Implement self-testing infrastructure to test the pseudo-random function, key derivation, encryption and checksumming.
Signed-off-by: David Howells <dhowe...@redhat.com> --- crypto/krb5/Kconfig | 4 crypto/krb5/Makefile | 4 crypto/krb5/internal.h | 48 ++++ crypto/krb5/main.c | 12 + crypto/krb5/selftest.c | 543 +++++++++++++++++++++++++++++++++++++++++++ crypto/krb5/selftest_data.c | 38 +++ 6 files changed, 649 insertions(+) create mode 100644 crypto/krb5/selftest.c create mode 100644 crypto/krb5/selftest_data.c diff --git a/crypto/krb5/Kconfig b/crypto/krb5/Kconfig index 881754500732..e2eba1d689ab 100644 --- a/crypto/krb5/Kconfig +++ b/crypto/krb5/Kconfig @@ -9,3 +9,7 @@ config CRYPTO_KRB5 select CRYPTO_AES help Provide Kerberos-5-based security. + +config CRYPTO_KRB5_SELFTESTS + bool "Kerberos 5 crypto selftests" + depends on CRYPTO_KRB5 diff --git a/crypto/krb5/Makefile b/crypto/krb5/Makefile index b81e2efac3c8..b7da03cae6d1 100644 --- a/crypto/krb5/Makefile +++ b/crypto/krb5/Makefile @@ -9,4 +9,8 @@ krb5-y += \ rfc3961_simplified.o \ rfc3962_aes.o +krb5-$(CONFIG_CRYPTO_KRB5_SELFTESTS) += \ + selftest.o \ + selftest_data.o + obj-$(CONFIG_CRYPTO_KRB5) += krb5.o diff --git a/crypto/krb5/internal.h b/crypto/krb5/internal.h index 5d55a574536e..47424b433778 100644 --- a/crypto/krb5/internal.h +++ b/crypto/krb5/internal.h @@ -88,6 +88,37 @@ struct krb5_crypto_profile { crypto_roundup(crypto_sync_skcipher_ivsize(TFM)) #define round16(x) (((x) + 15) & ~15) +/* + * Self-testing data. + */ +struct krb5_prf_test { + const struct krb5_enctype *krb5; + const char *name, *key, *octet, *prf; +}; + +struct krb5_key_test_one { + u32 use; + const char *key; +}; + +struct krb5_key_test { + const struct krb5_enctype *krb5; + const char *name, *key; + struct krb5_key_test_one Kc, Ke, Ki; +}; + +struct krb5_enc_test { + const struct krb5_enctype *krb5; + const char *name, *plain, *conf, *K0, *Ke, *Ki, *ct; + __be32 usage; +}; + +struct krb5_mic_test { + const struct krb5_enctype *krb5; + const char *name, *plain, *K0, *Kc, *mic; + __be32 usage; +}; + /* * main.c */ @@ -126,3 +157,20 @@ int rfc3961_verify_mic(const struct krb5_enctype *krb5, */ extern const struct krb5_enctype krb5_aes128_cts_hmac_sha1_96; extern const struct krb5_enctype krb5_aes256_cts_hmac_sha1_96; + +/* + * selftest.c + */ +#ifdef CONFIG_CRYPTO_KRB5_SELFTESTS +void krb5_selftest(void); +#else +static inline void krb5_selftest(void) {} +#endif + +/* + * selftest_data.c + */ +extern const struct krb5_prf_test krb5_prf_tests[]; +extern const struct krb5_key_test krb5_key_tests[]; +extern const struct krb5_enc_test krb5_enc_tests[]; +extern const struct krb5_mic_test krb5_mic_tests[]; diff --git a/crypto/krb5/main.c b/crypto/krb5/main.c index bce47580c33f..b79127027551 100644 --- a/crypto/krb5/main.c +++ b/crypto/krb5/main.c @@ -214,3 +214,15 @@ int crypto_krb5_verify_mic(const struct krb5_enctype *krb5, _offset, _len, _error_code); } EXPORT_SYMBOL(crypto_krb5_verify_mic); + +static int __init crypto_krb5_init(void) +{ + krb5_selftest(); + return 0; +} +module_init(crypto_krb5_init); + +static void __exit crypto_krb5_exit(void) +{ +} +module_exit(crypto_krb5_exit); diff --git a/crypto/krb5/selftest.c b/crypto/krb5/selftest.c new file mode 100644 index 000000000000..df57ab24cc6e --- /dev/null +++ b/crypto/krb5/selftest.c @@ -0,0 +1,543 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxGK self-testing + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowe...