/*#*
*#* $Log$
+ *#* 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.
*#*
*#*
*#*/
+#include "md2.h"
+
+#include <string.h> //memset(), memcpy();
+#include <cfg/compiler.h>
+#include <cfg/debug.h> //ASSERT()
+#include <cfg/macros.h> //MIN(), countof();
+#include <mware/pgm.h>
+
+
/*
- * Array of 256 byte pemutation contructed from digits of pi.
+ * Official array of 256 byte pemutation contructed from digits of pi, defined
+ * in the RFC 1319.
*/
-static uint8_t md2_perm[256] = {
+static const uint8_t PROGMEM 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,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
-static void md2_pad(void *block)
+#if CPU_HARVARD
+ #define MD2_PERM(x) pgm_read_char(&md2_perm[x]) //Read from program memory, if CPU is harvard
+#else
+ #define MD2_PERM(x) md2_perm[x] //Normaly from a const array.
+#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)
+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)
{
- context->counter=0;
- memset(context->state, 0, sizeof(context->state));
- memset(context->checksum, 0, sizeof(context->checksum));
+
+ memset(context, 0, sizeof(Md2Context));
}
-void md2_update(Md2Context *context, void *block_in, size_t block_len)
+/**
+ * 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.
+ *
+ */
+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(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