crypto_sha512crypt.c is a clone of nss_sha512crypt.c with the exception that
all usage of NSS and related libraries has been switched to libcrypto. I
renamed nss_sha512crypt.h to sha512crypt.h since it is common to both
crypto_sha512crypt.c and nss_sha512crypt.c. Note that the random number
generator is not seeded manually and thus relies on seeding done automatically
by libcrypto. On some systems without /dev/urandom seeding may not be
performed. See http://www.openssl.org/docs/crypto/RAND_add.html.
Signed-off-by: George McCollister <geor...@novatech-llc.com>
---
server/Makefile.am | 28 ++-
server/configure.ac | 14 +-
server/db/sysdb_ops.c | 2 +-
server/responder/pam/pam_LOCAL_domain.c | 2 +-
server/util/crypto_sha512crypt.c | 380 +++++++++++++++++++++++++++++++
server/util/nss_sha512crypt.h | 4 -
server/util/sha512crypt.h | 4 +
7 files changed, 423 insertions(+), 11 deletions(-)
create mode 100644 server/util/crypto_sha512crypt.c
delete mode 100644 server/util/nss_sha512crypt.h
create mode 100644 server/util/sha512crypt.h
diff --git a/server/Makefile.am b/server/Makefile.am
index 7ba7ffa..0b96cca 100644
--- a/server/Makefile.am
+++ b/server/Makefile.am
@@ -102,12 +102,22 @@ endif
noinst_LTLIBRARIES = \
libsss_crypt.la
+
+if HAVE_NSS
libsss_crypt_la_SOURCES = \
util/nss_sha512crypt.c
libsss_crypt_la_CPPFLAGS = \
$(NSS_CFLAGS)
libsss_crypt_la_LIBADD = \
$(NSS_LIBS)
+else
+libsss_crypt_la_SOURCES = \
+ util/crypto_sha512crypt.c
+libsss_crypt_la_CPPFLAGS = \
+ $(CRYPTO_CFLAGS)
+libsss_crypt_la_LIBADD = \
+ $(CRYPTO_LIBS)
+endif
if BUILD_PYTHON_BINDINGS
pyexec_LTLIBRARIES = \
@@ -243,8 +253,13 @@ SSSD_LIBS = \
$(COLLECTION_LIBS) \
$(DHASH_LIBS) \
$(REPLACE_LIBS) \
- libsss_crypt.la \
- $(NSS_LIBS)
+ libsss_crypt.la
+
+if HAVE_NSS
+ SSSD_LIBS += $(NSS_LIBS)
+else
+ SSSD_LIBS += $(CRYPTO_LIBS)
+endif
PYTHON_BINDINGS_LIBS = \
$(TALLOC_LIBS) \
@@ -254,9 +269,14 @@ PYTHON_BINDINGS_LIBS = \
$(DBUS_LIBS) \
$(REPLACE_LIBS) \
$(PCRE_LIBS) \
- $(NSS_LIBS) \
libsss_crypt.la
+if HAVE_NSS
+ PYTHON_BINDINGS_LIBS += $(NSS_LIBS)
+else
+ PYTHON_BINDINGS_LIBS += $(CRYPTO_LIBS)
+endif
+
TOOLS_LIBS = \
$(TALLOC_LIBS) \
$(TEVENT_LIBS) \
@@ -276,7 +296,7 @@ endif
dist_noinst_HEADERS = \
monitor/monitor.h \
- util/nss_sha512crypt.h \
+ util/sha512crypt.h \
util/dlinklist.h \
util/util.h \
util/strtonum.h \
diff --git a/server/configure.ac b/server/configure.ac
index 75c07da..d1cce47 100644
--- a/server/configure.ac
+++ b/server/configure.ac
@@ -77,6 +77,12 @@ m4_include([external/python.m4])
m4_include([external/selinux.m4])
m4_include([util/signal.m4])
+AC_ARG_ENABLE(crypto,
+ [ --enable-crypto Use OpenSSL crypto instead of NSS],
+ [CRYPTO="$enableval"],
+ [CRYPTO="no"]
+)
+