@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/slab.h> +#include <crypto/skcipher.h> +#include <crypto/hash.h> +#include "internal.h" + +#define VALID(X) \ + ({ \ + bool __x = (X); \ + if (__x) { \ + pr_warn("!!! TESTINVAL %s:%u\n", __FILE__, __LINE__); \ + } \ + __x; \ + }) + +#define CHECK(X) \ + ({ \ + bool __x = (X); \ + if (__x) { \ + pr_warn("!!! TESTFAIL %s:%u\n", __FILE__, __LINE__); \ + } \ + __x; \ + }) + +enum which_key { + TEST_KC, TEST_KE, TEST_KI, +}; + +static int prep_buf(struct krb5_buffer *buf) +{ + buf->data = kmalloc(buf->len, GFP_KERNEL); + if (!buf->data) + return -ENOMEM; + return 0; +} + +#define PREP_BUF(BUF, LEN) \ + do { \ + (BUF)->len = (LEN); \ + if ((ret = prep_buf((BUF))) < 0) \ + goto out; \ + } while(0) + +static int load_buf(struct krb5_buffer *buf, const char *from) +{ + size_t len = strlen(from); + int ret; + + if (len > 1 && from[0] == '\'') { + PREP_BUF(buf, len - 1); + memcpy(buf->data, from + 1, len - 1); + ret = 0; + goto out; + } + + if (VALID(len & 1)) + return -EINVAL; + + PREP_BUF(buf, len / 2); + if ((ret = hex2bin(buf->data, from, buf->len)) < 0) { + VALID(1); + goto out; + } +out: + return ret; +} + +#define LOAD_BUF(BUF, FROM) do { if ((ret = load_buf(BUF, FROM)) < 0) goto out; } while(0) + +static void clear_buf(struct krb5_buffer *buf) +{ + kfree(buf->data); + buf->len = 0; + buf->data = NULL; +} + +/* + * Perform a pseudo-random function check. + */ +static int krb5_test_one_prf(const struct krb5_prf_test *test) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct krb5_buffer key = {}, octet = {}, result = {}, prf = {}; + int ret; + + pr_notice("Running %s %s\n", krb5->name, test->name); + + LOAD_BUF(&key, test->key); + LOAD_BUF(&octet, test->octet); + LOAD_BUF(&prf, test->prf); + PREP_BUF(&result, krb5->prf_len); + + if (VALID(result.len != prf.len)) { + ret = -EINVAL; + goto out; + } + + if ((ret = krb5->profile->calc_PRF(krb5, &key, &octet, &result, GFP_KERNEL)) < 0) { + CHECK(1); + pr_warn("PRF calculation failed %d\n", ret); + goto out; + } + + if (memcmp(result.data, prf.data, result.len) != 0) { + CHECK(1); + ret = -EKEYREJECTED; + goto out; + } + + ret = 0; + +out: + clear_buf(&result); + clear_buf(&octet); + clear_buf(&key); + return ret; +} + +/* + * Perform a key derivation check. + */ +static int krb5_test_key(const struct krb5_enctype *krb5, + const struct krb5_buffer *base_key, + const struct krb5_key_test_one *test, + enum which_key which) +{ + struct krb5_buffer key = {}, result = {}; + int ret; + + LOAD_BUF(&key, test->key); + PREP_BUF(&result, key.len); + + switch (which) { + case TEST_KC: + ret = crypto_krb5_get_Kc(krb5, base_key, test->use, &result, + NULL, GFP_KERNEL); + break; + case TEST_KE: + ret = crypto_krb5_get_Ke(krb5, base_key, test->use, &result, + NULL, GFP_KERNEL); + break; + case TEST_KI: + ret = crypto_krb5_get_Ki(krb5, base_key, test->use, &result, + NULL, GFP_KERNEL); + break; + default: + VALID(1); + ret = -EINVAL; + goto out; + } + + if (ret < 