| 1 |  |  | /* $OpenBSD: bn_mpi.c,v 1.7 2014/07/11 08:44:48 jsing Exp $ */ | 
    
    | 2 |  |  | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | 
    
    | 3 |  |  |  * All rights reserved. | 
    
    | 4 |  |  |  * | 
    
    | 5 |  |  |  * This package is an SSL implementation written | 
    
    | 6 |  |  |  * by Eric Young (eay@cryptsoft.com). | 
    
    | 7 |  |  |  * The implementation was written so as to conform with Netscapes SSL. | 
    
    | 8 |  |  |  * | 
    
    | 9 |  |  |  * This library is free for commercial and non-commercial use as long as | 
    
    | 10 |  |  |  * the following conditions are aheared to.  The following conditions | 
    
    | 11 |  |  |  * apply to all code found in this distribution, be it the RC4, RSA, | 
    
    | 12 |  |  |  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation | 
    
    | 13 |  |  |  * included with this distribution is covered by the same copyright terms | 
    
    | 14 |  |  |  * except that the holder is Tim Hudson (tjh@cryptsoft.com). | 
    
    | 15 |  |  |  * | 
    
    | 16 |  |  |  * Copyright remains Eric Young's, and as such any Copyright notices in | 
    
    | 17 |  |  |  * the code are not to be removed. | 
    
    | 18 |  |  |  * If this package is used in a product, Eric Young should be given attribution | 
    
    | 19 |  |  |  * as the author of the parts of the library used. | 
    
    | 20 |  |  |  * This can be in the form of a textual message at program startup or | 
    
    | 21 |  |  |  * in documentation (online or textual) provided with the package. | 
    
    | 22 |  |  |  * | 
    
    | 23 |  |  |  * Redistribution and use in source and binary forms, with or without | 
    
    | 24 |  |  |  * modification, are permitted provided that the following conditions | 
    
    | 25 |  |  |  * are met: | 
    
    | 26 |  |  |  * 1. Redistributions of source code must retain the copyright | 
    
    | 27 |  |  |  *    notice, this list of conditions and the following disclaimer. | 
    
    | 28 |  |  |  * 2. Redistributions in binary form must reproduce the above copyright | 
    
    | 29 |  |  |  *    notice, this list of conditions and the following disclaimer in the | 
    
    | 30 |  |  |  *    documentation and/or other materials provided with the distribution. | 
    
    | 31 |  |  |  * 3. All advertising materials mentioning features or use of this software | 
    
    | 32 |  |  |  *    must display the following acknowledgement: | 
    
    | 33 |  |  |  *    "This product includes cryptographic software written by | 
    
    | 34 |  |  |  *     Eric Young (eay@cryptsoft.com)" | 
    
    | 35 |  |  |  *    The word 'cryptographic' can be left out if the rouines from the library | 
    
    | 36 |  |  |  *    being used are not cryptographic related :-). | 
    
    | 37 |  |  |  * 4. If you include any Windows specific code (or a derivative thereof) from | 
    
    | 38 |  |  |  *    the apps directory (application code) you must include an acknowledgement: | 
    
    | 39 |  |  |  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | 
    
    | 40 |  |  |  * | 
    
    | 41 |  |  |  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | 
    
    | 42 |  |  |  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | 
    
    | 43 |  |  |  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | 
    
    | 44 |  |  |  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | 
    
    | 45 |  |  |  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | 
    
    | 46 |  |  |  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | 
    
    | 47 |  |  |  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | 
    
    | 48 |  |  |  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | 
    
    | 49 |  |  |  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | 
    
    | 50 |  |  |  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | 
    
    | 51 |  |  |  * SUCH DAMAGE. | 
    
    | 52 |  |  |  * | 
    
    | 53 |  |  |  * The licence and distribution terms for any publically available version or | 
    
    | 54 |  |  |  * derivative of this code cannot be changed.  i.e. this code cannot simply be | 
    
