1 /* $OpenBSD: server.c,v 1.8 2019/03/21 17:52:26 bluhm Exp $ */ 2 /* 3 * Copyright (c) 2018-2019 Alexander Bluhm <bluhm@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <sys/types.h> 19 #include <sys/socket.h> 20 21 #include <err.h> 22 #include <netdb.h> 23 #include <stdio.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <unistd.h> 27 28 #include <openssl/err.h> 29 #include <openssl/ssl.h> 30 31 #include "util.h" 32 33 void __dead usage(void); 34 35 void __dead 36 usage(void) 37 { 38 fprintf(stderr, "usage: server [-Lsvv] [-C CA] [-c crt -k key] " 39 "[-l ciphers] [-p dhparam] [host port]\n"); 40 exit(2); 41 } 42 43 int 44 main(int argc, char *argv[]) 45 { 46 const SSL_METHOD *method; 47 SSL_CTX *ctx; 48 SSL *ssl; 49 BIO *abio, *cbio; 50 SSL_SESSION *session; 51 int ch, error, listciphers = 0, sessionreuse = 0, verify = 0; 52 char buf[256], *dhparam = NULL; 53 char *ca = NULL, *crt = NULL, *key = NULL, *ciphers = NULL; 54 char *host_port, *host = "127.0.0.1", *port = "0"; 55 56 while ((ch = getopt(argc, argv, "C:c:k:Ll:p:sv")) != -1) { 57 switch (ch) { 58 case 'C': 59 ca = optarg; 60 break; 61 case 'c': 62 crt = optarg; 63 break; 64 case 'k': 65 key = optarg; 66 break; 67 case 'L': 68 listciphers = 1; 69 break; 70 case 'l': 71 ciphers = optarg; 72 break; 73 case 'p': 74 dhparam = optarg; 75 break; 76 case 's': 77 /* multiple reueses are possible */ 78 sessionreuse++; 79 break; 80 case 'v': 81 /* use twice to force client cert */ 82 verify++; 83 break; 84 default: 85 usage(); 86 } 87 } 88 argc -= optind; 89 argv += optind; 90 if (argc == 2) { 91 host = argv[0]; 92 port = argv[1]; 93 } else if (argc != 0 && !listciphers) { 94 usage(); 95 } 96 if (asprintf(&host_port, strchr(host, ':') ? "[%s]:%s" : "%s:%s", 97 host, port) == -1) 98 err(1, "asprintf host port"); 99 if ((crt == NULL && key != NULL) || (crt != NULL && key == NULL)) 100 errx(1, "certificate and private key must be used together"); 101 if (crt == NULL && asprintf(&crt, "%s.crt", host) == -1) 102 err(1, "asprintf crt"); 103 if (key == NULL && asprintf(&key, "%s.key", host) == -1) 104 err(1, "asprintf key"); 105 106 SSL_library_init(); 107 SSL_load_error_strings(); 108 print_version(); 109 110 /* setup method and context */ 111 #if OPENSSL_VERSION_NUMBER >= 0x1010000f 112 method = TLS_server_method(); 113 if (method == NULL) 114 err_ssl(1, "TLS_server_method"); 115 #else 116 method = SSLv23_server_method(); 117 if (method == NULL) 118 err_ssl(1, "SSLv23_server_method"); 119 #endif 120 ctx = SSL_CTX_new(method); 121 if (ctx == NULL) 122 err_ssl(1, "SSL_CTX_new"); 123 124 #if OPENSSL_VERSION_NUMBER >= 0x10100000 125 /* needed to use DHE cipher with libressl */ 126 if (SSL_CTX_set_dh_auto(ctx, 1) <= 0) 127 err_ssl(1, "SSL_CTX_set_dh_auto"); 128 #endif 129 /* needed to use ADH, EDH, DHE cipher with openssl */ 130 if (dhparam != NULL) { 131 DH *dh; 132 FILE *file; 133 134 file = fopen(dhparam, "r"); 135 if (file == NULL) 136 err(1, "fopen %s", dhparam); 137 dh = PEM_read_DHparams(file, NULL, NULL, NULL); 138 if (dh == NULL) 139 err_ssl(1, "PEM_read_DHparams"); 140 if (SSL_CTX_set_tmp_dh(ctx, dh) <= 0) 141 err_ssl(1, "SSL_CTX_set_tmp_dh"); 142 fclose(file); 143 } 144 145 /* needed when linking with OpenSSL 1.0.2p */ 146 if (SSL_CTX_set_ecdh_auto(ctx, 1) <= 0) 147 err_ssl(1, "SSL_CTX_set_ecdh_auto"); 148 149 /* load server certificate */ 150 if (SSL_CTX_use_certificate_file(ctx, crt, SSL_FILETYPE_PEM) <= 0) 151 err_ssl(1, "SSL_CTX_use_certificate_file"); 152 if (SSL_CTX_use_PrivateKey_file(ctx, key, SSL_FILETYPE_PEM) <= 0) 153 