static void scam_decrypt_packet(uint8_t *packet, uint32_t packetLength, uint8_t *key, uint32_t dataLength, uint32_t dataOffset, uint8_t *xorOffset)
{
uint8_t tmpKey[8], iv[8];
uint32_t i;
memcpy(tmpKey, key, 8);
memset(iv, 0, 8);
for(i=0; i<packetLength; i++) {
tmpKey[*xorOffset] ^= packet[i];
*xorOffset = (*xorOffset + 1) & 7;
}
des_cbc_decrypt(packet + dataOffset, iv, key, dataLength);
memcpy(key, tmpKey, 8);
}
bool Des::Decrypt(const char *szInput, char *szOutput)
{
int i = 0;
int inlen = strlen(szInput);
int datalen = 0;
if(inlen <= 8 || inlen > 512)
return false;
i = 0;
char src[MAX_LEN] = {0};
while(i < inlen)
{
int len = 0;
int hi = map_index(szInput[i], len);
i += len;
int lo = map_index(szInput[i], len);
i += len;
if(hi == 99 || lo == 99)
return false;
src[datalen++] = hi * 0x10 + lo;
}
des_key_setup(GET_32BIT_MSB_FIRST(key8),
GET_32BIT_MSB_FIRST(key8 + 4), &crkey);
unsigned char dest[256] = {0};
des_cbc_decrypt(dest, (unsigned char *)src, datalen, &crkey);
sprintf(szOutput, "%s", dest);
//memset(key, 0, 8);
//memset(map, 0, 256);
return true;
}
void cipher_decrypt(CipherContext * context, unsigned char *dest, const unsigned char *src, unsigned int len)
{
switch (context->type) {
case SSH_CIPHER_NONE:
memcpy(dest, src, len);
break;
#ifdef WITH_IDEA
case SSH_CIPHER_IDEA:
idea_cfb_decrypt(&context->u.idea.key, context->u.idea.iv, dest, src, len);
break;
#endif /* WITH_IDEA */
#ifdef WITH_DES
case SSH_CIPHER_DES:
des_cbc_decrypt(&context->u.des.key, context->u.des.iv, dest, src, len);
break;
#endif /* WITH_DES */
case SSH_CIPHER_3DES:
des_3cbc_decrypt(&context->u.des3.key1, context->u.des3.iv1, &context->u.des3.key2, context->u.des3.iv2, &context->u.des3.key3, context->u.des3.iv3, dest, src, len);
break;
#ifdef WITH_ARCFOUR
case SSH_CIPHER_ARCFOUR:
arcfour_decrypt(&context->u.arcfour, dest, src, len);
break;
#endif /* WITH_ARCFOUR */
#ifdef WITH_BLOWFISH
case SSH_CIPHER_BLOWFISH:
blowfish_cbc_decrypt(&context->u.blowfish, dest, src, len);
break;
#endif /* WITH_BLOWFISH */
default:
fatal("cipher_decrypt: unknown cipher: %d", context->type);
}
}
static void des_decrypt_blk(unsigned char *blk, int len) {
des_cbc_decrypt(blk, blk, len, cskeys);
}
static void des_3cbc_decrypt(unsigned char *dest, const unsigned char *src,
unsigned int len, DESContext *scheds) {
des_cbc_decrypt(dest, src, len, &scheds[2]);
des_cbc_encrypt(dest, src, len, &scheds[1]);
des_cbc_decrypt(dest, src, len, &scheds[0]);
}
//! \brief Main example doing DES encryption/decryption.
int main( void )
{
uint8_t i;
board_init();
sleepmgr_init();
bool success = true;
/* Example of how to use Single DES encryption and decryption functions. */
des_encrypt(data, single_ans, keys);
des_decrypt(single_ans, single_ans, keys);
/* Check if decrypted answer is equal to plaintext. */
for (i = 0; i < DES_BLOCK_LENGTH ; i++ ){
if (data[i] != single_ans[i]){
success = false;
break;
}
}
if (success){
/* Example of how to use 3DES encryption and decryption functions. */
des_3des_encrypt(data, single_ans, keys);
des_3des_decrypt(single_ans, single_ans, keys);
/* Check if decrypted answer is equal to plaintext. */
for (i = 0; i < DES_BLOCK_LENGTH ; i++ ){
if (data[i] != single_ans[i]){
success = false;
break;
}
}
}
if (success){
/* Example of how to use DES Cipher Block Chaining encryption and
* decryption functions.
*/
des_cbc_encrypt(data_block, cipher_block_ans, keys, init, true, DES_BLOCK_COUNT);
des_cbc_decrypt(cipher_block_ans, block_ans, keys, init, true, DES_BLOCK_COUNT);
/* Check if decrypted answer is equal to plaintext. */
for (i = 1; i < (DES_BLOCK_LENGTH * DES_BLOCK_COUNT); i++ ){
if (data_block[i] != block_ans[i]){
success = false;
break;
}
}
}
/* Indicate final result by lighting LED. */
if (success) {
/* If the example ends up here every thing is ok. */
ioport_set_pin_low(LED0_GPIO);
} else {
/* If the example ends up here something is wrong. */
ioport_set_pin_low(LED1_GPIO);
}
while (true) {
/* Go to sleep. */
sleepmgr_enter_sleep();
}
}
