/*#*
*#* $Log$
+ *#* Revision 1.10 2007/02/02 15:37:45 asterix
+ *#* Change md2_end prototype. Remove a unneeded memcpy in md2_end. Add comments.
+ *#*
+ *#* 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()
+
/*
* Official array of 256 byte pemutation contructed from digits of pi, defined
* in the RFC 1319.
*/
-static uint8_t md2_perm[256] =
-{
+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,
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];
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];
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));
*/
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, void *block_in, size_t block_len)
+void md2_update(Md2Context *context, void *_block_in, size_t block_len)
{
-}
+ uint8_t *block_in;
+
+ /*
+ * Choose a number of block that fill input context buffer.
+ */
+ size_t missing_len = MIN(block_len, CONFIG_MD2_BLOCK_LEN - context->counter);
+
+ block_in = (uint8_t *)_block_in;
+
+ while(block_len > 0)
+ {
+ /*
+ * Copy in the buffer input block.
+ */
+ memcpy(&context->buffer[context->counter], block_in, missing_len);
+
+ /*
+ * Update a context counter, input block length and remaning
+ * context buffer block lenght.
+ */
+ context->counter += missing_len;
+ block_len -= missing_len;
+ block_in += missing_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).
*/
-void md2_end(Md2Context *context, void *msg_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.
}
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