--- /dev/null
+// Copyright (c) 1996-2022 by the citadel.org team
+//
+// This program is open source software. You can redistribute it and/or
+// modify 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 "sysdep.h"
+#ifdef HAVE_OPENSSL
+
+#include "webcit.h"
+#include "webserver.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;
+
+pthread_key_t ThreadSSL; // Per-thread SSL context
+
+
+// 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) {
+
+ SSL_CTX *old_ctx, *new_ctx;
+
+ 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);
+ }
+
+ if (!(new_ctx = SSL_CTX_new(SSLv23_server_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(new_ctx, ssl_cipher_list))) {
+ syslog(LOG_WARNING, "SSL_CTX_set_cipher_list failed: %s", ERR_reason_error_string(ERR_get_error()));
+ return;
+ }
+
+ syslog(LOG_DEBUG, "crypto: [re]installing key \"%s\" and certificate \"%s\"", key_file, cert_file);
+
+ SSL_CTX_use_certificate_chain_file(new_ctx, cert_file);
+ SSL_CTX_use_PrivateKey_file(new_ctx, key_file, SSL_FILETYPE_PEM);
+
+ if ( !SSL_CTX_check_private_key(new_ctx) ) {
+ syslog(LOG_WARNING, "crypto: cannot install certificate: %s", ERR_reason_error_string(ERR_get_error()));
+ }
+
+ old_ctx = ssl_ctx;
+ ssl_ctx = new_ctx;
+ sleep(1);
+ SSL_CTX_free(old_ctx);
+}
+
+
+// initialize ssl engine, load certs and initialize openssl internals
+void init_ssl(void) {
+
+ // Initialize the OpenSSL library
+ SSL_load_error_strings();
+ ERR_load_crypto_strings();
+ OpenSSL_add_all_algorithms();
+ SSL_library_init();
+
+ // 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 either one changed
+void update_key_and_cert_if_needed(void) {
+ static time_t previous_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 + certstat.st_mtime) != previous_mtime) {
+ bind_to_key_and_certificate();
+ previous_mtime = keystat.st_mtime + certstat.st_mtime;
+ }
+}
+
+
+// starts SSL/TLS encryption for the current session.
+int starttls(int sock) {
+ SSL *newssl;
+ int retval, bits, alg_bits;
+
+ // Check the modification time of the key and certificate -- reload if they changed
+ update_key_and_cert_if_needed();
+
+ // SSL is a thread-specific thing, I think.
+ pthread_setspecific(ThreadSSL, NULL);
+
+ if (!ssl_ctx) {
+ return(1);
+ }
+ if (!(newssl = SSL_new(ssl_ctx))) {
+ syslog(LOG_WARNING, "SSL_new failed: %s", ERR_reason_error_string(ERR_get_error()));
+ return(2);
+ }
+ if (!(SSL_set_fd(newssl, sock))) {
+ syslog(LOG_WARNING, "SSL_set_fd failed: %s", ERR_reason_error_string(ERR_get_error()));
+ SSL_free(newssl);
+ return(3);
+ }
+ retval = SSL_accept(newssl);
+ if (retval < 1) {
+ // Can't notify the client of an error here; they will
+ // discover the problem at the SSL layer and should
+ // revert to unencrypted communications.
+ long errval;
+ const char *ssl_error_reason = NULL;
+
+ errval = SSL_get_error(newssl, retval);
+ ssl_error_reason = ERR_reason_error_string(ERR_get_error());
+ if (ssl_error_reason == NULL) {
+ syslog(LOG_WARNING, "first SSL_accept failed: errval=%ld, retval=%d %s", errval, retval, strerror(errval));
+ }
+ else {
+ syslog(LOG_WARNING, "first SSL_accept failed: %s", ssl_error_reason);
+ }
+ }
+ else {
+ syslog(LOG_INFO, "SSL_accept success");
+ }
+ BIO_set_close(SSL_get_rbio(newssl), BIO_NOCLOSE);
+ bits = SSL_CIPHER_get_bits(SSL_get_current_cipher(newssl), &alg_bits);
+ syslog(LOG_INFO, "SSL/TLS using %s on %s (%d of %d bits)",
+ SSL_CIPHER_get_name(SSL_get_current_cipher(newssl)),
+ SSL_CIPHER_get_version(SSL_get_current_cipher(newssl)),
+ bits, alg_bits);
+
+ pthread_setspecific(ThreadSSL, newssl);
+ syslog(LOG_INFO, "SSL started");
+ return(0);
+}
+
+
+// shuts down the TLS connection
+//
+// WARNING: This may make your session vulnerable to a known plaintext
+// attack in the current implmentation.
+void endtls(void) {
+
+ if (THREADSSL == NULL) {
+ return;
+ }
+
+ syslog(LOG_INFO, "Ending SSL/TLS");
+ SSL_shutdown(THREADSSL);
+ SSL_get_SSL_CTX(THREADSSL);
+ SSL_free(THREADSSL);
+ pthread_setspecific(ThreadSSL, NULL);
+}
+
+
+// Send binary data to the client encrypted.
+int client_write_ssl(const StrBuf *Buf) {
+ const char *buf;
+ int retval;
+ int nremain;
+ long nbytes;
+ char junk[1];
+
+ if (THREADSSL == NULL) return -1;
+
+ nbytes = nremain = StrLength(Buf);
+ buf = ChrPtr(Buf);
+
+ while (nremain > 0) {
+ if (SSL_want_write(THREADSSL)) {
+ if ((SSL_read(THREADSSL, junk, 0)) < 1) {
+ syslog(LOG_WARNING, "SSL_read in client_write: %s", ERR_reason_error_string(ERR_get_error()));
+ }
+ }
+ retval = SSL_write(THREADSSL, &buf[nbytes - nremain], nremain);
+ if (retval < 1) {
+ long errval;
+
+ errval = SSL_get_error(THREADSSL, retval);
+ if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
+ sleeeeeeeeeep(1);
+ continue;
+ }
+ syslog(LOG_WARNING, "SSL_write: %s", ERR_reason_error_string(ERR_get_error()));
+ if (retval == -1) {
+ syslog(LOG_WARNING, "errno is %d\n", errno);
+ }
+ endtls();
+ return -1;
+ }
+ nremain -= retval;
+ }
+ return 0;
+}
+
+
+// read data from the encrypted layer.
+int client_read_sslbuffer(StrBuf *buf, int timeout) {
+ char sbuf[16384]; // OpenSSL communicates in 16k blocks, so let's speak its native tongue.
+ int rlen;
+ char junk[1];
+ SSL *pssl = THREADSSL;
+
+ if (pssl == NULL) return(-1);
+
+ while (1) {
+ if (SSL_want_read(pssl)) {
+ if ((SSL_write(pssl, junk, 0)) < 1) {
+ syslog(LOG_WARNING, "SSL_write in client_read");
+ }
+ }
+ rlen = SSL_read(pssl, sbuf, sizeof(sbuf));
+ if (rlen < 1) {
+ long errval;
+
+ errval = SSL_get_error(pssl, rlen);
+ if (errval == SSL_ERROR_WANT_READ || errval == SSL_ERROR_WANT_WRITE) {
+ sleeeeeeeeeep(1);
+ continue;
+ }
+ syslog(LOG_WARNING, "SSL_read in client_read: %s", ERR_reason_error_string(ERR_get_error()));
+ endtls();
+ return (-1);
+ }
+ StrBufAppendBufPlain(buf, sbuf, rlen, 0);
+ return rlen;
+ }
+ return (0);
+}
+
+#endif /* HAVE_OPENSSL */
projects / citadel.git / blobdiff