C++ (Cpp) ctr_XOR Examples

Example #1

File: fips_drbg_ctr.c Project: leloulight/eme

static void ctr_Update(DRBG_CTX *dctx,
		const unsigned char *in1, size_t in1len,
		const unsigned char *in2, size_t in2len,
		const unsigned char *nonce, size_t noncelen)
	{
	DRBG_CTR_CTX *cctx = &dctx->d.ctr;
	/* ks is already setup for correct key */
	inc_128(cctx);
	AES_encrypt(cctx->V, cctx->K, &cctx->ks);
	/* If keylen longer than 128 bits need extra encrypt */
	if (cctx->keylen != 16)
		{
		inc_128(cctx);
		AES_encrypt(cctx->V, cctx->K + 16, &cctx->ks);
		}
	inc_128(cctx);
	AES_encrypt(cctx->V, cctx->V, &cctx->ks);
	/* If 192 bit key part of V is on end of K */
	if (cctx->keylen == 24)
		{
		memcpy(cctx->V + 8, cctx->V, 8);
		memcpy(cctx->V, cctx->K + 24, 8);
		}

	if (dctx->flags & DRBG_FLAG_CTR_USE_DF)
		{
		/* If no input reuse existing derived value */
		if (in1 || nonce || in2)
			ctr_df(cctx, in1, in1len, nonce, noncelen, in2, in2len);
		/* If this a reuse input in1len != 0 */
		if (in1len)
			ctr_XOR(cctx, cctx->KX, dctx->seedlen);
		}
	else
		{
		ctr_XOR(cctx, in1, in1len);
		ctr_XOR(cctx, in2, in2len);
		}

	AES_set_encrypt_key(cctx->K, dctx->strength, &cctx->ks);
#if 0
fprintf(stderr, "K+V after update is:\n");
BIO_dump_fp(stderr, cctx->K, cctx->keylen);
BIO_dump_fp(stderr, cctx->V, 16);
#endif
	}

Example #2

File: drbg_rand.c Project: Bilibili/openssl

/*
 * NB the no-df Update in SP800-90A specifies a constant input length
 * of seedlen, however other uses of this algorithm pad the input with
 * zeroes if necessary and have up to two parameters XORed together,
 * so we handle both cases in this function instead.
 */
static void ctr_update(RAND_DRBG *drbg,
                       const unsigned char *in1, size_t in1len,
                       const unsigned char *in2, size_t in2len,
                       const unsigned char *nonce, size_t noncelen)
{
    RAND_DRBG_CTR *ctr = &drbg->ctr;

    /* ks is already setup for correct key */
    inc_128(ctr);
    AES_encrypt(ctr->V, ctr->K, &ctr->ks);

    /* If keylen longer than 128 bits need extra encrypt */
    if (ctr->keylen != 16) {
        inc_128(ctr);
        AES_encrypt(ctr->V, ctr->K + 16, &ctr->ks);
    }
    inc_128(ctr);
    AES_encrypt(ctr->V, ctr->V, &ctr->ks);

    /* If 192 bit key part of V is on end of K */
    if (ctr->keylen == 24) {
        memcpy(ctr->V + 8, ctr->V, 8);
        memcpy(ctr->V, ctr->K + 24, 8);
    }

    if (drbg->flags & RAND_DRBG_FLAG_CTR_USE_DF) {
        /* If no input reuse existing derived value */
        if (in1 != NULL || nonce != NULL || in2 != NULL)
            ctr_df(ctr, in1, in1len, nonce, noncelen, in2, in2len);
        /* If this a reuse input in1len != 0 */
        if (in1len)
            ctr_XOR(ctr, ctr->KX, drbg->seedlen);
    } else {
        ctr_XOR(ctr, in1, in1len);
        ctr_XOR(ctr, in2, in2len);
    }

    AES_set_encrypt_key(ctr->K, drbg->strength, &ctr->ks);
}