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 883cb9229..1e3a7524b 100644
--- a/include/asterisk/tcptls.h
+++ b/include/asterisk/tcptls.h
@@ -94,6 +94,9 @@ 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
@@ -138,6 +141,7 @@ 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 */
 };
 
 /*! \brief
diff --git a/main/tcptls.c b/main/tcptls.c
index c8ebab434..fce1558b7 100644
--- a/main/tcptls.c
+++ b/main/tcptls.c
@@ -36,6 +36,7 @@
 #endif
 
 #include <signal.h>
+#include <sys/stat.h>
 
 #include "asterisk/compat.h"
 #include "asterisk/tcptls.h"
@@ -46,6 +47,7 @@
 #include "asterisk/manager.h"
 #include "asterisk/astobj2.h"
 #include "asterisk/pbx.h"
+#include "asterisk/app.h"
 
 static void session_instance_destructor(void *obj)
 {
@@ -588,9 +590,64 @@ 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;
 	}
@@ -646,6 +703,22 @@ 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;
 
@@ -676,6 +749,17 @@ 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);
 }