8 files changed, 132 insertions, 2 deletions
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 9f036c72d89..104ee7dd5ed 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -256,6 +256,7 @@ extern char *XLogFileNameP(TimeLineID tli, XLogSegNo segno);
 
 extern void UpdateControlFile(void);
 extern uint64 GetSystemIdentifier(void);
+extern char *GetMockAuthenticationNonce(void);
 extern bool DataChecksumsEnabled(void);
 extern XLogRecPtr GetFakeLSNForUnloggedRel(void);
 extern Size XLOGShmemSize(void);
diff --git a/src/include/catalog/pg_control.h b/src/include/catalog/pg_control.h
index e4194b9de1f..3a25cc84b2a 100644
--- a/src/include/catalog/pg_control.h
+++ b/src/include/catalog/pg_control.h
@@ -20,8 +20,10 @@
 #include "port/pg_crc32c.h"
 
 
+#define MOCK_AUTH_NONCE_LEN		32
+
 /* Version identifier for this pg_control format */
-#define PG_CONTROL_VERSION	1001
+#define PG_CONTROL_VERSION	1002
 
 /*
  * Body of CheckPoint XLOG records.  This is declared here because we keep
@@ -222,6 +224,13 @@ typedef struct ControlFileData
 	/* Are data pages protected by checksums? Zero if no checksum version */
 	uint32		data_checksum_version;
 
+	/*
+	 * Random nonce, used in authentication requests that need to proceed
+	 * based on values that are cluster-unique, like a SASL exchange that
+	 * failed at an early stage.
+	 */
+	char		mock_authentication_nonce[MOCK_AUTH_NONCE_LEN];
+
 	/* CRC of all above ... MUST BE LAST! */
 	pg_crc32c	crc;
 } ControlFileData;
diff --git a/src/include/common/base64.h b/src/include/common/base64.h
new file mode 100644
index 00000000000..47c28c3b62f
--- /dev/null
+++ b/src/include/common/base64.h
@@ -0,0 +1,19 @@
+/*
+ * base64.h
+ *	  Encoding and decoding routines for base64 without whitespace
+ *	  support.
+ *
+ * Portions Copyright (c) 2001-2016, PostgreSQL Global Development Group
+ *
+ * src/include/common/base64.h
+ */
+#ifndef BASE64_H
+#define BASE64_H
+
+/* base 64 */
+extern int	pg_b64_encode(const char *src, int len, char *dst);
+extern int	pg_b64_decode(const char *src, int len, char *dst);
+extern int	pg_b64_enc_len(int srclen);
+extern int	pg_b64_dec_len(int srclen);
+
+#endif   /* BASE64_H */
diff --git a/src/include/common/scram-common.h b/src/include/common/scram-common.h
new file mode 100644
index 00000000000..14bb0538321
--- /dev/null
+++ b/src/include/common/scram-common.h
@@ -0,0 +1,62 @@
+/*-------------------------------------------------------------------------
+ *
+ * scram-common.h
+ *		Declarations for helper functions used for SCRAM authentication
+ *
+ * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/common/relpath.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SCRAM_COMMON_H
+#define SCRAM_COMMON_H
+
+#include "common/sha2.h"
+
+/* Length of SCRAM keys (client and server) */
+#define SCRAM_KEY_LEN				PG_SHA256_DIGEST_LENGTH
+
+/* length of HMAC */
+#define SHA256_HMAC_B				PG_SHA256_BLOCK_LENGTH
+
+/*
+ * Size of random nonce generated in the authentication exchange.  This
+ * is in "raw" number of bytes, the actual nonces sent over the wire are
+ * encoded using only ASCII-printable characters.
+ */
+#define SCRAM_RAW_NONCE_LEN			10
+
+/* length of salt when generating new verifiers */
+#define SCRAM_SALT_LEN				10
+
+/* number of bytes used when sending iteration number during exchange */
+#define SCRAM_ITERATION_LEN			10
+
+/* default number of iterations when generating verifier */
+#define SCRAM_ITERATIONS_DEFAULT	4096
+
+/* Base name of keys used for proof generation */
+#define SCRAM_SERVER_KEY_NAME "Server Key"
+#define SCRAM_CLIENT_KEY_NAME "Client Key"
+
+/*
+ * Context data for HMAC used in SCRAM authentication.
+ */
+typedef struct
+{
+	pg_sha256_ctx sha256ctx;
+	uint8		k_opad[SHA256_HMAC_B];
+} scram_HMAC_ctx;
+
+extern void scram_HMAC_init(scram_HMAC_ctx *ctx, const uint8 *key, int keylen);
+extern void scram_HMAC_update(scram_HMAC_ctx *ctx, const char *str, int slen);
+extern void scram_HMAC_final(uint8 *result, scram_HMAC_ctx *ctx);
+
+extern void scram_H(const uint8 *str, int len, uint8 *result);
+extern void scram_ClientOrServerKey(const char *password, const char *salt,
+						int saltlen, int iterations,
+						const char *keystr, uint8 *result);
+
+#endif   /* SCRAM_COMMON_H */
diff --git a/src/include/libpq/crypt.h b/src/include/libpq/crypt.h
index f94bc6339bf..0502d6a0e5b 100644
--- a/src/include/libpq/crypt.h
+++ b/src/include/libpq/crypt.h
@@ -24,7 +24,8 @@
 typedef enum PasswordType
 {
 	PASSWORD_TYPE_PLAINTEXT = 0,
-	PASSWORD_TYPE_MD5
+	PASSWORD_TYPE_MD5,
+	PASSWORD_TYPE_SCRAM
 } PasswordType;
 
