X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=algos%2Fmd2.c;h=edd9fa8c2a54df0ce4652544302f1276a9e7ac0e;hb=43cc9dde2073972fc586ee95d2de5797d654f6cb;hp=2179bb6c6098bb3fc9b01af102163739b7726b4e;hpb=8a9e503866fea71f11ba1d061338f410fd73b7f5;p=bertos.git diff --git a/algos/md2.c b/algos/md2.c index 2179bb6c..edd9fa8c 100755 --- a/algos/md2.c +++ b/algos/md2.c @@ -7,27 +7,340 @@ * * \brief MD2 Message-Digest algorithm. * + * The MD2 algorithm work with a constant array of 256 permutationt + * defined in RFC1319. If you don't want to use a standard array of + * permutatione you can use a md2_perm() function that generate an + * array of 256 "casual" permutation. To swich from a standard array + * to md2_perm function you must chanche CONFIG_MD2_STD_PERM defined in + * appconfig.h. + * If you need to store array in program memory you must define + * a macro _PROGMEM (for more info see mware/pgm.h). + * + * * \version $Id$ * \author Daniele Basile */ /*#* *#* $Log$ + *#* Revision 1.15 2007/02/06 15:53:34 asterix + *#* Add ROTR macro in m2d_perm, add comments, typos. + *#* + *#* Revision 1.13 2007/02/05 18:44:42 asterix + *#* Add md2_perm function. + *#* + *#* Revision 1.12 2007/02/05 16:52:44 asterix + *#* Add define for harvard architecture. + *#* + *#* Revision 1.11 2007/02/02 18:15:31 asterix + *#* Add function MD2_test. Fix bug in md2_update function. + *#* + *#* Revision 1.9 2007/02/02 13:10:01 asterix + *#* Fix some bugs in md2_pad and md2_update fuction. + *#* + *#* Revision 1.8 2007/02/01 14:45:56 asterix + *#* Rewrite md2_update function and fix some bug. + *#* + *#* Revision 1.7 2007/01/31 18:04:15 asterix + *#* Write md2_end function + *#* + *#* Revision 1.4 2007/01/31 13:51:57 asterix + *#* Write md2_compute function. + *#* + *#* Revision 1.2 2007/01/30 17:31:44 asterix + *#* Add function prototypes. + *#* *#* Revision 1.1 2007/01/30 15:53:26 batt *#* Add first md2 skel. *#* *#*/ +#include "md2.h" + +#include //memset(), memcpy(); +#include +#include //ASSERT() +#include //MIN(), countof(), ROTR(); +#include + + +#if CONFIG_MD2_STD_PERM + /* + * Official array of 256 byte pemutation contructed from digits of pi, defined + * in the RFC 1319. + */ + static const uint8_t PGM_ATTR md2_perm[256] = + { + 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, + 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, + 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, + 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, + 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, + 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, + 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, + 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, + 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157, + 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27, + 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15, + 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197, + 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65, + 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123, + 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233, + 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228, + 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237, + 31, 26, 219, 153, 141, 51, 159, 17, 131, 20 + }; + + #define MD2_PERM(x) PGM_READ_CHAR(&md2_perm[x]) +#else + /** + * Md2_perm() function generate an array of 256 "casual" permutation. + */ + + /** + * Costant define for computing an array of 256 "casual" permutation. + * \{ + */ + #define K1 5 + #define K2 3 + #define R 2 + #define X 172 + /*\}*/ + + static uint8_t md2_perm(uint8_t i) + { + + i = i * K1; + i = ROTR(i, R); + i ^= X; + i = i * K2; + + return i; + } + + #define MD2_PERM(x) md2_perm(x) + +#endif + + +/** + * Pad function. Put len_pad unsigned char in + * input block. + */ +static void md2_pad(void *_block, size_t len_pad) +{ + uint8_t *block; + + block = (uint8_t *)_block; + + ASSERT(len_pad <= CONFIG_MD2_BLOCK_LEN); + + /* + * Fill input block with len_pad char. + */ + memset(block, len_pad, len_pad); + +} + +static void md2_compute(void *_state, void *_checksum, void *_block) +{ + int i = 0; + uint16_t