PKG_CHECK_MODULES([DBUS],[dbus-1])
dnl if test -n "`$PKG_CONFIG --modversion dbus-1 | grep '^0\.'`" ; then
if ! $PKG_CONFIG --atleast-version 1.0.0 dbus-1; then
@@ -93,7 +99,13 @@ if test x$has_dbus != xno; then
LDFLAGS="$SAFE_LDFLAGS"
fi
-PKG_CHECK_MODULES([NSS],[nss])
+if test x$CRYPTO != xyes; then
+ PKG_CHECK_MODULES([NSS],[nss],[have_nss=1],[have_nss=])
+else
+ PKG_CHECK_MODULES([CRYPTO],[libcrypto],[have_crypto=1],[have_crypto=])
+fi
+AM_CONDITIONAL([HAVE_NSS], [test x$have_nss != x])
+AM_CONDITIONAL([HAVE_CRYPTO], [test x$have_crypto != x])
if test x$HAVE_MANPAGES != x; then
CHECK_XML_TOOLS
diff --git a/server/db/sysdb_ops.c b/server/db/sysdb_ops.c
index 36b5867..38686ae 100644
--- a/server/db/sysdb_ops.c
+++ b/server/db/sysdb_ops.c
@@ -21,7 +21,7 @@
#include "util/util.h"
#include "db/sysdb_private.h"
-#include "util/nss_sha512crypt.h"
+#include "util/sha512crypt.h"
#include <time.h>
static int add_string(struct ldb_message *msg, int flags,
diff --git a/server/responder/pam/pam_LOCAL_domain.c b/server/responder/pam/pam_LOCAL_domain.c
index 9d3738c..6fa42a4 100644
--- a/server/responder/pam/pam_LOCAL_domain.c
+++ b/server/responder/pam/pam_LOCAL_domain.c
@@ -24,7 +24,7 @@
#include "util/util.h"
#include "db/sysdb.h"
-#include "util/nss_sha512crypt.h"
+#include "util/sha512crypt.h"
#include "providers/data_provider.h"
#include "responder/pam/pamsrv.h"
diff --git a/server/util/crypto_sha512crypt.c b/server/util/crypto_sha512crypt.c
new file mode 100644
index 0000000..6acd654
--- /dev/null
+++ b/server/util/crypto_sha512crypt.c
@@ -0,0 +1,380 @@
+/* This file is based on the work of Ulrich Drepper
+ * (http://people.redhat.com/drepper/SHA-crypt.txt). I have replaced the
+ * included SHA512 implementation by calls to NSS
+ * (http://www.mozilla.org/projects/security/pki/nss/).
+ *
+ * Sumit Bose <sb...@redhat.com>
+ */
+/* SHA512-based Unix crypt implementation.
+ Released into the Public Domain by Ulrich Drepper <drep...@redhat.com>. */
+
+#define _GNU_SOURCE
+#include <endian.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/param.h>
+#include <sys/types.h>
+
+#include "util/util.h"
+
+#include <openssl/evp.h>
+#include <openssl/rand.h>
+
+/* Define our magic string to mark salt for SHA512 "encryption" replacement. */
+const char sha512_salt_prefix[] = "$6$";
+#define SALT_PREF_SIZE (sizeof(sha512_salt_prefix) - 1)
+
+/* Prefix for optional rounds specification. */
+const char sha512_rounds_prefix[] = "rounds=";
+#define ROUNDS_SIZE (sizeof(sha512_rounds_prefix) - 1)
+
+#define SALT_LEN_MAX 16
+#define ROUNDS_DEFAULT 5000
+#define ROUNDS_MIN 1000
+#define ROUNDS_MAX 999999999
+
+/* Table with characters for base64 transformation. */
+const char b64t[64] =
