Encryption patch follow-up

* PBKDF2 implementation changed to OpenSSL implementation.

* HKDF implementation moved to its own file and tests
  added to ensure correctness.

* Removed libzfs's now unnecessary dependency on libzpool
  and libicp.

* Ztest can now create and test encrypted datasets. This is
  currently disabled until issue #6526 is resolved, but
  otherwise functions as advertised.

* Several small bug fixes discovered after enabling ztest
  to run on encrypted datasets.

* Fixed coverity defects added by the encryption patch.

* Updated man pages for encrypted send / receive behavior.

* Fixed a bug where encrypted datasets could receive
  DRR_WRITE_EMBEDDED records.

* Minor code cleanups / consolidation.

Signed-off-by: Tom Caputi <[email protected]>

1 files changed, 171 insertions, 0 deletions

diff --git a/module/zfs/hkdf.c b/module/zfs/hkdf.c
new file mode 100644
index 000000000..14265472d
--- /dev/null
+++ b/module/zfs/hkdf.c
@@ -0,0 +1,171 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2017, Datto, Inc. All rights reserved.
+ */
+
+#include <sys/crypto/api.h>
+#include <sys/sha2.h>
+#include <sys/hkdf.h>
+
+static int
+hkdf_sha512_extract(uint8_t *salt, uint_t salt_len, uint8_t *key_material,
+    uint_t km_len, uint8_t *out_buf)
+{
+	int ret;
+	crypto_mechanism_t mech;
+	crypto_key_t key;
+	crypto_data_t input_cd, output_cd;
+
+	/* initialize HMAC mechanism */
+	mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
+	mech.cm_param = NULL;
+	mech.cm_param_len = 0;
+
+	/* initialize the salt as a crypto key */
+	key.ck_format = CRYPTO_KEY_RAW;
+	key.ck_length = CRYPTO_BYTES2BITS(salt_len);
+	key.ck_data = salt;
+
+	/* initialize crypto data for the input and output data */
+	input_cd.cd_format = CRYPTO_DATA_RAW;
+	input_cd.cd_offset = 0;
+	input_cd.cd_length = km_len;
+	input_cd.cd_raw.iov_base = (char *)key_material;
+	input_cd.cd_raw.iov_len = input_cd.cd_length;
+
+	output_cd.cd_format = CRYPTO_DATA_RAW;
+	output_cd.cd_offset = 0;
+	output_cd.cd_length = SHA512_DIGEST_LENGTH;
+	output_cd.cd_raw.iov_base = (char *)out_buf;
+	output_cd.cd_raw.iov_len = output_cd.cd_length;
+
+	ret = crypto_mac(&mech, &input_cd, &key, NULL, &output_cd, NULL);
+	if (ret != CRYPTO_SUCCESS)
+		return (SET_ERROR(EIO));
+
+	return (0);
+}
+
+static int
+hkdf_sha512_expand(uint8_t *extract_key, uint8_t *info, uint_t info_len,
+    uint8_t *out_buf, uint_t out_len)
+{
+	int ret;
+	crypto_mechanism_t mech;
+	crypto_context_t ctx;
+	crypto_key_t key;
+	crypto_data_t T_cd, info_cd, c_cd;
+	uint_t i, T_len = 0, pos = 0;
+	uint8_t c;
+	uint_t N = (out_len + SHA512_DIGEST_LENGTH) / SHA512_DIGEST_LENGTH;
+	uint8_t T[SHA512_DIGEST_LENGTH];
+
+	if (N > 255)
+		return (SET_ERROR(EINVAL));
+
+	/* initialize HMAC mechanism */
+	mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
+	mech.cm_param = NULL;
+	mech.cm_param_len = 0;
+
+	/* initialize the salt as a crypto key */
+	key.ck_format = CRYPTO_KEY_RAW;
+	key.ck_length = CRYPTO_BYTES2BITS(SHA512_DIGEST_LENGTH);
+	key.ck_data = extract_key;
+
+	/* initialize crypto data for the input and output data */
+	T_cd.cd_format = CRYPTO_DATA_RAW;
+	T_cd.cd_offset = 0;
+	T_cd.cd_raw.iov_base = (char *)T;
+
+	c_cd.cd_format = CRYPTO_DATA_RAW;
+	c_cd.cd_offset = 0;
+	c_cd.cd_length = 1;
+	c_cd.cd_raw.iov_base = (char *)&c;
+	c_cd.cd_raw.iov_len = c_cd.cd_length;
+
+	info_cd.cd_format = CRYPTO_DATA_RAW;
+	info_cd.cd_offset = 0;
+	info_cd.cd_length = info_len;
+	info_cd.cd_raw.iov_base = (char *)info;
+	info_cd.cd_raw.iov_len = info_cd.cd_length;
+
+	for (i = 1; i <= N; i++) {
+		c = i;
+
+		T_cd.cd_length = T_len;
+		T_cd.cd_raw.iov_len = T_cd.cd_length;
+
+		ret = crypto_mac_init(&mech, &key, NULL, &ctx, NULL);
+		if (ret != CRYPTO_SUCCESS)
+			return (SET_ERROR(EIO));
+
+		ret = crypto_mac_update(ctx, &T_cd, NULL);
+		if (ret != CRYPTO_SUCCESS)
+			return (SET_ERROR(EIO));
+
+		ret = crypto_mac_update(ctx, &info_cd, NULL);
+		if (ret != CRYPTO_SUCCESS)
+			return (SET_ERROR(EIO));
+
+		ret = crypto_mac_update(ctx, &c_cd, NULL);
+		if (ret != CRYPTO_SUCCESS)
+			return (SET_ERROR(EIO));
+
+		T_len = SHA512_DIGEST_LENGTH;
+		T_cd.cd_length = T_len;
+		T_cd.cd_raw.iov_len = T_cd.cd_length;
+
+		ret = crypto_mac_final(ctx, &T_cd, NULL);
+		if (ret != CRYPTO_SUCCESS)
+			return (SET_ERROR(EIO));
+
+		bcopy(T, out_buf + pos,
+		    (i != N) ? SHA512_DIGEST_LENGTH : (out_len - pos));
+		pos += SHA512_DIGEST_LENGTH;
+	}
+
+	return (0);
+}
+
+/*
+ * HKDF is designed to be a relatively fast function for deriving keys from a
+ * master key + a salt. We use this function to generate new encryption keys
+ * so as to avoid hitting the cryptographic limits of the underlying
+ * encryption modes. Note that, for the sake of deriving encryption keys, the
+ * info parameter is called the "salt" everywhere else in the code.
+ */
+int
+hkdf_sha512(uint8_t *key_material, uint_t km_len, uint8_t *salt,
+    uint_t salt_len, uint8_t *info, uint_t info_len, uint8_t *output_key,
+    uint_t out_len)
+{
+	int ret;
+	uint8_t extract_key[SHA512_DIGEST_LENGTH];
+
+	ret = hkdf_sha512_extract(salt, salt_len, key_material, km_len,
+	    extract_key);
+	if (ret != 0)
+		return (ret);
+
+	ret = hkdf_sha512_expand(extract_key, info, info_len, output_key,
+	    out_len);
+	if (ret != 0)
+		return (ret);
+
+	return (0);
+}