1 |
#include <string.h> |
2 |
#include <errno.h> |
3 |
#include <unistd.h> |
4 |
#include <sys/time.h> |
5 |
#include <sys/types.h> |
6 |
#include <sys/socket.h> |
7 |
#include <netinet/in.h> |
8 |
#include <netdb.h> |
9 |
#include <fcntl.h> |
10 |
|
11 |
#include "config.h" |
12 |
#include "imapfilter.h" |
13 |
|
14 |
#ifdef SSL_TLS |
15 |
#include <openssl/ssl.h> |
16 |
#include <openssl/err.h> |
17 |
#include <openssl/x509.h> |
18 |
|
19 |
|
20 |
static SSL *ssl; |
21 |
#endif |
22 |
|
23 |
static int sock; |
24 |
|
25 |
|
26 |
/* |
27 |
* Connect to mail server. |
28 |
*/ |
29 |
#ifndef SSL_TLS |
30 |
int init_connection(char *serv, unsigned int port) |
31 |
#else |
32 |
int init_connection(char *serv, unsigned int port, unsigned int protocol) |
33 |
#endif |
34 |
{ |
35 |
struct sockaddr_in sa; |
36 |
struct hostent *he; |
37 |
|
38 |
memset((char *) &sa, 0, sizeof(struct sockaddr_in)); |
39 |
|
40 |
sock = socket(PF_INET, SOCK_STREAM, 0); |
41 |
|
42 |
if (sock < 0) { |
43 |
error("imapfilter: create socket; %s\n", strerror(errno)); |
44 |
return ERROR_NETWORK; |
45 |
} |
46 |
if (!(he = gethostbyname(serv))) { |
47 |
error("imapfilter: get network host entry; %s\n", strerror(errno)); |
48 |
close_connection(); |
49 |
return ERROR_NETWORK; |
50 |
} |
51 |
sa.sin_family = AF_INET; |
52 |
sa.sin_port = htons(port); |
53 |
sa.sin_addr = *(struct in_addr *) he->h_addr; |
54 |
|
55 |
xstrncpy(serv, he->h_name, SERVER_LEN - 1); |
56 |
|
57 |
if (connect(sock, (struct sockaddr *) & sa, sizeof(struct sockaddr))) { |
58 |
error("imapfilter: initiating connection to %s; %s\n", serv, strerror(errno)); |
59 |
close_connection(); |
60 |
return ERROR_NETWORK; |
61 |
} |
62 |
log_info(LOG_SERVER, serv); |
63 |
|
64 |
#ifdef SSL_TLS |
65 |
if (protocol != SSL_DISABLED && !ssl_init(protocol)) { |
66 |
info("Connected to %s using %s.\n", serv, SSL_get_cipher(ssl)); |
67 |
return 0; |
68 |
} else |
69 |
ssl = NULL; |
70 |
#endif |
71 |
|
72 |
info("Connected to %s.\n", serv); |
73 |
|
74 |
return 0; |
75 |
} |
76 |
|
77 |
|
78 |
#ifdef SSL_TLS |
79 |
/* |
80 |
* Initialize Secure Socket Layer connection. |
81 |
*/ |
82 |
int ssl_init(unsigned int protocol) |
83 |
{ |
84 |
int e; |
85 |
unsigned int i, n = 0; |
86 |
SSL_CTX *ctx; |
87 |
SSL_METHOD *method = NULL; |
88 |
X509 *cert; |
89 |
char *c; |
90 |
EVP_MD *evp; |
91 |
unsigned char digest[EVP_MAX_MD_SIZE]; |
92 |
|
93 |
SSL_library_init(); |
94 |
|
95 |
switch (protocol) { |
96 |
case SSL_SSL_V2: |
97 |
method = SSLv2_client_method(); |
98 |
break; |
99 |
case SSL_SSL_V3: |
100 |
method = SSLv3_client_method(); |
101 |
break; |
102 |
case SSL_TLS_V1: |
103 |
method = TLSv1_client_method(); |
104 |
break; |
105 |
} |
106 |
|
107 |
if (!(ctx = SSL_CTX_new(method))) |
108 |
return ERROR_SSL; |
109 |
|
110 |
if (!(ssl = SSL_new(ctx))) |
111 |
return ERROR_SSL; |
112 |
|
113 |
SSL_set_fd(ssl, sock); |
114 |
|
115 |
e = SSL_connect(ssl); |
116 |
|
117 |
if (e <= 0) { |
118 |
error("imapfilter: initiating SSL connection; %s", |
119 |
ERR_error_string(e, NULL)); |
120 |
return ERROR_SSL; |
121 |
} |
122 |
/* Get server's certificate. */ |
123 |
if (!(cert = SSL_get_peer_certificate(ssl))) |
124 |
return ERROR_SSL; |
125 |
|
126 |
