1 /* $OpenBSD: dh_pmeth.c,v 1.10 2017/01/29 17:49:22 beck 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 "evp_locl.h" 71 72 /* DH pkey context structure */ 73 74 typedef struct { 75 /* Parameter gen parameters */ 76 int prime_len; 77 int generator; 78 int use_dsa; 79 /* Keygen callback info */ 80 int gentmp[2]; 81 /* message digest */ 82 } DH_PKEY_CTX; 83 84 static int 85 pkey_dh_init(EVP_PKEY_CTX *ctx) 86 { 87 DH_PKEY_CTX *dctx; 88 89 dctx = malloc(sizeof(DH_PKEY_CTX)); 90 if (!dctx) 91 return 0; 92 dctx->prime_len = 1024; 93 dctx->generator = 2; 94 dctx->use_dsa = 0; 95 96 ctx->data = dctx; 97 ctx->keygen_info = dctx->gentmp; 98 ctx->keygen_info_count = 2; 99 100 return 1; 101 } 102 103 static int 104 pkey_dh_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) 105 { 106 DH_PKEY_CTX *dctx, *sctx; 107 108 if (!pkey_dh_init(dst)) 109 return 0; 110 sctx = src->data; 111 dctx = dst->data; 112 dctx->prime_len = sctx->prime_len; 113 dctx->generator = sctx->generator; 114 dctx->use_dsa = sctx->use_dsa; 115 return 1; 116 } 117 118 static void 119 pkey_dh_cleanup(EVP_PKEY_CTX *ctx) 120 { 121 DH_PKEY_CTX *dctx = ctx->data; 122 123 free(dctx); 124 } 125 126 static int 127 pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) 128 { 129 DH_PKEY_CTX *dctx = ctx->data; 130 131 switch (type) { 132 case EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN: 133 if (p1 < 256) 134 return -2; 135 dctx->prime_len = p1; 136 return 1; 137 138 case EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR: 139 dctx->generator = p1; 140 return 1; 141 142 case EVP_PKEY_CTRL_PEER_KEY: 143 /* Default behaviour is OK */ 144 return 1; 145 146 default: 147 return -2; 148 } 149 } 150 151 static int 152 pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value) 153 { 154 long lval; 155 char *ep; 156 int len; 157 158 if (!strcmp(type, "dh_paramgen_prime_len")) { 159 errno = 0; 160 lval = strtol(value, &ep, 10); 161 if (value[0] == '\0' || *ep != '\0') 162 goto not_a_number; 163 if ((errno == ERANGE && 164 (lval == LONG_MAX || lval == LONG_MIN)) || 165 (lval > INT_MAX || lval < INT_MIN)) 166 goto out_of_range; 167 len = lval; 168 return EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len); 169 } else if (!strcmp(type, "dh_paramgen_generator")) { 170 errno = 0; 171 lval = strtol(value, &ep, 10); 172 if (value[0] == '\0' || *ep != '\0') 173 goto not_a_number; 174 if ((errno == ERANGE && 175 (lval == LONG_MAX || lval == LONG_MIN)) || 176 (lval > INT_MAX || lval < INT_MIN)) 177 goto out_of_range; 178 len = lval; 179 return EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, len); 180 } 181 182 not_a_number: 183 out_of_range: 184 return -2; 185 } 186 187 static int 188 pkey_dh_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 189 { 190 DH *dh = NULL; 191 DH_PKEY_CTX *dctx = ctx->data; 192 BN_GENCB *pcb, cb; 193 int ret; 194 195 if (ctx->pkey_gencb) { 196 pcb = &cb; 197 evp_pkey_set_cb_translate(pcb, ctx); 198 } else 199 pcb = NULL; 200 dh = DH_new(); 201 if (!dh) 202 return 0; 203 ret = DH_generate_parameters_ex(dh, dctx->prime_len, dctx->generator, 204 pcb); 205 if (ret) 206 EVP_PKEY_assign_DH(pkey, dh); 207 else 208 DH_free(dh); 209 return ret; 210 } 211 212 static int 213 pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) 214 { 215 DH *dh = NULL; 216 217 if (ctx->pkey == NULL) { 218 DHerror(DH_R_NO_PARAMETERS_SET); 219 return 0; 220 } 221 dh = DH_new(); 222 if (!dh) 223 return 0; 224 EVP_PKEY_assign_DH(pkey, dh); 225 /* Note: if error return, pkey is freed by parent routine */ 226 if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) 227 return 0; 228 return DH_generate_key(pkey->pkey.dh); 229 } 230 231 static int 232 pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen) 233 { 234 int ret; 235 236 if (!ctx->pkey || !ctx->peerkey) { 237 DHerror(DH_R_KEYS_NOT_SET); 238 return 0; 239 } 240 ret = DH_compute_key(key, ctx->peerkey->pkey.dh->pub_key, 241 ctx->pkey->pkey.dh); 242 if (ret < 0) 243 return ret; 244 *keylen = ret; 245 return 1; 246 } 247 248 const EVP_PKEY_METHOD dh_pkey_meth = { 249 .pkey_id = EVP_PKEY_DH, 250 .flags = EVP_PKEY_FLAG_AUTOARGLEN, 251 252 .init = pkey_dh_init, 253 .copy = pkey_dh_copy, 254 .cleanup = pkey_dh_cleanup, 255 256 .paramgen = pkey_dh_paramgen, 257 258 .keygen = pkey_dh_keygen, 259 260 .derive = pkey_dh_derive, 261 262 .ctrl = pkey_dh_ctrl, 263 .ctrl_str = pkey_dh_ctrl_str 264 }; 265