1 // Copyright (c) 1996-2021 by the citadel.org team
3 // This program is open source software. You can redistribute it and/or
4 // modify it under the terms of the GNU General Public License, version 3.
6 // This program is distributed in the hope that it will be useful,
7 // but WITHOUT ANY WARRANTY; without even the implied warranty of
8 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 // GNU General Public License for more details.
15 #include "webserver.h"
18 SSL_CTX *ssl_ctx; // Global SSL context
19 char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
21 pthread_key_t ThreadSSL; // Per-thread SSL context
23 void shutdown_ssl(void) {
28 // initialize ssl engine, load certs and initialize openssl internals
30 const SSL_METHOD *ssl_method;
32 #ifndef OPENSSL_NO_EGD
33 if (!access("/var/run/egd-pool", F_OK)) {
34 RAND_egd("/var/run/egd-pool");
39 syslog(LOG_WARNING, "PRNG not adequately seeded, won't do SSL/TLS");
43 // Initialize SSL transport layer
45 SSL_load_error_strings();
46 ssl_method = SSLv23_server_method();
47 if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
48 syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
52 syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
53 if (!(SSL_CTX_set_cipher_list(ssl_ctx, ssl_cipher_list))) {
54 syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
59 // Now try to bind to the key and certificate.
60 // Note that we use SSL_CTX_use_certificate_chain_file() which allows
61 // the certificate file to contain intermediate certificates.
64 char *key_file[PATH_MAX];
65 char *cert_file[PATH_MAX];
66 snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
67 snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
69 SSL_CTX_use_certificate_chain_file(ssl_ctx, cert_file);
70 SSL_CTX_use_PrivateKey_file(ssl_ctx, key_file, SSL_FILETYPE_PEM);
72 if ( !SSL_CTX_check_private_key(ssl_ctx) ) {
73 syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
78 // starts SSL/TLS encryption for the current session.
79 int starttls(int sock) {
80 int retval, bits, alg_bits;
83 pthread_setspecific(ThreadSSL, NULL);
88 if (!(newssl = SSL_new(ssl_ctx))) {
89 syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
92 if (!(SSL_set_fd(newssl, sock))) {
93 syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
97 retval = SSL_accept(newssl);
99 // Can't notify the client of an error here; they will
100 // discover the problem at the SSL layer and should
101 // revert to unencrypted communications.
103 const char *ssl_error_reason = NULL;
105 errval = SSL_get_error(newssl, retval);
106 ssl_error_reason = ERR_reason_error_string(ERR_get_error());
107 if (ssl_error_reason == NULL) {
108 syslog(LOG_WARNING, "first SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
111 syslog(LOG_WARNING, "first SSL_accept failed: %s", ssl_error_reason);
114 // retval = SSL_accept(newssl);
118 // const char *ssl_error_reason = NULL;
120 // errval = SSL_get_error(newssl, retval);
121 // ssl_error_reason = ERR_reason_error_string(ERR_get_error());
122 // if (ssl_error_reason == NULL) {
123 // syslog(LOG_WARNING, "second SSL_accept failed: errval=%ld, retval=%d (%s)", errval, retval, strerror(errval));
126 // syslog(LOG_WARNING, "second SSL_accept failed: %s", ssl_error_reason);
133 syslog(LOG_INFO, "SSL_accept success");
135 /*r = */BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
136 bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(newssl), &alg_bits);
137 syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
138 SSL_CIPHER_get_name(SSL_get_current_cipher(newssl)),
139 SSL_CIPHER_get_version(SSL_get_current_cipher(newssl)),
142 pthread_setspecific(ThreadSSL, newssl);
143 syslog(LOG_INFO, "SSL started");
148 // shuts down the TLS connection
150 // WARNING: This may make your session vulnerable to a known plaintext
151 // attack in the current implmentation.
154 if (THREADSSL == NULL) {
158 syslog(LOG_INFO, "Ending SSL/TLS");
159 SSL_shutdown(THREADSSL);
160 SSL_get_SSL_CTX(THREADSSL);
162 pthread_setspecific(ThreadSSL, NULL);
166 // Send binary data to the client encrypted.
167 int client_write_ssl(const StrBuf *Buf) {
174 if (THREADSSL == NULL) return -1;
176 nbytes = nremain = StrLength(Buf);
179 while (nremain > 0) {
180 if (SSL_want_write(THREADSSL)) {
181 if ((SSL_read(THREADSSL, junk, 0)) < 1) {
182 syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
185 retval = SSL_write(THREADSSL, &buf[nbytes - nremain], nremain);
189 errval = SSL_get_error(THREADSSL, retval);
190 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
194 syslog(LOG_WARNING, "SSL_write got error %ld, ret %d", errval, retval);
196 syslog(LOG_WARNING, "errno is %d\n", errno);
207 // read data from the encrypted layer.
208 int client_read_sslbuffer(StrBuf *buf, int timeout) {
209 char sbuf[16384]; // OpenSSL communicates in 16k blocks, so let's speak its native tongue.
212 SSL *pssl = THREADSSL;
214 if (pssl == NULL) return(-1);
217 if (SSL_want_read(pssl)) {
218 if ((SSL_write(pssl, junk, 0)) < 1) {
219 syslog(LOG_WARNING, "SSL_write in client_read");
222 rlen = SSL_read(pssl, sbuf, sizeof(sbuf));
226 errval = SSL_get_error(pssl, rlen);
227 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
231 syslog(LOG_WARNING, "SSL_read got error %ld", errval);
235 StrBufAppendBufPlain(buf, sbuf, rlen, 0);
241 #endif /* HAVE_OPENSSL */