git ssb

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/*	$OpenBSD: bcrypt.c,v 1.22 2007/02/20 01:44:16 ray Exp $	*/
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/* 
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 * Modified by <coda.hale@gmail.com> on 2009-09-16:
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 *
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 *   - Standardized on stdint.h's numerical types and removed some debug cruft.
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 *
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 * Modified by <hongli@phusion.nl> on 2009-08-05:
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 *
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 *   - Got rid of the global variables; they're not thread-safe.
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 *     Modified the functions to accept local buffers instead.
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 *
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 * Modified by <coda.hale@gmail.com> on 2007-02-27:
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 *
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 *   - Changed bcrypt_gensalt to accept a random seed as a parameter,
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 *     to remove the code's dependency on arc4random(), which isn't
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 *     available on Linux. 
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 */
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/*
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 * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. All advertising materials mentioning features or use of this software
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 *    must display the following acknowledgement:
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 *      This product includes software developed by Niels Provos.
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 * 4. The name of the author may not be used to endorse or promote products
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 *    derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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/* This password hashing algorithm was designed by David Mazieres
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 * <dm@lcs.mit.edu> and works as follows:
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 *
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 * 1. state := InitState ()
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 * 2. state := ExpandKey (state, salt, password) 3.
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 * REPEAT rounds:
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 *	state := ExpandKey (state, 0, salt)
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 *      state := ExpandKey(state, 0, password)
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 * 4. ctext := "OrpheanBeholderScryDoubt"
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 * 5. REPEAT 64:
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 * 	ctext := Encrypt_ECB (state, ctext);
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 * 6. RETURN Concatenate (salt, ctext);
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 *
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "blf.h"
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#include "bcrypt.h"
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/* This implementation is adaptable to current computing power.
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 * You can have up to 2^31 rounds which should be enough for some
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 * time to come.
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 */
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static void encode_salt(char *, uint8_t *, uint16_t, uint8_t);
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static void encode_base64(uint8_t *, uint8_t *, uint16_t);
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static void decode_base64(uint8_t *, uint16_t, uint8_t *);
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const static uint8_t Base64Code[] =
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"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
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const static uint8_t index_64[128] = {
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	255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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	255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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	255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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	255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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	255, 255, 255, 255, 255, 255, 0, 1, 54, 55,
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	56, 57, 58, 59, 60, 61, 62, 63, 255, 255,
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	255, 255, 255, 255, 255, 2, 3, 4, 5, 6,
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	7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
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	17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
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	255, 255, 255, 255, 255, 255, 28, 29, 30,
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	31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
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	41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
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	51, 52, 53, 255, 255, 255, 255, 255
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};
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#define CHAR64(c)  ( (c) > 127 ? 255 : index_64[(c)])
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static void
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decode_base64(uint8_t *buffer, uint16_t len, uint8_t *data)
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{
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	uint8_t *bp = buffer;
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	uint8_t *p = data;
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	uint8_t c1, c2, c3, c4;
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	while (bp < buffer + len) {
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		c1 = CHAR64(*p);
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		c2 = CHAR64(*(p + 1));
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		/* Invalid data */
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		if (c1 == 255 || c2 == 255)
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			break;
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		*bp++ = (c1 << 2) | ((c2 & 0x30) >> 4);
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		if (bp >= buffer + len)
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			break;
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		c3 = CHAR64(*(p + 2));
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		if (c3 == 255)
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			break;
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		*bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2);
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		if (bp >= buffer + len)
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			break;
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		c4 = CHAR64(*(p + 3));
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		if (c4 == 255)
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			break;
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		*bp++ = ((c3 & 0x03) << 6) | c4;
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		p += 4;
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	}
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}
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static void
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encode_salt(char *salt, uint8_t *csalt, uint16_t clen, uint8_t logr)
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{
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	salt[0] = '$';
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	salt[1] = BCRYPT_VERSION;
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	salt[2] = 'a';
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	salt[3] = '$';
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	snprintf(salt + 4, 4, "%2.2u$", logr);
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	encode_base64((uint8_t *) salt + 7, csalt, clen);
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}
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/* Generates a salt for this version of crypt.
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   Since versions may change. Keeping this here
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   seems sensible.
