diff options
Diffstat (limited to 'crypto/kdf_sp800108.c')
| -rw-r--r-- | crypto/kdf_sp800108.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/crypto/kdf_sp800108.c b/crypto/kdf_sp800108.c new file mode 100644 index 0000000000..c3f9938e1a --- /dev/null +++ b/crypto/kdf_sp800108.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * SP800-108 Key-derivation function + * + * Copyright (C) 2021, Stephan Mueller <smueller@chronox.de> + */ + +#include <linux/fips.h> +#include <linux/module.h> +#include <crypto/kdf_sp800108.h> +#include <crypto/internal/kdf_selftest.h> + +/* + * SP800-108 CTR KDF implementation + */ +int crypto_kdf108_ctr_generate(struct crypto_shash *kmd, + const struct kvec *info, unsigned int info_nvec, + u8 *dst, unsigned int dlen) +{ + SHASH_DESC_ON_STACK(desc, kmd); + __be32 counter = cpu_to_be32(1); + const unsigned int h = crypto_shash_digestsize(kmd), dlen_orig = dlen; + unsigned int i; + int err = 0; + u8 *dst_orig = dst; + + desc->tfm = kmd; + + while (dlen) { + err = crypto_shash_init(desc); + if (err) + goto out; + + err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32)); + if (err) + goto out; + + for (i = 0; i < info_nvec; i++) { + err = crypto_shash_update(desc, info[i].iov_base, + info[i].iov_len); + if (err) + goto out; + } + + if (dlen < h) { + u8 tmpbuffer[HASH_MAX_DIGESTSIZE]; + + err = crypto_shash_final(desc, tmpbuffer); + if (err) + goto out; + memcpy(dst, tmpbuffer, dlen); + memzero_explicit(tmpbuffer, h); + goto out; + } + + err = crypto_shash_final(desc, dst); + if (err) + goto out; + + dlen -= h; + dst += h; + counter = cpu_to_be32(be32_to_cpu(counter) + 1); + } + +out: + if (err) + memzero_explicit(dst_orig, dlen_orig); + shash_desc_zero(desc); + return err; +} +EXPORT_SYMBOL(crypto_kdf108_ctr_generate); + +/* + * The seeding of the KDF + */ +int crypto_kdf108_setkey(struct crypto_shash *kmd, + const u8 *key, size_t keylen, + const u8 *ikm, size_t ikmlen) +{ + unsigned int ds = crypto_shash_digestsize(kmd); + + /* SP800-108 does not support IKM */ + if (ikm || ikmlen) + return -EINVAL; + + /* Check according to SP800-108 section 7.2 */ + if (ds > keylen) + return -EINVAL; + + /* Set the key for the MAC used for the KDF. */ + return crypto_shash_setkey(kmd, key, keylen); +} +EXPORT_SYMBOL(crypto_kdf108_setkey); + +/* + * Test vector obtained from + * http://csrc.nist.gov/groups/STM/cavp/documents/KBKDF800-108/CounterMode.zip + */ +static const struct kdf_testvec kdf_ctr_hmac_sha256_tv_template[] = { + { + .key = "\xdd\x1d\x91\xb7\xd9\x0b\x2b\xd3" + "\x13\x85\x33\xce\x92\xb2\x72\xfb" + "\xf8\xa3\x69\x31\x6a\xef\xe2\x42" + "\xe6\x59\xcc\x0a\xe2\x38\xaf\xe0", + .keylen = 32, + .ikm = NULL, + .ikmlen = 0, + .info = { + .iov_base = "\x01\x32\x2b\x96\xb3\x0a\xcd\x19" + "\x79\x79\x44\x4e\x46\x8e\x1c\x5c" + "\x68\x59\xbf\x1b\x1c\xf9\x51\xb7" + "\xe7\x25\x30\x3e\x23\x7e\x46\xb8" + "\x64\xa1\x45\xfa\xb2\x5e\x51\x7b" + "\x08\xf8\x68\x3d\x03\x15\xbb\x29" + "\x11\xd8\x0a\x0e\x8a\xba\x17\xf3" + "\xb4\x13\xfa\xac", + .iov_len = 60 + }, + .expected = "\x10\x62\x13\x42\xbf\xb0\xfd\x40" + "\x04\x6c\x0e\x29\xf2\xcf\xdb\xf0", + .expectedlen = 16 + } +}; + +static int __init crypto_kdf108_init(void) +{ + int ret; + + if (IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS)) + return 0; + + ret = kdf_test(&kdf_ctr_hmac_sha256_tv_template[0], "hmac(sha256)", + crypto_kdf108_setkey, crypto_kdf108_ctr_generate); + if (ret) { + if (fips_enabled) + panic("alg: self-tests for CTR-KDF (hmac(sha256)) failed (rc=%d)\n", + ret); + + WARN(1, + "alg: self-tests for CTR-KDF (hmac(sha256)) failed (rc=%d)\n", + ret); + } else if (fips_enabled) { + pr_info("alg: self-tests for CTR-KDF (hmac(sha256)) passed\n"); + } + + return ret; +} + +static void __exit crypto_kdf108_exit(void) { } + +module_init(crypto_kdf108_init); +module_exit(crypto_kdf108_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); +MODULE_DESCRIPTION("Key Derivation Function conformant to SP800-108"); |