+ "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+/* base64 conversion function */
+static inline void b64_from_24bit(char **dest, size_t *len, size_t n,
+ uint8_t b2, uint8_t b1, uint8_t b0)
+{
+ uint32_t w;
+ size_t i;
+
+ if (*len < n) n = *len;
+
+ w = (b2 << 16) | (b1 << 8) | b0;
+ for (i = 0; i < n; i++) {
+ (*dest)[i] = b64t[w & 0x3f];
+ w >>= 6;
+ }
+
+ *len -= i;
+ *dest += i;
+}
+
+#define PTR_2_INT(x) ((x) - ((__typeof__ (x)) NULL))
+#define ALIGN64 __alignof__(uint64_t)
+
+static int sha512_crypt_r(const char *key,
+ const char *salt,
+ char *buffer, size_t buflen)
+{
+ unsigned char temp_result[64] __attribute__((__aligned__(ALIGN64)));
+ unsigned char alt_result[64] __attribute__((__aligned__(ALIGN64)));
+ size_t rounds = ROUNDS_DEFAULT;
+ bool rounds_custom = false;
+ EVP_MD_CTX alt_ctx;
+ EVP_MD_CTX ctx;
+ size_t salt_len;
+ size_t key_len;
+ size_t cnt;
+ char *copied_salt = NULL;
+ char *copied_key = NULL;
+ char *p_bytes = NULL;
+ char *s_bytes = NULL;
+ int p1, p2, p3, pt, n;
+ unsigned int part;
+ char *cp, *tmp;
+ int ret;
+
+ /* Find beginning of salt string. The prefix should normally always be
+ * present. Just in case it is not. */
+ if (strncmp(salt, sha512_salt_prefix, SALT_PREF_SIZE) == 0) {
+ /* Skip salt prefix. */
+ salt += SALT_PREF_SIZE;
+ }
+
+ if (strncmp(salt, sha512_rounds_prefix, ROUNDS_SIZE) == 0) {
+ unsigned long int srounds;
+ const char *num;
+ char *endp;
+
+ num = salt + ROUNDS_SIZE;
+ srounds = strtoul(num, &endp, 10);
+ if (*endp == '$') {
+ salt = endp + 1;
+ if (srounds < ROUNDS_MIN) srounds = ROUNDS_MIN;
+ if (srounds > ROUNDS_MAX) srounds = ROUNDS_MAX;
+ rounds = srounds;
+ rounds_custom = true;
+ }
+ }
+
+ salt_len = MIN(strcspn(salt, "$"), SALT_LEN_MAX);
+ key_len = strlen(key);
+
+ if ((PTR_2_INT(key) % ALIGN64) != 0) {
+ tmp = (char *)alloca(key_len + ALIGN64);
+ key = copied_key = memcpy(tmp + ALIGN64 - PTR_2_INT(tmp) % ALIGN64, key, key_len);
+ }
+
+ if (PTR_2_INT(salt) % ALIGN64 != 0) {
+ tmp = (char *)alloca(salt_len + ALIGN64);
+ salt = copied_salt = memcpy(tmp + ALIGN64 - PTR_2_INT(tmp) % ALIGN64, salt, salt_len);
+ }
+
+ EVP_MD_CTX_init(&ctx);
+
+ EVP_MD_CTX_init(&alt_ctx);
+
+ /* Prepare for the real work. */
+ if (!EVP_DigestInit_ex(&ctx, EVP_sha512(), NULL)) {
+ ret = EIO;
+ goto done;
+ }
+
+ /* Add the key string. */
+ EVP_DigestUpdate(&ctx, (const unsigned char *)key, key_len);
+
+ /* The last part is the salt string. This must be at most 16
+ * characters and it ends at the first `$' character (for
+ * compatibility with existing implementations). */
+ EVP_DigestUpdate(&ctx, (const unsigned char *)salt, salt_len);
+
+
+ /* Compute alternate SHA512 sum with input KEY, SALT, and KEY.
