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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | // 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 = 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 { 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"); |