Merge pull request #559 from deltachat/noverisplit

avoid group-splits on verification problems

Author: r10s

src/dc_mimeparser.c

@@ -943,6 +943,35 @@ void dc_mimeparser_empty(dc_mimeparser_t* mimeparser)
 }
 
 
+void dc_mimeparser_repl_msg_by_error(dc_mimeparser_t* mimeparser,
+                                     const char* error_msg)
+{
+	dc_mimepart_t* part = NULL;
+	int            i = 0;
+
+	if (mimeparser==NULL || mimeparser->parts==NULL
+	 || carray_count(mimeparser->parts)<=0) {
+		return;
+	}
+
+	// part->raw_msg is unchanged
+	// so that the original message can be retrieved using dc_get_msg_info()
+	part = (dc_mimepart_t*)carray_get(mimeparser->parts, 0);
+	part->type = DC_MSG_TEXT;
+	free(part->msg);
+	part->msg = dc_mprintf(DC_EDITORIAL_OPEN "%s" DC_EDITORIAL_CLOSE, error_msg);
+
+	for (i = 1; i < carray_count(mimeparser->parts); i++) {
+		part = (dc_mimepart_t*)carray_get(mimeparser->parts, i);
+		if (part) {
+			dc_mimepart_unref(part);
+		}
+	}
+
+	carray_set_size(mimeparser->parts, 1);
+}
+
+
 static void do_add_single_part(dc_mimeparser_t* parser, dc_mimepart_t* part)
 {
 	/* add a single part to the list of parts, the parser takes the ownership of the part, so you MUST NOT unref it after calling this function. */

src/dc_mimeparser.h

@@ -81,7 +81,7 @@ dc_mimepart_t*                 dc_mimeparser_get_last_nonmeta       (dc_mimepars
 #define                        dc_mimeparser_has_nonmeta(a)         (dc_mimeparser_get_last_nonmeta((a))!=NULL)
 int                            dc_mimeparser_is_mailinglist_message (dc_mimeparser_t*);
 int                            dc_mimeparser_sender_equals_recipient(dc_mimeparser_t*);
-
+void                           dc_mimeparser_repl_msg_by_error      (dc_mimeparser_t*, const char* error_msg);
 
 
 /* low-level-tools for working with mailmime structures directly */

src/dc_receive_imf.c

@@ -490,7 +490,8 @@ static void create_or_lookup_adhoc_group(dc_context_t* context, dc_mimeparser_t*
 
 
 static int check_verified_properties(dc_context_t* context, dc_mimeparser_t* mimeparser,
-                                       uint32_t from_id, const dc_array_t* to_ids)
+                                     uint32_t from_id, const dc_array_t* to_ids,
+                                     char** failure_reason)
 {
 	int              everythings_okay = 0;
 	dc_contact_t*    contact = dc_contact_new(context);
@@ -499,8 +500,18 @@ static int check_verified_properties(dc_context_t* context, dc_mimeparser_t* mim
 	char*            q3 = NULL;
 	sqlite3_stmt*    stmt = NULL;
 
+	#define VERIFY_FAIL(a) \
+		*failure_reason = dc_mprintf("%s. See \"Info\" for details.", (a)); \
+		dc_log_warning(context, 0, *failure_reason);
+
 	if (!dc_contact_load_from_db(contact, context->sql, from_id)) {
-		dc_log_warning(context, 0, "Cannot verifiy group; cannot load contact.");
+		VERIFY_FAIL("Internal Error; cannot load contact.")
+		goto cleanup;
+	}
+
+	// ensure, the message is encrypted
+	if (!mimeparser->e2ee_helper->encrypted) {
+		VERIFY_FAIL("This message is not encrypted.")
 		goto cleanup;
 	}
 
@@ -511,23 +522,17 @@ static int check_verified_properties(dc_context_t* context, dc_mimeparser_t* mim
 	if (from_id!=DC_CONTACT_ID_SELF)
 	{
 		if (!dc_apeerstate_load_by_addr(peerstate, context->sql, contact->addr)
-		 || dc_contact_is_verified_ex(contact, peerstate) < DC_BIDIRECT_VERIFIED) {
-			dc_log_warning(context, 0, "Cannot verifiy group; sender is not verified.");
+		 || dc_contact_is_verified_ex(contact, peerstate) != DC_BIDIRECT_VERIFIED) {
+			VERIFY_FAIL("The sender of this message is not verified.")
 			goto cleanup;
 		}
 
 		if (!dc_apeerstate_has_verified_key(peerstate, mimeparser->e2ee_helper->signatures)) {
-			dc_log_warning(context, 0, "Cannot verifiy group; message is not signed properly.");
+			VERIFY_FAIL("The message was sent with non-verified encryption.")
 			goto cleanup;
 		}
 	}
 
