/*#*
*#* $Log$
+ *#* 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.
*#*
#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)
{
uint8_t *block;
-
+
block = (uint8_t *)_block;
- 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;
- }
- }
+ 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 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, 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(int i = 0; i < NUM_COMPUTE_ROUNDS; i++)
+ 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.
+ * Update checksum.
*/
t = checksum[CONFIG_MD2_BLOCK_LEN - 1];
- for(int 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 block.
*/
void md2_update(Md2Context *context, void *_block_in, size_t block_len)
-{
-
+{
+
uint8_t *block_in;
- size_t len = CONFIG_MD2_BLOCK_LEN;
- size_t i = 0;
-
+
+ /*
+ * 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)
{
- len -= context->counter; //Free space of buffer.
+ /*
+ * 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 (block_len > len)
+ /*
+ * If buffer is full, compute it.
+ */
+ if (context->counter >= CONFIG_MD2_BLOCK_LEN)
{
- /*
- * Fill or copy into buffer a input block length CONFIG_MD2_BLOCK_LEN and compute it.
- */
- memcpy(&context->buffer[context->counter], &block_in[i],len);
- md2_compute(context->state,context->checksum, context->buffer);
+ md2_compute(context->state, context->checksum, context->buffer);
context->counter = 0;
- block_len -= len;
}
- else
- {
- /*
- * Copy into buffer remaning input block.
- */
- memcpy(&context->buffer[context->counter], &block_in[i], block_len);
- context->counter += len;
- break;
-
-
- }
- i = len;
- len = CONFIG_MD2_BLOCK_LEN;
}
-
+
}
/**
* Ends MD2 message digest operation, writing the message digest and cleaning context.
*/
void md2_end(Md2Context *context, void *msg_digest)
{
+ uint8_t buf[CONFIG_MD2_BLOCK_LEN];
+
/*
* Pad remaning context buffer.
*/
- md2_pad(context->buffer, CONFIG_MD2_BLOCK_LEN - context->counter);
+ md2_pad(buf, CONFIG_MD2_BLOCK_LEN - context->counter);
/*
* Update context and checksum.
*/
- md2_update(context, context->buffer, CONFIG_MD2_BLOCK_LEN);
-
- md2_update(context, context->checksum, CONFIG_MD2_BLOCK_LEN);
+ md2_update(context, buf, CONFIG_MD2_BLOCK_LEN - context->counter);
+
+ memcpy(buf, context->checksum, CONFIG_MD2_BLOCK_LEN);
+
+ md2_update(context, buf, CONFIG_MD2_BLOCK_LEN);
/*
* Copy first CONFIG_MD2_BLOCK_LEN byte of context's state
* MD2 algorithm.
*/
memcpy(msg_digest, context->state, CONFIG_MD2_BLOCK_LEN);
-
+
/*
* Clean the context.
*/
memset(context, 0, sizeof(context));
-
+
}
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