1 /* $OpenBSD: dh_pmeth.c,v 1.11 2021/12/04 16:08:32 tb Exp $ */ 2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 3 * project 2006. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <limits.h> 60 #include <stdio.h> 61 #include <string.h> 62 63 #include <openssl/asn1t.h> 64 #include <openssl/bn.h> 65 #include <openssl/dh.h> 66 #include <openssl/err.h> 67 #include <openssl/evp.h> 68 #include <openssl/x509.h> 69 70 #include "bn_lcl.h" 71 #include "evp_locl.h" 72 73 /* DH pkey context structure */ 74 75 typedef struct { 76 /* Parameter gen parameters */ 77 int prime_len; 78 int generator; 79 int use_dsa; 80 /* Keygen callback info */ 81 int gentmp[2]; 82 /* message digest */ 83 } DH_PKEY_CTX; 84 85 static int 86 pkey_dh_init(EVP_PKEY_CTX *ctx) 87 { 88 DH_PKEY_CTX *dctx; 89 90 dctx = malloc(sizeof(DH_PKEY_CTX)); 91 if (!dctx) 92 return 0; 93 dctx->prime_len = 1024; 94 dctx->generator = 2; 95 dctx->use_dsa = 0; 96 97 ctx->data = dctx; 98 ctx->keygen_info = dctx->gentmp; 99 ctx->keygen_info_count = 2; 100 101 return 1; 102 } 103 104 static int 105 pkey_dh_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) 106 { 107 DH_PKEY_CTX *dctx, *sctx; 108 109 if (!pkey_dh_init(dst)) 110 return 0; 111 sctx = src->data; 112 dctx = dst->data; 113 dctx->prime_len = sctx->prime_len; 114 dctx->generator = sctx->generator; 115 dctx->use_dsa = sctx->use_dsa; 116 return 1; 117 } 118 119 static void 120 pkey_dh_cleanup(EVP_PKEY_CTX *ctx) 121 { 122 DH_PKEY_CTX *dctx = ctx->data; 123 124 free(dctx); 125 } 126 127 static int 128 pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) 129 { 130 DH_PKEY_CTX *dctx = ctx->data; 131 132 switch (type) { 133 case EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN: 134 if (p1 < 256) 135 return -2; 136 dctx->prime_len = p1; 137 return 1; 138 139 case EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR: 140 dctx->generator = p1; 141 return 1; 142 143 case EVP_PKEY_CTRL_PEER_KEY: 144 /* Default behaviour is OK */ 145 return 1; 146 147 default: 148 return -2; 149 } 150 } 151 152 static int 153 pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value) 154 { 155 long lval; 156 char *ep; 157 int len; 158 159 if (!strcmp(type, "dh_paramgen_prime_len")) { 160 errno = 0; 161 lval = strtol(value, &ep, 10); 162 if (value[0] == '\0' || *ep != '\0') 163 goto not_a_number; 164 if ((errno == ERANGE && 165 (lval == LONG_MAX || lval == LONG_MIN)) || 166 (lval > INT_MAX || lval < INT_MIN)) 167 goto out_of_range; 168 len = lval; 169 return EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len); 170 } else if (!strcmp(type, "dh_paramgen_generator")) { 171 errno = 0; 172 lval = strtol(value, &ep, 10); 173 if (value[0] == '\0' || *ep != '\0') 174 goto not_a_number; 175 if ((errno == ERANGE && 176 (lval == LONG_MAX || lval == LONG_MIN)) || 177 (lval > INT_MAX || lval < INT_MIN)) 178 goto out_of_range; 179 len = lval; 180 return EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, len); 181 } 182 183 not_a_number: 184 out_of_range: 185 return -2; 186 } 187 188 static int 189 pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 190 { 191 DH *dh = NULL; 192 DH_PKEY_CTX *dctx = ctx->data; 193 BN_GENCB *pcb, cb; 194 int ret; 195 196 if (ctx->pkey_gencb) { 197 pcb = &cb; 198 evp_pkey_set_cb_translate(pcb, ctx); 199 } else 200 pcb = NULL; 201 dh = DH_new(); 202 if (!dh) 203 return 0; 204 ret = DH_generate_parameters_ex(dh, dctx->prime_len, dctx->generator, 205 pcb); 206 if (ret) 207 EVP_PKEY_assign_DH(pkey, dh); 208 else 209 DH_free(dh); 210 return ret; 211 } 212 213 static int 214 pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 215 { 216 DH *dh = NULL; 217 218 if (ctx->pkey == NULL) { 219 DHerror(DH_R_NO_PARAMETERS_SET); 220 return 0; 221 } 222 dh = DH_new(); 223 if (!dh) 224 return 0; 225 EVP_PKEY_assign_DH(pkey, dh); 226 /* Note: if error return, pkey is freed by parent routine */ 227 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) 228 return 0; 229 return DH_generate_key(pkey->pkey.dh); 230 } 231 232 static int 233 pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen) 234 { 235 int ret; 236 237 if (!ctx->pkey || !ctx->peerkey) { 238 DHerror(DH_R_KEYS_NOT_SET); 239 return 0; 240 } 241 ret = DH_compute_key(key, ctx->peerkey->pkey.dh->pub_key, 242 ctx->pkey->pkey.dh); 243 if (ret < 0) 244 return ret; 245 *keylen = ret; 246 return 1; 247 } 248 249 const EVP_PKEY_METHOD dh_pkey_meth = { 250 .pkey_id = EVP_PKEY_DH, 251 .flags = EVP_PKEY_FLAG_AUTOARGLEN, 252 253 .init = pkey_dh_init, 254 .copy = pkey_dh_copy, 255 .cleanup = pkey_dh_cleanup, 256 257 .paramgen = pkey_dh_paramgen, 258 259 .keygen = pkey_dh_keygen, 260 261 .derive = pkey_dh_derive, 262 263 .ctrl = pkey_dh_ctrl, 264 .ctrl_str = pkey_dh_ctrl_str 265 }; 266