For Init or Reset call these: */
void
sha3_Init256(void *priv)
{
sha3_context *ctx = (sha3_context *) priv;
memset(ctx, 0, sizeof(*ctx));
ctx->capacityWords = 2 * 256 / (8 * sizeof(uint64_t));
}
void
sha3_Init384(void *priv)
{
sha3_context *ctx = (sha3_context *) priv;
memset(ctx, 0, sizeof(*ctx));
ctx->capacityWords = 2 * 384 / (8 * sizeof(uint64_t));
}
void
sha3_Init512(void *priv)
{
sha3_context *ctx = (sha3_context *) priv;
memset(ctx, 0, sizeof(*ctx));
ctx->capacityWords = 2 * 512 / (8 * sizeof(uint64_t));
}
void
sha3_Update(void *priv, void const *bufIn, size_t len)
{
sha3_context *ctx = (sha3_context *) priv;
/* 0...7 -- how much is needed to have a word */
unsigned old_tail = (8 - ctx->byteIndex) & 7;
size_t words;
unsigned tail;
size_t i;
const uint8_t *buf = bufIn;
SHA3_TRACE_BUF("called to update with:", buf, len);
SHA3_ASSERT(ctx->byteIndex < 8);
SHA3_ASSERT(ctx->wordIndex < sizeof(ctx->s) / sizeof(ctx->s[0]));
if(len < old_tail) { /* have no complete word or haven't started
* the word yet */
SHA3_TRACE("because %d<%d, store it and return", (unsigned)len,
(unsigned)old_tail);
/* endian-independent code follows: */
while (len--)
ctx->saved |= (uint64_t) (*(buf++)) << ((ctx->byteIndex++) * 8);
SHA3_ASSERT(ctx->byteIndex < 8);
return;
}
if(old_tail) { /* will have one word to process */
SHA3_TRACE("completing one word with %d bytes", (unsigned)old_tail);
/* endian-independent code follows: */
len -= old_tail;
while (old_tail--)
ctx->saved |= (uint64_t) (*(buf++)) << ((ctx->byteIndex++) * 8);
/* now ready to add saved to the sponge */
ctx->s[ctx->wordIndex] ^= ctx->saved;
SHA3_ASSERT(ctx->byteIndex == 8);
ctx->byteIndex = 0;
ctx->saved = 0;
if(++ctx->wordIndex ==
(SHA3_KECCAK_SPONGE_WORDS - ctx->capacityWords)) {
keccakf(ctx->s);
ctx->wordIndex = 0;
}
}
/* now work in full words directly from input */
SHA3_ASSERT(ctx->byteIndex == 0);
words = len / sizeof(uint64_t);
tail = len - words * sizeof(uint64_t);
SHA3_TRACE("have %d full words to process", (unsigned)words);
for(i = 0; i < words; i++, buf += sizeof(uint64_t)) {
const uint64_t t = (uint64_t) (buf[0]) |
((uint64_t) (buf[1]) << 8 * 1) |
((uint64_t) (buf[2]) << 8 * 2) |
((uint64_t) (buf[3]) << 8 * 3) |
((uint64_t) (buf[4]) << 8 * 4) |
((uint64_t) (buf[5]) << 8 * 5) |
((uint64_t) (buf[6]) << 8 * 6) |
((uint64_t) (buf[7]) << 8 * 7);
#if defined(__x86_64__ ) || defined(__i386__)
SHA3_ASSERT(memcmp(&t, buf, 8) == 0);
#endif
ctx->s[ctx->wordIndex] ^= t;
if(++ctx->wordIndex ==
(SHA3_KECCAK_SPONGE_WORDS - ctx->capacityWords)) {
keccakf(ctx->s);
ctx->wordIndex = 0;
}
}
SHA3_TRACE("have %d bytes left to process, save them", (unsigned)tail);
/* finally, save the partial word */
SHA3_ASSERT(ctx->byteIndex == 0 && tail < 8);
while (tail--) {
SHA3_TRACE("Store byte %02x '%c'", *buf, *buf);
ctx->saved |= (uint64_t) (*(buf++)) << ((ctx->byteIndex++) * 8);
}
SHA3_ASSERT(ctx->byteIndex < 8);
SHA3_TRACE("Have saved=0x%016" PRIx64 " at the end", ctx->saved);
}
/* This is simply the 'update' with the padding block.
* The padding block is 0x01 || 0x00* || 0x80. First 0x01 and last 0x80
* bytes are always present, but they can be the same byte.
*/
void const *
sha3_Finalize(void *priv)
{
sha3_context *ctx = (sha3_context *) priv;
SHA3_TRACE("called with %d bytes in the buffer", ctx->byteIndex);
/* Append 2-bit suffix 01, per SHA-3 spec. Instead of 1 for padding we
* use 1<<2 below. The 0x02 below corresponds to the suffix 01.
* Overall, we feed 0, then 1, and finally 1 to start padding. Without
* M || 01, we would simply use 1 to start padding. */
#ifndef SHA3_USE_KECCAK
/* SHA3 version */
ctx->s[ctx->wordIndex] ^=
(ctx->saved ^ ((uint64_t) ((uint64_t) (0x02 | (1 << 2)) <<
((ctx->byteIndex) * 8))));
#else
/* For testing the "pure" Keccak version */
ctx->s[ctx->wordIndex] ^=
(ctx->saved ^ ((uint64_t) ((uint64_t) 1 << (ctx->byteIndex *
8))));
#endif
ctx->s[SHA3_KECCAK_SPONGE_WORDS - ctx->capacityWords - 1] ^=
SHA3_CONST(0x8000000000000000UL);
keccakf(ctx->s);
/* Return first bytes of the ctx->s. This conversion is not needed for
* little-endian platforms e.g. wrap with #if !defined(__BYTE_ORDER__)
* || !defined(__ORDER_LITTLE_ENDIAN__) || __BYTE_ORDER__!=__ORDER_LITTLE_ENDIAN__
* ... the conversion below ...
* #endif */
{
unsigned i;
for(i = 0; i < SHA3_KECCAK_SPONGE_WORDS; i++) {
const unsigned t1 = (uint32_t) ctx->s[i];
const unsigned t2 = (uint32_t) ((ctx->s[i] >> 16) >> 16);
ctx->sb[i * 8 + 0] = (uint8_t) (t1);
ctx->sb[i * 8 + 1] = (uint8_t) (t1 >> 8);
ctx->sb[i * 8 + 2] = (uint8_t) (t1 >> 16);
ctx->sb[i * 8 + 3] = (uint8_t) (t1 >> 24);
ctx->sb[i * 8 + 4] = (uint8_t) (t2);
ctx->sb[i * 8 + 5] = (uint8_t) (t2 >> 8);
ctx->sb[i * 8 + 6] = (uint8_t) (t2 >> 16);
ctx->sb[i * 8 + 7] = (uint8_t) (t2 >> 24);
}
}
SHA3_TRACE_BUF("Hash: (first 32 bytes)", ctx->sb, 256 / 8);
return (ctx->sb);
}