1 /*-
2  * Copyright (c) 2009,2010 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Alistair Crooks (agc@NetBSD.org)
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  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34 #include <sys/select.h>
35 
36 #include <netinet/in.h>
37 
38 #include <errno.h>
39 #include <netdb.h>
40 #include <netpgp.h>
41 #include <regex.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include "hkpd.h"
48 
49 /* make the string have %xx -> %c */
50 static size_t
frompercent(char * in,size_t insize,char * out,size_t outsize)51 frompercent(char *in, size_t insize, char *out, size_t outsize)
52 {
53 	size_t	 outcc;
54 	char	*next;
55 	char	*pc;
56 
57 	outcc = 0;
58 	for (pc = in ; (next = strchr(pc, '%')) != NULL ; pc = next + 3) {
59 		(void) memcpy(&out[outcc], pc, (size_t)(next - pc));
60 		outcc += (size_t)(next - pc);
61 		out[outcc++] = (char)strtol(next + 1, NULL, 16);
62 	}
63 	(void) memcpy(&out[outcc], pc, insize - (int)(pc - in));
64 	outcc += insize - (int)(pc - in);
65 	out[outcc] = 0x0;
66 	return outcc;
67 }
68 
69 #define HKP_HTTP_LEVEL	"HTTP/1.0"
70 #define HKP_NAME	"hkpd"
71 #define HKP_MIME_GET	"application/pgp-keys"
72 #define HKP_MIME_INDEX	"text/plain"
73 #define HKP_MACHREAD	"info:1:1\r\n"
74 
75 #define HKP_SUCCESS	200
76 #define HKP_NOT_FOUND	404
77 
78 /* make into html */
79 static int
htmlify(char * buf,size_t size,const int code,const int get,const char * title,const char * out,const char * body)80 htmlify(char *buf, size_t size, const int code, const int get, const char *title, const char *out, const char *body)
81 {
82 	return snprintf(buf, size,
83 		"%s %d %s\r\n"
84 		"Server: %s/%d\r\n"
85 		"Content-type: %s\r\n"
86 		"\r\n"
87 		"%s"
88 		"%s",
89 		HKP_HTTP_LEVEL, code, (code == HKP_SUCCESS) ? "OK" : "not found",
90 		HKP_NAME, HKPD_VERSION,
91 		(get) ? HKP_MIME_GET : HKP_MIME_INDEX,
92 		(get || strcmp(out, "mr") != 0) ? "" : HKP_MACHREAD,
93 		body);
94 }
95 
96 /* send the response now */
97 static int
response(int sock,const int code,const char * search,const int get,char * buf,int cc,const char * out)98 response(int sock, const int code, const char *search, const int get, char *buf, int cc, const char *out)
99 {
100 	char	outbuf[1024 * 512];
101 	char	item[BUFSIZ];
102 	int	tot;
103 	int	wc;
104 	int	n;
105 
106 	if (buf == NULL) {
107 		(void) snprintf(item, sizeof(item),
108 			"Error handling request: No keys found for '%s'\r\n", search);
109 		n = htmlify(outbuf, sizeof(outbuf), code, get,
110 			"Error handling request\r\n",
111 			out,
112 			item);
113 	} else {
114 		(void) snprintf(item, sizeof(item), "Search results for '%s'", search);
115 		n = htmlify(outbuf, sizeof(outbuf), code, get,
116 			item,
117 			out,
118 			buf);
119 	}
120 	for (tot = 0 ; (wc = write(sock, &outbuf[tot], n - tot)) > 0 && tot < n ; tot += wc) {
121 	}
122 	return 1;
123 }
124 
125 /* get a socket (we'll bind it later) */
126 static int
hkpd_sock_get(const int fam)127 hkpd_sock_get(const int fam)
128 {
129 	int	sock;
130 	int	on = 1;
131 
132 	sock = socket((fam == 4) ? AF_INET : AF_INET6, SOCK_STREAM, 0);