    | 55 |  |  |  * copied and put under another distribution licence | 
    
    | 56 |  |  |  * [including the GNU Public Licence.] | 
    
    | 57 |  |  |  */ | 
    
    | 58 |  |  |  | 
    
    | 59 |  |  | #include <stdio.h> | 
    
    | 60 |  |  |  | 
    
    | 61 |  |  | #include <openssl/err.h> | 
    
    | 62 |  |  |  | 
    
    | 63 |  |  | #include "bn_lcl.h" | 
    
    | 64 |  |  |  | 
    
    | 65 |  |  | int | 
    
    | 66 |  |  | BN_bn2mpi(const BIGNUM *a, unsigned char *d) | 
    
    | 67 |  |  | { | 
    
    | 68 |  |  | 	int bits; | 
    
    | 69 |  |  | 	int num = 0; | 
    
    | 70 |  |  | 	int ext = 0; | 
    
    | 71 |  |  | 	long l; | 
    
    | 72 |  |  |  | 
    
    | 73 |  |  | 	bits = BN_num_bits(a); | 
    
    | 74 |  |  | 	num = (bits + 7) / 8; | 
    
    | 75 |  |  | 	if (bits > 0) { | 
    
    | 76 |  |  | 		ext = ((bits & 0x07) == 0); | 
    
    | 77 |  |  | 	} | 
    
    | 78 |  |  | 	if (d == NULL) | 
    
    | 79 |  |  | 		return (num + 4 + ext); | 
    
    | 80 |  |  |  | 
    
    | 81 |  |  | 	l = num + ext; | 
    
    | 82 |  |  | 	d[0] = (unsigned char)(l >> 24) & 0xff; | 
    
    | 83 |  |  | 	d[1] = (unsigned char)(l >> 16) & 0xff; | 
    
    | 84 |  |  | 	d[2] = (unsigned char)(l >> 8) & 0xff; | 
    
    | 85 |  |  | 	d[3] = (unsigned char)(l) & 0xff; | 
    
    | 86 |  |  | 	if (ext) | 
    
    | 87 |  |  | 		d[4] = 0; | 
    
    | 88 |  |  | 	num = BN_bn2bin(a, &(d[4 + ext])); | 
    
    | 89 |  |  | 	if (a->neg) | 
    
    | 90 |  |  | 		d[4] |= 0x80; | 
    
    | 91 |  |  | 	return (num + 4 + ext); | 
    
    | 92 |  |  | } | 
    
    | 93 |  |  |  | 
    
    | 94 |  |  | BIGNUM * | 
    
    | 95 |  |  | BN_mpi2bn(const unsigned char *d, int n, BIGNUM *a) | 
    
    | 96 |  |  | { | 
    
    | 97 |  |  | 	long len; | 
    
    | 98 |  |  | 	int neg = 0; | 
    
    | 99 |  |  |  | 
    
    | 100 |  |  | 	if (n < 4) { | 
    
    | 101 |  |  | 		BNerr(BN_F_BN_MPI2BN, BN_R_INVALID_LENGTH); | 
    
    | 102 |  |  | 		return (NULL); | 
    
    | 103 |  |  | 	} | 
    
    | 104 |  |  | 	len = ((long)d[0] << 24) | ((long)d[1] << 16) | ((int)d[2] << 8) | | 
    
    | 105 |  |  | 	    (int)d[3]; | 
    
    | 106 |  |  | 	if ((len + 4) != n) { | 
    
    | 107 |  |  | 		BNerr(BN_F_BN_MPI2BN, BN_R_ENCODING_ERROR); | 
    
    | 108 |  |  | 		return (NULL); | 
    
    | 109 |  |  | 	} | 
    
    | 110 |  |  |  | 
    
    | 111 |  |  | 	if (a == NULL) | 
    
    | 112 |  |  | 		a = BN_new(); | 
    
    | 113 |  |  | 	if (a == NULL) | 
    
    | 114 |  |  | 		return (NULL); | 
    
    | 115 |  |  |  | 
    
    | 116 |  |  | 	if (len == 0) { | 
    
    | 117 |  |  | 		a->neg = 0; | 
    
    | 118 |  |  | 		a->top = 0; | 
    
    | 119 |  |  | 		return (a); | 
    
    | 120 |  |  | 	} | 
    
    | 121 |  |  | 	d += 4; | 
    
    | 122 |  |  | 	if ((*d) & 0x80) | 
    
    | 123 |  |  | 		neg = 1; | 
    
    | 124 |  |  | 	if (BN_bin2bn(d, (int)len, a) == NULL) | 
    
    | 125 |  |  | 		return (NULL); | 
    
    | 126 |  |  | 	a->neg = neg; | 
    
    | 127 |  |  | 	if (neg) { | 
    
    | 128 |  |  | 		BN_clear_bit(a, BN_num_bits(a) - 1); | 
    
    | 129 |  |  | 	} | 
    
    | 130 |  |  | 	bn_check_top(a); | 
    
    | 131 |  |  | 	return (a); | 
    
    | 132 |  |  | } |