*
* \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 <asterix@develer.com>
*/
/*#*
*#* $Log$
+ *#* Revision 1.17 2007/06/07 16:06:39 batt
+ *#* Fix some doxygen errors.
+ *#*
+ *#* Revision 1.16 2007/02/15 13:29:49 asterix
+ *#* Add MD2_DIGEST_LEN macro.
+ *#*
+ *#* 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.
*#*
#include "md2.h"
-#include <string.h> //memset();
+#include <string.h> //memset(), memcpy();
#include <cfg/compiler.h>
+#include <cfg/debug.h> //ASSERT()
+#include <cfg/macros.h> //MIN(), countof(), ROTR();
+#include <mware/pgm.h>
+
+
+#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
+
-/*
- * Official array of 256 byte pemutation contructed from digits of pi, defined
- * in the RFC 1319.
- */
-static uint8_t 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
-};
/**
- * Pad function. Fill input array with unsigned char until
- * lenght of block is equal to CONFIG_MD2_BLOCK_LEN.
- *
+ * Pad function. Put len_pad unsigned char in
+ * input block.
*/
-static void md2_pad(void *block, size_t len_pad)
+static void md2_pad(void *_block, size_t len_pad)
{
- if (len_pad <= CONFIG_MD2_BLOCK_LEN)
- {
- for(int i=(CONFIG_MD2_BLOCK_LEN-len_pad);i<len_pad; i++)
- {
- block[i]=(uint8_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)
+static void md2_compute(void *_state, void *_checksum, void *_block)
{
- int t=0;
- uint8_t compute_array[CONFIG_MD2_BLOCK_LEN * 3];
-
+ 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.
- */
+ * Copy state and checksum context in compute array.
+ */
memcpy(compute_array, state, CONFIG_MD2_BLOCK_LEN);
- memcpy(compute_array + CONFIG_MD2_BLOCK_LEN, 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(int i=0; i< CONFIG_MD2_BLOCK_LEN; i++)
+ * 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(i = 0; i < NUM_COMPUTE_ROUNDS; i++)
{
- for(int j=0; j<COMPUTE_ARRAY_LEN; j++)
+ for(int j = 0; j < COMPUTE_ARRAY_LEN; j++)
{
- compute_array[j] ^= md2_perm [t];
+ compute_array[j] ^= MD2_PERM(t);
t = compute_array[j];
}
-
+
t = (t + i) & 0xff; //modulo 256.
}
/*
- * Update checksum.
+ * Update checksum.
*/
t = checksum[CONFIG_MD2_BLOCK_LEN - 1];
- for(i=0; i< CONFIG_MD2_BLOCK_LEN; i++)
+ for(i = 0; i < CONFIG_MD2_BLOCK_LEN; i++)
{
- checksum[i] ^= md2_perm [block[i] ^ t];
+ checksum[i] ^= MD2_PERM(block[i] ^ t);
t = checksum[i];
}
-
+
/*
- * Update state and clean compute array.
+ * 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.
+ * \param context empty context.
*/
void md2_init(Md2Context *context)
{
- context->counter=0;
- memset(context->state, 0, sizeof(context->state));
- memset(context->checksum, 0, sizeof(context->checksum));
+
+ memset(context, 0, sizeof(Md2Context));
}
+
/**
- * Update bock.
+ * 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];
+
+ /*
+ * 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.
*
*/
-void md2_update(Md2Context *context, void *block_in, size_t block_len)
+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), MD2_DIGEST_LEN))
+ return false;
+ }
+
+ return true;
}
-/**
- *
- */
-void md2_end(Md2Context *context, void *msg_digest)
+#if 0
+
+#include <stdio.h>
+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
+
projects / bertos.git / blobdiff