added support for escapes inside of msg keyword

src/detect-msg.c

@@ -16,6 +16,10 @@ void DetectMsgRegister (void) {
 int DetectMsgSetup (DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *msgstr)
 {
     char *str = NULL;
+    uint16_t len;
+
+    if (strlen(msgstr) == 0)
+        goto error;
 
     /* strip "'s */
     if (msgstr[0] == '\"' && msgstr[strlen(msgstr)-1] == '\"') {
@@ -28,12 +32,61 @@ int DetectMsgSetup (DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *ms
         //printf("DetectMsgSetup: format hack applied: \'%s\'\n", str);
     } else {
         printf("DetectMsgSetup: format error \'%s\'\n", msgstr);
-        return -1;
+        goto error;
+    }
+
+    len = strlen(str);
+    if (len == 0)
+        goto error;
+
+    char converted = 0;
+
+    {
+        uint16_t i, x;
+        uint8_t escape = 0;
+
+        for (i = 0, x = 0; i < len; i++) {
+            //printf("str[%02u]: %c\n", i, str[i]);
+            if(!escape && str[i] == '\\') {
+                escape = 1;
+            } else if (escape) {
+                if (str[i] == ':' ||
+                        str[i] == ';' ||
+                        str[i] == '\\' ||
+                        str[i] == '\"')
+                {
+                    str[x] = str[i];
+                    x++;
+                } else {
+                    printf("Can't escape %c\n", str[i]);
+                    goto error;
+                }
+
+                escape = 0;
+                converted = 1;
+            } else {
+                str[x] = str[i];
+                x++;
+            }
+        }
+#ifdef DEBUG
+        for (i = 0; i < x; i++) {
+            printf("%c", str[i]);
+        }
+        printf("\n");
+#endif
+
+        if (converted) {
+            len = x;
+        }
     }
 
     s->msg = strdup(str);
 
     free(str);
     return 0;
-}
 
+error:
+    free(str);
+    return -1;
+}