sha256

Simple C SHA256 implementation. Author: Brad Conte
git clone https://noulin.net/git/sha256.git
Log | Files | Refs | LICENSE

commit e6fe92a005d006e2382266ab3d2a57b53ca0c83f
parent 6aa5738fb23bf1fe924827ba54875bb464daca5b
Author: Remy Noulin <loader2x@gmail.com>
Date:   Sun, 20 May 2018 10:41:32 +0200

sha256 library

bconSha256.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
bconSha256.h |   0
package.yml  |  14 ++++++
sha256.c     |  37 ++++++++++++++
sha256.h     |  39 +++++++++++++++
test.c       |  14 ++++++
6 files changed, 262 insertions(+)

Diffstat:
AbconSha256.c | 158+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AbconSha256.h | 0
Apackage.yml | 14++++++++++++++
Asha256.c | 37+++++++++++++++++++++++++++++++++++++
Asha256.h | 39+++++++++++++++++++++++++++++++++++++++
Atest.c | 14++++++++++++++
6 files changed, 262 insertions(+), 0 deletions(-)

diff --git a/bconSha256.c b/bconSha256.c @@ -0,0 +1,158 @@ +/********************************************************************* +* Filename: sha256.c +* Author: Brad Conte (brad AT bradconte.com) +* Copyright: +* Disclaimer: This code is presented "as is" without any guarantees. +* Details: Implementation of the SHA-256 hashing algorithm. + SHA-256 is one of the three algorithms in the SHA2 + specification. The others, SHA-384 and SHA-512, are not + offered in this implementation. + Algorithm specification can be found here: + * http://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf + This implementation uses little endian byte order. +*********************************************************************/ + +/*************************** HEADER FILES ***************************/ +#include <stdlib.h> +#include <memory.h> +#include "sha256.h" + +/****************************** MACROS ******************************/ +#define ROTLEFT(a,b) (((a) << (b)) | ((a) >> (32-(b)))) +#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b)))) + +#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z))) +#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z))) +#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22)) +#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25)) +#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3)) +#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10)) + +/**************************** VARIABLES *****************************/ +static const WORD k[64] = { + 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 +}; + +/*********************** FUNCTION DEFINITIONS ***********************/ +void sha256_transform(SHA256_CTX *ctx, const BYTE data[]) +{ + WORD a, b, c, d, e, f, g, h, i, j, t1, t2, m[64]; + + for (i = 0, j = 0; i < 16; ++i, j += 4) + m[i] = (data[j] << 24) | (data[j + 1] << 16) | (data[j + 2] << 8) | (data[j + 3]); + for ( ; i < 64; ++i) + m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16]; + + a = ctx->state[0]; + b = ctx->state[1]; + c = ctx->state[2]; + d = ctx->state[3]; + e = ctx->state[4]; + f = ctx->state[5]; + g = ctx->state[6]; + h = ctx->state[7]; + + for (i = 0; i < 64; ++i) { + t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i]; + t2 = EP0(a) + MAJ(a,b,c); + h = g; + g = f; + f = e; + e = d + t1; + d = c; + c = b; + b = a; + a = t1 + t2; + } + + ctx->state[0] += a; + ctx->state[1] += b; + ctx->state[2] += c; + ctx->state[3] += d; + ctx->state[4] += e; + ctx->state[5] += f; + ctx->state[6] += g; + ctx->state[7] += h; +} + +void sha256_init(SHA256_CTX *ctx) +{ + ctx->datalen = 0; + ctx->bitlen = 0; + 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; +} + +void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len) +{ + WORD i; + + for (i = 0; i < len; ++i) { + ctx->data[ctx->datalen] = data[i]; + ctx->datalen++; + if (ctx->datalen == 64) { + sha256_transform(ctx, ctx->data); + ctx->bitlen += 512; + ctx->datalen = 0; + } + } +} + +void sha256_final(SHA256_CTX *ctx, BYTE hash[]) +{ + WORD i; + + i = ctx->datalen; + + // Pad whatever data is left in the buffer. + if (ctx->datalen < 56) { + ctx->data[i++] = 0x80; + while (i < 56) + ctx->data[i++] = 0x00; + } + else { + ctx->data[i++] = 0x80; + while (i < 64) + ctx->data[i++] = 