static mrb_value mrb_des_decrypt(mrb_state *mrb, mrb_value self) {
mrb_value mode, key, source, dest, iv;
unsigned char output[100];
des_context ctx;
mrb_int len=8;
memset(output, 0, sizeof(output));
mrb_get_args(mrb, "SSSS", &mode, &key, &source, &iv);
des_init(&ctx);
des_setkey_dec(&ctx, RSTRING_PTR(key));
if (mrb_str_cmp(mrb, mode, mrb_str_new(mrb, "CBC", 3)) == 0) {
des_crypt_cbc(&ctx, DES_DECRYPT, RSTRING_LEN(source), RSTRING_PTR(iv),
RSTRING_PTR(source), output);
len = RSTRING_LEN(source);
} else if (mrb_str_cmp(mrb, mode, mrb_str_new(mrb, "ECB", 3)) == 0) {
des_crypt_ecb(&ctx, RSTRING_PTR(source), output);
} else {
des_free(&ctx);
return mrb_nil_value();
}
des_free(&ctx);
return mrb_str_new(mrb, output, len);
}
void eid2_decrypt_block(u8 *block, u32 length)
{
u8 tmp[0x08], iv[0x08];
int block_size = 8;
int num_blocks = (int)(length / block_size);
memcpy(iv, eid2_des_iv, 0x08);
if(num_blocks > 0)
{
int i, j;
des_context ctx;
des_setkey_dec(&ctx, eid2_des_key);
for(i = 0; i < num_blocks - 1; ++i)
{
u8 *ptr = block + i * block_size;
memcpy(tmp, ptr, block_size);
des_crypt_ecb(&ctx, ptr, ptr);
if(i > 0)
{
for(j = 0; j < block_size; ++j)
ptr[j] = ptr[j] ^ iv[j];
}
memcpy(iv, tmp, block_size);
}
}
}
void
cipher_des_encrypt_ecb (const unsigned char key[DES_KEY_LENGTH],
unsigned char *src,
unsigned char *dst)
{
des_context ctx;
des_setkey_enc(&ctx, key);
des_crypt_ecb(&ctx, src, dst);
}
void
cipher_des_encrypt_ecb (const unsigned char key[DES_KEY_LENGTH],
unsigned char *src,
unsigned char *dst)
{
des_context ctx;
ASSERT (polar_ok(des_setkey_enc(&ctx, key)));
ASSERT (polar_ok(des_crypt_ecb(&ctx, src, dst)));
}
void test_suite_des_decrypt_ecb( char *hex_key_string, char *hex_src_string, char *hex_dst_string ) {
unsigned char key_str[100];
unsigned char src_str[100];
unsigned char dst_str[100];
des_context ctx;
memset(key_str, 0x00, 100);
memset(src_str, 0x00, 100);
memset(dst_str, 0x00, 100);
memcpy(key_str, hex_key_string, strlen(hex_key_string) + 1);
memcpy(src_str, hex_src_string, strlen(hex_src_string) + 1);
des_setkey_dec( &ctx, key_str);
TEST_ASSERT( des_crypt_ecb( &ctx, src_str, dst_str ) == 0 );
memcpy(hex_dst_string, dst_str, strlen(dst_str) + 1);
}
static int des_crypt_ecb_wrap( void *ctx, operation_t operation,
const unsigned char *input, unsigned char *output )
{
((void) operation);
return des_crypt_ecb( (des_context *) ctx, input, output );
}
