1 /* Written by Dr Stephen N Henson (steve (at) openssl.org) for the OpenSSL 2 * project 2000. 3 */ 4 /* ==================================================================== 5 * Copyright (c) 2000-2005 The OpenSSL Project. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 19 * 3. All advertising materials mentioning features or use of this 20 * software must display the following acknowledgment: 21 * "This product includes software developed by the OpenSSL Project 22 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 23 * 24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 25 * endorse or promote products derived from this software without 26 * prior written permission. For written permission, please contact 27 * licensing (at) OpenSSL.org. 28 * 29 * 5. Products derived from this software may not be called "OpenSSL" 30 * nor may "OpenSSL" appear in their names without prior written 31 * permission of the OpenSSL Project. 32 * 33 * 6. Redistributions of any form whatsoever must retain the following 34 * acknowledgment: 35 * "This product includes software developed by the OpenSSL Project 36 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 37 * 38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 41 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 49 * OF THE POSSIBILITY OF SUCH DAMAGE. 50 * ==================================================================== 51 * 52 * This product includes cryptographic software written by Eric Young 53 * (eay (at) cryptsoft.com). This product includes software written by Tim 54 * Hudson (tjh (at) cryptsoft.com). */ 55 56 #include <openssl/dh.h> 57 58 #include <assert.h> 59 #include <limits.h> 60 61 #include <openssl/bn.h> 62 #include <openssl/bytestring.h> 63 #include <openssl/err.h> 64 65 #include "../bytestring/internal.h" 66 67 68 static int parse_integer(CBS *cbs, BIGNUM **out) { 69 assert(*out == NULL); 70 *out = BN_new(); 71 if (*out == NULL) { 72 return 0; 73 } 74 return BN_parse_asn1_unsigned(cbs, *out); 75 } 76 77 static int marshal_integer(CBB *cbb, BIGNUM *bn) { 78 if (bn == NULL) { 79 // A DH object may be missing some components. 80 OPENSSL_PUT_ERROR(DH, ERR_R_PASSED_NULL_PARAMETER); 81 return 0; 82 } 83 return BN_marshal_asn1(cbb, bn); 84 } 85 86 DH *DH_parse_parameters(CBS *cbs) { 87 DH *ret = DH_new(); 88 if (ret == NULL) { 89 return NULL; 90 } 91 92 CBS child; 93 if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) || 94 !parse_integer(&child, &ret->p) || 95 !parse_integer(&child, &ret->g)) { 96 goto err; 97 } 98 99 uint64_t priv_length; 100 if (CBS_len(&child) != 0) { 101 if (!CBS_get_asn1_uint64(&child, &priv_length) || 102 priv_length > UINT_MAX) { 103 goto err; 104 } 105 ret->priv_length = (unsigned)priv_length; 106 } 107 108 if (CBS_len(&child) != 0) { 109 goto err; 110 } 111 112 return ret; 113 114 err: 115 OPENSSL_PUT_ERROR(DH, DH_R_DECODE_ERROR); 116 DH_free(ret); 117 return NULL; 118 } 119 120 int DH_marshal_parameters(CBB *cbb, const DH *dh) { 121 CBB child; 122 if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) || 123 !marshal_integer(&child, dh->p) || 124 !marshal_integer(&child, dh->g) || 125 (dh->priv_length != 0 && 126 !CBB_add_asn1_uint64(&child, dh->priv_length)) || 127 !CBB_flush(cbb)) { 128 OPENSSL_PUT_ERROR(DH, DH_R_ENCODE_ERROR); 129 return 0; 130 } 131 return 1; 132 } 133 134 DH *d2i_DHparams(DH **out, const uint8_t **inp, long len) { 135 if (len < 0) { 136 return NULL; 137 } 138 CBS cbs; 139 CBS_init(&cbs, *inp, (size_t)len); 140 DH *ret = DH_parse_parameters(&cbs); 141 if (ret == NULL) { 142 return NULL; 143 } 144 if (out != NULL) { 145 DH_free(*out); 146 *out = ret; 147 } 148 *inp = CBS_data(&cbs); 149 return ret; 150 } 151 152 int i2d_DHparams(const DH *in, uint8_t **outp) { 153 CBB cbb; 154 if (!CBB_init(&cbb, 0) || 155 !DH_marshal_parameters(&cbb, in)) { 156 CBB_cleanup(&cbb); 157 return -1; 158 } 159 return CBB_finish_i2d(&cbb, outp); 160 } 161