+ * The final result will be added to the first context. */
+ if (!EVP_DigestInit_ex(&alt_ctx, EVP_sha512(), NULL)) {
+ ret = EIO;
+ goto done;
+ }
+
+ /* Add key. */
+ EVP_DigestUpdate(&alt_ctx, (const unsigned char *)key, key_len);
+
+ /* Add salt. */
+ EVP_DigestUpdate(&alt_ctx, (const unsigned char *)salt, salt_len);
+
+ /* Add key again. */
+ EVP_DigestUpdate(&alt_ctx, (const unsigned char *)key, key_len);
+
+ /* Now get result of this (64 bytes) and add it to the other context. */
+ EVP_DigestFinal_ex(&alt_ctx, alt_result, &part);
+
+ /* Add for any character in the key one byte of the alternate sum. */
+ for (cnt = key_len; cnt > 64; cnt -= 64) {
+ EVP_DigestUpdate(&ctx, alt_result, 64);
+ }
+ EVP_DigestUpdate(&ctx, alt_result, cnt);
+
+ /* Take the binary representation of the length of the key and for every
+ * 1 add the alternate sum, for every 0 the key. */
+ for (cnt = key_len; cnt > 0; cnt >>= 1) {
+ if ((cnt & 1) != 0) {
+ EVP_DigestUpdate(&ctx, alt_result, 64);
+ } else {
+ EVP_DigestUpdate(&ctx, (const unsigned char *)key, key_len);
+ }
+ }
+
+ /* Create intermediate result. */
+ EVP_DigestFinal_ex(&ctx, alt_result, &part);
+
+ /* Start computation of P byte sequence. */
+ if (!EVP_DigestInit_ex(&alt_ctx, EVP_sha512(), NULL)) {
+ ret = EIO;
+ goto done;
+ }
+
+ /* For every character in the password add the entire password. */
+ for (cnt = 0; cnt < key_len; cnt++) {
+ EVP_DigestUpdate(&alt_ctx, (const unsigned char *)key, key_len);
+ }
+
+ /* Finish the digest. */
+ EVP_DigestFinal_ex(&alt_ctx, temp_result, &part);
+
+ /* Create byte sequence P. */
+ cp = p_bytes = alloca(key_len);
+ for (cnt = key_len; cnt >= 64; cnt -= 64) {
+ cp = mempcpy(cp, temp_result, 64);
+ }
+ memcpy(cp, temp_result, cnt);
+
+ /* Start computation of S byte sequence. */
+ if (!EVP_DigestInit_ex(&alt_ctx, EVP_sha512(), NULL)) {
+ ret = EIO;
+ goto done;
+ }
+
+ /* For every character in the password add the entire salt. */
+ for (cnt = 0; cnt < 16 + alt_result[0]; cnt++) {
+ EVP_DigestUpdate(&alt_ctx, (const unsigned char *)salt, salt_len);
+ }
+
+ /* Finish the digest. */
+ EVP_DigestFinal_ex(&alt_ctx, temp_result, &part);
+
+ /* Create byte sequence S. */
+ cp = s_bytes = alloca(salt_len);
+ for (cnt = salt_len; cnt >= 64; cnt -= 64) {
+ cp = mempcpy(cp, temp_result, 64);
+ }
+ memcpy(cp, temp_result, cnt);
+
+ /* Repeatedly run the collected hash value through SHA512 to burn CPU cycles. */
+ for (cnt = 0; cnt < rounds; cnt++) {
+
+ if (!EVP_DigestInit_ex(&ctx, EVP_sha512(), NULL)) {
+ ret = EIO;
+ goto done;
+ }
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0) {
+ EVP_DigestUpdate(&ctx, (const unsigned char *)p_bytes, key_len);
+ } else {
+ EVP_DigestUpdate(&ctx, alt_result, 64);
+ }
+
+ /* Add salt for numbers not divisible by 3. */
+ if (cnt % 3 != 0) {
+ EVP_DigestUpdate(&ctx, (const unsigned char *)s_bytes, salt_len);
+ }
+
+ /* Add key for numbers not divisible by 7. */
+ if (cnt % 7 != 0) {
+ EVP_DigestUpdate(&ctx, (const unsigned char *)p_bytes, key_len);
+ }
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0) {
+ EVP_DigestUpdate(&ctx, alt_result, 64);
+ } else {
+ EVP_DigestUpdate(&ctx, (const unsigned char *)p_bytes, key_len);
+ }
+
+ /* Create intermediate result. */
+ EVP_DigestFinal_ex(&ctx, alt_result, &part);
+ }
+
+ /* Now we can construct the result string.
