diff options
Diffstat (limited to 'fitz')
-rw-r--r-- | fitz/crypt_sha2.c | 182 | ||||
-rw-r--r-- | fitz/fitz.h | 18 |
2 files changed, 200 insertions, 0 deletions
diff --git a/fitz/crypt_sha2.c b/fitz/crypt_sha2.c new file mode 100644 index 00000000..6796c5ab --- /dev/null +++ b/fitz/crypt_sha2.c @@ -0,0 +1,182 @@ +/* +This code is based on the code found from 7-Zip, which has a modified +version of the SHA-256 found from Crypto++ <http://www.cryptopp.com/>. +The code was modified a little to fit into liblzma and fitz. + +This file has been put into the public domain. +You can do whatever you want with this file. +*/ + +#include "fitz.h" + +static inline int isbigendian(void) +{ + static const int one = 1; + return *(char*)&one == 0; +} + +static inline unsigned int bswap32(unsigned int num) +{ + if (!isbigendian()) + { + return ( (((num) << 24)) + | (((num) << 8) & 0x00FF0000) + | (((num) >> 8) & 0x0000FF00) + | (((num) >> 24)) ); + } + return num; +} + +/* At least on x86, GCC is able to optimize this to a rotate instruction. */ +#define rotr_32(num, amount) ((num) >> (amount) | (num) << (32 - (amount))) + +#define blk0(i) (W[i] = data[i]) +#define blk2(i) (W[i & 15] += s1(W[(i - 2) & 15]) + W[(i - 7) & 15] \ + + s0(W[(i - 15) & 15])) + +#define Ch(x, y, z) (z ^ (x & (y ^ z))) +#define Maj(x, y, z) ((x & y) | (z & (x | y))) + +#define a(i) T[(0 - i) & 7] +#define b(i) T[(1 - i) & 7] +#define c(i) T[(2 - i) & 7] +#define d(i) T[(3 - i) & 7] +#define e(i) T[(4 - i) & 7] +#define f(i) T[(5 - i) & 7] +#define g(i) T[(6 - i) & 7] +#define h(i) T[(7 - i) & 7] + +#define R(i) \ + h(i) += S1(e(i)) + Ch(e(i), f(i), g(i)) + SHA256_K[i + j] \ + + (j ? blk2(i) : blk0(i)); \ + d(i) += h(i); \ + h(i) += S0(a(i)) + Maj(a(i), b(i), c(i)) + +#define S0(x) (rotr_32(x, 2) ^ rotr_32(x, 13) ^ rotr_32(x, 22)) +#define S1(x) (rotr_32(x, 6) ^ rotr_32(x, 11) ^ rotr_32(x, 25)) +#define s0(x) (rotr_32(x, 7) ^ rotr_32(x, 18) ^ (x >> 3)) +#define s1(x) (rotr_32(x, 17) ^ rotr_32(x, 19) ^ (x >> 10)) + +static const unsigned int SHA256_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, +}; + +static void +transform(unsigned int state[8], const unsigned int data_xe[16]) +{ + unsigned int data[16]; + unsigned int W[16]; + unsigned int T[8]; + unsigned int j; + + /* ensure big-endian integers */ + for (j = 0; j < 16; j++) + data[j] = bswap32(data_xe[j]); + + /* Copy state[] to working vars. */ + memcpy(T, state, sizeof(T)); + + /* 64 operations, partially loop unrolled */ + for (j = 0; j < 64; j += 16) { + R( 0); R( 1); R( 2); R( 3); + R( 4); R( 5); R( 6); R( 7); + R( 8); R( 9); R(10); R(11); + R(12); R(13); R(14); R(15); + } + + /* Add the working vars back into state[]. */ + state[0] += a(0); + state[1] += b(0); + state[2] += c(0); + state[3] += d(0); + state[4] += e(0); + state[5] += f(0); + state[6] += g(0); + state[7] += h(0); +} + +void fz_sha256init(fz_sha256 *context) +{ + context->count[0] = context->count[1] = 0; + + context->state[0] = 0x6A09E667; + context->state[1] = 0xBB67AE85; + context->state[2] = 0x3C6EF372; + context->state[3] = 0xA54FF53A; + context->state[4] = 0x510E527F; + context->state[5] = 0x9B05688C; + context->state[6] = 0x1F83D9AB; + context->state[7] = 0x5BE0CD19; +} + +void fz_sha256update(fz_sha256 *context, const unsigned char *input, unsigned int inlen) +{ + /* Copy the input data into a properly aligned temporary buffer. + * This way we can be called with arbitrarily sized buffers + * (no need to be multiple of 64 bytes), and the code works also + * on architectures that don't allow unaligned memory access. */ + while (inlen > 0) + { + const unsigned int copy_start = context->count[0] & 0x3F; + unsigned int copy_size = 64 - copy_start; + if (copy_size > inlen) + copy_size = inlen; + + memcpy(context->buffer.u8 + copy_start, input, copy_size); + + input += copy_size; + inlen -= copy_size; + context->count[0] += copy_size; + /* carry overflow from low to high */ + if (context->count[0] < copy_size) + context->count[1]++; + + if ((context->count[0] & 0x3F) == 0) + transform(context->state, context->buffer.u32); + } +} + +void fz_sha256final(fz_sha256 *context, unsigned char digest[32]) +{ + /* Add padding as described in RFC 3174 (it describes SHA-1 but + * the same padding style is used for SHA-256 too). */ + unsigned int j = context->count[0] & 0x3F; + context->buffer.u8[j++] = 0x80; + + while (j != 56) + { + if (j == 64) + { + transform(context->state, context->buffer.u32); + j = 0; + } + context->buffer.u8[j++] = 0x00; + } + + /* Convert the message size from bytes to bits. */ + context->count[1] = (context->count[1] << 3) + (context->count[0] >> 29); + context->count[0] = context->count[0] << 3; + + context->buffer.u32[14] = bswap32(context->count[1]); + context->buffer.u32[15] = bswap32(context->count[0]); + transform(context->state, context->buffer.u32); + + for (j = 0; j < 8; j++) + ((unsigned int *)digest)[j] = bswap32(context->state[j]); + memset(context, 0, sizeof(fz_sha256)); +} diff --git a/fitz/fitz.h b/fitz/fitz.h index 8f756895..6a339303 100644 --- a/fitz/fitz.h +++ b/fitz/fitz.h @@ -285,6 +285,24 @@ void fz_md5init(fz_md5 *state); void fz_md5update(fz_md5 *state, const unsigned char *input, const unsigned inlen); void fz_md5final(fz_md5 *state, unsigned char digest[16]); +/* sha-256 digests */ + +typedef struct fz_sha256_s fz_sha256; + +struct fz_sha256_s +{ + unsigned int state[8]; + unsigned int count[2]; + union { + unsigned char u8[64]; + unsigned int u32[16]; + } buffer; +}; + +void fz_sha256init(fz_sha256 *state); +void fz_sha256update(fz_sha256 *state, const unsigned char *input, unsigned int inlen); +void fz_sha256final(fz_sha256 *state, unsigned char digest[32]); + /* arc4 crypto */ typedef struct fz_arc4_s fz_arc4; |