From e3cbdb719393a59caa16bd29e1586bfadb6c2127 Mon Sep 17 00:00:00 2001 From: Max Shegai Date: Wed, 23 Jan 2019 14:51:34 -0800 Subject: [PATCH] use sha256 instead of md5 --- Makefile | 4 +- kernel.c | 18 ++-- md5.c | 299 ------------------------------------------------------- md5.h | 43 -------- sha256.c | 160 +++++++++++++++++++++++++++++ sha256.h | 31 ++++++ 6 files changed, 202 insertions(+), 353 deletions(-) delete mode 100644 md5.c delete mode 100644 md5.h create mode 100644 sha256.c create mode 100644 sha256.h diff --git a/Makefile b/Makefile index a21c8ca..52614af 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ CC=gcc CFLAGS=-c -m32 -OBJECT_FILES=boot.o kernel.o md5.o +OBJECT_FILES=boot.o kernel.o sha256.o LDFLAGS=-m elf_i386 all: kernel @@ -8,7 +8,7 @@ all: kernel %.o: %.S $(CC) $(CFLAGS) $< -o $@ -kernel: boot.o kernel.o md5.o +kernel: boot.o kernel.o sha256.o $(LD) $(LDFLAGS) $^ -o $@ .PHONY: all clean diff --git a/kernel.c b/kernel.c index 279f26f..70d60c6 100644 --- a/kernel.c +++ b/kernel.c @@ -16,8 +16,8 @@ */ #include -#include "md5.h" #include "multiboot.h" +#include "sha256.h" /* Macros. */ /* Check if the bit BIT in FLAGS is set. */ @@ -31,15 +31,15 @@ void printf(const char *format, ...); void print_module(multiboot_uint32_t start, multiboot_uint32_t end, multiboot_uint32_t cmdline) { - MD5_CTX ctx; - MD5_Init(&ctx); - MD5_Update(&ctx, (void *)start, end - start); - unsigned char res[16]; - MD5_Final(res, &ctx); + SHA256_CTX ctx; + sha256_init(&ctx); + sha256_update(&ctx, (void *)start, end - start); + unsigned char res[32]; + sha256_final(&ctx, res); - printf("{\"start\": %u, \"end\": %u, \"cmdline\": \"%s\", \"md5\": \"", + printf("{\"start\": %u, \"end\": %u, \"cmdline\": \"%s\", \"sha256\": \"", (unsigned)start, (unsigned)end, (char *)cmdline); - for (int i = 0; i < 16; i++) { + for (int i = 0; i < 32; i++) { printf("%02x", res[i]); } printf("\"}"); @@ -51,7 +51,7 @@ void cmain(unsigned long magic, unsigned long addr) { multiboot_info_t *mbi; /* Clear the screen. */ printf("Starting multiboot kernel\n"); - + printf("{\n"); /* Am I booted by a Multiboot-compliant boot loader? */ if (magic != MULTIBOOT_BOOTLOADER_MAGIC) { diff --git a/md5.c b/md5.c deleted file mode 100644 index f68b120..0000000 --- a/md5.c +++ /dev/null @@ -1,299 +0,0 @@ -/* - * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc. - * MD5 Message-Digest Algorithm (RFC 1321). - * - * Homepage: - * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5 - * - * Author: - * Alexander Peslyak, better known as Solar Designer - * - * This software was written by Alexander Peslyak in 2001. No copyright is - * claimed, and the software is hereby placed in the public domain. - * In case this attempt to disclaim copyright and place the software in the - * public domain is deemed null and void, then the software is - * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the - * general public under the following terms: - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted. - * - * There's ABSOLUTELY NO WARRANTY, express or implied. - * - * (This is a heavily cut-down "BSD license".) - * - * This differs from Colin Plumb's older public domain implementation in that - * no exactly 32-bit integer data type is required (any 32-bit or wider - * unsigned integer data type will do), there's no compile-time endianness - * configuration, and the function prototypes match OpenSSL's. No code from - * Colin Plumb's implementation has been reused; this comment merely compares - * the properties of the two independent implementations. - * - * The primary goals of this implementation are portability and ease of use. - * It is meant to be fast, but not as fast as possible. Some known - * optimizations are not included to reduce source code size and avoid - * compile-time configuration. - */ - -#ifndef HAVE_OPENSSL - -#include "md5.h" - -/* - * The basic MD5 functions. - * - * F and G are optimized compared to their RFC 1321 definitions for - * architectures that lack an AND-NOT instruction, just like in Colin Plumb's - * implementation. - */ -#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) -#define G(x, y, z) ((y) ^ ((z) & ((x) ^ (y)))) -#define H(x, y, z) (((x) ^ (y)) ^ (z)) -#define H2(x, y, z) ((x) ^ ((y) ^ (z))) -#define I(x, y, z) ((y) ^ ((x) | ~(z))) - -/* - * The MD5 transformation for all four rounds. - */ -#define STEP(f, a, b, c, d, x, t, s) \ - (a) += f((b), (c), (d)) + (x) + (t); \ - (a) = (((a) << (s)) | (((a)&0xffffffff) >> (32 - (s)))); \ - (a) += (b); - -/* - * SET reads 4 input bytes in little-endian byte order and stores them in a - * properly aligned word in host byte order. - * - * The check for little-endian architectures that tolerate unaligned memory - * accesses is just an optimization. Nothing