1 files changed, 460 insertions, 0 deletions
diff --git a/lib/crypto_backend/crypto_nettle.c b/lib/crypto_backend/crypto_nettle.c
new file mode 100644
index 0000000..086e4fc
--- /dev/null
+++ b/lib/crypto_backend/crypto_nettle.c
@@ -0,0 +1,460 @@
+/*
+ * Nettle crypto backend implementation
+ *
+ * Copyright (C) 2011-2023 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2011-2023 Milan Broz
+ *
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This file 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <nettle/sha.h>
+#include <nettle/sha3.h>
+#include <nettle/hmac.h>
+#include <nettle/pbkdf2.h>
+#include <nettle/memops.h>
+#include "crypto_backend_internal.h"
+
+#if HAVE_NETTLE_VERSION_H
+#include <nettle/version.h>
+#define VSTR(s) STR(s)
+#define STR(s) #s
+static const char *version = "Nettle "VSTR(NETTLE_VERSION_MAJOR)"."VSTR(NETTLE_VERSION_MINOR);
+#else
+static const char *version = "Nettle";
+#endif
+
+typedef void (*init_func) (void *);
+typedef void (*update_func) (void *, size_t, const uint8_t *);
+typedef void (*digest_func) (void *, size_t, uint8_t *);
+typedef void (*set_key_func) (void *, size_t, const uint8_t *);
+
+struct hash_alg {
+	const char *name;
+	int length;
+	init_func init;
+	update_func update;
+	digest_func digest;
+	update_func hmac_update;
+	digest_func hmac_digest;
+	set_key_func hmac_set_key;
+};
+
+/* Missing HMAC wrappers in Nettle */
+#define HMAC_FCE(xxx) \
+struct xhmac_##xxx##_ctx HMAC_CTX(struct xxx##_ctx); \
+static void xhmac_##xxx##_set_key(struct xhmac_##xxx##_ctx *ctx, \
+size_t key_length, const uint8_t *key) \
+{HMAC_SET_KEY(ctx, &nettle_##xxx, key_length, key);} \
+static void xhmac_##xxx##_update(struct xhmac_##xxx##_ctx *ctx, \
+size_t length, const uint8_t *data) \
+{xxx##_update(&ctx->state, length, data);} \
+static void xhmac_##xxx##_digest(struct xhmac_##xxx##_ctx *ctx, \
+size_t length, uint8_t *digest) \
+{HMAC_DIGEST(ctx, &nettle_##xxx, length, digest);}
+
+HMAC_FCE(sha3_224);
+HMAC_FCE(sha3_256);
+HMAC_FCE(sha3_384);
+HMAC_FCE(sha3_512);
+
+static struct hash_alg hash_algs[] = {
+	{ "sha1", SHA1_DIGEST_SIZE,
+		(init_func) sha1_init,
+		(update_func) sha1_update,
+		(digest_func) sha1_digest,
+		(update_func) hmac_sha1_update,
+		(digest_func) hmac_sha1_digest,
+		(set_key_func) hmac_sha1_set_key,
+	},
+	{ "sha224", SHA224_DIGEST_SIZE,
+		(init_func) sha224_init,
+		(update_func) sha224_update,
+		(digest_func) sha224_digest,
+		(update_func) hmac_sha224_update,
+		(digest_func) hmac_sha224_digest,
+		(set_key_func) hmac_sha224_set_key,
+	},
+	{ "sha256", SHA256_DIGEST_SIZE,
+		(init_func) sha256_init,
+		(update_func) sha256_update,
+		(digest_func) sha256_digest,
+		(update_func) hmac_sha256_update,
+		(digest_func) hmac_sha256_digest,
+		(set_key_func) hmac_sha256_set_key,
+	},
+	{ "sha384", SHA384_DIGEST_SIZE,
+		(init_func) sha384_init,
+		(update_func) sha384_update,
+		(digest_func) sha384_digest,
+		(update_func) hmac_sha384_update,
+		(digest_func) hmac_sha384_digest,
+		(set_key_func) hmac_sha384_set_key,
+	},
+	{ "sha512", SHA512_DIGEST_SIZE,
+		(init_func) sha512_init,
+		(update_func) sha512_update,
+		(digest_func) sha512_digest,
+		(update_func) hmac_sha512_update,
+		(digest_func) hmac_sha512_digest,
+		(set_key_func) hmac_sha512_set_key,
+	},
+	{ "ripemd160", RIPEMD160_DIGEST_SIZE,
+		(init_func) ripemd160_init,
+		(update_func) ripemd160_update,
+		(digest_func) ripemd160_digest,
+		(update_func) hmac_ripemd160_update,
+		(digest_func) hmac_ripemd160_digest,
+		(set_key_func) hmac_ripemd160_set_key,
+	},
+/* Nettle prior to version 3.2 has incompatible SHA3 implementation */
+#if NETTLE_SHA3_FIPS202
+	{ "sha3-224", SHA3_224_DIGEST_SIZE,
+		(init_func) sha3_224_init,
