1 /* $OpenBSD: dh_pmeth.c,v 1.12 2022/01/07 09:27:13 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 "dh_local.h" 72 #include "evp_locl.h" 73 74 /* DH pkey context structure */ 75 76 typedef struct { 77 /* Parameter gen parameters */ 78 int prime_len; 79 int generator; 80 int use_dsa; 81 /* Keygen callback info */ 82 int gentmp[2]; 83 /* message digest */ 84 } DH_PKEY_CTX; 85 86 static int 87 pkey_dh_init(EVP_PKEY_CTX *ctx) 88 { 89 DH_PKEY_CTX *dctx; 90 91 dctx = malloc(sizeof(DH_PKEY_CTX)); 92 if (!dctx) 93 return 0; 94 dctx->prime_len = 1024; 95 dctx->generator = 2; 96 dctx->use_dsa = 0; 97 98 ctx->data = dctx; 99 ctx->keygen_info = dctx->gentmp; 100 ctx->keygen_info_count = 2; 101 102 return 1; 103 } 104 105 static int 106 pkey_dh_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) 107 { 108 DH_PKEY_CTX *dctx, *sctx; 109 110 if (!pkey_dh_init(dst)) 111 return 0; 112 sctx = src->data; 113 dctx = dst->data; 114 dctx->prime_len = sctx->prime_len; 115 dctx->generator = sctx->generator; 116 dctx->use_dsa = sctx->use_dsa; 117 return 1; 118 } 119 120 static void 121 pkey_dh_cleanup(EVP_PKEY_CTX *ctx) 122 { 123 DH_PKEY_CTX *dctx = ctx->data; 124 125 free(dctx); 126 } 127 128 static int 129 pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) 130 { 131 DH_PKEY_CTX *dctx = ctx->data; 132 133 switch (type) { 134 case EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN: 135 if (p1 < 256) 136 return -2; 137 dctx->prime_len = p1; 138 return 1; 139 140 case EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR: 141 dctx->generator = p1; 142 return 1; 143 144 case EVP_PKEY_CTRL_PEER_KEY: 145 /* Default behaviour is OK */ 146 return 1; 147 148 default: 149 return -2; 150 } 151 } 152 153 static int 154 pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value) 155 { 156 long lval; 157 char *ep; 158 int len; 159 160 if (!strcmp(type, "dh_paramgen_prime_len")) { 161 errno = 0; 162 lval = strtol(value, &ep, 10); 163 if (value[0] == '\0' || *ep != '\0') 164 goto not_a_number; 165 if ((errno == ERANGE && 166 (lval == LONG_MAX || lval == LONG_MIN)) || 167 (lval > INT_MAX || lval < INT_MIN)) 168 goto out_of_range; 169 len = lval; 170 return EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len); 171 } else if (!strcmp(type, "dh_paramgen_generator")) { 172 errno = 0; 173 lval = strtol(value, &ep, 10); 174 if (value[0] == '\0' || *ep != '\0') 175 goto not_a_number; 176 if ((errno == ERANGE && 177 (lval == LONG_MAX || lval == LONG_MIN)) || 178 (lval > INT_MAX || lval < INT_MIN)) 179 goto out_of_range; 180 len = lval; 181 return EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, len); 182 } 183 184 not_a_number: 185 out_of_range: 186 return -2; 187 } 188 189 static int 190 pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 191 { 192 DH *dh = NULL; 193 DH_PKEY_CTX *dctx = ctx->data; 194 BN_GENCB *pcb, cb; 195 int ret; 196 197 if (ctx->pkey_gencb) { 198 pcb = &cb; 199 evp_pkey_set_cb_translate(pcb, ctx); 200 } else 201 pcb = NULL; 202 dh = DH_new(); 203 if (!dh) 204 return 0; 205 ret = DH_generate_parameters_ex(dh, dctx->prime_len, dctx->generator, 206 pcb); 207 if (ret) 208 EVP_PKEY_assign_DH(pkey, dh); 209 else 210 DH_free(dh); 211 return ret; 212 } 213 214 static int 215 pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 216 { 217 DH *dh = NULL; 218 219 if (ctx->pkey == NULL) { 220 DHerror(DH_R_NO_PARAMETERS_SET); 221 return 0; 222 } 223 dh = DH_new(); 224 if (!dh) 225 return 0; 226 EVP_PKEY_assign_DH(pkey, dh); 227 /* Note: if error return, pkey is freed by parent routine */ 228 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) 229 return 0; 230 return DH_generate_key(pkey->pkey.dh); 231 } 232 233 static int 234 pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen) 235 { 236 int ret; 237 238 if (!ctx->pkey || !ctx->peerkey) { 239 DHerror(DH_R_KEYS_NOT_SET); 240 return 0; 241 } 242 ret = DH_compute_key(key, ctx->peerkey->pkey.dh->pub_key, 243 ctx->pkey->pkey.dh); 244 if (ret < 0) 245 return ret; 246 *keylen = ret; 247 return 1; 248 } 249 250 const EVP_PKEY_METHOD dh_pkey_meth = { 251 .pkey_id = EVP_PKEY_DH, 252 .flags = EVP_PKEY_FLAG_AUTOARGLEN, 253 254 .init = pkey_dh_init, 255 .copy = pkey_dh_copy, 256 .cleanup = pkey_dh_cleanup, 257 258 .paramgen = pkey_dh_paramgen, 259 260 .keygen = pkey_dh_keygen, 261 262 .derive = pkey_dh_derive, 263 264 .ctrl = pkey_dh_ctrl, 265 .ctrl_str = pkey_dh_ctrl_str 266 }; 267