Commit f2bb770a authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: testmgr - add helpers for fuzzing against generic implementation 



Add some helper functions in preparation for fuzz testing algorithms
against their generic implementation.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 951d1332

crypto/testmgr.c

+128 −0
Original line number Diff line number Diff line
@@ -128,6 +128,7 @@ struct kpp_test_suite { 


struct alg_test_desc {

	const char *alg;

	const char *generic_driver;

	int (*test)(const struct alg_test_desc *desc, const char *driver,

		    u32 type, u32 mask);

	int fips_allowed;	/* set if alg is allowed in fips mode */
@@ -745,6 +746,91 @@ static int build_cipher_test_sglists(struct cipher_test_sglists *tsgls, 
}



#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS



/* Generate a random length in range [0, max_len], but prefer smaller values */

static unsigned int generate_random_length(unsigned int max_len)

{

	unsigned int len = prandom_u32() % (max_len + 1);



	switch (prandom_u32() % 4) {

	case 0:

		return len % 64;

	case 1:

		return len % 256;

	case 2:

		return len % 1024;

	default:

		return len;

	}

}



/* Sometimes make some random changes to the given data buffer */

static void mutate_buffer(u8 *buf, size_t count)

{

	size_t num_flips;

	size_t i;

	size_t pos;



	/* Sometimes flip some bits */

	if (prandom_u32() % 4 == 0) {

		num_flips = min_t(size_t, 1 << (prandom_u32() % 8), count * 8);

		for (i = 0; i < num_flips; i++) {

			pos = prandom_u32() % (count * 8);

			buf[pos / 8] ^= 1 << (pos % 8);

		}

	}



	/* Sometimes flip some bytes */

	if (prandom_u32() % 4 == 0) {

		num_flips = min_t(size_t, 1 << (prandom_u32() % 8), count);

		for (i = 0; i < num_flips; i++)

			buf[prandom_u32() % count] ^= 0xff;

	}

}



/* Randomly generate 'count' bytes, but sometimes make them "interesting" */

static void generate_random_bytes(u8 *buf, size_t count)

{

	u8 b;

	u8 increment;

	size_t i;



	if (count == 0)

		return;



	switch (prandom_u32() % 8) { /* Choose a generation strategy */

	case 0:

	case 1:

		/* All the same byte, plus optional mutations */

		switch (prandom_u32() % 4) {

		case 0:

			b = 0x00;

			break;

		case 1:

			b = 0xff;

			break;

		default:

			b = (u8)prandom_u32();

			break;

		}

		memset(buf, b, count);

		mutate_buffer(buf, count);

		break;

	case 2:

		/* Ascending or descending bytes, plus optional mutations */

		increment = (u8)prandom_u32();

		b = (u8)prandom_u32();

		for (i = 0; i < count; i++, b += increment)

			buf[i] = b;

		mutate_buffer(buf, count);

		break;

	default:

		/* Fully random bytes */

		for (i = 0; i < count; i++)

			buf[i] = (u8)prandom_u32();

	}

}



static char *generate_random_sgl_divisions(struct test_sg_division *divs,

					   size_t max_divs, char *p, char *end,

					   bool gen_flushes, u32 req_flags)
@@ -899,6 +985,48 @@ static void crypto_reenable_simd_for_test(void) 
	__this_cpu_write(crypto_simd_disabled_for_test, false);

	preempt_enable();

}



/*

 * Given an algorithm name, build the name of the generic implementation of that

 * algorithm, assuming the usual naming convention.  Specifically, this appends

 * "-generic" to every part of the name that is not a template name.  Examples:

 *

 *	aes => aes-generic

 *	cbc(aes) => cbc(aes-generic)

 *	cts(cbc(aes)) => cts(cbc(aes-generic))

 *	rfc7539(chacha20,poly1305) => rfc7539(chacha20-generic,poly1305-generic)

 *

 * Return: 0 on success, or -ENAMETOOLONG if the generic name would be too long

 */

static int build_generic_driver_name(const char *algname,

				     char driver_name[CRYPTO_MAX_ALG_NAME])

{

	const char *in = algname;

	char *out = driver_name;

	size_t len = strlen(algname);



	if (len >= CRYPTO_MAX_ALG_NAME)

		goto too_long;

	do {

		const char *in_saved = in;



		while (*in && *in != '(' && *in != ')' && *in != ',')

			*out++ = *in++;

		if (*in != '(' && in > in_saved) {

			len += 8;

			if (len >= CRYPTO_MAX_ALG_NAME)

				goto too_long;

			memcpy(out, "-generic", 8);

			out += 8;

		}

	} while ((*out++ = *in++) != '\0');

	return 0;



too_long:

	pr_err("alg: generic driver name for \"%s\" would be too long\n",

	       algname);

	return -ENAMETOOLONG;

}

#else /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */

static void crypto_disable_simd_for_test(void)

{