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 disclosure is subject to the GNU General Public License v3.
10 SSL_CTX *ssl_ctx; // global SSL context
11 char key_file[PATH_MAX] = "";
12 char cert_file[PATH_MAX] = "";
13 char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
16 // Set the private key and certificate chain for the global SSL Context.
17 // This is called during initialization, and can be called again later if the certificate changes.
18 void bind_to_key_and_certificate(void) {
19 SSL_CTX *old_ctx, *new_ctx;
21 if (!(new_ctx = SSL_CTX_new(SSLv23_server_method()))) {
22 syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
26 syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
27 if (!(SSL_CTX_set_cipher_list(new_ctx, ssl_cipher_list))) {
28 syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
32 if (IsEmptyStr(key_file)) {
33 snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
35 if (IsEmptyStr(cert_file)) {
36 snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
39 syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
41 SSL_CTX_use_certificate_chain_file(new_ctx, cert_file);
42 SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM);
44 if ( !SSL_CTX_check_private_key(new_ctx) ) {
45 syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
51 SSL_CTX_free(old_ctx);
55 // Initialize ssl engine, load certs and initialize openssl internals
58 // Initialize the OpenSSL library
59 SSL_load_error_strings();
60 ERR_load_crypto_strings();
61 OpenSSL_add_all_algorithms();
64 // Now try to bind to the key and certificate.
65 bind_to_key_and_certificate();
69 // Check the modification time of the key and certificate -- reload if they changed
70 void update_key_and_cert_if_needed(void) {
71 static time_t previous_mtime = 0;
75 if (stat(key_file, &keystat) != 0) {
76 syslog(LOG_ERR, "%s: %s", key_file, strerror(errno));
79 if (stat(cert_file, &certstat) != 0) {
80 syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno));
84 if ((keystat.st_mtime + certstat.st_mtime) != previous_mtime) {
85 bind_to_key_and_certificate();
86 previous_mtime = keystat.st_mtime + certstat.st_mtime;
91 // starts SSL/TLS encryption for the current session.
92 void starttls(struct client_handle *ch) {
93 int retval, bits, alg_bits;
99 // Check the modification time of the key and certificate -- reload if they changed
100 update_key_and_cert_if_needed();
102 if (!(ch->ssl_handle = SSL_new(ssl_ctx))) {
103 syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
106 if (!(SSL_set_fd(ch->ssl_handle, ch->sock))) {
107 syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
108 SSL_free(ch->ssl_handle);
111 retval = SSL_accept(ch->ssl_handle);
113 syslog(LOG_WARNING, "SSL_accept failed: %s", ERR_reason_error_string(ERR_get_error()));
116 syslog(LOG_INFO, "SSL_accept success");
118 bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(ch->ssl_handle), &alg_bits);
119 syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
120 SSL_CIPHER_get_name(SSL_get_current_cipher(ch->ssl_handle)),
121 SSL_CIPHER_get_version(SSL_get_current_cipher(ch->ssl_handle)), bits, alg_bits);
122 syslog(LOG_INFO, "SSL started");
126 // shuts down the TLS connection
127 void endtls(struct client_handle *ch) {
128 syslog(LOG_INFO, "Ending SSL/TLS");
129 if (ch->ssl_handle != NULL) {
130 SSL_shutdown(ch->ssl_handle);
131 SSL_get_SSL_CTX(ch->ssl_handle);
132 SSL_free(ch->ssl_handle);
134 ch->ssl_handle = NULL;
138 // Send binary data to the client encrypted.
139 int client_write_ssl(struct client_handle *ch, char *buf, int nbytes) {
144 if (ch->ssl_handle == NULL)
148 while (nremain > 0) {
149 if (SSL_want_write(ch->ssl_handle)) {
150 if ((SSL_read(ch->ssl_handle, junk, 0)) < 1) {
151 syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
154 retval = SSL_write(ch->ssl_handle, &buf[nbytes - nremain], nremain);
158 errval = SSL_get_error(ch->ssl_handle, retval);
159 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
163 syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
165 syslog(LOG_WARNING, "errno is %d", errno);
176 // read data from the encrypted layer
177 int client_read_ssl(struct client_handle *ch, char *buf, int nbytes) {
182 if (ch->ssl_handle == NULL)
185 while (bytes_read < nbytes) {
186 if (SSL_want_read(ch->ssl_handle)) {
187 if ((SSL_write(ch->ssl_handle, junk, 0)) < 1) {
188 syslog(LOG_WARNING, "SSL_write in client_read");
191 rlen = SSL_read(ch->ssl_handle, &buf[bytes_read], nbytes - bytes_read);
194 errval = SSL_get_error(ch->ssl_handle, rlen);
195 if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
199 syslog(LOG_WARNING, "SSL_read error %ld", errval);