+ * It consists of three parts. */
+ if (buflen <= SALT_PREF_SIZE) {
+ ret = ERANGE;
+ goto done;
+ }
+
+ cp = __stpncpy(buffer, sha512_salt_prefix, SALT_PREF_SIZE);
+ buflen -= SALT_PREF_SIZE;
+
+ if (rounds_custom) {
+ n = snprintf(cp, buflen, "%s%zu$",
+ sha512_rounds_prefix, rounds);
+ if (n < 0 || n >= buflen) {
+ ret = ERANGE;
+ goto done;
+ }
+ cp += n;
+ buflen -= n;
+ }
+
+ if (buflen <= salt_len + 1) {
+ ret = ERANGE;
+ goto done;
+ }
+ cp = __stpncpy(cp, salt, salt_len);
+ *cp++ = '$';
+ buflen -= salt_len + 1;
+
+ /* fuzzyfill the base 64 string */
+ p1 = 0;
+ p2 = 21;
+ p3 = 42;
+ for (n = 0; n < 21; n++) {
+ b64_from_24bit(&cp, &buflen, 4, alt_result[p1], alt_result[p2], alt_result[p3]);
+ if (buflen == 0) {
+ ret = ERANGE;
+ goto done;
+ }
+ pt = p1;
+ p1 = p2 + 1;
+ p2 = p3 + 1;
+ p3 = pt + 1;
+ }
+ /* 64th and last byte */
+ b64_from_24bit(&cp, &buflen, 2, 0, 0, alt_result[p3]);
+ if (buflen == 0) {
+ ret = ERANGE;
+ goto done;
+ }
+
+ *cp = '\0';
+ ret = EOK;
+
+done:
+ /* Clear the buffer for the intermediate result so that people attaching
+ * to processes or reading core dumps cannot get any information. We do it
+ * in this way to clear correct_words[] inside the SHA512 implementation
+ * as well. */
+ EVP_MD_CTX_cleanup(&ctx);
+ EVP_MD_CTX_cleanup(&alt_ctx);
+ if (p_bytes) memset(p_bytes, '\0', key_len);
+ if (s_bytes) memset(s_bytes, '\0', salt_len);
+ if (copied_key) memset(copied_key, '\0', key_len);
+ if (copied_salt) memset(copied_salt, '\0', salt_len);
+ memset(temp_result, '\0', sizeof(temp_result));
+
+ return ret;
+}
+
+int s3crypt_sha512(TALLOC_CTX *memctx,
+ const char *key, const char *salt, char **_hash)
+{
+ char *hash;
+ int hlen = (sizeof (sha512_salt_prefix) - 1
+ + sizeof (sha512_rounds_prefix) + 9 + 1
+ + strlen (salt) + 1 + 86 + 1);
+ int ret;
+
+ hash = talloc_size(memctx, hlen);
+ if (!hash) return ENOMEM;
+
+ ret = sha512_crypt_r(key, salt, hash, hlen);
+ if (ret) return ret;
+
+ *_hash = hash;
+ return ret;
+}
+
+#define SALT_RAND_LEN 12
+
+int s3crypt_gen_salt(TALLOC_CTX *memctx, char **_salt)
+{
+ uint8_t rb[SALT_RAND_LEN];
+ char *salt, *cp;
+ size_t slen;
+ int ret;
+
+ salt = talloc_size(memctx, SALT_LEN_MAX + 1);
+ if (!salt) {
+ return ENOMEM;
+ }
+
+ ret = RAND_bytes(rb, SALT_RAND_LEN);
+ if (ret == 0) {
+ return EIO;
+ }
+
+ slen = SALT_LEN_MAX;
+ cp = salt;
+ b64_from_24bit(&cp, &slen, 4, rb[0], rb[1], rb[2]);
+ b64_from_24bit(&cp, &slen, 4, rb[3], rb[4], rb[5]);
+ b64_from_24bit(&cp, &slen, 4, rb[6], rb[7], rb[8]);
+ b64_from_24bit(&cp, &slen, 4, rb[9], rb[10], rb[11]);
+ *cp = '\0';
+
+ *_salt = salt;
+
+ return EOK;
+}
+
diff --git a/server/util/nss_sha512crypt.h b/server/util/nss_sha512crypt.h
deleted file mode 100644
index 5512c5d..0000000
--- a/server/util/nss_sha512crypt.h
+++ /dev/null
@@ -1,4 +0,0 @@
-
-int s3crypt_sha512(TALLOC_CTX *mmectx,
- const char *key, const char *salt, char **_hash);
-int s3crypt_gen_salt(TALLOC_CTX *memctx, char **_salt);
diff --git a/server/util/sha512crypt.h b/server/util/sha512crypt.h
new file mode 100644
index 0000000..5512c5d
--- /dev/null
+++ b/server/util/sha512crypt.h
@@ -0,0 +1,4 @@
+
+int s3crypt_sha512(TALLOC_CTX *mmectx,
+ const char *key, const char *salt, char **_hash);
+int s3crypt_gen_salt(TALLOC_CTX *memctx, char **_salt);
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