t = 0; + uint8_t compute_array[COMPUTE_ARRAY_LEN]; + uint8_t *state; + uint8_t *checksum; + uint8_t *block; + + state = (uint8_t *)_state; + checksum = (uint8_t *)_checksum; + block = (uint8_t *)_block; + + /* + * Copy state and checksum context in compute array. + */ + memcpy(compute_array, state, CONFIG_MD2_BLOCK_LEN); + memcpy(compute_array + CONFIG_MD2_BLOCK_LEN, block, CONFIG_MD2_BLOCK_LEN); + + /* + * Fill compute array with state XOR block + */ + for(i = 0; i < CONFIG_MD2_BLOCK_LEN; i++) + compute_array[i + (CONFIG_MD2_BLOCK_LEN * 2)] = state[i] ^ block[i]; + + /* + * Encryt block. + */ + for(i = 0; i < NUM_COMPUTE_ROUNDS; i++) + { + for(int j = 0; j < COMPUTE_ARRAY_LEN; j++) + { + compute_array[j] ^= MD2_PERM(t); + t = compute_array[j]; + } + + t = (t + i) & 0xff; //modulo 256. + } + /* + * Update checksum. + */ + t = checksum[CONFIG_MD2_BLOCK_LEN - 1]; + + for(i = 0; i < CONFIG_MD2_BLOCK_LEN; i++) + { + checksum[i] ^= MD2_PERM(block[i] ^ t); + t = checksum[i]; + } + + /* + * Update state and clean compute array. + */ + memcpy(state, compute_array, CONFIG_MD2_BLOCK_LEN); + memset(compute_array, 0, sizeof(compute_array)); +} + +/** + * Algorithm initialization. + * + * \param empty context. + */ +void md2_init(Md2Context *context) +{ + + memset(context, 0, sizeof(Md2Context)); -void md2_init() +} + +/** + * Update block. + */ +void md2_update(Md2Context *context, const void *_block_in, size_t block_len) { + + const uint8_t *block_in; + size_t cpy_len; + + + block_in = (const uint8_t *)_block_in; + + while(block_len > 0) + { + /* + * Choose a number of block that fill input context buffer. + */ + cpy_len = MIN(block_len, CONFIG_MD2_BLOCK_LEN - context->counter); + + + /* + * Copy in the buffer input block. + */ + memcpy(&context->buffer[context->counter], block_in, cpy_len); + + /* + * Update a context counter, input block length and remaning + * context buffer block lenght. + */ + context->counter += cpy_len; + block_len -= cpy_len; + block_in += cpy_len; + + /* + * If buffer is full, compute it. + */ + if (context->counter >= CONFIG_MD2_BLOCK_LEN) + { + md2_compute(context->state, context->checksum, context->buffer); + context->counter = 0; + } + } + + } +/** + * Ends an MD2 message digest operation. + * This fuction take an context and return a pointer + * to context state. + * + * \param context in input. + * \return a pointer to context state (message digest). + */ +uint8_t *md2_end(Md2Context *context) +{ + + uint8_t buf[CONFIG_MD2_BLOCK_LEN]; -void md2_update() + /* + * Fill remaning empty context buffer. + */ + md2_pad(buf, CONFIG_MD2_BLOCK_LEN - context->counter); + + /* + * Update context buffer and compute it. + */ + md2_update(context, buf, CONFIG_MD2_BLOCK_LEN - context->counter); + + /* + * Add context checksum to message input. + */ + md2_update(context, context->checksum, CONFIG_MD2_BLOCK_LEN); + + + return context->state; //return a pointer to message digest. +} +/** + * MD2 test fuction. + * This function test MD2 algorithm with a standard string specified + * in RFC 1319. + * + * \note This test work with official array of 256 byte pemutation + * contructed from digits of pi, defined in the RFC 1319. + * + */ +bool md2_test(void) { + + Md2Context context; + + const char *test[] = + { + "", + "message digest", + "abcdefghijklmnopqrstuvwxyz", + "12345678901234567890123456789012345678901234567890123456789012345678901234567890" + }; + + + const uint8_t *result[] = { + "\x83\x50\xe5\xa3\xe2\x4c\x15\x3d\xf2\x27\x5c\x9f\x80\x69\x27\x73", + "\xab\x4f\x49\x6b\xfb\x2a\x53\x0b\x21\x9f\xf3\x30\x31\xfe\x06\xb0", + "\x4e\x8d\xdf\xf3\x65\x02\x92\xab\x5a\x41\x08\xc3\xaa\x47\x94\x0b", + "\xd5\x97\x6f\x79\xd8\x3d\x3a\x0d\xc9\x80\x6c\x3c\x66\xf3\xef\xd8", + }; + + + for (int i = 0; i < countof(test); i++) + { + md2_init(&context); + md2_update(&context, test[i], strlen(test[i])); + + if(memcmp(result[i], md2_end(&context), CONFIG_MD2_BLOCK_LEN)) + return false; + } + + return true; } -void md2_end() +#if 0 + +#include +int main(int argc, char * argv[]) { + + if(md2_test()) + printf("MD2 algorithm work well!\n"); + else + printf("MD2 algorithm doesn't work well.\n"); + } +#endif +