0x00; + sha256_transform(ctx, ctx->data); + memset(ctx->data, 0, 56); + } + + // Append to the padding the total message's length in bits and transform. + ctx->bitlen += ctx->datalen * 8; + ctx->data[63] = ctx->bitlen; + ctx->data[62] = ctx->bitlen >> 8; + ctx->data[61] = ctx->bitlen >> 16; + ctx->data[60] = ctx->bitlen >> 24; + ctx->data[59] = ctx->bitlen >> 32; + ctx->data[58] = ctx->bitlen >> 40; + ctx->data[57] = ctx->bitlen >> 48; + ctx->data[56] = ctx->bitlen >> 56; + sha256_transform(ctx, ctx->data); + + // Since this implementation uses little endian byte ordering and SHA uses big endian, + // reverse all the bytes when copying the final state to the output hash. + for (i = 0; i < 4; ++i) { + hash[i] = (ctx->state[0] >> (24 - i * 8)) & 0x000000ff; + hash[i + 4] = (ctx->state[1] >> (24 - i * 8)) & 0x000000ff; + hash[i + 8] = (ctx->state[2] >> (24 - i * 8)) & 0x000000ff; + hash[i + 12] = (ctx->state[3] >> (24 - i * 8)) & 0x000000ff; + hash[i + 16] = (ctx->state[4] >> (24 - i * 8)) & 0x000000ff; + hash[i + 20] = (ctx->state[5] >> (24 - i * 8)) & 0x000000ff; + hash[i + 24] = (ctx->state[6] >> (24 - i * 8)) & 0x000000ff; + hash[i + 28] = (ctx->state[7] >> (24 - i * 8)) & 0x000000ff; + } +} diff --git a/bconSha256.h b/bconSha256.h diff --git a/package.yml b/package.yml @@ -0,0 +1,14 @@ +--- + name: sha256 + version: 0.0.1 + description: "Simple C SHA256 implementation. Author: Brad Conte" + repository: + type: git + url: git+https://github.com/B-Con/crypto-algorithms + keywords: + - cryptography + author: remy + license: MIT + bugs: + url: https://github.com/B-Con/crypto-algorithms/issues + homepage: http://bradconte.com/sha256_c diff --git a/sha256.c b/sha256.c @@ -0,0 +1,37 @@ +/* + * Author: Remy Noulin + * License: MIT + */ + +#include "bconSha256.h" +#include "sha256.h" +#include "stdlib.h" +#include "string.h" + +char *sha256S(const char *bufferToHash); +char *sha256_byteToHexString(BYTE data[]); + +char *sha256S(const char *bufferToHash) { + if (!bufferToHash) return NULL; + + SHA256_CTX ctx; + sha256_init(&ctx); + sha256_update(&ctx, bufferToHash, strlen(bufferToHash)); + BYTE result[32]; + sha256_final(&ctx, result); + + char *hexS = sha256_byteToHexString(result); + return hexS; +} + +char *sha256_byteToHexString(BYTE data[]) { + char *hexC = "0123456789abcdef"; + char *hexS = malloc(65); + if (!hexS) return NULL; + for(BYTE i; i<32; i++) { + hexS[i*2] = hexC[data[i]>>4]; + hexS[i*2+1] = hexC[data[i]&0xF]; + } + hexS[64] = 0; + return hexS; +} diff --git a/sha256.h b/sha256.h @@ -0,0 +1,39 @@ +/********************************************************************* +* Filename: sha256.h +* Author: Brad Conte (brad AT bradconte.com) +* Copyright: +* Disclaimer: This code is presented "as is" without any guarantees. +* Details: Defines the API for the corresponding SHA1 implementation. +*********************************************************************/ + +#ifndef SHA256_H +#define SHA256_H + +/** + * sha256S returns the hash in the form of a hex string + */ +char *sha256S(const char *bufferToHash); + +/*************************** HEADER FILES ***************************/ +#include <stddef.h> + +/****************************** MACROS ******************************/ +#define SHA256_BLOCK_SIZE 32 // SHA256 outputs a 32 byte digest + +/**************************** DATA TYPES ****************************/ +typedef unsigned char BYTE; // 8-bit byte +typedef unsigned int WORD; // 32-bit word, change to "long" for 16-bit machines + +typedef struct { + BYTE data[64]; + WORD datalen; + unsigned long long bitlen; + WORD state[8]; +} SHA256_CTX; + +/*********************** FUNCTION DECLARATIONS **********************/ +void sha256_init(SHA256_CTX *ctx); +void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len); +void sha256_final(SHA256_CTX *ctx, BYTE hash[]); + +#endif // SHA256_H diff --git a/test.c b/test.c @@ -0,0 +1,14 @@ +#! /usr/bin/env sheepy + +#include "libsheepyObject.h" +#include "sha256.h" + +int main(int ARGC, char** ARGV) { + + char *clear = "a random password"; + + char *result = sha256S(clear); + + puts(result); + free(result); +}