-//
-// Functions in this module handle SSL encryption when WebCit is running
-// as an HTTPS server.
-//
-// Copyright (c) 1996-2022 by the citadel.org team
-//
-// This program is open source software. It runs great on the
-// Linux operating system (and probably elsewhere). You can use,
-// copy, and run it under the terms of the GNU General Public
-// License version 3.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-
-#include "webcit.h"
-
-SSL_CTX *ssl_ctx; // global SSL context
-char key_file[PATH_MAX] = "";
-char cert_file[PATH_MAX] = "";
-char *ssl_cipher_list = DEFAULT_SSL_CIPHER_LIST;
-
-
-// Set the private key and certificate chain for the global SSL Context.
-// This is called during initialization, and can be called again later if the certificate changes.
-void bind_to_key_and_certificate(void) {
- if (IsEmptyStr(key_file)) {
- snprintf(key_file, sizeof key_file, "%s/keys/citadel.key", ctdl_dir);
- }
- if (IsEmptyStr(cert_file)) {
- snprintf(cert_file, sizeof key_file, "%s/keys/citadel.cer", ctdl_dir);
- }
-
- syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
-
- SSL_CTX_use_certificate_chain_file(ssl_ctx, cert_file);
- SSL_CTX_use_PrivateKey_file(ssl_ctx, key_file, SSL_FILETYPE_PEM);
-
- if ( !SSL_CTX_check_private_key(ssl_ctx) ) {
- syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
- }
-}
-
-
-// Initialize ssl engine, load certs and initialize openssl internals
-void init_ssl(void) {
- const SSL_METHOD *ssl_method;
- RSA *rsa = NULL;
- X509_REQ *req = NULL;
- X509 *cer = NULL;
- EVP_PKEY *pk = NULL;
- EVP_PKEY *req_pkey = NULL;
- X509_NAME *name = NULL;
- FILE *fp;
- char buf[SIZ];
- int rv = 0;
-
- // Initialize SSL transport layer
- SSL_library_init();
- SSL_load_error_strings();
- ssl_method = SSLv23_server_method();
- if (!(ssl_ctx = SSL_CTX_new(ssl_method))) {
- syslog(LOG_WARNING, "SSL_CTX_new failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
-
- syslog(LOG_INFO, "Requesting cipher list: %s", ssl_cipher_list);
- if (!(SSL_CTX_set_cipher_list(ssl_ctx, ssl_cipher_list))) {
- syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
-
- // Now try to bind to the key and certificate.
- bind_to_key_and_certificate();
-}
-
-
-// Check the modification time of the key and certificate -- reload if they changed
-void update_key_and_cert_if_needed(void) {
- static time_t cert_mtime = 0;
- struct stat keystat;
- struct stat certstat;
-
- if (stat(key_file, &keystat) != 0) {
- syslog(LOG_ERR, "%s: %s", key_file, strerror(errno));
- return;
- }
- if (stat(cert_file, &certstat) != 0) {
- syslog(LOG_ERR, "%s: %s", cert_file, strerror(errno));
- return;
- }
-
- if ((keystat.st_mtime > cert_mtime) || (certstat.st_mtime > cert_mtime)) {
- bind_to_key_and_certificate();
- cert_mtime = certstat.st_mtime;
- }
-}
-
-
-// starts SSL/TLS encryption for the current session.
