76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include "sm4_core.h"
|
||
|
|
|
||
|
|
struct ctr_state {
|
||
|
|
unsigned char ivec[SM4_BLOCK_SIZE];
|
||
|
|
unsigned char ecount[SM4_BLOCK_SIZE];
|
||
|
|
unsigned int num;
|
||
|
|
};
|
||
|
|
|
||
|
|
static void rk_init_ctr(struct ctr_state * state, const unsigned char *iv)
|
||
|
|
{
|
||
|
|
state->num = 0;
|
||
|
|
memset(state->ecount, 0, SM4_BLOCK_SIZE);
|
||
|
|
memcpy(state->ivec, iv, SM4_BLOCK_SIZE);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* increment counter (128-bit int) by 1 */
|
||
|
|
static void rk_ctr128_inc(unsigned char *counter) {
|
||
|
|
unsigned int n=SM4_BLOCK_SIZE;
|
||
|
|
unsigned char c;
|
||
|
|
|
||
|
|
do {
|
||
|
|
--n;
|
||
|
|
c = counter[n];
|
||
|
|
++c;
|
||
|
|
counter[n] = c;
|
||
|
|
if (c) return;
|
||
|
|
} while (n);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void rk_crypto_ctr128_encrypt(void *ctx, const unsigned char *in, unsigned char *out,
|
||
|
|
unsigned int len, unsigned char *ivec, unsigned char *ecount_buf,
|
||
|
|
unsigned int *num, block128_f block)
|
||
|
|
{
|
||
|
|
unsigned int n, l=0;
|
||
|
|
|
||
|
|
n = *num;
|
||
|
|
while (l<len) {
|
||
|
|
if (n==0) {
|
||
|
|
(*block)(ivec, ecount_buf, ctx);
|
||
|
|
rk_ctr128_inc(ivec);
|
||
|
|
}
|
||
|
|
out[l] = in[l] ^ ecount_buf[n];
|
||
|
|
++l;
|
||
|
|
n = (n+1) % SM4_BLOCK_SIZE;
|
||
|
|
}
|
||
|
|
|
||
|
|
*num = n;
|
||
|
|
}
|
||
|
|
|
||
|
|
int rk_sm4_ctr_encrypt(const unsigned char *in, unsigned char *out,
|
||
|
|
unsigned int length, const unsigned char *key, const int key_len,
|
||
|
|
unsigned char *ivec, const int enc)
|
||
|
|
{
|
||
|
|
sm4_context ctx;
|
||
|
|
struct ctr_state state;
|
||
|
|
|
||
|
|
if(key_len != 16)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if(length == 0)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
rk_init_ctr(&state, ivec);
|
||
|
|
rk_sm4_setkey_enc(&ctx, key);
|
||
|
|
rk_crypto_ctr128_encrypt((void*)(&ctx),in, out, length,
|
||
|
|
state.ivec, state.ecount,
|
||
|
|
&state.num, rk_rk_sm4_crypt_ecb);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
|