Solution for enhancement "bug" #1254: "MSSQL / TDS parser should decode

passwords"

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@20032 f5534014-38df-0310-8fa8-9805f1628bb7

diff --git a/epan/dissectors/packet-tds.c b/epan/dissectors/packet-tds.c
index e3cb283128b87e2642cedc9b1ec4ad35fa9d3e08..796a4c601e2d124536d6b3dabb7e08179d7b0339 100644 (file)
--- a/epan/dissectors/packet-tds.c
+++ b/epan/dissectors/packet-tds.c
@@ -792,8 +792,8 @@ dissect_tds_query5_packet(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tre
 static void
 dissect_tds7_login(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
-       guint offset, i, offset2, len;
-       char *val;
+       guint offset, i, j, k, offset2, len;
+       char *val, *val2;
 
        proto_item *login_hdr;
        proto_tree *login_tree;
@@ -882,10 +882,30 @@ dissect_tds7_login(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
                                val = tvb_get_ephemeral_faked_unicode(tvb, offset2, len, TRUE);
                                len *= 2;
                                proto_tree_add_text(login_tree, tvb, offset2, len, "%s: %s", val_to_str(i, login_field_names, "Unknown"), val);
-                       }
-                       else {
+                       } else {
+                               /* This field is the password.  We retrieve it from the packet 
+                                * as a non-unicode string and then perform two operations on it
+                                * to "decrypt" it.  Finally, we create a new string that consists
+                                * of ASCII characters instead of unicode by skipping every other
+                                * byte in the original string.
+                                */
+
                                len *= 2;
-                               proto_tree_add_text(login_tree, tvb, offset2, len, "%s", val_to_str(i, login_field_names, "Unknown"));
+                               val = tvb_get_ephemeral_string(tvb, offset2, len);
+                               val2 = g_malloc((len/2)+1);
+
+                               for(j = 0, k = 0; j < len; j += 2, k++) {
+                                       val[j] ^= 0xA5;
+
+                                       /* Swap the most and least significant bits */
+                                       val[j] = ((val[j] & 0x0F) << 4) | ((val[j] & 0xF0) >> 4);
+
+                                       val2[k] = val[j];
+                               }
+                               val2[k] = '\0'; /* Null terminate our new string */
+
+                               proto_tree_add_text(login_tree, tvb, offset2, len, "%s: %s", val_to_str(i, login_field_names, "Unknown"), val2);
+                               g_free(val2);
                        }
                }
        }