-void starttls(struct client_handle *ch) {
- int retval, bits, alg_bits;
-
- if (!ssl_ctx) {
- return;
- }
-
- // Check the modification time of the key and certificate -- reload if they changed
- update_key_and_cert_if_needed();
-
- if (!(ch->ssl_handle = SSL_new(ssl_ctx))) {
- syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
- return;
- }
- if (!(SSL_set_fd(ch->ssl_handle, ch->sock))) {
- syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
- SSL_free(ch->ssl_handle);
- return;
- }
- retval = SSL_accept(ch->ssl_handle);
- if (retval < 1) {
- long errval;
- const char *ssl_error_reason = NULL;
-
- errval = SSL_get_error(ch->ssl_handle, retval);
- ssl_error_reason = ERR_reason_error_string(ERR_get_error());
- if (ssl_error_reason == NULL) {
- syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
- }
- else {
- syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
- }
- //sleep(1);
- //retval = SSL_accept(ch->ssl_handle);
- }
- //if (retval < 1) {
- //long errval;
- //const char *ssl_error_reason = NULL;
-//
- //errval = SSL_get_error(ch->ssl_handle, retval);
- //ssl_error_reason = ERR_reason_error_string(ERR_get_error());
- //if (ssl_error_reason == NULL) {
- //syslog(LOG_WARNING, "SSL_accept failed: errval=%ld, retval=%d (%s)", errval, retval, strerror(errval));
- //}
- //else {
- //syslog(LOG_WARNING, "SSL_accept failed: %s", ssl_error_reason);
- //}
- //SSL_free(ch->ssl_handle);
- //ch->ssl_handle = NULL;
- //return;
- //}
- else {
- syslog(LOG_INFO, "SSL_accept success");
- }
- bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(ch->ssl_handle), &alg_bits);
- syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
- SSL_CIPHER_get_name(SSL_get_current_cipher(ch->ssl_handle)),
- SSL_CIPHER_get_version(SSL_get_current_cipher(ch->ssl_handle)), bits, alg_bits);
- syslog(LOG_INFO, "SSL started");
-}
-
-
-// shuts down the TLS connection
-void endtls(struct client_handle *ch) {
- syslog(LOG_INFO, "Ending SSL/TLS");
- if (ch->ssl_handle != NULL) {
- SSL_shutdown(ch->ssl_handle);
- SSL_get_SSL_CTX(ch->ssl_handle);
- SSL_free(ch->ssl_handle);
- }
- ch->ssl_handle = NULL;
-}
-
-
-// Send binary data to the client encrypted.
-int client_write_ssl(struct client_handle *ch, char *buf, int nbytes) {
- int retval;
- int nremain;
- char junk[1];
-
- if (ch->ssl_handle == NULL)
- return (-1);
-
- nremain = nbytes;
- while (nremain > 0) {
- if (SSL_want_write(ch->ssl_handle)) {
- if ((SSL_read(ch->ssl_handle, junk, 0)) < 1) {
- syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
- }
- }
- retval = SSL_write(ch->ssl_handle, &buf[nbytes - nremain], nremain);
- if (retval < 1) {
- long errval;
-
- errval = SSL_get_error(ch->ssl_handle, retval);
- if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
- sleep(1);
- continue;
- }
- syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
- if (retval == -1) {
- syslog(LOG_WARNING, "errno is %d", errno);
- endtls(ch);
- }
- return -1;
- }
- nremain -= retval;
- }
- return 0;
-}
-
-
-// read data from the encrypted layer
-int client_read_ssl(struct client_handle *ch, char *buf, int nbytes) {
- int bytes_read = 0;
- int rlen = 0;
- char junk[1];
-
- if (ch->ssl_handle == NULL)
- return (-1);
-
- while (bytes_read < nbytes) {
- if (SSL_want_read(ch->ssl_handle)) {
- if ((SSL_write(ch->ssl_handle, junk, 0)) < 1) {
- syslog(LOG_WARNING, "SSL_write in client_read");
- }
- }
- rlen = SSL_read(ch->ssl_handle, &buf[bytes_read], nbytes - bytes_read);
- if (rlen < 1) {
- long errval;
- errval = SSL_get_error(ch->ssl_handle, rlen);
- if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
- sleep(1);
- continue;
- }
- syslog(LOG_WARNING, "SSL_read error %ld", errval);
- endtls(ch);
- return (-1);
- }
- bytes_read += rlen;
- }
- return (bytes_read);
-}