will break if it fails to detect - * a suitable architecture. - * - * Unfortunately, this optimization may be a C strict aliasing rules violation - * if the caller's data buffer has effective type that cannot be aliased by - * MD5_u32plus. In practice, this problem may occur if these MD5 routines are - * inlined into a calling function, or with future and dangerously advanced - * link-time optimizations. For the time being, keeping these MD5 routines in - * their own translation unit avoids the problem. - */ -#if defined(__i386__) || defined(__x86_64__) || defined(__vax__) -#define SET(n) (*(MD5_u32plus *)&ptr[(n)*4]) -#define GET(n) SET(n) -#else -#define SET(n) \ - (ctx->block[(n)] = (MD5_u32plus)ptr[(n)*4] | \ - ((MD5_u32plus)ptr[(n)*4 + 1] << 8) | \ - ((MD5_u32plus)ptr[(n)*4 + 2] << 16) | \ - ((MD5_u32plus)ptr[(n)*4 + 3] << 24)) -#define GET(n) (ctx->block[(n)]) -#endif - -void *memcpy(void *dest, const void *src, int n) { - int i; - char *cd = dest; - char *cs = src; - for (i = 0; i < n; i++) { - *cd = *cs; - cd++; - cs++; - } - return dest; -} - -void *memset(void *s, int c, int n) { - int i; - char *p = s; - for (i = 0; i < n; i++) *p++ = c; - return s; -} - -/* - * This processes one or more 64-byte data blocks, but does NOT update the bit - * counters. There are no alignment requirements. - */ -static const void *body(MD5_CTX *ctx, const void *data, unsigned long size) { - const unsigned char *ptr; - MD5_u32plus a, b, c, d; - MD5_u32plus saved_a, saved_b, saved_c, saved_d; - - ptr = (const unsigned char *)data; - - a = ctx->a; - b = ctx->b; - c = ctx->c; - d = ctx->d; - - do { - saved_a = a; - saved_b = b; - saved_c = c; - saved_d = d; - - /* Round 1 */ - STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7) - STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12) - STEP(F, c, d, a, b, SET(2), 0x242070db, 17) - STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22) - STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7) - STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12) - STEP(F, c, d, a, b, SET(6), 0xa8304613, 17) - STEP(F, b, c, d, a, SET(7), 0xfd469501, 22) - STEP(F, a, b, c, d, SET(8), 0x698098d8, 7) - STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12) - STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17) - STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22) - STEP(F, a, b, c, d, SET(12), 0x6b901122, 7) - STEP(F, d, a, b, c, SET(13), 0xfd987193, 12) - STEP(F, c, d, a, b, SET(14), 0xa679438e, 17) - STEP(F, b, c, d, a, SET(15), 0x49b40821, 22) - - /* Round 2 */ - STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5) - STEP(G, d, a, b, c, GET(6), 0xc040b340, 9) - STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14) - STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20) - STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5) - STEP(G, d, a, b, c, GET(10), 0x02441453, 9) - STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14) - STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20) - STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5) - STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9) - STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14) - STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20) - STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5) - STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9) - STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14) - STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20) - - /* Round 3 */ - STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4) - STEP(H2, d, a, b, c, GET(8), 0x8771f681, 11) - STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16) - STEP(H2, b, c, d, a, GET(14), 0xfde5380c, 23) - STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4) - STEP(H2, d, a, b, c, GET(4), 0x4bdecfa9, 11) - STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16) - STEP(H2, b, c, d, a, GET(10), 0xbebfbc70, 23) - STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4) - STEP(H2, d, a, b, c, GET(0), 0xeaa127fa, 11) - STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16) - STEP(H2, b, c, d, a, GET(6), 0x04881d05, 23) - STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4) - STEP(H2, d, a, b, c, GET(12), 0xe6db99e5, 11) - STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16) - STEP(H2, b, c, d, a, GET(2), 0xc4ac5665, 23) - - /* Round 4 */ - STEP(I, a, b, c, d, GET(0), 0xf4292244, 6) - STEP(I, d, a, b, c, GET(7), 0x432aff97, 10) - STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15) - STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21) - STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6) - STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10) - STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15) - STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21) - STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6) - STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10) - STEP(I, c, d, a, b, GET(6), 