133 	if (sock < 0) {
134 		(void) fprintf(stderr,"hkpd_sock_get: can't get a socket\n");
135 		return -1;
136         }
137 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
138 			(void *)&on, sizeof(on)) == -1) {
139 		(void) fprintf(stderr,
140 			"hkpd_sock_get: can't set SO_REUSEADDR\n");
141 		return -1;
142 	}
143 	if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
144 			(void *)&on, sizeof(on)) == -1) {
145 		(void) fprintf(stderr,
146 			"hkpd_sock_get: can't set SO_KEEPALIVE\n");
147 		return -1;
148 	}
149 	return sock;
150 }
151 
152 /**************************************************************************/
153 
154 /* get a socket and bind it to the server */
155 int
hkpd_sock_bind(const char * hostname,const int port,const int fam)156 hkpd_sock_bind(const char *hostname, const int port, const int fam)
157 {
158         struct addrinfo  hints;
159         struct addrinfo *res;
160         char             portstr[32];
161 	int		 sock;
162         int              rc = 0;
163 
164         (void) memset(&hints, 0, sizeof(hints));
165         hints.ai_family = (fam == 4) ? PF_INET : PF_INET6;
166         hints.ai_socktype = SOCK_STREAM;
167         (void) snprintf(portstr, sizeof(portstr), "%d", port);
168         /* Attempt connection */
169 #ifdef AI_NUMERICSERV
170         hints.ai_flags = AI_NUMERICSERV;
171 #endif
172         if ((rc = getaddrinfo(hostname, portstr, &hints, &res)) != 0) {
173                 hints.ai_flags = 0;
174                 if ((rc = getaddrinfo(hostname, "hkp", &hints, &res)) != 0) {
175                         (void) fprintf(stderr, "getaddrinfo: %s",
176 					gai_strerror(rc));
177                         return -1;
178                 }
179         }
180 	if ((sock = hkpd_sock_get(fam)) < 0) {
181                 (void) fprintf(stderr, "hkpd_sock_get failed %d\n", errno);
182                 freeaddrinfo(res);
183                 return -1;
184 	}
185         if ((rc = bind(sock, res->ai_addr, res->ai_addrlen)) < 0) {
186                 (void) fprintf(stderr, "bind failed %d\n", errno);
187                 freeaddrinfo(res);
188                 return -1;
189         }
190         freeaddrinfo(res);
191         if (rc < 0) {
192                 (void) fprintf(stderr, "bind() to %s:%d failed (rc %d)\n",
193 				hostname, port, rc);
194         }
195         return sock;
196 }
197 
198 /* netpgp key daemon - does not return */
199 int
hkpd(netpgp_t * netpgp,int sock4,int sock6)200 hkpd(netpgp_t *netpgp, int sock4, int sock6)
201 {
202 	struct sockaddr_in	from;
203 	regmatch_t		searchmatches[10];
204 	regmatch_t		opmatches[10];
205 	regmatch_t		fmtmatch[3];
206 	socklen_t		fromlen;
207 	regex_t			searchterm;
208 	regex_t			fmtterm;
209 	regex_t			opterm;
210 	regex_t			get;
211 	fd_set			sockets;
212 	char			search[BUFSIZ];
213 	char			buf[BUFSIZ];
214 	char			*cp;
215 	char			fmt[10];
216 	int			newsock;
217 	int			sock;
218 	int			code;
219 	int			ok;
220 	int			cc;
221 	int			n;
222 
223 /* GET /pks/lookup?search=agc%40netbsd.org&op=index&options=mr HTTP/1.1\n */
224 #define HTTPGET		"GET /pks/lookup\\?"
