sensor-watch/movement/lib/TOTP/sha256.c
EmilienCourt 9ebea46300
totp : rework and add SHA256/512 (#151)
* totp : rework and add SHA256/512

* totp : comment code

* totp : fix SHA224/SHA384 and examples

* totp : fix bug in totp_face_lfs

* totp : init_totp_record to SHA1

* totp : move TOTP-MCU to TOTP, update README and example

* totp : SHAX, use size_t n instead of harcoded 8

* clarify what to put in TOTP face

Co-authored-by: Emilien <Emilien>
Co-authored-by: joeycastillo <joeycastillo@utexas.edu>
2023-01-14 11:58:03 -05:00

372 lines
12 KiB
C

/*
* FIPS-180-2 compliant SHA-256 implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* The SHA-256 Secure Hash Standard was published by NIST in 2002.
*
* http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
*/
#include "sha256.h"
#include <string.h>
#include <stdio.h>
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i) \
do { \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); \
} while( 0 )
#endif
#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i) \
do { \
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
(b)[(i) + 3] = (unsigned char) ( (n) ); \
} while( 0 )
#endif
void mbedtls_sha256_init( mbedtls_sha256_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_sha256_context ) );
}
void mbedtls_sha256_free( mbedtls_sha256_context *ctx )
{
if( ctx == NULL )
return;
mbedtls_zeroize( ctx, sizeof( mbedtls_sha256_context ) );
}
void mbedtls_sha256_clone( mbedtls_sha256_context *dst,
const mbedtls_sha256_context *src )
{
*dst = *src;
}
/*
* SHA-256 context setup
*/
void mbedtls_sha256_starts( mbedtls_sha256_context *ctx, int is224 )
{
ctx->total[0] = 0;
ctx->total[1] = 0;
if( is224 == 0 )
{
/* SHA-256 */
ctx->state[0] = 0x6A09E667;
ctx->state[1] = 0xBB67AE85;
ctx->state[2] = 0x3C6EF372;
ctx->state[3] = 0xA54FF53A;
ctx->state[4] = 0x510E527F;
ctx->state[5] = 0x9B05688C;
ctx->state[6] = 0x1F83D9AB;
ctx->state[7] = 0x5BE0CD19;
}
else
{
/* SHA-224 */
ctx->state[0] = 0xC1059ED8;
ctx->state[1] = 0x367CD507;
ctx->state[2] = 0x3070DD17;
ctx->state[3] = 0xF70E5939;
ctx->state[4] = 0xFFC00B31;
ctx->state[5] = 0x68581511;
ctx->state[6] = 0x64F98FA7;
ctx->state[7] = 0xBEFA4FA4;
}
ctx->is224 = is224;
}
static const uint32_t K[] =
{
0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5,
0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5,
0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3,
0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174,
0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC,
0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7,
0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967,
0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13,
0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85,
0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3,
0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5,
0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3,
0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208,
0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2,
};
#define SHR(x,n) ((x & 0xFFFFFFFF) >> n)
#define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))
#define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^ SHR(x, 3))
#define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10))
#define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
#define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))
#define F0(x,y,z) ((x & y) | (z & (x | y)))
#define F1(x,y,z) (z ^ (x & (y ^ z)))
#define R(t) \
( \
W[t] = S1(W[t - 2]) + W[t - 7] + \
S0(W[t - 15]) + W[t - 16] \
)
#define P(a,b,c,d,e,f,g,h,x,K) \
{ \
temp1 = h + S3(e) + F1(e,f,g) + K + x; \
temp2 = S2(a) + F0(a,b,c); \
d += temp1; h = temp1 + temp2; \
}
void mbedtls_sha256_process( mbedtls_sha256_context *ctx, const unsigned char data[SHA256_BLOCK_LENGTH] )
{
uint32_t temp1, temp2, W[64];
uint32_t A[8];
unsigned int i;
for( i = 0; i < 8; i++ )
A[i] = ctx->state[i];
for( i = 0; i < 16; i++ )
GET_UINT32_BE( W[i], data, 4 * i );
for( i = 0; i < 16; i += 8 )
{
P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i+0], K[i+0] );
P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], W[i+1], K[i+1] );
P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], W[i+2], K[i+2] );
P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], W[i+3], K[i+3] );
P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], W[i+4], K[i+4] );
P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], W[i+5], K[i+5] );
P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], W[i+6], K[i+6] );
P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], W[i+7], K[i+7] );
}
for( i = 16; i < 64; i += 8 )
{
P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], R(i+0), K[i+0] );
P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], R(i+1), K[i+1] );