if (!(c = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0))) |
127 |
return ERROR_SSL; |
128 |
verbose("Server certificate subject: %s\n", c); |
129 |
free(c); |
130 |
|
131 |
if (!(c = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0))) |
132 |
return ERROR_SSL; |
133 |
verbose("Server certificate issuer: %s\n", c); |
134 |
free(c); |
135 |
|
136 |
if (!(evp = EVP_md5())) |
137 |
return ERROR_SSL; |
138 |
if (!(X509_digest(cert, evp, digest, &n))) |
139 |
return ERROR_SSL; |
140 |
|
141 |
verbose("Server key fingerprint: "); |
142 |
for (i = 0; i < n; i++) |
143 |
verbose(i != n - 1 ? "%02X:" : "%02X\n", digest[i]); |
144 |
|
145 |
X509_free(cert); |
146 |
SSL_CTX_free(ctx); |
147 |
|
148 |
return 0; |
149 |
} |
150 |
#endif |
151 |
|
152 |
|
153 |
/* |
154 |
* Disconnect from mail server. |
155 |
*/ |
156 |
int close_connection(void) |
157 |
{ |
158 |
#ifdef SSL_TLS |
159 |
if (ssl) { |
160 |
SSL_shutdown(ssl); |
161 |
SSL_free(ssl); |
162 |
} |
163 |
#endif |
164 |
|
165 |
if (close(sock)) { |
166 |
error("imapfilter: closing socket; %s\n", strerror(errno)); |
167 |
return ERROR_NETWORK; |
168 |
} else |
169 |
return 0; |
170 |
} |
171 |
|
172 |
|
173 |
/* |
174 |
* Read data from socket. |
175 |
*/ |
176 |
int socket_read(char *buf) |
177 |
{ |
178 |
int flags, r, s; |
179 |
fd_set fds; |
180 |
struct timeval tv; |
181 |
|
182 |
r = 0; |
183 |
s = 1; |
184 |
|
185 |
memset(buf, 0, RESPONSE_BUF); |
186 |
|
187 |
tv.tv_sec = 60; |
188 |
tv.tv_usec = 0; |
189 |
|
190 |
flags = fcntl(sock, F_GETFL, 0); |
191 |
fcntl(sock, F_SETFL, flags | O_NONBLOCK); |
192 |
|
193 |
FD_ZERO(&fds); |
194 |
FD_SET(sock, &fds); |
195 |
|
196 |
#ifdef SSL_TLS |
197 |
if (ssl) { |
198 |
if (SSL_pending(ssl) |
199 |
|| ((s = select(sock + 1, &fds, NULL, NULL, &tv)) > 0 |
200 |
&& FD_ISSET(sock, &fds))) |
201 |
r = SSL_read(ssl, buf, RESPONSE_BUF - 1); |
202 |
} else |
203 |
#endif |
204 |
if ((s = select(sock + 1, &fds, NULL, NULL, &tv)) > 0 |
205 |
&& FD_ISSET(sock, &fds)) |
206 |
r = read(sock, buf, RESPONSE_BUF - 1); |
207 |
|
208 |
fcntl(sock, F_SETFL, flags); |
209 |
|
210 |
if (s == -1) |
211 |
fatal(ERROR_NETWORK, "imapfilter: waiting input from socket; %s\n", |
212 |
strerror(errno)); |
213 |
else if (!s) |
214 |
fatal(ERROR_NETWORK, |
215 |
"imapfilter: timeout period expired while waiting data\n"); |
216 |
|
217 |
#ifdef SSL_TLS |
218 |
if (ssl) { |
219 |
if (r < 0) |
220 |
fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
221 |
ERR_error_string(r, NULL)); |
222 |
} else |
223 |
#endif |
224 |
if (r == -1) |
225 |
fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
226 |
strerror(errno)); |
227 |
|
228 |
return 0; |
229 |
} |
230 |
|
231 |
|
232 |
/* |
233 |
* Write data to socket. |
234 |
*/ |
235 |
int socket_write(char *data) |
236 |
{ |
237 |
#ifdef SSL_TLS |
238 |
int e; |
239 |
|
240 |
if (ssl) { |
241 |
e = SSL_write(ssl, data, strlen(data)); |
242 |
if (e <= 0) |
243 |
fatal(ERROR_NETWORK, |
244 |
"imapfilter: sending data; %s", |
245 |
ERR_error_string(e, NULL)); |
246 |
} else |
247 |
#endif |
248 |
if (write(sock, data, strlen(data)) == -1) |
249 |
fatal(ERROR_NETWORK, "imapfilter: sending data; %s", |
250 |
strerror(errno)); |
251 |
|
252 |
return 0; |
253 |
} |