225 #define OPTERM		"op=([a-zA-Z]+)"
226 #define SEARCHTERM	"search=([^ \t&]+)"
227 #define FMT		"options=(mr|json)"
228 
229 	(void) regcomp(&get, HTTPGET, REG_EXTENDED);
230 	(void) regcomp(&opterm, OPTERM, REG_EXTENDED);
231 	(void) regcomp(&searchterm, SEARCHTERM, REG_EXTENDED);
232 	(void) regcomp(&fmtterm, FMT, REG_EXTENDED);
233 	if (sock4 >= 0) {
234 		listen(sock4, 32);
235 	}
236 	if (sock6 >= 0) {
237 		listen(sock6, 32);
238 	}
239 	for (;;) {
240 		/* find out which socket we have data on */
241 		FD_ZERO(&sockets);
242 		if (sock4 >= 0) {
243 			FD_SET(sock4, &sockets);
244 		}
245 		if (sock6 >= 0) {
246 			FD_SET(sock6, &sockets);
247 		}
248 		if (select(32, &sockets, NULL, NULL, NULL) < 0) {
249 			(void) fprintf(stderr, "bad select call\n");
250 			continue;
251 		}
252 		sock = (sock4 >= 0 && FD_ISSET(sock4, &sockets)) ? sock4 : sock6;
253 		/* read data from socket */
254 		fromlen = sizeof(from);
255 		newsock = accept(sock, (struct sockaddr *) &from, &fromlen);
256 		cc = read(newsock, buf, sizeof(buf));
257 		/* parse the request */
258 		ok = 1;
259 		if (regexec(&get, buf, 10, opmatches, 0) != 0) {
260 			(void) fprintf(stderr, "not a valid get request\n");
261 			ok = 0;
262 		}
263 		if (ok && regexec(&opterm, buf, 10, opmatches, 0) != 0) {
264 			(void) fprintf(stderr, "no operation in request\n");
265 			ok = 0;
266 		}
267 		if (ok && regexec(&fmtterm, buf, 3, fmtmatch, 0) == 0) {
268 			(void) snprintf(fmt, sizeof(fmt), "%.*s",
269 				(int)(fmtmatch[1].rm_eo - fmtmatch[1].rm_so),
270 				&buf[(int)fmtmatch[1].rm_so]);
271 		} else {
272 			fmt[0] = 0x0;
273 		}
274 		if (ok && regexec(&searchterm, buf, 10, searchmatches, 0) != 0) {
275 			(void) fprintf(stderr, "no search term in request\n");
276 			ok = 0;
277 		}
278 		if (!ok) {
279 			(void) close(newsock);
280 			continue;
281 		}
282 		/* convert from %2f to / etc */
283 		n = frompercent(&buf[searchmatches[1].rm_so],
284 			(int)(searchmatches[1].rm_eo - searchmatches[1].rm_so),
285 			search,
286 			sizeof(search));
287 		code = HKP_NOT_FOUND;
288 		cc = 0;
289 		if (strncmp(&buf[opmatches[1].rm_so], "vindex", 6) == 0) {
290 			cc = 0;
291 			netpgp_setvar(netpgp, "subkey sigs", "yes");
292 			if (strcmp(fmt, "json") == 0) {
293 				if (netpgp_match_keys_json(netpgp, &cp, search, "human", 1)) {
294 					cc = strlen(cp);
295 					code = HKP_SUCCESS;
296 				}
297 			} else if ((cp = netpgp_get_key(netpgp, search, fmt)) != NULL) {
298 				cc = strlen(cp);
299 				code = HKP_SUCCESS;
300 			}
301 			response(newsock, code, search, 0, cp, cc, fmt);
302 			netpgp_unsetvar(netpgp, "subkey sigs");
303 		} else if (strncmp(&buf[opmatches[1].rm_so], "index", 5) == 0) {
304 			cc = 0;
305 			netpgp_unsetvar(netpgp, "subkey sigs");
306 			if (strcmp(fmt, "json") == 0) {
307 				if (netpgp_match_keys_json(netpgp, &cp, search, "human", 0)) {
308 					cc = strlen(cp);
309 					code = HKP_SUCCESS;
310 				}
311 			} else if ((cp = netpgp_get_key(netpgp, search, fmt)) != NULL) {
312 				cc = strlen(cp);
313 				code = HKP_SUCCESS;
314 			}
315 			response(newsock, code, search, 0, cp, cc, fmt);
316 		} else if (strncmp(&buf[opmatches[1].rm_so], "get", 3) == 0) {
317 			if ((cp = netpgp_export_key(netpgp, search)) != NULL) {
318 				cc = strlen(cp);
319 				code = HKP_SUCCESS;
320 			}
321 			response(newsock, code, search, 1, cp, cc, fmt);
322 		}
323 		free(cp);
324 		(void) close(newsock);
325 	}
326 }
327