xauth-pam: Add workaround for null-terminated passwords

Fixes #631.

src/libcharon/plugins/xauth_pam/xauth_pam.c

@@ -153,7 +153,12 @@ METHOD(xauth_method_t, process, status_t,
 				attr2string(user, sizeof(user), chunk);
 				break;
 			case XAUTH_USER_PASSWORD:
-				attr2string(pass, sizeof(pass), attr->get_chunk(attr));
+				chunk = attr->get_chunk(attr);
+				if (chunk.len && chunk.ptr[chunk.len - 1] == 0)
+				{	/* fix null-terminated passwords (Android etc.) */
+					chunk.len -= 1;
+				}
+				attr2string(pass, sizeof(pass), chunk);
 				break;
 			default:
 				break;