text: /*-------------------------------------------------------------------------
   *
   * scram-common.h
   *		Declarations for helper functions used for SCRAM authentication
   *
   * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * src/include/common/scram-common.h
   *
   *-------------------------------------------------------------------------
   */
  #ifndef SCRAM_COMMON_H
  #define SCRAM_COMMON_H
  
  #include "common/cryptohash.h"
  #include "common/sha2.h"
  
  /* Name of SCRAM mechanisms per IANA */
  #define SCRAM_SHA_256_NAME "SCRAM-SHA-256"
  #define SCRAM_SHA_256_PLUS_NAME "SCRAM-SHA-256-PLUS"	/* with channel binding */
  
  /* 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			18
  
  /*
   * Length of salt when generating new secrets, in bytes.  (It will be stored
   * and sent over the wire encoded in Base64.)  16 bytes is what the example in
   * RFC 7677 uses.
   */
  #define SCRAM_DEFAULT_SALT_LEN		16
  
  /*
   * Default number of iterations when generating secret.  Should be at least
   * 4096 per RFC 7677.
   */
  #define SCRAM_DEFAULT_ITERATIONS	4096
  
  extern int	scram_SaltedPassword(const char *password, const char *salt,
  								 int saltlen, int iterations, uint8 *result,
  								 const char **errstr);
  extern int	scram_H(const uint8 *str, int len, uint8 *result,
  					const char **errstr);
  extern int	scram_ClientKey(const uint8 *salted_password, uint8 *result,
  							const char **errstr);
  extern int	scram_ServerKey(const uint8 *salted_password, uint8 *result,
  							const char **errstr);
  
  extern char *scram_build_secret(const char *salt, int saltlen, int iterations,
  								const char *password, const char **errstr);
  
  #endif							/* SCRAM_COMMON_H */
  