summaryrefslogtreecommitdiff
path: root/server/util
diff options
context:
space:
mode:
Diffstat (limited to 'server/util')
-rw-r--r--server/util/nss_sha512crypt.c419
-rw-r--r--server/util/nss_sha512crypt.h3
2 files changed, 422 insertions, 0 deletions
diff --git a/server/util/nss_sha512crypt.c b/server/util/nss_sha512crypt.c
new file mode 100644
index 00000000..84cb61c2
--- /dev/null
+++ b/server/util/nss_sha512crypt.c
@@ -0,0 +1,419 @@
+/* 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 <sbose@redhat.com>
+ */
+/* SHA512-based Unix crypt implementation.
+ Released into the Public Domain by Ulrich Drepper <drepper@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 <prinit.h>
+#include <nss.h>
+#include <sechash.h>
+#include <pk11func.h>
+
+
+static int nspr_nss_init_done = 0;
+
+/* according to
+ * http://www.mozilla.org/projects/security/pki/nss/ref/ssl/sslfnc.html#1234224
+ * PR_Init must be called, but at least for the HASH_* calls it seems to work
+ * quite well without. */
+static int nspr_nss_init(void)
+{
+ int ret;
+ PR_Init(PR_USER_THREAD, PR_PRIORITY_NORMAL, 0);
+ ret = NSS_NoDB_Init(NULL);
+ if (ret != SECSuccess) {
+ return ret;
+ }
+ nspr_nss_init_done = 1;
+ return 0;
+}
+
+/* added for completness, so far not used */
+static int nspr_nss_cleanup(void)
+{
+ int ret;
+ ret=NSS_Shutdown();
+ if (ret != SECSuccess ) {
+ return ret;
+ }
+ PR_Cleanup();
+ nspr_nss_init_done = 0;
+ return 0;
+}
+
+/* Define our magic string to mark salt for SHA512 "encryption"
+ replacement. */
+static const char sha512_salt_prefix[] = "$6$";
+
+/* Prefix for optional rounds specification. */
+static const char sha512_rounds_prefix[] = "rounds=";
+
+/* Maximum salt string length. */
+#define SALT_LEN_MAX 16
+/* Default number of rounds if not explicitly specified. */
+#define ROUNDS_DEFAULT 5000
+/* Minimum number of rounds. */
+#define ROUNDS_MIN 1000
+/* Maximum number of rounds. */
+#define ROUNDS_MAX 999999999
+
+/* Table with characters for base64 transformation. */
+static const char b64t[64] =
+"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+
+static char *
+sha512_crypt_r (const char *key, const char *salt, char *buffer, int buflen)
+{
+ unsigned char alt_result[64]
+ __attribute__ ((__aligned__ (__alignof__ (uint64_t))));
+ unsigned char temp_result[64]
+ __attribute__ ((__aligned__ (__alignof__ (uint64_t))));
+ HASHContext *ctx;
+ HASHContext *alt_ctx;
+ size_t salt_len;
+ size_t key_len;
+ size_t cnt;
+ char *cp;
+ char *copied_key = NULL;
+ char *copied_salt = NULL;
+ char *p_bytes;
+ char *s_bytes;
+ /* Default number of rounds. */
+ size_t rounds = ROUNDS_DEFAULT;
+ bool rounds_custom = false;
+
+ int ret;
+ unsigned int part;
+
+ /* Find beginning of salt string. The prefix should normally always
+ be present. Just in case it is not. */
+ if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
+ /* Skip salt prefix. */
+ salt += sizeof (sha512_salt_prefix) - 1;
+
+ if (strncmp (salt, sha512_rounds_prefix, sizeof (sha512_rounds_prefix) - 1)
+ == 0)
+ {
+ const char *num = salt + sizeof (sha512_rounds_prefix) - 1;
+ char *endp;
+ unsigned long int srounds = strtoul (num, &endp, 10);
+ if (*endp == '$')
+ {
+ salt = endp + 1;
+ rounds = MAX (ROUNDS_MIN, MIN (srounds, ROUNDS_MAX));
+ rounds_custom = true;
+ }
+ }
+
+ salt_len = MIN (strcspn (salt, "$"), SALT_LEN_MAX);
+ key_len = strlen (key);
+
+ if ((key - (char *) 0) % __alignof__ (uint64_t) != 0)
+ {
+ char *tmp = (char *) alloca (key_len + __alignof__ (uint64_t));
+ key = copied_key =
+ memcpy (tmp + __alignof__ (uint64_t)
+ - (tmp - (char *) 0) % __alignof__ (uint64_t),
+ key, key_len);
+ }
+
+ if ((salt - (char *) 0) % __alignof__ (uint64_t) != 0)
+ {