0xa3014314, 15) - STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21) - STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6) - STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10) - STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15) - STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21) - - a += saved_a; - b += saved_b; - c += saved_c; - d += saved_d; - - ptr += 64; - } while (size -= 64); - - ctx->a = a; - ctx->b = b; - ctx->c = c; - ctx->d = d; - - return ptr; -} - -void MD5_Init(MD5_CTX *ctx) { - ctx->a = 0x67452301; - ctx->b = 0xefcdab89; - ctx->c = 0x98badcfe; - ctx->d = 0x10325476; - - ctx->lo = 0; - ctx->hi = 0; -} - -void MD5_Update(MD5_CTX *ctx, const void *data, unsigned long size) { - MD5_u32plus saved_lo; - unsigned long used, available; - - saved_lo = ctx->lo; - if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo) ctx->hi++; - ctx->hi += size >> 29; - - used = saved_lo & 0x3f; - - if (used) { - available = 64 - used; - - if (size < available) { - memcpy(&ctx->buffer[used], data, size); - return; - } - - memcpy(&ctx->buffer[used], data, available); - data = (const unsigned char *)data + available; - size -= available; - body(ctx, ctx->buffer, 64); - } - - if (size >= 64) { - data = body(ctx, data, size & ~(unsigned long)0x3f); - size &= 0x3f; - } - - memcpy(ctx->buffer, data, size); -} - -#define OUT(dst, src) \ - (dst)[0] = (unsigned char)(src); \ - (dst)[1] = (unsigned char)((src) >> 8); \ - (dst)[2] = (unsigned char)((src) >> 16); \ - (dst)[3] = (unsigned char)((src) >> 24); - -void MD5_Final(unsigned char *result, MD5_CTX *ctx) { - unsigned long used, available; - - used = ctx->lo & 0x3f; - - ctx->buffer[used++] = 0x80; - - available = 64 - used; - - if (available < 8) { - memset(&ctx->buffer[used], 0, available); - body(ctx, ctx->buffer, 64); - used = 0; - available = 64; - } - - memset(&ctx->buffer[used], 0, available - 8); - - ctx->lo <<= 3; - OUT(&ctx->buffer[56], ctx->lo) - OUT(&ctx->buffer[60], ctx->hi) - - body(ctx, ctx->buffer, 64); - - OUT(&result[0], ctx->a) - OUT(&result[4], ctx->b) - OUT(&result[8], ctx->c) - OUT(&result[12], ctx->d) - - memset(ctx, 0, sizeof(*ctx)); -} - -#endif diff --git a/md5.h b/md5.h deleted file mode 100644 index a7ebda6..0000000 --- a/md5.h +++ /dev/null @@ -1,43 +0,0 @@ -/* - * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc. - * MD5 Message-Digest Algorithm (RFC 1321). - * - * Homepage: - * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5 - * - * Author: - * Alexander Peslyak, better known as Solar Designer - * - * This software was written by Alexander Peslyak in 2001. No copyright is - * claimed, and the software is hereby placed in the public domain. - * In case this attempt to disclaim copyright and place the software in the - * public domain is deemed null and void, then the software is - * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the - * general public under the following terms: - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted. - * - * There's ABSOLUTELY NO WARRANTY, express or implied. - * - * See md5.c for more information. - */ - -#if !defined(_MD5_H) -#define _MD5_H - -/* Any 32-bit or wider unsigned integer data type will do */ -typedef unsigned int MD5_u32plus; - -typedef struct { - MD5_u32plus lo, hi; - MD5_u32plus a, b, c, d; - unsigned char buffer[64]; - MD5_u32plus block[16]; -} MD5_CTX; - -extern void MD5_Init(MD5_CTX *ctx); -extern void MD5_Update(MD5_CTX *ctx, const void *data, unsigned long size); -extern void MD5_Final(unsigned char *result, MD5_CTX *ctx); - -#endif diff --git a/sha256.c b/sha256.c new file mode 100644 index 0000000..7ac9a8b --- /dev/null +++ b/sha256.c @@ -0,0 +1,160 @@ +/********************************************************************* +* 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 "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)) + +void *memset(void *s, int c, int n) { + int i; + char *p = s; + for (i = 0; i < n; i++) *p++ = c; + return s; +} + +/**************************** 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[], int 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/sha256.h b/sha256.h new file mode 100644 index 0000000..d74fc6a --- /dev/null +++ b/sha256.h @@ -0,0 +1,31 @@ +/********************************************************************* +* 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 + +/****************************** 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[], int len); +void sha256_final(SHA256_CTX *ctx, BYTE hash[]); + +#endif // SHA256_H