0) { + CHECK(1); + pr_warn("Key derivation failed %d\n", ret); + goto out; + } + + if (memcmp(result.data, key.data, result.len) != 0) { + CHECK(1); + ret = -EKEYREJECTED; + goto out; + } + +out: + clear_buf(&key); + clear_buf(&result); + return ret; +} + +static int krb5_test_one_key(const struct krb5_key_test *test) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct krb5_buffer base_key = {}; + int ret; + + pr_notice("Running %s %s\n", krb5->name, test->name); + + LOAD_BUF(&base_key, test->key); + + if ((ret = krb5_test_key(krb5, &base_key, &test->Kc, TEST_KC)) < 0) + goto out; + if ((ret = krb5_test_key(krb5, &base_key, &test->Ke, TEST_KE)) < 0) + goto out; + if ((ret = krb5_test_key(krb5, &base_key, &test->Ki, TEST_KI)) < 0) + goto out; + +out: + clear_buf(&base_key); + return ret; +} + +static int krb5_test_get_Kc(const struct krb5_mic_test *test, + struct crypto_shash **_Kc) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct crypto_shash *shash; + struct krb5_buffer K0 = {}, key = {}; + int ret; + + shash = crypto_alloc_shash(krb5->cksum_name, 0, 0); + if (IS_ERR(shash)) + return (PTR_ERR(shash) == -ENOENT) ? -ENOPKG : PTR_ERR(shash); + *_Kc = shash; + + if (test->Kc) { + LOAD_BUF(&key, test->Kc); + } else { + char usage_data[5]; + struct krb5_buffer usage = { .len = 5, .data = usage_data }; + memcpy(usage_data, &test->usage, 4); + usage_data[4] = 0x99; + LOAD_BUF(&K0, test->K0); + PREP_BUF(&key, krb5->Kc_len); + ret = krb5->profile->calc_Kc(krb5, &K0, &usage, &key, GFP_KERNEL); + } + + ret = crypto_shash_setkey(shash, key.data, key.len); +out: + clear_buf(&key); + clear_buf(&K0); + return ret; +} + +static int krb5_test_get_Ke(const struct krb5_enc_test *test, + struct krb5_enc_keys *keys) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct crypto_sync_skcipher *ci; + struct krb5_buffer K0 = {}, key = {}; + int ret; + + ci = crypto_alloc_sync_skcipher(krb5->encrypt_name, 0, 0); + if (IS_ERR(ci)) + return (PTR_ERR(ci) == -ENOENT) ? -ENOPKG : PTR_ERR(ci); + keys->Ke = ci; + + if (test->Ke) { + LOAD_BUF(&key, test->Ke); + } else { + char usage_data[5]; + struct krb5_buffer usage = { .len = 5, .data = usage_data }; + memcpy(usage_data, &test->usage, 4); + usage_data[4] = 0xAA; + LOAD_BUF(&K0, test->K0); + PREP_BUF(&key, krb5->Ke_len); + ret = krb5->profile->calc_Ke(krb5, &K0, &usage, &key, GFP_KERNEL); + } + + ret = crypto_sync_skcipher_setkey(ci, key.data, key.len); +out: + clear_buf(&key); + clear_buf(&K0); + return ret; +} + +static int krb5_test_get_Ki(const struct krb5_enc_test *test, + struct krb5_enc_keys *keys) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct crypto_shash *shash; + struct krb5_buffer K0 = {}, key = {}; + int ret; + + shash = crypto_alloc_shash(krb5->cksum_name, 0, 0); + if (IS_ERR(shash)) + return (PTR_ERR(shash) == -ENOENT) ? -ENOPKG : PTR_ERR(shash); + keys->Ki = shash; + + if (test->Ki) { + LOAD_BUF(&key, test->Ki); + } else { + char usage_data[5]; + struct krb5_buffer usage = { .len = 5, .data = usage_data }; + memcpy(usage_data, &test->usage, 4); + usage_data[4] = 0x55; + LOAD_BUF(&K0, test->K0); + PREP_BUF(&key, krb5->Ki_len); + ret = krb5->profile->calc_Ki(krb5, &K0, &usage, &key, GFP_KERNEL); + } + + ret = crypto_shash_setkey(shash, key.data, key.len); +out: + clear_buf(&key); + clear_buf(&K0); + return ret; +} + +/* + * Generate a buffer containing encryption test data. + */ +static int krb5_load_enc_buf(const struct krb5_enc_test *test, + const struct krb5_buffer *plain, + void *buf) +{ + const struct krb5_enctype *krb5 = test->krb5; + unsigned int conf_len, pad_len, enc_len, ct_len; + int ret; + + conf_len = strlen(test->conf); + if (VALID((conf_len & 1) || conf_len / 2 != krb5->conf_len)) + return -EINVAL; + + if (krb5->pad) { + enc_len = round_up(krb5->conf_len + plain->len, krb5->block_len); + pad_len = enc_len - (krb5->conf_len + plain->len); + } else { + enc_len = krb5->conf_len + plain->len; + pad_len = 0; + } + + ct_len = strlen(test->ct); + if (VALID((ct_len & 1) || ct_len / 2 != enc_len + krb5->cksum_len)) + return -EINVAL; + ct_len = enc_len + krb5->cksum_len; + + if ((ret = hex2bin(buf, test->conf, krb5->conf_len)) < 0) + return ret; + buf += krb5->conf_len; + memcpy(buf, plain->data, plain->len); + return 0; +} + +/* + * Load checksum test data into a buffer. + */ +static int krb5_load_mic_buf(const struct krb5_mic_test *test, + const struct krb5_buffer *plain, + void *buf) +{ + const struct krb5_enctype *krb5 = test->krb5; + + memcpy(buf + krb5->cksum_len, plain->data, plain->len); + return 0; +} + +/* + * Perform an encryption test. + */ +static int krb5_test_one_enc(const struct krb5_enc_test *test, void *buf) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct krb5_enc_keys keys = {}; + struct krb5_buffer plain = {}, ct = {}; + struct scatterlist sg[1]; + size_t offset, len; + int ret, error_code; + + pr_notice("Running %s %s\n", krb5->name, test->name); + + if ((ret = krb5_test_get_Ke(test, &keys)) < 0 || + (ret = krb5_test_get_Ki(test, &keys)) < 0) + goto out; + + LOAD_BUF(&plain, test->plain); + LOAD_BUF(&ct, test->ct); + + ret = krb5_load_enc_buf(test, &plain, buf); + if (ret < 0) + goto out; + + sg_init_one(sg, buf, 1024); + ret = crypto_krb5_encrypt(krb5, &keys, sg, 1, 1024, + krb5->conf_len, plain.len, true); + if (ret < 0) { + CHECK(1); + pr_warn("Encryption failed %d\n", ret); + goto out; + } + len = ret; + + if (CHECK(len != ct.len)) { + pr_warn("Encrypted length mismatch %zu != %u\n", len, ct.len); + goto out; + } + + if (memcmp(buf, ct.data, ct.len) != 0) { + CHECK(1); + pr_warn("Ciphertext mismatch\n"); + pr_warn("BUF %*phN\n", ct.len, buf); + pr_warn("CT %*phN\n", ct.len, ct.data); + ret = -EKEYREJECTED; + goto out; + } + + offset = 0; + ret = crypto_krb5_decrypt(krb5, &keys, sg, 1, &offset, &len, &error_code); + if (ret < 0) { + CHECK(1); + pr_warn("Decryption failed %d\n", ret); + goto out; + } + + if (CHECK(len != plain.len)) + goto out; + + if (memcmp(buf + offset, plain.data, plain.len) != 0) { + CHECK(1); + pr_warn("Plaintext mismatch\n"); + pr_warn("BUF %*phN\n", plain.len, buf + offset); + pr_warn("PT %*phN\n", plain.len, plain.data); + ret = -EKEYREJECTED; + goto out; + } + + ret = 0; + +out: + clear_buf(&ct); + clear_buf(&plain); + crypto_krb5_free_enc_keys(&keys); + return ret; +} + +static int krb5_test_one_mic(const struct krb5_mic_test *test, void *buf) +{ + const struct krb5_enctype *krb5 = test->krb5; + struct crypto_shash *Kc = NULL; + struct