-	// ensure, the message is encrypted
-	if (!mimeparser->e2ee_helper->encrypted) {
-		dc_log_warning(context, 0, "Cannot verifiy group; message is not encrypted properly.");
-		goto cleanup;
-	}
-
 	// check that all members are verified.
 	// if a verification is missing, check if this was just gossiped - as we've verified the sender, we verify the member then.
 	to_ids_str = dc_array_get_string(to_ids, ",");
@@ -554,7 +559,7 @@ static int check_verified_properties(dc_context_t* context, dc_mimeparser_t* mim
 			 ||   (strcmp(peerstate->verified_key_fingerprint, peerstate->public_key_fingerprint)!=0
 			    && strcmp(peerstate->verified_key_fingerprint, peerstate->gossip_key_fingerprint)!=0))
 			{
-				dc_log_info(context, 0, "Marking gossipped key %s as verified due to verified %s.", to_addr, contact->addr);
+				dc_log_info(context, 0, "%s has verfied %s.", contact->addr, to_addr);
 				dc_apeerstate_set_verified(peerstate, DC_PS_GOSSIP_KEY, peerstate->gossip_key_fingerprint, DC_BIDIRECT_VERIFIED);
 				dc_apeerstate_save_to_db(peerstate, context->sql, 0);
 				is_verified = 1;
@@ -563,7 +568,9 @@ static int check_verified_properties(dc_context_t* context, dc_mimeparser_t* mim
 
 		if (!is_verified)
 		{
-			dc_log_warning(context, 0, "Cannot verifiy group; recipient %s is not gossipped.", to_addr);
+			char* err = dc_mprintf("%s is not a member of this verified group.", to_addr);
+			VERIFY_FAIL(err)
+			free(err);
 			goto cleanup;
 		}
 	}
@@ -614,6 +621,7 @@ static void create_or_lookup_group(dc_context_t* context, dc_mimeparser_t* mime_
 	int           X_MrGrpNameChanged = 0;
 	const char*   X_MrGrpImageChanged = NULL;
 	char*         better_msg = NULL;
+	char*         failure_reason = NULL;
 
 	/* search the grpid in the header */
 	{
@@ -713,14 +721,8 @@ static void create_or_lookup_group(dc_context_t* context, dc_mimeparser_t* mime_
 	/* check, if we have a chat with this group ID */
 	if ((chat_id=dc_get_chat_id_by_grpid(context, grpid, &chat_id_blocked, &chat_id_verified))!=0) {
 		if (chat_id_verified
-		 && !check_verified_properties(context, mime_parser, from_id, to_ids)) {
-			chat_id          = 0; // force the creation of an unverified ad-hoc group.
-			chat_id_blocked  = 0;
-			chat_id_verified = 0;
-			free(grpid);
-			grpid = NULL;
-			free(grpname);
-			grpname = NULL;
+		 && !check_verified_properties(context, mime_parser, from_id, to_ids, &failure_reason)) {
+			dc_mimeparser_repl_msg_by_error(mime_parser, failure_reason);
 		}
 	}
 
@@ -744,8 +746,9 @@ static void create_or_lookup_group(dc_context_t* context, dc_mimeparser_t* mime_
 	{
 		int create_verified = 0;
 		if (dc_mimeparser_lookup_field(mime_parser, "Chat-Verified")) {
-			if (check_verified_properties(context, mime_parser, from_id, to_ids)) {
-				create_verified = 1;
+			create_verified = 1;
+			if (!check_verified_properties(context, mime_parser, from_id, to_ids, &failure_reason)) {
+				dc_mimeparser_repl_msg_by_error(mime_parser, failure_reason);
 			}
 		}
 
@@ -868,6 +871,7 @@ static void create_or_lookup_group(dc_context_t* context, dc_mimeparser_t* mime_
 	free(grpname);
 	free(self_addr);
 	free(better_msg);
+	free(failure_reason);
 	if (ret_chat_id)         { *ret_chat_id = chat_id; }
 	if (ret_chat_id_blocked) { *ret_chat_id_blocked = chat_id? chat_id_blocked : 0; }
 }