diff options
Diffstat (limited to 'lib/luks2/luks2_digest_pbkdf2.c')
| -rw-r--r-- | lib/luks2/luks2_digest_pbkdf2.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/lib/luks2/luks2_digest_pbkdf2.c b/lib/luks2/luks2_digest_pbkdf2.c new file mode 100644 index 0000000..1009cfb --- /dev/null +++ b/lib/luks2/luks2_digest_pbkdf2.c @@ -0,0 +1,210 @@ +/* + * LUKS - Linux Unified Key Setup v2, PBKDF2 digest handler (LUKS1 compatible) + * + * Copyright (C) 2015-2023 Red Hat, Inc. All rights reserved. + * Copyright (C) 2015-2023 Milan Broz + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "luks2_internal.h" + +#define LUKS_DIGESTSIZE 20 // since SHA1 +#define LUKS_SALTSIZE 32 +#define LUKS_MKD_ITERATIONS_MS 125 + +static int PBKDF2_digest_verify(struct crypt_device *cd, + int digest, + const char *volume_key, + size_t volume_key_len) +{ + char checkHashBuf[64]; + json_object *jobj_digest, *jobj1; + const char *hashSpec; + char *mkDigest = NULL, *mkDigestSalt = NULL; + unsigned int mkDigestIterations; + size_t len; + int r = -EINVAL; + + /* This can be done only for internally linked digests */ + jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest); + if (!jobj_digest) + return -EINVAL; + + if (!json_object_object_get_ex(jobj_digest, "hash", &jobj1)) + return -EINVAL; + hashSpec = json_object_get_string(jobj1); + + if (!json_object_object_get_ex(jobj_digest, "iterations", &jobj1)) + return -EINVAL; + mkDigestIterations = json_object_get_int64(jobj1); + + if (!json_object_object_get_ex(jobj_digest, "salt", &jobj1)) + return -EINVAL; + r = crypt_base64_decode(&mkDigestSalt, &len, json_object_get_string(jobj1), + json_object_get_string_len(jobj1)); + if (r < 0) + goto out; + if (len != LUKS_SALTSIZE) + goto out; + + if (!json_object_object_get_ex(jobj_digest, "digest", &jobj1)) + goto out; + r = crypt_base64_decode(&mkDigest, &len, json_object_get_string(jobj1), + json_object_get_string_len(jobj1)); + if (r < 0) + goto out; + if (len < LUKS_DIGESTSIZE || + len > sizeof(checkHashBuf) || + (len != LUKS_DIGESTSIZE && len != (size_t)crypt_hash_size(hashSpec))) + goto out; + + r = -EPERM; + if (crypt_pbkdf(CRYPT_KDF_PBKDF2, hashSpec, volume_key, volume_key_len, + mkDigestSalt, LUKS_SALTSIZE, + checkHashBuf, len, + mkDigestIterations, 0, 0) < 0) { + r = -EINVAL; + } else { + if (crypt_backend_memeq(checkHashBuf, mkDigest, len) == 0) + r = 0; + } +out: + free(mkDigest); + free(mkDigestSalt); + return r; +} + +static int PBKDF2_digest_store(struct crypt_device *cd, + int digest, + const char *volume_key, + size_t volume_key_len) +{ + json_object *jobj_digest, *jobj_digests; + char salt[LUKS_SALTSIZE], digest_raw[128]; + int hmac_size, r; + char *base64_str; + struct luks2_hdr *hdr; + struct crypt_pbkdf_limits pbkdf_limits; + const struct crypt_pbkdf_type *pbkdf_cd; + struct crypt_pbkdf_type pbkdf = { + .type = CRYPT_KDF_PBKDF2, + .time_ms = LUKS_MKD_ITERATIONS_MS, + }; + + /* Inherit hash from PBKDF setting */ + pbkdf_cd = crypt_get_pbkdf_type(cd); + if (pbkdf_cd) + pbkdf.hash = pbkdf_cd->hash; + if (!pbkdf.hash) + pbkdf.hash = DEFAULT_LUKS1_HASH; + + log_dbg(cd, "Setting PBKDF2 type key digest %d.", digest); + + r = crypt_random_get(cd, salt, LUKS_SALTSIZE, CRYPT_RND_SALT); + if (r < 0) + return r; + + r = crypt_pbkdf_get_limits(CRYPT_KDF_PBKDF2, &pbkdf_limits); + if (r < 0) + return r; + + if (crypt_get_pbkdf(cd)->flags & CRYPT_PBKDF_NO_BENCHMARK) + pbkdf.iterations = pbkdf_limits.min_iterations; + else { + r = crypt_benchmark_pbkdf_internal(cd, &pbkdf, volume_key_len); + if (r < 0) + return r; + } + + hmac_size = crypt_hmac_size(pbkdf.hash); + if (hmac_size < 0 || hmac_size > (int)sizeof(digest_raw)) + return -EINVAL; + + r = crypt_pbkdf(CRYPT_KDF_PBKDF2, pbkdf.hash, volume_key, volume_key_len, + salt, LUKS_SALTSIZE, digest_raw, hmac_size, + pbkdf.iterations, 0, 0); + if (r < 0) + return r; + + jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest); + jobj_digests = NULL; + if (!jobj_digest) { + hdr = crypt_get_hdr(cd, CRYPT_LUKS2); + jobj_digest = json_object_new_object(); + json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests); + } + + json_object_object_add(jobj_digest, "type", json_object_new_string("pbkdf2")); + json_object_object_add(jobj_digest, "keyslots", json_object_new_array()); + json_object_object_add(jobj_digest, "segments", json_object_new_array()); + json_object_object_add(jobj_digest, "hash", json_object_new_string(pbkdf.hash)); + json_object_object_add(jobj_digest, "iterations", json_object_new_int(pbkdf.iterations)); + + r = crypt_base64_encode(&base64_str, NULL, salt, LUKS_SALTSIZE); + if (r < 0) { + json_object_put(jobj_digest); + return r; + } + json_object_object_add(jobj_digest, "salt", json_object_new_string(base64_str)); + free(base64_str); + + r = crypt_base64_encode(&base64_str, NULL, digest_raw, hmac_size); + if (r < 0) { + json_object_put(jobj_digest); + return r; + } + json_object_object_add(jobj_digest, "digest", json_object_new_string(base64_str)); + free(base64_str); + + if (jobj_digests) + json_object_object_add_by_uint(jobj_digests, digest, jobj_digest); + + JSON_DBG(cd, jobj_digest, "Digest JSON:"); + return 0; +} + +static int PBKDF2_digest_dump(struct crypt_device *cd, int digest) +{ + json_object *jobj_digest, *jobj1; + + /* This can be done only for internally linked digests */ + jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest); + if (!jobj_digest) + return -EINVAL; + + json_object_object_get_ex(jobj_digest, "hash", &jobj1); + log_std(cd, "\tHash: %s\n", json_object_get_string(jobj1)); + + json_object_object_get_ex(jobj_digest, "iterations", &jobj1); + log_std(cd, "\tIterations: %" PRIu64 "\n", json_object_get_int64(jobj1)); + + json_object_object_get_ex(jobj_digest, "salt", &jobj1); + log_std(cd, "\tSalt: "); + hexprint_base64(cd, jobj1, " ", " "); + + json_object_object_get_ex(jobj_digest, "digest", &jobj1); + log_std(cd, "\tDigest: "); + hexprint_base64(cd, jobj1, " ", " "); + + return 0; +} + +const digest_handler PBKDF2_digest = { + .name = "pbkdf2", + .verify = PBKDF2_digest_verify, + .store = PBKDF2_digest_store, + .dump = PBKDF2_digest_dump, +}; |