P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], R(i+2), K[i+2] );
P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], R(i+3), K[i+3] );
P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], R(i+4), K[i+4] );
P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], R(i+5), K[i+5] );
P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], R(i+6), K[i+6] );
P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], R(i+7), K[i+7] );
}
for( i = 0; i < 8; i++ )
ctx->state[i] += A[i];
}
/*
* SHA-256 process buffer
*/
void mbedtls_sha256_update( mbedtls_sha256_context *ctx, const unsigned char *input,
size_t ilen )
{
size_t fill;
uint32_t left;
if( ilen == 0 )
return;
left = ctx->total[0] & 0x3F;
fill = 64 - left;
ctx->total[0] += (uint32_t) ilen;
ctx->total[0] &= 0xFFFFFFFF;
if( ctx->total[0] < (uint32_t) ilen )
ctx->total[1]++;
if( left && ilen >= fill )
{
memcpy( (void *) (ctx->buffer + left), input, fill );
mbedtls_sha256_process( ctx, ctx->buffer );
input += fill;
ilen -= fill;
left = 0;
}
while( ilen >= 64 )
{
mbedtls_sha256_process( ctx, input );
input += 64;
ilen -= 64;
}
if( ilen > 0 )
memcpy( (void *) (ctx->buffer + left), input, ilen );
}
static const unsigned char sha256_padding[SHA256_BLOCK_LENGTH] =
{
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/*
* SHA-256 final digest
*/
void mbedtls_sha256_finish( mbedtls_sha256_context *ctx, unsigned char* output )
{
uint32_t last, padn;
uint32_t high, low;
unsigned char msglen[8];
high = ( ctx->total[0] >> 29 )
| ( ctx->total[1] << 3 );
low = ( ctx->total[0] << 3 );
PUT_UINT32_BE( high, msglen, 0 );
PUT_UINT32_BE( low, msglen, 4 );
last = ctx->total[0] & 0x3F;
padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
mbedtls_sha256_update( ctx, sha256_padding, padn );
mbedtls_sha256_update( ctx, msglen, 8 );
PUT_UINT32_BE( ctx->state[0], output, 0 );
PUT_UINT32_BE( ctx->state[1], output, 4 );
PUT_UINT32_BE( ctx->state[2], output, 8 );
PUT_UINT32_BE( ctx->state[3], output, 12 );
PUT_UINT32_BE( ctx->state[4], output, 16 );
PUT_UINT32_BE( ctx->state[5], output, 20 );
PUT_UINT32_BE( ctx->state[6], output, 24 );
if( ctx->is224 == 0 )
PUT_UINT32_BE( ctx->state[7], output, 28 );
}
/*
* output = SHA-256( input buffer )
*/
void mbedtls_sha256( const unsigned char *input, size_t ilen,
unsigned char* output, int is224 )
{
mbedtls_sha256_context ctx;
mbedtls_sha256_init( &ctx );
mbedtls_sha256_starts( &ctx, is224 );
mbedtls_sha256_update( &ctx, input, ilen );
mbedtls_sha256_finish( &ctx, output );
mbedtls_sha256_free( &ctx );
}
/*
* Compute HMAC_SHA224/256 using key, key length, text to hash, size of the text, output buffer and a switch for SHA224
*/
void HMAC_SHA256(const uint8_t* key, size_t key_length, const uint8_t *in, size_t n, uint8_t* out, int is224){
int digest_length = SHA256_DIGEST_LENGTH;
if (is224 == 1) {
digest_length = SHA224_DIGEST_LENGTH;
}
uint8_t i;
uint8_t k_ipad[SHA256_BLOCK_LENGTH]; /* inner padding - key XORd with ipad */
uint8_t k_opad[SHA256_BLOCK_LENGTH]; /* outer padding - key XORd with opad */
uint8_t buffer[SHA256_BLOCK_LENGTH + digest_length];
/* start out by storing key in pads */
memset(k_ipad, 0, sizeof(k_ipad));
memset(k_opad, 0, sizeof(k_opad));
if (key_length <= SHA256_BLOCK_LENGTH) {
memcpy(k_ipad, key, key_length);
memcpy(k_opad, key, key_length);
}
else {
mbedtls_sha256(key, key_length, k_ipad, is224);
memcpy(k_opad, k_ipad, SHA256_BLOCK_LENGTH);
}
/* XOR key with ipad and opad values */
for (i = 0; i < SHA256_BLOCK_LENGTH; i++) {
k_ipad[i] ^= HMAC_IPAD;
k_opad[i] ^= HMAC_OPAD;
}
// perform inner SHA256
memcpy(buffer, k_ipad, SHA256_BLOCK_LENGTH);
memcpy(buffer + SHA256_BLOCK_LENGTH, in, n);
mbedtls_sha256(buffer, SHA256_BLOCK_LENGTH + n, out, is224);
memset(buffer, 0, SHA256_BLOCK_LENGTH + n);
// perform outer SHA256
memcpy(buffer, k_opad, SHA256_BLOCK_LENGTH);
memcpy(buffer + SHA256_BLOCK_LENGTH, out, digest_length);
mbedtls_sha256(buffer, SHA256_BLOCK_LENGTH + digest_length, out, is224);
}
/*
* Compute TOTP_HMAC_SHA224/256 using key, key length, text to hash, size of the text and a switch for SHA224
*/
uint32_t TOTP_HMAC_SHA256(const uint8_t* key, size_t key_length, const uint8_t *in, size_t n, int is224){
int digest_length = SHA256_DIGEST_LENGTH;
if (is224 == 1) {
digest_length = SHA224_DIGEST_LENGTH;
}
// STEP 1, get the HMAC-SHA256 hash from counter and key
uint8_t hash[digest_length];
HMAC_SHA256(key, key_length, in, n, hash, is224);
// STEP 2, apply dynamic truncation to obtain a 4-bytes string
uint32_t truncated_hash = 0;
uint8_t _offset = hash[digest_length - 1] & 0xF;
uint8_t j;
for (j = 0; j < 4; ++j) {
truncated_hash <<= 8;
truncated_hash |= hash[_offset + j];
}
// STEP 3, compute the OTP value
truncated_hash &= 0x7FFFFFFF; //Disabled
truncated_hash %= 1000000;
return truncated_hash;
}