text: /* -------------------------------------------------------------------------
   *
   * md5.h
   *	  Interface to libpq/md5.c
   *
   * These definitions are needed by both frontend and backend code to work
   * with MD5-encrypted passwords.
   *
   * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * src/include/libpq/md5.h
   *
   * -------------------------------------------------------------------------
   */
  #ifndef PG_MD5_H
  #define PG_MD5_H
  
  #define MD5_PASSWD_CHARSET "0123456789abcdef"
  #define MD5_PASSWD_LEN 35
  
  /*
   * md5 produces a 16 byte (128 bit) hash; double it for hex.
   */
  #define MD5_HASH_LEN 32
  
  #define isMD5(passwd)                                                          \
      ((strncmp(passwd, "md5", 3) == 0) && (strlen(passwd) == MD5_PASSWD_LEN) && \
          (strspn(passwd + 3, MD5_PASSWD_CHARSET) == MD5_PASSWD_LEN - 3))
  
  extern bool pg_md5_hash(const void* buff, size_t len, char* hexsum);
  extern bool pg_md5_binary(const void* buff, size_t len, void* outbuf);
  extern bool pg_md5_encrypt(const char* passwd, const char* salt, size_t salt_len, char* buf);
  
  #endif
  