scatterlist sg[1]; + struct krb5_buffer plain = {}, mic = {}; + size_t offset, len; + int ret, error_code; + + pr_notice("Running %s %s\n", krb5->name, test->name); + + if ((ret = krb5_test_get_Kc(test, &Kc)) < 0) + goto out; + + LOAD_BUF(&plain, test->plain); + LOAD_BUF(&mic, test->mic); + + ret = krb5_load_mic_buf(test, &plain, buf); + if (ret < 0) + goto out; + + sg_init_one(sg, buf, 1024); + + ret = crypto_krb5_get_mic(krb5, Kc, NULL, sg, 1, 1024, + krb5->cksum_len, plain.len); + if (ret < 0) { + CHECK(1); + pr_warn("Get MIC failed %d\n", ret); + goto out; + } + len = ret; + + if (CHECK(len != plain.len + mic.len)) { + pr_warn("MIC length mismatch %zu != %u\n", len, plain.len + mic.len); + goto out; + } + + if (memcmp(buf, mic.data, mic.len) != 0) { + CHECK(1); + pr_warn("MIC mismatch\n"); + pr_warn("BUF %*phN\n", mic.len, buf); + pr_warn("MIC %*phN\n", mic.len, mic.data); + ret = -EKEYREJECTED; + goto out; + } + + offset = 0; + ret = crypto_krb5_verify_mic(krb5, Kc, NULL, sg, 1, + &offset, &len, &error_code); + if (ret < 0) { + CHECK(1); + pr_warn("Verify MIC failed %d\n", ret); + goto out; + } + + if (CHECK(len != plain.len)) + goto out; + if (CHECK(offset != mic.len)) + goto out; + + if (memcmp(buf + offset, plain.data, plain.len) != 0) { + CHECK(1); + pr_warn("Plaintext mismatch\n"); + pr_warn("BUF %*phN\n", plain.len, buf + offset); + pr_warn("PT %*phN\n", plain.len, plain.data); + ret = -EKEYREJECTED; + goto out; + } + + ret = 0; + +out: + clear_buf(&mic); + clear_buf(&plain); + if (Kc) + crypto_free_shash(Kc); + return ret; +} + +void krb5_selftest(void) +{ + void *buf; + bool fail = false; + int i; + + buf = kmalloc(1024, GFP_KERNEL); + if (!buf) + return; + + printk("\n"); + pr_notice("Running selftests\n"); + + for (i = 0; krb5_prf_tests[i].krb5; i++) { + fail |= krb5_test_one_prf(&krb5_prf_tests[i]) < 0; + if (fail) + goto out; + } + + for (i = 0; krb5_key_tests[i].krb5; i++) { + fail |= krb5_test_one_key(&krb5_key_tests[i]) < 0; + if (fail) + goto out; + } + + for (i = 0; krb5_enc_tests[i].krb5; i++) { + memset(buf, 0x5a, 1024); + fail |= krb5_test_one_enc(&krb5_enc_tests[i], buf) < 0; + if (fail) + goto out; + } + + for (i = 0; krb5_mic_tests[i].krb5; i++) { + memset(buf, 0x5a, 1024); + fail |= krb5_test_one_mic(&krb5_mic_tests[i], buf) < 0; + if (fail) + goto out; + } + +out: + pr_notice("Selftests %s\n", fail ? "failed" : "succeeded"); + kfree(buf); +} diff --git a/crypto/krb5/selftest_data.c b/crypto/krb5/selftest_data.c new file mode 100644 index 000000000000..9085723b730b --- /dev/null +++ b/crypto/krb5/selftest_data.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Data for RxGK self-testing + * + * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowe...@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include "internal.h" + +/* + * Pseudo-random function tests. + */ +const struct krb5_prf_test krb5_prf_tests[] = { + {/* END */} +}; + +/* + * Key derivation tests. + */ +const struct krb5_key_test krb5_key_tests[] = { + {/* END */} +}; + +/* + * Encryption tests. + */ +const struct krb5_enc_test krb5_enc_tests[] = { + {/* END */} +}; + +/* + * Checksum generation tests. + */ +const struct krb5_mic_test krb5_mic_tests[] = { + {/* END */} +};