From d435e10e67be0a0df70502aee434cb62a9d65b10 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 11 Apr 2019 21:57:40 -0700 Subject: [PATCH] crypto: testmgr - fuzz skciphers against their generic implementation When the extra crypto self-tests are enabled, test each skcipher algorithm against its generic implementation when one is available. This involves: checking the algorithm properties for consistency, then randomly generating test vectors using the generic implementation and running them against the implementation under test. Both good and bad inputs are tested. This has already detected a bug in the skcipher_walk API, a bug in the LRW template, and an inconsistency in the cts implementations. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- crypto/testmgr.c | 197 +++++++++++++++++++++++++++++++++++++++++++++++ crypto/testmgr.h | 2 +- 2 files changed, 198 insertions(+), 1 deletion(-) diff --git a/crypto/testmgr.c b/crypto/testmgr.c index cafeba6ba16c..fe0cdf162d99 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -2124,6 +2124,186 @@ static int test_skcipher_vec(const char *driver, int enc, return 0; } +#ifdef CONFIG_CRYPTO_MANAGER_EXTRA_TESTS +/* + * Generate a symmetric cipher test vector from the given implementation. + * Assumes the buffers in 'vec' were already allocated. + */ +static void generate_random_cipher_testvec(struct skcipher_request *req, + struct cipher_testvec *vec, + unsigned int maxdatasize, + char *name, size_t max_namelen) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const unsigned int maxkeysize = tfm->keysize; + const unsigned int ivsize = crypto_skcipher_ivsize(tfm); + struct scatterlist src, dst; + u8 iv[MAX_IVLEN]; + DECLARE_CRYPTO_WAIT(wait); + + /* Key: length in [0, maxkeysize], but usually choose maxkeysize */ + vec->klen = maxkeysize; + if (prandom_u32() % 4 == 0) + vec->klen = prandom_u32() % (maxkeysize + 1); + generate_random_bytes((u8 *)vec->key, vec->klen); + vec->setkey_error = crypto_skcipher_setkey(tfm, vec->key, vec->klen); + + /* IV */ + generate_random_bytes((u8 *)vec->iv, ivsize); + + /* Plaintext */ + vec->len = generate_random_length(maxdatasize); + generate_random_bytes((u8 *)vec->ptext, vec->len); + + /* If the key couldn't be set, no need to continue to encrypt. */ + if (vec->setkey_error) + goto done; + + /* Ciphertext */ + sg_init_one(&src, vec->ptext, vec->len); + sg_init_one(&dst, vec->ctext, vec->len); + memcpy(iv, vec->iv, ivsize); + skcipher_request_set_callback(req, 0, crypto_req_done, &wait); + skcipher_request_set_crypt(req, &src, &dst, vec->len, iv); + vec->crypt_error = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); +done: + snprintf(name, max_namelen, "\"random: len=%u klen=%u\"", + vec->len, vec->klen); +} + +/* + * Test the skcipher algorithm represented by @req against the corresponding + * generic implementation, if one is available. + */ +static int test_skcipher_vs_generic_impl(const char *driver, + const char *generic_driver, + struct skcipher_request *req, + struct cipher_test_sglists *tsgls) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + const unsigned int ivsize = crypto_skcipher_ivsize(tfm); + const unsigned int blocksize = crypto_skcipher_blocksize(tfm); + const unsigned int maxdatasize = (2 * PAGE_SIZE) - TESTMGR_POISON_LEN; + const char *algname = crypto_skcipher_alg(tfm)->base.cra_name; + char _generic_driver[CRYPTO_MAX_ALG_NAME]; + struct crypto_skcipher *generic_tfm = NULL; + struct skcipher_request *generic_req = NULL; + unsigned int i; + struct cipher_testvec vec = { 0 }; + char vec_name[64]; + struct testvec_config cfg; + char cfgname[TESTVEC_CONFIG_NAMELEN]; + int err; + + if (noextratests) + return 0; + + /* Keywrap isn't supported here yet as it handles its IV differently. */ + if (strncmp(algname, "kw(", 3) == 0) + return 0; + + if (!generic_driver) { /* Use default naming convention? */ + err = build_generic_driver_name(algname, _generic_driver); + if (err) + return err; + generic_driver = _generic_driver; + } + + if (strcmp(generic_driver, driver) == 0) /* Already the generic impl? */ + return 0; + + generic_tfm = crypto_alloc_skcipher(generic_driver, 0, 0); + if (IS_ERR(generic_tfm)) { + err = PTR_ERR(generic_tfm); + if (err == -ENOENT) { + pr_warn("alg: skcipher: skipping comparison tests for %s because %s is unavailable\n", + driver, generic_driver); + return 0; + } + pr_err("alg: skcipher: error allocating %s (generic impl of %s): %d\n", + generic_driver, algname, err); + return err; + } + + generic_req = skcipher_request_alloc(generic_tfm, GFP_KERNEL); + if (!generic_req) { + err = -ENOMEM; + goto out; + } + + /* Check the algorithm properties for consistency. */ + + if (tfm->keysize != generic_tfm->keysize) { + pr_err("alg: skcipher: max keysize for %s (%u) doesn't match generic impl (%u)\n", + driver, tfm->keysize, generic_tfm->keysize); + err = -EINVAL; + goto out; + } + + if (ivsize != crypto_skcipher_ivsize(generic_tfm)) { + pr_err("alg: skcipher: ivsize for %s (%u) doesn't match generic impl (%u)\n", + driver, ivsize, crypto_skcipher_ivsize(generic_tfm)); + err = -EINVAL; + goto out; + } + + if (blocksize != crypto_skcipher_blocksize(generic_tfm)) { + pr_err("alg: skcipher: blocksize for %s (%u) doesn't match generic impl (%u)\n", + driver, blocksize, + crypto_skcipher_blocksize(generic_tfm)); + err = -EINVAL; + goto out; + } + + /* + * Now generate test vectors using the generic implementation, and test + * the other implementation against them. + */ + + vec.key = kmalloc(tfm->keysize, GFP_KERNEL); + vec.iv = kmalloc(ivsize, GFP_KERNEL); + vec.ptext = kmalloc(maxdatasize, GFP_KERNEL); + vec.ctext = kmalloc(maxdatasize, GFP_KERNEL); + if (!vec.key || !vec.iv || !vec.ptext || !vec.ctext) { + err = -ENOMEM; + goto out; + } + + for (i = 0; i < fuzz_iterations * 8; i++) { + generate_random_cipher_testvec(generic_req, &vec, maxdatasize, + vec_name, sizeof(vec_name)); + generate_random_testvec_config(&cfg, cfgname, sizeof(cfgname)); + + err = test_skcipher_vec_cfg(driver, ENCRYPT, &vec, vec_name, + &cfg, req, tsgls); + if (err) + goto out; + err = test_skcipher_vec_cfg(driver, DECRYPT, &vec, vec_name, + &cfg, req, tsgls); + if (err) + goto out; + cond_resched(); + } + err = 0; +out: + kfree(vec.key); + kfree(vec.iv); + kfree(vec.ptext); + kfree(vec.ctext); + crypto_free_skcipher(generic_tfm); + skcipher_request_free(generic_req); + return err; +} +#else /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */ +static int test_skcipher_vs_generic_impl(const char *driver, + const char *generic_driver, + struct skcipher_request *req, + struct cipher_test_sglists *tsgls) +{ + return 0; +} +#endif /* !CONFIG_CRYPTO_MANAGER_EXTRA_TESTS */ + static int test_skcipher(const char *driver, int enc, const struct cipher_test_suite *suite, struct skcipher_request *req, @@ -2183,6 +2363,11 @@ static int alg_test_skcipher(const struct alg_test_desc *desc, goto out; err = test_skcipher(driver, DECRYPT, suite, req, tsgls); + if (err) + goto out; + + err = test_skcipher_vs_generic_impl(driver, desc->generic_driver, req, + tsgls); out: free_cipher_test_sglists(tsgls); skcipher_request_free(req); @@ -3164,12 +3349,14 @@ static int alg_test_null(const struct alg_test_desc *desc, static const struct alg_test_desc alg_test_descs[] = { { .alg = "adiantum(xchacha12,aes)", + .generic_driver = "adiantum(xchacha12-generic,aes-generic,nhpoly1305-generic)", .test = alg_test_skcipher, .suite = { .cipher = __VECS(adiantum_xchacha12_aes_tv_template) }, }, { .alg = "adiantum(xchacha20,aes)", + .generic_driver = "adiantum(xchacha20-generic,aes-generic,nhpoly1305-generic)", .test = alg_test_skcipher, .suite = { .cipher = __VECS(adiantum_xchacha20_aes_tv_template) @@ -3948,30 +4135,35 @@ static const struct alg_test_desc alg_test_descs[] = { } }, { .alg = "lrw(aes)", + .generic_driver = "lrw(ecb(aes-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(aes_lrw_tv_template) } }, { .alg = "lrw(camellia)", + .generic_driver = "lrw(ecb(camellia-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(camellia_lrw_tv_template) } }, { .alg = "lrw(cast6)", + .generic_driver = "lrw(ecb(cast6-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(cast6_lrw_tv_template) } }, { .alg = "lrw(serpent)", + .generic_driver = "lrw(ecb(serpent-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(serpent_lrw_tv_template) } }, { .alg = "lrw(twofish)", + .generic_driver = "lrw(ecb(twofish-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(tf_lrw_tv_template) @@ -4306,6 +4498,7 @@ static const struct alg_test_desc alg_test_descs[] = { }, }, { .alg = "xts(aes)", + .generic_driver = "xts(ecb(aes-generic))", .test = alg_test_skcipher, .fips_allowed = 1, .suite = { @@ -4313,12 +4506,14 @@ static const struct alg_test_desc alg_test_descs[] = { } }, { .alg = "xts(camellia)", + .generic_driver = "xts(ecb(camellia-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(camellia_xts_tv_template) } }, { .alg = "xts(cast6)", + .generic_driver = "xts(ecb(cast6-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(cast6_xts_tv_template) @@ -4332,12 +4527,14 @@ static const struct alg_test_desc alg_test_descs[] = { .fips_allowed = 1, }, { .alg = "xts(serpent)", + .generic_driver = "xts(ecb(serpent-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(serpent_xts_tv_template) } }, { .alg = "xts(twofish)", + .generic_driver = "xts(ecb(twofish-generic))", .test = alg_test_skcipher, .suite = { .cipher = __VECS(tf_xts_tv_template) diff --git a/crypto/testmgr.h b/crypto/testmgr.h index 3db3603ef480..9a13c634b207 100644 --- a/crypto/testmgr.h +++ b/crypto/testmgr.h @@ -73,7 +73,7 @@ struct cipher_testvec { const char *ptext; const char *ctext; unsigned char wk; /* weak key flag */ - unsigned char klen; + unsigned short klen; unsigned short len; bool fips_skip; bool generates_iv; -- 2.30.2