+		(update_func) sha3_224_update,
+		(digest_func) sha3_224_digest,
+		(update_func) xhmac_sha3_224_update,
+		(digest_func) xhmac_sha3_224_digest,
+		(set_key_func) xhmac_sha3_224_set_key,
+	},
+	{ "sha3-256", SHA3_256_DIGEST_SIZE,
+		(init_func) sha3_256_init,
+		(update_func) sha3_256_update,
+		(digest_func) sha3_256_digest,
+		(update_func) xhmac_sha3_256_update,
+		(digest_func) xhmac_sha3_256_digest,
+		(set_key_func) xhmac_sha3_256_set_key,
+	},
+	{ "sha3-384", SHA3_384_DIGEST_SIZE,
+		(init_func) sha3_384_init,
+		(update_func) sha3_384_update,
+		(digest_func) sha3_384_digest,
+		(update_func) xhmac_sha3_384_update,
+		(digest_func) xhmac_sha3_384_digest,
+		(set_key_func) xhmac_sha3_384_set_key,
+	},
+	{ "sha3-512", SHA3_512_DIGEST_SIZE,
+		(init_func) sha3_512_init,
+		(update_func) sha3_512_update,
+		(digest_func) sha3_512_digest,
+		(update_func) xhmac_sha3_512_update,
+		(digest_func) xhmac_sha3_512_digest,
+		(set_key_func) xhmac_sha3_512_set_key,
+	},
+#endif
+	{ NULL, 0, NULL, NULL, NULL, NULL, NULL, NULL, }
+};
+
+struct crypt_hash {
+	const struct hash_alg *hash;
+	union {
+		struct sha1_ctx sha1;
+		struct sha224_ctx sha224;
+		struct sha256_ctx sha256;
+		struct sha384_ctx sha384;
+		struct sha512_ctx sha512;
+		struct ripemd160_ctx ripemd160;
+		struct sha3_224_ctx sha3_224;
+		struct sha3_256_ctx sha3_256;
+		struct sha3_384_ctx sha3_384;
+		struct sha3_512_ctx sha3_512;
+	} nettle_ctx;
+};
+
+struct crypt_hmac {
+	const struct hash_alg *hash;
+	union {
+		struct hmac_sha1_ctx sha1;
+		struct hmac_sha224_ctx sha224;
+		struct hmac_sha256_ctx sha256;
+		struct hmac_sha384_ctx sha384;
+		struct hmac_sha512_ctx sha512;
+		struct hmac_ripemd160_ctx ripemd160;
+		struct xhmac_sha3_224_ctx sha3_224;
+		struct xhmac_sha3_256_ctx sha3_256;
+		struct xhmac_sha3_384_ctx sha3_384;
+		struct xhmac_sha3_512_ctx sha3_512;
+	} nettle_ctx;
+	size_t key_length;
+	uint8_t *key;
+};
+
+struct crypt_cipher {
+	struct crypt_cipher_kernel ck;
+};
+
+uint32_t crypt_backend_flags(void)
+{
+	return 0;
+}
+
+static struct hash_alg *_get_alg(const char *name)
+{
+	int i = 0;
+
+	while (name && hash_algs[i].name) {
+		if (!strcmp(name, hash_algs[i].name))
+			return &hash_algs[i];
+		i++;
+	}
+	return NULL;
+}
+
+int crypt_backend_init(bool fips __attribute__((unused)))
+{
+	return 0;
+}
+
+void crypt_backend_destroy(void)
+{
+	return;
+}
+
+const char *crypt_backend_version(void)
+{
+	return version;
+}
+
+/* HASH */
+int crypt_hash_size(const char *name)
+{
+	struct hash_alg *ha = _get_alg(name);
+
+	return ha ? ha->length : -EINVAL;
+}
+
+int crypt_hash_init(struct crypt_hash **ctx, const char *name)
+{
+	struct crypt_hash *h;
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+
+	h->hash = _get_alg(name);
+	if (!h->hash) {
+		free(h);
+		return -EINVAL;
+	}
+
+	h->hash->init(&h->nettle_ctx);
+
+	*ctx = h;
+	return 0;
+}
+
+static void crypt_hash_restart(struct crypt_hash *ctx)
+{
+	ctx->hash->init(&ctx->nettle_ctx);
+}
+
+int crypt_hash_write(struct crypt_hash *ctx, const char *buffer, size_t length)
+{
+	ctx->hash->update(&ctx->nettle_ctx, length, (const uint8_t*)buffer);
+	return 0;
+}
+
+int crypt_hash_final(struct crypt_hash *ctx, char *buffer, size_t length)
+{
+	if (length > (size_t)ctx->hash->length)
+		return -EINVAL;
+
+	ctx->hash->digest(&ctx->nettle_ctx, length, (uint8_t *)buffer);
+	crypt_hash_restart(ctx);
+	return 0;
+}
+
+void crypt_hash_destroy(struct crypt_hash *ctx)
+{
+	memset(ctx, 0, sizeof(*ctx));
+	free(ctx);
+}
+
+/* HMAC */
+int crypt_hmac_size(const char *name)
+{
+	return crypt_hash_size(name);
+}
+
+int crypt_hmac_init(struct crypt_hmac **ctx, const char *name,
+		    const void *key, size_t key_length)
+{
+	struct crypt_hmac *h;
