Big thanks to Solar Designer who pointed out a bug in bcrypt

salt generation code.  He also urged using better random source
and making possible to choose using bcrypt and xdes rounds more
easily.  So, here's patch:

* For all salt generation, use Solar Designer's own code.  This
  is mostly due fact that his code is more fit for get_random_bytes()
  style interface.
* New function: gen_salt(type, rounds).  This lets specify iteration
  count for algorithm.
* random.c: px_get_random_bytes() function.
  Supported randomness soure: /dev/urandom, OpenSSL PRNG, libc random()
  Default: /dev/urandom.
* Draft description of C API for pgcrypto functions.

New files: API, crypt-gensalt.c, random.c

Marko Kreen

1 files changed, 181 insertions, 0 deletions

diff --git a/contrib/pgcrypto/crypt-gensalt.c b/contrib/pgcrypto/crypt-gensalt.c
new file mode 100644
index 00000000000..8bb17147334
--- /dev/null
+++ b/contrib/pgcrypto/crypt-gensalt.c
@@ -0,0 +1,181 @@
+/*
+ * Written by Solar Designer and placed in the public domain.
+ * See crypt_blowfish.c for more information.
+ *
+ * This file contains salt generation functions for the traditional and
+ * other common crypt(3) algorithms, except for bcrypt which is defined
+ * entirely in crypt_blowfish.c.
+ *
+ * Put bcrypt generator also here as crypt-blowfish.c
+ * may not be compiled always.        -- marko
+ */
+
+#include <postgres.h>
+#include "px-crypt.h"
+
+#include <errno.h>
+#ifndef __set_errno
+#define __set_errno(val) errno = (val)
+#endif
+
+#undef __CONST
+#ifdef __GNUC__
+#define __CONST __const
+#else
+#define __CONST
+#endif
+
+typedef unsigned int BF_word;
+
+unsigned char _crypt_itoa64[64 + 1] =
+	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+char *_crypt_gensalt_traditional_rn(unsigned long count,
+	__CONST char *input, int size, char *output, int output_size)
+{
+	if (size < 2 || output_size < 2 + 1 || (count && count != 25)) {
+		if (output_size > 0) output[0] = '\0';
+		__set_errno((output_size < 2 + 1) ? ERANGE : EINVAL);
+		return NULL;
+	}
+
+	output[0] = _crypt_itoa64[(unsigned int)input[0] & 0x3f];
+	output[1] = _crypt_itoa64[(unsigned int)input[1] & 0x3f];
+	output[2] = '\0';
+
+	return output;
+}
+
+char *_crypt_gensalt_extended_rn(unsigned long count,
+	__CONST char *input, int size, char *output, int output_size)
+{
+	unsigned long value;
+
+/* Even iteration counts make it easier to detect weak DES keys from a look
+ * at the hash, so they should be avoided */
+	if (size < 3 || output_size < 1 + 4 + 4 + 1 ||
+	    (count && (count > 0xffffff || !(count & 1)))) {
+		if (output_size > 0) output[0] = '\0';
+		__set_errno((output_size < 1 + 4 + 4 + 1) ? ERANGE : EINVAL);
+		return NULL;
+	}
+
+	if (!count) count = 725;
+
+	output[0] = '_';
+	output[1] = _crypt_itoa64[count & 0x3f];
+	output[2] = _crypt_itoa64[(count >> 6) & 0x3f];
+	output[3] = _crypt_itoa64[(count >> 12) & 0x3f];
+	output[4] = _crypt_itoa64[(count >> 18) & 0x3f];
+	value = (unsigned long)input[0] |
+		((unsigned long)input[1] << 8) |
+		((unsigned long)input[2] << 16);
+	output[5] = _crypt_itoa64[value & 0x3f];
+	output[6] = _crypt_itoa64[(value >> 6) & 0x3f];
+	output[7] = _crypt_itoa64[(value >> 12) & 0x3f];
+	output[8] = _crypt_itoa64[(value >> 18) & 0x3f];
+	output[9] = '\0';
+
+	return output;
+}
+
+char *_crypt_gensalt_md5_rn(unsigned long count,
+	__CONST char *input, int size, char *output, int output_size)
+{
+	unsigned long value;
+
+	if (size < 3 || output_size < 3 + 4 + 1 || (count && count != 1000)) {
+		if (output_size > 0) output[0] = '\0';
+		__set_errno((output_size < 3 + 4 + 1) ? ERANGE : EINVAL);
+		return NULL;
+	}
+
+	output[0] = '$';
+	output[1] = '1';
+	output[2] = '$';
+	value = (unsigned long)input[0] |
+		((unsigned long)input[1] << 8) |
+		((unsigned long)input[2] << 16);
+	output[3] = _crypt_itoa64[value & 0x3f];
+	output[4] = _crypt_itoa64[(value >> 6) & 0x3f];
+	output[5] = _crypt_itoa64[(value >> 12) & 0x3f];
+	output[6] = _crypt_itoa64[(value >> 18) & 0x3f];
+	output[7] = '\0';
+
+	if (size >= 6 && output_size >= 3 + 4 + 4 + 1) {
+		value = (unsigned long)input[3] |
+			((unsigned long)input[4] << 8) |
+			((unsigned long)input[5] << 16);
+		output[7] = _crypt_itoa64[value & 0x3f];
+		output[8] = _crypt_itoa64[(value >> 6) & 0x3f];
+		output[9] = _crypt_itoa64[(value >> 12) & 0x3f];
+		output[10] = _crypt_itoa64[(value >> 18) & 0x3f];
+		output[11] = '\0';
+	}
+
+	return output;
+}
+
+
+
+static unsigned char BF_itoa64[64 + 1] =
+	"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+
+static void BF_encode(char *dst, __CONST BF_word *src, int size)
+{
+	unsigned char *sptr = (unsigned char *)src;
+	unsigned char *end = sptr + size;
+	unsigned char *dptr = (unsigned char *)dst;
+	unsigned int c1, c2;
+
+	do {
+		c1 = *sptr++;
+		*dptr++ = BF_itoa64[c1 >> 2];
+		c1 = (c1 & 0x03) << 4;
+		if (sptr >= end) {
+			*dptr++ = BF_itoa64[c1];
+			break;
+		}
+
+		c2 = *sptr++;
+		c1 |= c2 >> 4;
+		*dptr++ = BF_itoa64[c1];
+		c1 = (c2 & 0x0f) << 2;
+		if (sptr >= end) {
+			*dptr++ = BF_itoa64[c1];
+			break;
+		}
+
+		c2 = *sptr++;
+		c1 |= c2 >> 6;
+		*dptr++ = BF_itoa64[c1];
+		*dptr++ = BF_itoa64[c2 & 0x3f];
+	} while (sptr < end);
+}
+
+char *_crypt_gensalt_blowfish_rn(unsigned long count,
+	__CONST char *input, int size, char *output, int output_size)
+{
+	if (size < 16 || output_size < 7 + 22 + 1 ||
+	    (count && (count < 4 || count > 31))) {
+		if (output_size > 0) output[0] = '\0';
+		__set_errno((output_size < 7 + 22 + 1) ? ERANGE : EINVAL);
+		return NULL;
+	}
+
+	if (!count) count = 5;
+
+	output[0] = '$';
+	output[1] = '2';
+	output[2] = 'a';
+	output[3] = '$';
+	output[4] = '0' + count / 10;
+	output[5] = '0' + count % 10;
+	output[6] = '$';
+
+	BF_encode(&output[7], (BF_word *)input, 16);
+	output[7 + 22] = '\0';
+
+	return output;
+}
+