C++ (Cpp) gcm_ghash_add Examples

Example #1

File: aes.c Project: TomMD/cipher-aes128

void tmd_aes_generic_gcm_decrypt(uint8_t *output, const aes_gcm *gcm, const aes_ctx *ctx, const aes_key *key, const uint8_t *input, uint32_t length, aes_ctx *newCTX)
{
    aes_block out;

    memcpy(newCTX, ctx, sizeof(aes_ctx));
    newCTX->length_input += length;
    for (; length >= 16; input += 16, output += 16, length -= 16) {
        block128_inc_be(&newCTX->civ);

        aes_encrypt_block(&out, key, &newCTX->civ);
        gcm_ghash_add(gcm, newCTX, (block128 *) input);
        block128_xor(&out, (block128 *) input);
        block128_copy((block128 *) output, &out);
    }
    if (length > 0) {
        aes_block tmp;
        int i;

        block128_inc_be(&newCTX->civ);

        block128_zero(&tmp);
        block128_copy_bytes(&tmp, input, length);
        gcm_ghash_add(gcm, newCTX, &tmp);

        aes_encrypt_block(&out, key, &newCTX->civ);
        block128_xor_bytes(&tmp, out.b, length);

        for (i = 0; i < length; i++) {
            output[i] = tmp.b[i];
        }
    }
}

Example #2

File: aes.c Project: cjwatson/hs-cipher-aes

void aes_gcm_decrypt(uint8_t *output, aes_gcm *gcm, uint8_t *input, uint32_t length)
{
	aes_block out;

	gcm->length_input += length;
	for (; length >= 16; input += 16, output += 16, length -= 16) {
		block128_inc_be(&gcm->civ);

		aes_encrypt_block(&out, &gcm->key, &gcm->civ);
		gcm_ghash_add(gcm, (block128 *) input);
		block128_xor(&out, (block128 *) input);
		block128_copy((block128 *) output, &out);
	}
	if (length > 0) {
		aes_block tmp;
		int i;

		block128_inc_be(&gcm->civ);

		block128_zero(&tmp);
		block128_copy_bytes(&tmp, input, length);
		gcm_ghash_add(gcm, &tmp);

		aes_encrypt_block(&out, &gcm->key, &gcm->civ);
		block128_xor_bytes(&tmp, out.b, length); 

		for (i = 0; i < length; i++) {
			output[i] = tmp.b[i];
		}
	}
}

Example #3

File: aes.c Project: TomMD/cipher-aes128

void tmd_aes_gcm_aad(const aes_gcm *gcm, aes_ctx *ctx, const uint8_t *input, uint32_t length)
{
    ctx->length_aad += length;
    for (; length >= 16; input += 16, length -= 16) {
        gcm_ghash_add(gcm, ctx, (block128 *) input);
    }
    if (length > 0) {
        aes_block tmp;
        block128_zero(&tmp);
        block128_copy_bytes(&tmp, input, length);
        gcm_ghash_add(gcm, ctx, &tmp);
    }

}

Example #4

File: aes.c Project: cjwatson/hs-cipher-aes

void aes_gcm_aad(aes_gcm *gcm, uint8_t *input, uint32_t length)
{
	gcm->length_aad += length;
	for (; length >= 16; input += 16, length -= 16) {
		gcm_ghash_add(gcm, (block128 *) input);
	}
	if (length > 0) {
		aes_block tmp;
		block128_zero(&tmp);
		block128_copy_bytes(&tmp, input, length);
		gcm_ghash_add(gcm, &tmp);
	}

}

Example #5

File: aes.c Project: TomMD/cipher-aes128

void tmd_aes_gcm_finish(uint8_t *tag, const aes_gcm *gcm, const aes_key *key, aes_ctx *ctx)
{
    aes_block lblock;
    int i;

    /* tag = (tag-1 xor (lenbits(a) | lenbits(c)) ) . H */
    lblock.q[0] = cpu_to_be64(ctx->length_aad << 3);
    lblock.q[1] = cpu_to_be64(ctx->length_input << 3);
    gcm_ghash_add(gcm, ctx, &lblock);

    aes_encrypt_block(&lblock, key, &ctx->iv);
    block128_xor(&ctx->tag, &lblock);

    for (i = 0; i < 16; i++) {
        tag[i] = ctx->tag.b[i];
    }
}

Example #6

File: aes.c Project: cjwatson/hs-cipher-aes

void aes_gcm_finish(uint8_t *tag, aes_gcm *gcm)
{
	aes_block lblock;
	int i;

	/* tag = (tag-1 xor (lenbits(a) | lenbits(c)) ) . H */
	lblock.q[0] = cpu_to_be64(gcm->length_aad << 3);
	lblock.q[1] = cpu_to_be64(gcm->length_input << 3);
	gcm_ghash_add(gcm, &lblock);

	aes_encrypt_block(&lblock, &gcm->key, &gcm->iv);
	block128_xor(&gcm->tag, &lblock);

	for (i = 0; i < 16; i++) {
		tag[i] = gcm->tag.b[i];
	}
}