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+	memset(ctx, 0, sizeof(*ctx));
+
+
+	h->hash = _get_alg(name);
+	if (!h->hash) {
+		free(h);
+		return -EINVAL;
+	}
+
+	h->key = malloc(key_length);
+	if (!h->key) {
+		free(h);
+		return -ENOMEM;
+	}
+
+	memcpy(h->key, key, key_length);
+	h->key_length = key_length;
+
+	h->hash->init(&h->nettle_ctx);
+	h->hash->hmac_set_key(&h->nettle_ctx, h->key_length, h->key);
+
+	*ctx = h;
+	return 0;
+}
+
+static void crypt_hmac_restart(struct crypt_hmac *ctx)
+{
+	ctx->hash->hmac_set_key(&ctx->nettle_ctx, ctx->key_length, ctx->key);
+}
+
+int crypt_hmac_write(struct crypt_hmac *ctx, const char *buffer, size_t length)
+{
+	ctx->hash->hmac_update(&ctx->nettle_ctx, length, (const uint8_t *)buffer);
+	return 0;
+}
+
+int crypt_hmac_final(struct crypt_hmac *ctx, char *buffer, size_t length)
+{
+	if (length > (size_t)ctx->hash->length)
+		return -EINVAL;
+
+	ctx->hash->hmac_digest(&ctx->nettle_ctx, length, (uint8_t *)buffer);
+	crypt_hmac_restart(ctx);
+	return 0;
+}
+
+void crypt_hmac_destroy(struct crypt_hmac *ctx)
+{
+	memset(ctx->key, 0, ctx->key_length);
+	free(ctx->key);
+	memset(ctx, 0, sizeof(*ctx));
+	free(ctx);
+}
+
+/* RNG - N/A */
+int crypt_backend_rng(char *buffer __attribute__((unused)),
+		      size_t length __attribute__((unused)),
+		      int quality __attribute__((unused)),
+		      int fips __attribute__((unused)))
+{
+	return -EINVAL;
+}
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		uint32_t iterations, uint32_t memory, uint32_t parallel)
+{
+	struct crypt_hmac *h;
+	int r;
+
+	if (!kdf)
+		return -EINVAL;
+
+	if (!strcmp(kdf, "pbkdf2")) {
+		r = crypt_hmac_init(&h, hash, password, password_length);
+		if (r < 0)
+			return r;
+
+		nettle_pbkdf2(&h->nettle_ctx, h->hash->hmac_update,
+			      h->hash->hmac_digest, h->hash->length, iterations,
+			      salt_length, (const uint8_t *)salt, key_length,
+			      (uint8_t *)key);
+		crypt_hmac_destroy(h);
+		return 0;
+	} else if (!strncmp(kdf, "argon2", 6)) {
+		return argon2(kdf, password, password_length, salt, salt_length,
+			      key, key_length, iterations, memory, parallel);
+	}
+
+	return -EINVAL;
+}
+
+/* Block ciphers */
+int crypt_cipher_init(struct crypt_cipher **ctx, const char *name,
+		    const char *mode, const void *key, size_t key_length)
+{
+	struct crypt_cipher *h;
+	int r;
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+
+	r = crypt_cipher_init_kernel(&h->ck, name, mode, key, key_length);
+	if (r < 0) {
+		free(h);
+		return r;
+	}
+
+	*ctx = h;
+	return 0;
+}
+
+void crypt_cipher_destroy(struct crypt_cipher *ctx)
+{
+	crypt_cipher_destroy_kernel(&ctx->ck);
+	free(ctx);
+}
+
+int crypt_cipher_encrypt(struct crypt_cipher *ctx,
+			 const char *in, char *out, size_t length,
+			 const char *iv, size_t iv_length)
+{
+	return crypt_cipher_encrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
+}
+
+int crypt_cipher_decrypt(struct crypt_cipher *ctx,
+			 const char *in, char *out, size_t length,
+			 const char *iv, size_t iv_length)
+{
+	return crypt_cipher_decrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
+}
+
+bool crypt_cipher_kernel_only(struct crypt_cipher *ctx __attribute__((unused)))
+{
+	return true;
+}
+
+int crypt_bitlk_decrypt_key(const void *key, size_t key_length,
+			    const char *in, char *out, size_t length,
+			    const char *iv, size_t iv_length,
+			    const char *tag, size_t tag_length)
+{
+	return crypt_bitlk_decrypt_key_kernel(key, key_length, in, out, length,
+					      iv, iv_length, tag, tag_length);
+}
+
+int crypt_backend_memeq(const void *m1, const void *m2, size_t n)
+{
+	/* The logic is inverse to memcmp... */
+	return !memeql_sec(m1, m2, n);
+}
+
+bool crypt_fips_mode(void)
+{
+	return false;
+}