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/*
* An generic implementation of the SHA-2 hash family, this is endian neutral
* so should work just about anywhere.
*
* This code works much like the MD5 code provided by RSA. You sha_init()
* a "sha_state" then sha_process() the bytes you want and sha_done() to get
* the output.
*
* Originally written by Tom St Denis -- http://tomstdenis.home.dhs.org
* Adapted for PyCrypto by Jeethu Rao, Taylor Boon, and others.
* Turned into a generic template by Lorenz Quack <don@amberfisharts.com>
*
* ===================================================================
* The contents of this file are dedicated to the public domain. To
* the extent that dedication to the public domain is not available,
* everyone is granted a worldwide, perpetual, royalty-free,
* non-exclusive license to exercise all rights associated with the
* contents of this file for any purpose whatsoever.
* No rights are reserved.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
* ===================================================================
*
*/
#include "pycrypto_common.h"
/* compress one block */
static void sha_compress(hash_state * hs)
{
sha2_word_t S[8], W[SCHEDULE_SIZE], T1, T2;
int i;
/* copy state into S */
for (i = 0; i < 8; i++)
S[i] = hs->state[i];
/* copy the state into W[0..15] */
for (i = 0; i < 16; i++){
W[i] = (
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+0]) << (WORD_SIZE_BITS- 8)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+1]) << (WORD_SIZE_BITS-16)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+2]) << (WORD_SIZE_BITS-24)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+3]) << (WORD_SIZE_BITS-32))
#if (WORD_SIZE_BITS == 64)
|
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+4]) << (WORD_SIZE_BITS-40)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+5]) << (WORD_SIZE_BITS-48)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+6]) << (WORD_SIZE_BITS-56)) |
(((sha2_word_t) hs->buf[(WORD_SIZE*i)+7]))
#endif
);
}
/* fill W[16..SCHEDULE_SIZE] */
for (i = 16; i < SCHEDULE_SIZE; i++)
W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];
/* Compress */
for (i = 0; i < SCHEDULE_SIZE; i++) {
T1 = S[7] + Sigma1(S[4]) + Ch(S[4], S[5], S[6]) + K[i] + W[i];
T2 = Sigma0(S[0]) + Maj(S[0], S[1], S[2]);
S[7] = S[6];
S[6] = S[5];
S[5] = S[4];
S[4] = S[3] + T1;
S[3] = S[2];
S[2] = S[1];
S[1] = S[0];
S[0] = T1 + T2;
}
/* feedback */
for (i = 0; i < 8; i++)
hs->state[i] += S[i];
}
/* adds *inc* to the length of the hash_state *hs*
* return 1 on success
* return 0 if the length overflows
*/
static int add_length(hash_state *hs, sha2_word_t inc) {
sha2_word_t overflow_detector;
overflow_detector = hs->length_lower;
hs->length_lower += inc;
if (overflow_detector > hs->length_lower) {
overflow_detector = hs->length_upper;
hs->length_upper++;
if (hs->length_upper > hs->length_upper)
return 0;
}
return 1;
}
/* init the SHA state */
static void sha_init(hash_state * hs)
{
int i;
hs->curlen = hs->length_upper = hs->length_lower = 0;
for (i = 0; i < 8; ++i)
hs->state[i] = H[i];
}
static void sha_process(hash_state * hs, unsigned char *buf, int len)
{
while (len--) {
/* copy byte */
hs->buf[hs->curlen++] = *buf++;
/* is a block full? */
if (hs->curlen == BLOCK_SIZE) {
sha_compress(hs);
add_length(hs, BLOCK_SIZE_BITS);
hs->curlen = 0;
}
}
}
static void sha_done(hash_state * hs, unsigned char *hash)
{
int i;
/* increase the length of the message */
add_length(hs, hs->curlen * 8);
/* append the '1' bit */
hs->buf[hs->curlen++] = 0x80;
/* if the length is currently above LAST_BLOCK_SIZE bytes we append
* zeros then compress. Then we can fall back to padding zeros and length
* encoding like normal.
*/
if (hs->curlen > LAST_BLOCK_SIZE) {
for (; hs->curlen < BLOCK_SIZE;)
hs->buf[hs->curlen++] = 0;
sha_compress(hs);
hs->curlen = 0;
}
/* pad upto LAST_BLOCK_SIZE bytes of zeroes */
for (; hs->curlen < LAST_BLOCK_SIZE;)
hs->buf[hs->curlen++] = 0;
/* append length */
for (i = 0; i < WORD_SIZE; i++)
hs->buf[i + LAST_BLOCK_SIZE] =
(hs->length_upper >> ((WORD_SIZE - 1 - i) * 8)) & 0xFF;
for (i = 0; i < WORD_SIZE; i++)
hs->buf[i + LAST_BLOCK_SIZE + WORD_SIZE] =
(hs->length_lower >> ((WORD_SIZE - 1 - i) * 8)) & 0xFF;
sha_compress(hs);
/* copy output */
for (i = 0; i < DIGEST_SIZE; i++)
hash[i] = (hs->state[i / WORD_SIZE] >>
((WORD_SIZE - 1 - (i % WORD_SIZE)) * 8)) & 0xFF;
}
// Done
static void hash_init (hash_state *ptr)
{
sha_init(ptr);
}
// Done
static void
hash_update (hash_state *self, const U8 *buf, int len)
{
sha_process(self,(unsigned char *)buf, len);
}
// Done
static void
hash_copy(hash_state *src, hash_state *dest)
{
memcpy(dest,src,sizeof(hash_state));
}
// Done
static PyObject *
hash_digest (const hash_state *self)
{
unsigned char digest[DIGEST_SIZE];
hash_state temp;
hash_copy((hash_state*)self,&temp);
sha_done(&temp,digest);
return PyBytes_FromStringAndSize((char *)digest, DIGEST_SIZE);
}
#include "hash_template.c"
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