 extern PasswordType get_password_type(const char *shadow_pass);
diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h
index 748a0728541..8f55edb16aa 100644
--- a/src/include/libpq/hba.h
+++ b/src/include/libpq/hba.h
@@ -30,6 +30,7 @@ typedef enum UserAuth
 	uaIdent,
 	uaPassword,
 	uaMD5,
+	uaSASL,
 	uaGSS,
 	uaSSPI,
 	uaPAM,
diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h
index de9ccc63b13..5441aaa93ac 100644
--- a/src/include/libpq/pqcomm.h
+++ b/src/include/libpq/pqcomm.h
@@ -172,6 +172,8 @@ extern bool Db_user_namespace;
 #define AUTH_REQ_GSS		7	/* GSSAPI without wrap() */
 #define AUTH_REQ_GSS_CONT	8	/* Continue GSS exchanges */
 #define AUTH_REQ_SSPI		9	/* SSPI negotiate without wrap() */
+#define AUTH_REQ_SASL	   10	/* SASL */
+#define AUTH_REQ_SASL_CONT 11	/* continue SASL exchange */
 
 typedef uint32 AuthRequest;
 
diff --git a/src/include/libpq/scram.h b/src/include/libpq/scram.h
new file mode 100644
index 00000000000..563462fb1cc
--- /dev/null
+++ b/src/include/libpq/scram.h
@@ -0,0 +1,35 @@
+/*-------------------------------------------------------------------------
+ *
+ * scram.h
+ *	  Interface to libpq/scram.c
+ *
+ * Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/libpq/scram.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_SCRAM_H
+#define PG_SCRAM_H
+
+/* Name of SCRAM-SHA-256 per IANA */
+#define SCRAM_SHA256_NAME "SCRAM-SHA-256"
+
+/* Status codes for message exchange */
+#define SASL_EXCHANGE_CONTINUE		0
+#define SASL_EXCHANGE_SUCCESS		1
+#define SASL_EXCHANGE_FAILURE		2
+
+/* Routines dedicated to authentication */
+extern void *pg_be_scram_init(const char *username, const char *shadow_pass, bool doomed);
+extern int pg_be_scram_exchange(void *opaq, char *input, int inputlen,
+					 char **output, int *outputlen, char **logdetail);
+
+/* Routines to handle and check SCRAM-SHA-256 verifier */
+extern char *scram_build_verifier(const char *username,
+					 const char *password,
+					 int iterations);
+extern bool is_scram_verifier(const char *verifier);
+
+#endif   /* PG_SCRAM_H */