1 files changed, 211 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..03c6f49
--- /dev/null
+++ b/lib/luks2/luks2_digest_pbkdf2.c
@@ -0,0 +1,211 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, PBKDF2 digest handler (LUKS1 compatible)
+ *
+ * Copyright (C) 2015-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2021 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[LUKS_SALTSIZE];
+	unsigned int mkDigestIterations;
+	size_t len;
+	int r;
+
+	/* 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;
+	len = sizeof(mkDigestSalt);
+	if (!base64_decode(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), mkDigestSalt, &len))
+		return -EINVAL;
+	if (len != LUKS_SALTSIZE)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_digest, "digest", &jobj1))
+		return -EINVAL;
+	len = 0;
+	if (!base64_decode_alloc(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), &mkDigest, &len))
+		return -EINVAL;
+	if (len < LUKS_DIGESTSIZE ||
+	    len > sizeof(checkHashBuf) ||
+	    (len != LUKS_DIGESTSIZE && len != (size_t)crypt_hash_size(hashSpec))) {
+		free(mkDigest);
+		return -EINVAL;
+	}
+
+	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 (memcmp(checkHashBuf, mkDigest, len) == 0)
+			r = 0;
+	}
+
+	free(mkDigest);
+	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));
+
+	base64_encode_alloc(salt, LUKS_SALTSIZE, &base64_str);
+	if (!base64_str) {
+		json_object_put(jobj_digest);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_digest, "salt", json_object_new_string(base64_str));
+	free(base64_str);
+
+	base64_encode_alloc(digest_raw, hmac_size, &base64_str);
+	if (!base64_str) {
+		json_object_put(jobj_digest);
+		return -ENOMEM;
+	}
+	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,
+};