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 */
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char   *
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ruby_bcrypt_gensalt(char *output, uint8_t log_rounds, uint8_t *rseed)
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{
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	if (log_rounds < 4)
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		log_rounds = 4;
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	else if (log_rounds > 31)
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		log_rounds = 31;
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	encode_salt(output, rseed, BCRYPT_MAXSALT, log_rounds);
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	return output;
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}
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/* We handle $Vers$log2(NumRounds)$salt+passwd$
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   i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */
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char   *
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ruby_bcrypt(char *output, const char *key, const char *salt)
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{
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	blf_ctx state;
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	uint32_t rounds, i, k;
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	uint16_t j;
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	uint8_t key_len, salt_len, logr, minor;
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	uint8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
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	uint8_t csalt[BCRYPT_MAXSALT];
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	uint32_t cdata[BCRYPT_BLOCKS];
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	int n;
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	/* Discard "$" identifier */
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	salt++;
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	if (*salt > BCRYPT_VERSION) {
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		return NULL;
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	}
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	/* Check for minor versions */
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	if (salt[1] != '$') {
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		 switch (salt[1]) {
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		 case 'a':
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			 /* 'ab' should not yield the same as 'abab' */
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			 minor = salt[1];
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			 salt++;
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			 break;
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		 default:
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			 return NULL;
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		 }
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	} else
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		 minor = 0;
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	/* Discard version + "$" identifier */
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	salt += 2;
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	if (salt[2] != '$')
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		/* Out of sync with passwd entry */
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		return NULL;
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	/* Computer power doesn't increase linear, 2^x should be fine */
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	n = atoi(salt);
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	if (n > 31 || n < 0)
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		return NULL;
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	logr = (uint8_t)n;
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	if ((rounds = (uint32_t) 1 << logr) < BCRYPT_MINROUNDS)
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		return NULL;
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	/* Discard num rounds + "$" identifier */
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	salt += 3;
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	if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT)
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		return NULL;
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	/* We dont want the base64 salt but the raw data */
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	decode_base64(csalt, BCRYPT_MAXSALT, (uint8_t *) salt);
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	salt_len = BCRYPT_MAXSALT;
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	key_len = strlen(key) + (minor >= 'a' ? 1 : 0);
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	/* Setting up S-Boxes and Subkeys */
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	Blowfish_initstate(&state);
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	Blowfish_expandstate(&state, csalt, salt_len,
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	    (uint8_t *) key, key_len);
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	for (k = 0; k < rounds; k++) {
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		Blowfish_expand0state(&state, (uint8_t *) key, key_len);
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		Blowfish_expand0state(&state, csalt, salt_len);
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	}
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	/* This can be precomputed later */
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	j = 0;
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	for (i = 0; i < BCRYPT_BLOCKS; i++)
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		cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j);
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	/* Now do the encryption */
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	for (k = 0; k < 64; k++)
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		blf_enc(&state, cdata, BCRYPT_BLOCKS / 2);
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	for (i = 0; i < BCRYPT_BLOCKS; i++) {
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		ciphertext[4 * i + 3] = cdata[i] & 0xff;
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		cdata[i] = cdata[i] >> 8;
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		ciphertext[4 * i + 2] = cdata[i] & 0xff;
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		cdata[i] = cdata[i] >> 8;
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		ciphertext[4 * i + 1] = cdata[i] & 0xff;
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		cdata[i] = cdata[i] >> 8;
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		ciphertext[4 * i + 0] = cdata[i] & 0xff;
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	}
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	i = 0;
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	output[i++] = '$';
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	output[i++] = BCRYPT_VERSION;
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	if (minor)
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		output[i++] = minor;
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	output[i++] = '$';
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	snprintf(output + i, 4, "%2.2u$", logr);
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	encode_base64((uint8_t *) output + i + 3, csalt, BCRYPT_MAXSALT);
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	encode_base64((uint8_t *) output + strlen(output), ciphertext,
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	    4 * BCRYPT_BLOCKS - 1);
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	return output;
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}
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static void
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encode_base64(uint8_t *buffer, uint8_t *data, uint16_t len)
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{
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	uint8_t *bp = buffer;
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	uint8_t *p = data;
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	uint8_t c1, c2;
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	while (p < data + len) {
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		c1 = *p++;
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		*bp++ = Base64Code[(c1 >> 2)];
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		c1 = (c1 & 0x03) << 4;
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		if (p >= data + len) {
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			*bp++ = Base64Code[c1];
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			break;
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		}
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		c2 = *p++;
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		c1 |= (c2 >> 4) & 0x0f;
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		*bp++ = Base64Code[c1];
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		c1 = (c2 & 0x0f) << 2;
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		if (p >= data + len) {
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			*bp++ = Base64Code[c1];
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			break;
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		}
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		c2 = *p++;
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		c1 |= (c2 >> 6) & 0x03;
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		*bp++ = Base64Code[c1];
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		*bp++ = Base64Code[c2 & 0x3f];
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	}
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	*bp = '\0';
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}
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