+ char *tmp = (char *) alloca (salt_len + __alignof__ (uint64_t));
+ salt = copied_salt =
+ memcpy (tmp + __alignof__ (uint64_t)
+ - (tmp - (char *) 0) % __alignof__ (uint64_t),
+ salt, salt_len);
+ }
+
+
+ if (!nspr_nss_init_done) {
+ ret = nspr_nss_init();
+ if (ret != SECSuccess) return NULL;
+ }
+
+ ctx = HASH_Create(HASH_AlgSHA512);
+ if ( ctx == NULL ) {
+ return NULL;
+ }
+
+ alt_ctx = HASH_Create(HASH_AlgSHA512);
+ if ( alt_ctx == NULL ) {
+ return NULL;
+ }
+
+
+ /* Prepare for the real work. */
+ HASH_Begin(ctx);
+
+ /* Add the key string. */
+ HASH_Update(ctx, 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). */
+ HASH_Update(ctx, salt, salt_len);
+
+
+ /* Compute alternate SHA512 sum with input KEY, SALT, and KEY. The
+ final result will be added to the first context. */
+ HASH_Begin(alt_ctx);
+
+ /* Add key. */
+ HASH_Update(alt_ctx, key, key_len);
+
+ /* Add salt. */
+ HASH_Update(alt_ctx, salt, salt_len);
+
+ /* Add key again. */
+ HASH_Update(alt_ctx, key, key_len);
+
+ /* Now get result of this (64 bytes) and add it to the other
+ context. */
+ HASH_End(alt_ctx, alt_result, &part, HASH_ResultLenContext(alt_ctx));
+
+ /* Add for any character in the key one byte of the alternate sum. */
+ for (cnt = key_len; cnt > 64; cnt -= 64) {
+ HASH_Update(ctx, alt_result, 64);
+ }
+ HASH_Update(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) {
+ HASH_Update(ctx, alt_result, 64);
+ } else {
+ HASH_Update(ctx, key, key_len);
+ }
+
+ /* Create intermediate result. */
+ HASH_End(ctx, alt_result, &part, HASH_ResultLenContext(ctx));
+
+ /* Start computation of P byte sequence. */
+ HASH_Begin(alt_ctx);
+
+ /* For every character in the password add the entire password. */
+ for (cnt = 0; cnt < key_len; ++cnt) {
+ HASH_Update(alt_ctx, key, key_len);
+ }
+
+ /* Finish the digest. */
+ HASH_End(alt_ctx, temp_result, &part, HASH_ResultLenContext(alt_ctx));
+
+ /* 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. */
+ HASH_Begin(alt_ctx);
+
+ /* For every character in the password add the entire password. */
+ for (cnt = 0; cnt < 16 + alt_result[0]; ++cnt) {
+ HASH_Update(alt_ctx, salt, salt_len);
+ }
+
+ /* Finish the digest. */
+ HASH_End(alt_ctx, temp_result, &part, HASH_ResultLenContext(alt_ctx));
+
+ /* 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)
+ {
+ /* New context. */
+ HASH_Begin(ctx);
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0) {
+ HASH_Update(ctx, p_bytes, key_len);
+ } else {
+ HASH_Update(ctx, alt_result, 64);
+ }
+
+ /* Add salt for numbers not divisible by 3. */
+ if (cnt % 3 != 0) {
+ HASH_Update(ctx, s_bytes, salt_len);
+ }
+
+ /* Add key for numbers not divisible by 7. */
+ if (cnt % 7 != 0) {
+ HASH_Update(ctx, p_bytes, key_len);
+ }
+
+ /* Add key or last result. */
+ if ((cnt & 1) != 0) {
+ HASH_Update(ctx, alt_result, 64);
+ } else {
+ HASH_Update(ctx, p_bytes, key_len);
+ }
+
+ /* Create intermediate result. */
+ HASH_End(ctx, alt_result, &part, HASH_ResultLenContext(ctx));
+ }
+
+ /* Now we can construct the result string. It consists of three
+ parts. */
+ cp = __stpncpy (buffer, sha512_salt_prefix, MAX (0, buflen));
+ buflen -= sizeof (sha512_salt_prefix) - 1;
+
+ if (rounds_custom)
+ {
+ int n = snprintf (cp, MAX (0, buflen), "%s%zu$",
+ sha512_rounds_prefix, rounds);
+ cp += n;
+ buflen -= n;
+ }
+
+ cp = __stpncpy (cp, salt, MIN ((size_t) MAX (0, buflen), salt_len));
+ buflen -= MIN ((size_t) MAX (0, buflen), salt_len);
+
+ if (buflen > 0)
+ {
+ *cp++ = '$';
+ --buflen;
+ }
+
+#define b64_from_24bit(B2, B1, B0, N) \
+ do { \
+ unsigned int w = ((B2) << 16) | ((B1) << 8) | (B0); \
+ int n = (N); \
+ while (n-- > 0 && buflen > 0) \
+ { \
+ *cp++ = b64t[w & 0x3f]; \
+ --buflen; \
+ w >>= 6; \
+ } \
+ } while (0)
+
