tcptls: Use new certificate upon sip reload

Previously, a TLS server socket would only be restarted upon sip reload if the
bind address had changed. This commit adds checking for changes to TLS
parameters like certificate, ciphers, etc. so they get picked up without
requiring a reload of the entire chan_sip module. This does not affect open
connections in any way, but new connections will use the new TLS parameters.
The changes also apply to HTTP and Manager.

ASTERISK-26604 #close

Change-Id: I169e86cefc6dcd627c915134015a6a1ab1aadbe6

2 files changed, 89 insertions, 1 deletions

diff --git a/include/asterisk/tcptls.h b/include/asterisk/tcptls.h
index e1a632cca..8a18a8fe7 100644
--- a/include/asterisk/tcptls.h
+++ b/include/asterisk/tcptls.h
@@ -106,6 +106,9 @@ struct ast_tls_config {
 	char *capath;
 	struct ast_flags flags;
 	SSL_CTX *ssl_ctx;
+	char certhash[41];
+	char pvthash[41];
+	char cahash[41];
 };
 
 /*! \page AstTlsOverview TLS Implementation Overview
@@ -150,6 +153,7 @@ struct ast_tcptls_session_args {
 	void (*periodic_fn)(void *);/*!< something we may want to run before after select on the accept socket */
 	void *(*worker_fn)(void *); /*!< the function in charge of doing the actual work */
 	const char *name;
+	struct ast_tls_config *old_tls_cfg; /*!< copy of the SSL configuration to determine whether changes have been made */
 };
 
 struct ast_tcptls_stream;
diff --git a/main/tcptls.c b/main/tcptls.c
index 34baf9a0e..19012e1e0 100644
--- a/main/tcptls.c
+++ b/main/tcptls.c
@@ -39,6 +39,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #include <signal.h>
 #include <sys/signal.h>
+#include <sys/stat.h>
 
 #include "asterisk/compat.h"
 #include "asterisk/tcptls.h"
@@ -49,6 +50,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/manager.h"
 #include "asterisk/astobj2.h"
 #include "asterisk/pbx.h"
+#include "asterisk/app.h"
 
 /*! ao2 object used for the FILE stream fopencookie()/funopen() cookie. */
 struct ast_tcptls_stream {
@@ -1037,9 +1039,64 @@ void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 {
 	int flags;
 	int x = 1;
+	int tls_changed = 0;
+
+	if (desc->tls_cfg) {
+		char hash[41];
+		char *str = NULL;
+		struct stat st;
+
+		/* Store the hashes of the TLS certificate etc. */
+		if (stat(desc->tls_cfg->certfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->certfile))) {
+			memset(hash, 0, 41);
+		} else {
+			ast_sha1_hash(hash, str);
+		}
+		ast_free(str);
+		str = NULL;
+		memcpy(desc->tls_cfg->certhash, hash, 41);
+		if (stat(desc->tls_cfg->pvtfile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->pvtfile))) {
+			memset(hash, 0, 41);
+		} else {
+			ast_sha1_hash(hash, str);
+		}
+		ast_free(str);
+		str = NULL;
+		memcpy(desc->tls_cfg->pvthash, hash, 41);
+		if (stat(desc->tls_cfg->cafile, &st) || NULL == (str = ast_read_textfile(desc->tls_cfg->cafile))) {
+			memset(hash, 0, 41);
+		} else {
+			ast_sha1_hash(hash, str);
+		}
+		ast_free(str);
+		str = NULL;
+		memcpy(desc->tls_cfg->cahash, hash, 41);
+
+		/* Check whether TLS configuration has changed */
+		if (!desc->old_tls_cfg) { /* No previous configuration */
+			tls_changed = 1;
+			desc->old_tls_cfg = ast_calloc(1, sizeof(*desc->old_tls_cfg));
+		} else if (memcmp(desc->tls_cfg->certhash, desc->old_tls_cfg->certhash, 41)) {
+			tls_changed = 1;
+		} else if (memcmp(desc->tls_cfg->pvthash, desc->old_tls_cfg->pvthash, 41)) {
+			tls_changed = 1;
+		} else if (strcmp(desc->tls_cfg->cipher, desc->old_tls_cfg->cipher)) {
+			tls_changed = 1;
+		} else if (memcmp(desc->tls_cfg->cahash, desc->old_tls_cfg->cahash, 41)) {
+			tls_changed = 1;
+		} else if (strcmp(desc->tls_cfg->capath, desc->old_tls_cfg->capath)) {
+			tls_changed = 1;
+		} else if (memcmp(&desc->tls_cfg->flags, &desc->old_tls_cfg->flags, sizeof(desc->tls_cfg->flags))) {
+			tls_changed = 1;
+		}
+
+		if (tls_changed) {
+			ast_debug(1, "Changed parameters for %s found\n", desc->name);
+		}
+	}
 
 	/* Do nothing if nothing has changed */
-	if (!ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
+	if (!tls_changed && !ast_sockaddr_cmp(&desc->old_address, &desc->local_address)) {
 		ast_debug(1, "Nothing changed in %s\n", desc->name);
 		return;
 	}
@@ -1095,6 +1152,22 @@ void ast_tcptls_server_start(struct ast_tcptls_session_args *desc)
 
 	/* Set current info */
 	ast_sockaddr_copy(&desc->old_address, &desc->local_address);
+	if (desc->old_tls_cfg) {
+		ast_free(desc->old_tls_cfg->certfile);
+		ast_free(desc->old_tls_cfg->pvtfile);
+		ast_free(desc->old_tls_cfg->cipher);
+		ast_free(desc->old_tls_cfg->cafile);
+		ast_free(desc->old_tls_cfg->capath);
+		desc->old_tls_cfg->certfile = ast_strdup(desc->tls_cfg->certfile);
+		desc->old_tls_cfg->pvtfile = ast_strdup(desc->tls_cfg->pvtfile);
+		desc->old_tls_cfg->cipher = ast_strdup(desc->tls_cfg->cipher);
+		desc->old_tls_cfg->cafile = ast_strdup(desc->tls_cfg->cafile);
+		desc->old_tls_cfg->capath = ast_strdup(desc->tls_cfg->capath);
+		memcpy(desc->old_tls_cfg->certhash, desc->tls_cfg->certhash, 41);
+		memcpy(desc->old_tls_cfg->pvthash, desc->tls_cfg->pvthash, 41);
+		memcpy(desc->old_tls_cfg->cahash, desc->tls_cfg->cahash, 41);
+		memcpy(&desc->old_tls_cfg->flags, &desc->tls_cfg->flags, sizeof(desc->old_tls_cfg->flags));
+	}
 
 	return;
 
@@ -1140,6 +1213,17 @@ void ast_tcptls_server_stop(struct ast_tcptls_session_args *desc)
 		close(desc->accept_fd);
 	}
 	desc->accept_fd = -1;
+
+	if (desc->old_tls_cfg) {
+		ast_free(desc->old_tls_cfg->certfile);
+		ast_free(desc->old_tls_cfg->pvtfile);
+		ast_free(desc->old_tls_cfg->cipher);
+		ast_free(desc->old_tls_cfg->cafile);
+		ast_free(desc->old_tls_cfg->capath);
+		ast_free(desc->old_tls_cfg);
+		desc->old_tls_cfg = NULL;
+	}
+
 	ast_debug(2, "Stopped server :: %s\n", desc->name);
 }