1 // Functions in this module handle SSL encryption when WebCit is running
4 // Copyright (c) 1996-2022 by the citadel.org team
6 // This program is open source software. Use, duplication, or
7 // disclosure is subject to the GNU General Public License v3.
11 SSL_CTX *ssl_ctx; // global SSL context
12 char key_file[PATH_MAX] = "";
13 char cert_file[PATH_MAX] = "";
14 char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
17 // Set the private key and certificate chain for the global SSL Context.
18 // This is called during initialization, and can be called again later if the certificate changes.
19 void bind_to_key_and_certificate(void) {
20 SSL_CTX *old_ctx, *new_ctx;
22 if (!(new_ctx = SSL_CTX_new(SSLv23_server_method()))) {
23 syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
27 syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
28 if (!(SSL_CTX_set_cipher_list(new_ctx, ssl_cipher_list))) {
29 syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
33 if (IsEmptyStr(key_file)) {
34 snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
36 if (IsEmptyStr(cert_file)) {
37 snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
40 syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
42 SSL_CTX_use_certificate_chain_file(new_ctx, cert_file);
43 SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM);
45 if ( !SSL_CTX_check_private_key(new_ctx) ) {
46 syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
52 SSL_CTX_free(old_ctx);
56 // Initialize ssl engine, load certs and initialize openssl internals
59 // Initialize the OpenSSL library
60 SSL_load_error_strings();
61 ERR_load_crypto_strings();
62 OpenSSL_add_all_algorithms();
65 // Now try to bind to the key and certificate.
66 bind_to_key_and_certificate();
70 // Check the modification time of the key and certificate -- reload if they changed
71 void update_key_and_cert_if_needed(void) {
72 static time_t previous_mtime = 0;
76 if (stat(key_file, &keystat) != 0) {
77 syslog(LOG_ERR, "%s: %s", key_file, strerror(errno));
80 if (stat(cert_file, &certstat) != 0) {
81 syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno));
85 if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) {
86 bind_to_key_and_certificate();
87 previous_mtime = keystat.st_mtime + certstat.st_mtime;
92 // starts SSL/TLS encryption for the current session.
93 void starttls(struct client_handle *ch) {
94 int retval, bits, alg_bits;
100 // Check the modification time of the key and certificate -- reload if they changed
101 update_key_and_cert_if_needed();
103 if (!(ch->ssl_handle = SSL_new(ssl_ctx))) {
104 syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
107 if (!(SSL_set_fd(ch->ssl_handle, ch->sock))) {
108 syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
109 SSL_free(ch->ssl_handle);
112 retval = SSL_accept(ch->ssl_handle);
114 syslog(LOG_WARNING, "SSL_accept failed: %s", ERR_reason_error_string(ERR_get_error()));
117 syslog(LOG_INFO, "SSL_accept success");
119 bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(ch->ssl_handle), &alg_bits);
120 syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
121 SSL_CIPHER_get_name(SSL_get_current_cipher(ch->ssl_handle)),
122 SSL_CIPHER_get_version(SSL_get_current_cipher(ch->ssl_handle)), bits, alg_bits);
123 syslog(LOG_INFO, "SSL started");
127 // shuts down the TLS connection
128 void endtls(struct client_handle *ch) {
129 syslog(LOG_INFO, "Ending SSL/TLS");
130 if (ch->ssl_handle != NULL) {
131 SSL_shutdown(ch->ssl_handle);
132 SSL_get_SSL_CTX(ch->ssl_handle);
133 SSL_free(ch->ssl_handle);
135 ch->ssl_handle = NULL;
139 // Send binary data to the client encrypted.
140 int client_write_ssl(struct client_handle *ch, char *buf, int nbytes) {
145 if (ch->ssl_handle == NULL)
149 while (nremain > 0) {
150 if (SSL_want_write(ch->ssl_handle)) {
151 if ((SSL_read(ch->ssl_handle, junk, 0)) < 1) {
152 syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
155 retval = SSL_write(ch->ssl_handle, &buf[nbytes - nremain], nremain);
159 errval = SSL_get_error(ch->ssl_handle, retval);
160 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
164 syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
166 syslog(LOG_WARNING, "errno is %d", errno);
177 // read data from the encrypted layer
178 int client_read_ssl(struct client_handle *ch, char *buf, int nbytes) {
183 if (ch->ssl_handle == NULL)
186 while (bytes_read < nbytes) {
187 if (SSL_want_read(ch->ssl_handle)) {
188 if ((SSL_write(ch->ssl_handle, junk, 0)) < 1) {
189 syslog(LOG_WARNING, "SSL_write in client_read");
192 rlen = SSL_read(ch->ssl_handle, &buf[bytes_read], nbytes - bytes_read);
195 errval = SSL_get_error(ch->ssl_handle, rlen);
196 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
200 syslog(LOG_WARNING, "SSL_read error %ld", errval);