+ b64_from_24bit (alt_result[0], alt_result[21], alt_result[42], 4);
+ b64_from_24bit (alt_result[22], alt_result[43], alt_result[1], 4);
+ b64_from_24bit (alt_result[44], alt_result[2], alt_result[23], 4);
+ b64_from_24bit (alt_result[3], alt_result[24], alt_result[45], 4);
+ b64_from_24bit (alt_result[25], alt_result[46], alt_result[4], 4);
+ b64_from_24bit (alt_result[47], alt_result[5], alt_result[26], 4);
+ b64_from_24bit (alt_result[6], alt_result[27], alt_result[48], 4);
+ b64_from_24bit (alt_result[28], alt_result[49], alt_result[7], 4);
+ b64_from_24bit (alt_result[50], alt_result[8], alt_result[29], 4);
+ b64_from_24bit (alt_result[9], alt_result[30], alt_result[51], 4);
+ b64_from_24bit (alt_result[31], alt_result[52], alt_result[10], 4);
+ b64_from_24bit (alt_result[53], alt_result[11], alt_result[32], 4);
+ b64_from_24bit (alt_result[12], alt_result[33], alt_result[54], 4);
+ b64_from_24bit (alt_result[34], alt_result[55], alt_result[13], 4);
+ b64_from_24bit (alt_result[56], alt_result[14], alt_result[35], 4);
+ b64_from_24bit (alt_result[15], alt_result[36], alt_result[57], 4);
+ b64_from_24bit (alt_result[37], alt_result[58], alt_result[16], 4);
+ b64_from_24bit (alt_result[59], alt_result[17], alt_result[38], 4);
+ b64_from_24bit (alt_result[18], alt_result[39], alt_result[60], 4);
+ b64_from_24bit (alt_result[40], alt_result[61], alt_result[19], 4);
+ b64_from_24bit (alt_result[62], alt_result[20], alt_result[41], 4);
+ b64_from_24bit (0, 0, alt_result[63], 2);
+
+ if (buflen <= 0)
+ {
+ errno = ERANGE;
+ buffer = NULL;
+ }
+ else
+ *cp = '\0'; /* Terminate the string. */
+
+ /* 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. */
+ HASH_Destroy(ctx);
+ HASH_Destroy(alt_ctx);
+
+ memset (temp_result, '\0', sizeof (temp_result));
+ memset (p_bytes, '\0', key_len);
+ memset (s_bytes, '\0', salt_len);
+ memset (&ctx, '\0', sizeof (ctx));
+ memset (&alt_ctx, '\0', sizeof (alt_ctx));
+ if (copied_key != NULL)
+ memset (copied_key, '\0', key_len);
+ if (copied_salt != NULL)
+ memset (copied_salt, '\0', salt_len);
+
+ return buffer;
+}
+
+
+/* This entry point is equivalent to the `crypt' function in Unix
+ libcs. */
+char *
+nss_sha512_crypt (const char *key, const char *salt)
+{
+ /* We don't want to have an arbitrary limit in the size of the
+ password. We can compute an upper bound for the size of the
+ result in advance and so we can prepare the buffer we pass to
+ `sha512_crypt_r'. */
+ static char *buffer;
+ static int buflen;
+ int needed = (sizeof (sha512_salt_prefix) - 1
+ + sizeof (sha512_rounds_prefix) + 9 + 1
+ + strlen (salt) + 1 + 86 + 1);
+
+ if (buflen < needed)
+ {
+ char *new_buffer = (char *) realloc (buffer, needed);
+ if (new_buffer == NULL)
+ return NULL;
+
+ buffer = new_buffer;
+ buflen = needed;
+ }
+
+ return sha512_crypt_r (key, salt, buffer, buflen);
+}
+
+char *gen_salt(void)
+{
+ int ret;
+ unsigned char bin_rand[12];
+ static char b64_rand[17];
+ char *cp;
+ int buflen;
+
+ if (!nspr_nss_init_done) {
+ ret = nspr_nss_init();
+ if (ret != SECSuccess) return NULL;
+ }
+
+ ret = PK11_GenerateRandom(bin_rand, sizeof(bin_rand)-1);
+ cp = b64_rand;
+ buflen = 16;
+ b64_from_24bit (bin_rand[0], bin_rand[1], bin_rand[2], 4);
+ b64_from_24bit (bin_rand[3], bin_rand[4], bin_rand[5], 4);
+ b64_from_24bit (bin_rand[6], bin_rand[7], bin_rand[8], 4);
+ b64_from_24bit (bin_rand[9], bin_rand[10], bin_rand[11], 4);
+
+ *cp++ = '\0';
+
+ return b64_rand;
+
+}
+
diff --git a/server/util/nss_sha512crypt.h b/server/util/nss_sha512crypt.h
new file mode 100644
index 00000000..0d063217
--- /dev/null
+++ b/server/util/nss_sha512crypt.h
@@ -0,0 +1,3 @@
+
+char * nss_sha512_crypt (const char *key, const char *salt);
+char *gen_salt(void);