err_ssl(1, "SSL_CTX_use_PrivateKey_file"); 154 if (SSL_CTX_check_private_key(ctx) <= 0) 155 err_ssl(1, "SSL_CTX_check_private_key"); 156 157 /* request client certificate and verify it */ 158 if (ca != NULL) { 159 STACK_OF(X509_NAME) *x509stack; 160 161 x509stack = SSL_load_client_CA_file(ca); 162 if (x509stack == NULL) 163 err_ssl(1, "SSL_load_client_CA_file"); 164 SSL_CTX_set_client_CA_list(ctx, x509stack); 165 if (SSL_CTX_load_verify_locations(ctx, ca, NULL) <= 0) 166 err_ssl(1, "SSL_CTX_load_verify_locations"); 167 } 168 SSL_CTX_set_verify(ctx, 169 verify == 0 ? SSL_VERIFY_NONE : 170 verify == 1 ? SSL_VERIFY_PEER : 171 SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, 172 verify_callback); 173 174 if (sessionreuse) { 175 uint32_t context; 176 177 SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_SERVER); 178 context = arc4random(); 179 if (SSL_CTX_set_session_id_context(ctx, 180 (unsigned char *)&context, sizeof(context)) <= 0) 181 err_ssl(1, "SSL_CTX_set_session_id_context"); 182 } 183 184 if (ciphers) { 185 if (SSL_CTX_set_cipher_list(ctx, ciphers) <= 0) 186 err_ssl(1, "SSL_CTX_set_cipher_list"); 187 } 188 189 if (listciphers) { 190 ssl = SSL_new(ctx); 191 if (ssl == NULL) 192 err_ssl(1, "SSL_new"); 193 print_ciphers(SSL_get_ciphers(ssl)); 194 return 0; 195 } 196 197 /* setup bio for socket operations */ 198 abio = BIO_new_accept(host_port); 199 if (abio == NULL) 200 err_ssl(1, "BIO_new_accept"); 201 202 /* bind, listen */ 203 if (BIO_do_accept(abio) <= 0) 204 err_ssl(1, "BIO_do_accept setup"); 205 printf("listen "); 206 print_sockname(abio); 207 208 /* fork to background and set timeout */ 209 if (daemon(1, 1) == -1) 210 err(1, "daemon"); 211 if ((int)alarm(10) == -1) 212 err(1, "alarm"); 213 214 do { 215 /* accept connection */ 216 if (BIO_do_accept(abio) <= 0) 217 err_ssl(1, "BIO_do_accept wait"); 218 cbio = BIO_pop(abio); 219 printf("accept "); 220 print_sockname(cbio); 221 printf("accept "); 222 print_peername(cbio); 223 224 /* do ssl server handshake */ 225 ssl = SSL_new(ctx); 226 if (ssl == NULL) 227 err_ssl(1, "SSL_new"); 228 SSL_set_bio(ssl, cbio, cbio); 229 if ((error = SSL_accept(ssl)) <= 0) 230 err_ssl(1, "SSL_accept %d", error); 231 printf("session %d: %s\n", sessionreuse, 232 SSL_session_reused(ssl) ? "reuse" : "new"); 233 if (fflush(stdout) != 0) 234 err(1, "fflush stdout"); 235 236 237 /* print session statistics */ 238 session = SSL_get_session(ssl); 239 if (session == NULL) 240 err_ssl(1, "SSL_get_session"); 241 if (SSL_SESSION_print_fp(stdout, session) <= 0) 242 err_ssl(1, "SSL_SESSION_print_fp"); 243 244 /* write server greeting and read client hello over TLS */ 245 strlcpy(buf, "greeting\n", sizeof(buf)); 246 printf(">>> %s", buf); 247 if (fflush(stdout) != 0) 248 err(1, "fflush stdout"); 249 if ((error = SSL_write(ssl, buf, 9)) <= 0) 250 err_ssl(1, "SSL_write %d", error); 251 if (error != 9) 252 errx(1, "write not 9 bytes greeting: %d", error); 253 if ((error = SSL_read(ssl, buf, 6)) <= 0) 254 err_ssl(1, "SSL_read %d", error); 255 if (error != 6) 256 errx(1, "read not 6 bytes hello: %d", error); 257 buf[6] = '\0'; 258 printf("<<< %s", buf); 259 if (fflush(stdout) != 0) 260 err(1, "fflush stdout"); 261 262 /* shutdown connection */ 263 if ((error = SSL_shutdown(ssl)) < 0) 264 err_ssl(1, "SSL_shutdown unidirectional %d", error); 265 if (error <= 0) { 266 if ((error = SSL_shutdown(ssl)) <= 0) 267 err_ssl(1, "SSL_shutdown bidirectional %d", 268 error); 269 } 270 271 SSL_free(ssl); 272 } while (sessionreuse--); 273 274 SSL_CTX_free(ctx); 275 276 printf("success\n"); 277 278 return 0; 279 } 280