1 files changed, 12 insertions, 1 deletions
diff --git a/src/include/libpq/sasl.h b/src/include/libpq/sasl.h
index 7a1f970ccae..0e8fa848304 100644
--- a/src/include/libpq/sasl.h
+++ b/src/include/libpq/sasl.h
@@ -27,7 +27,15 @@
 #define PG_SASL_EXCHANGE_FAILURE		2
 
 /*
- * Backend SASL mechanism callbacks.
+ * Maximum accepted size of SASL messages.
+ *
+ * The messages that the server or libpq generate are much smaller than this,
+ * but have some headroom.
+ */
+#define PG_MAX_SASL_MESSAGE_LENGTH	1024
+
+/*
+ * Backend SASL mechanism callbacks and metadata.
  *
  * To implement a backend mechanism, declare a pg_be_sasl_mech struct with
  * appropriate callback implementations.  Then pass the mechanism to
@@ -127,6 +135,9 @@ typedef struct pg_be_sasl_mech
 							 const char *input, int inputlen,
 							 char **output, int *outputlen,
 							 const char **logdetail);
+
+	/* The maximum size allowed for client SASLResponses. */
+	int			max_message_length;
 } pg_be_sasl_mech;
 
 /* Common implementation for auth.c */