1 /* 2 This is an example of how to hook up evhttp with bufferevent_ssl 3 4 It just GETs an https URL given on the command-line and prints the response 5 body to stdout. 6 7 Actually, it also accepts plain http URLs to make it easy to compare http vs 8 https code paths. 9 10 Loosely based on le-proxy.c. 11 */ 12 13 #include <stdio.h> 14 #include <assert.h> 15 #include <stdlib.h> 16 #include <string.h> 17 #include <errno.h> 18 19 #ifdef WIN32 20 #include <winsock2.h> 21 #include <ws2tcpip.h> 22 #else 23 #include <sys/socket.h> 24 #include <netinet/in.h> 25 #endif 26 27 #include <event2/bufferevent_ssl.h> 28 #include <event2/bufferevent.h> 29 #include <event2/buffer.h> 30 #include <event2/listener.h> 31 #include <event2/util.h> 32 #include <event2/http.h> 33 #include <event2/http_struct.h> 34 35 #include <openssl/ssl.h> 36 #include <openssl/err.h> 37 #include <openssl/rand.h> 38 39 static struct event_base *base; 40 41 static void 42 http_request_done(struct evhttp_request *req, void *ctx) 43 { 44 char buffer[256]; 45 int nread; 46 47 if (req == NULL) { 48 fprintf(stderr, "some request failed - no idea which one though!\n"); 49 return; 50 } 51 52 fprintf(stderr, "Response line: %d %s\n", 53 req->response_code, req->response_code_line); 54 55 while ((nread = evbuffer_remove(req->input_buffer, buffer, sizeof(buffer))) 56 > 0) { 57 /* These are just arbitrary chunks of 256 bytes. 58 * They are not lines, so we can't treat them as such. */ 59 fwrite(buffer, nread, 1, stdout); 60 } 61 } 62 63 static void 64 syntax(void) 65 { 66 fputs("Syntax:\n", stderr); 67 fputs(" https-client <https-url>\n", stderr); 68 fputs("Example:\n", stderr); 69 fputs(" https-client https://ip.appspot.com/\n", stderr); 70 71 exit(1); 72 } 73 74 static void 75 die(const char *msg) 76 { 77 fputs(msg, stderr); 78 exit(1); 79 } 80 81 int 82 main(int argc, char **argv) 83 { 84 int r; 85 86 struct evhttp_uri *http_uri; 87 const char *url, *scheme, *host, *path, *query; 88 char uri[256]; 89 int port; 90 91 SSL_CTX *ssl_ctx; 92 SSL *ssl; 93 struct bufferevent *bev; 94 struct evhttp_connection *evcon; 95 struct evhttp_request *req; 96 97 if (argc != 2) 98 syntax(); 99 100 url = argv[1]; 101 http_uri = evhttp_uri_parse(url); 102 if (http_uri == NULL) { 103 die("malformed url"); 104 } 105 106 scheme = evhttp_uri_get_scheme(http_uri); 107 if (scheme == NULL || (strcasecmp(scheme, "https") != 0 && 108 strcasecmp(scheme, "http") != 0)) { 109 die("url must be http or https"); 110 } 111 112 host = evhttp_uri_get_host(http_uri); 113 if (host == NULL) { 114 die("url must have a host"); 115 } 116 117 port = evhttp_uri_get_port(http_uri); 118 if (port == -1) { 119 port = (strcasecmp(scheme, "http") == 0) ? 80 : 443; 120 } 121 122 path = evhttp_uri_get_path(http_uri); 123 if (path == NULL) { 124 path = "/"; 125 } 126 127 query = evhttp_uri_get_query(http_uri); 128 if (query == NULL) { 129 snprintf(uri, sizeof(uri) - 1, "%s", path); 130 } else { 131 snprintf(uri, sizeof(uri) - 1, "%s?%s", path, query); 132 } 133 uri[sizeof(uri) - 1] = '\0'; 134 135 // Initialize OpenSSL 136 SSL_library_init(); 137 ERR_load_crypto_strings(); 138 SSL_load_error_strings(); 139 OpenSSL_add_all_algorithms(); 140 r = RAND_poll(); 141 if (r == 0) { 142 fprintf(stderr, "RAND_poll() failed.\n"); 143 return 1; 144 } 145 ssl_ctx = SSL_CTX_new(SSLv23_method()); 146 147 // Create event base 148 base = event_base_new(); 149 if (!base) { 150 perror("event_base_new()"); 151 return 1; 152 } 153 154 // Create OpenSSL bufferevent and stack evhttp on top of it 155 ssl = SSL_new(ssl_ctx); 156 if (ssl == NULL) { 157 fprintf(stderr, "SSL_new() failed\n"); 158 return 1; 159 } 160 161 if (strcasecmp(scheme, "http") == 0) { 162 bev = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE); 163 } else { 164 bev = bufferevent_openssl_socket_new(base, -1, ssl, 165 BUFFEREVENT_SSL_CONNECTING, 166 BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS); 167 } 168 169 if (bev == NULL) { 170 fprintf(stderr, "bufferevent_openssl_socket_new() failed\n"); 171 return 1; 172 } 173 174 bufferevent_openssl_set_allow_dirty_shutdown(bev, 1); 175 176 // For simplicity, we let DNS resolution block. Everything else should be 177 // asynchronous though. 178 evcon = evhttp_connection_base_bufferevent_new(base, NULL, bev, 179 host, port); 180 if (evcon == NULL) { 181 fprintf(stderr, "evhttp_connection_base_bufferevent_new() failed\n"); 182 return 1; 183 } 184 185 // Fire off the request 186 req = evhttp_request_new(http_request_done, NULL); 187 if (req == NULL) { 188 fprintf(stderr, "evhttp_request_new() failed\n"); 189 return 1; 190 } 191 192 evhttp_add_header(req->output_headers, "Host", host); 193 evhttp_add_header(req->output_headers, "Connection", "close"); 194 195 r = evhttp_make_request(evcon, req, EVHTTP_REQ_GET, uri); 196 if (r != 0) { 197 fprintf(stderr, "evhttp_make_request() failed\n"); 198 return 1; 199 } 200 201 event_base_dispatch(base); 202 203 evhttp_connection_free(evcon); 204 event_base_free(base); 205 206 return 0; 207 } 208