text: #ifndef HEADER_CURL_MD5_H
  #define HEADER_CURL_MD5_H
  /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
   *
   * This software is licensed as described in the file COPYING, which
   * you should have received as part of this distribution. The terms
   * are also available at https://curl.se/docs/copyright.html.
   *
   * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   * copies of the Software, and permit persons to whom the Software is
   * furnished to do so, under the terms of the COPYING file.
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   * KIND, either express or implied.
   *
   ***************************************************************************/
  
  #ifndef CURL_DISABLE_CRYPTO_AUTH
  #include "curl_hmac.h"
  
  #define MD5_DIGEST_LEN  16
  
  typedef CURLcode (* Curl_MD5_init_func)(void *context);
  typedef void (* Curl_MD5_update_func)(void *context,
                                        const unsigned char *data,
                                        unsigned int len);
  typedef void (* Curl_MD5_final_func)(unsigned char *result, void *context);
  
  struct MD5_params {
    Curl_MD5_init_func     md5_init_func;   /* Initialize context procedure */
    Curl_MD5_update_func   md5_update_func; /* Update context with data */
    Curl_MD5_final_func    md5_final_func;  /* Get final result procedure */
    unsigned int           md5_ctxtsize;  /* Context structure size */
    unsigned int           md5_resultlen; /* Result length (bytes) */
  };
  
  struct MD5_context {
    const struct MD5_params *md5_hash;    /* Hash function definition */
    void                  *md5_hashctx;   /* Hash function context */
  };
  
  extern const struct MD5_params Curl_DIGEST_MD5[1];
  extern const struct HMAC_params Curl_HMAC_MD5[1];
  
  CURLcode Curl_md5it(unsigned char *output, const unsigned char *input,
                      const size_t len);
  
  struct MD5_context *Curl_MD5_init(const struct MD5_params *md5params);
  CURLcode Curl_MD5_update(struct MD5_context *context,
                           const unsigned char *data,
                           unsigned int len);
  CURLcode Curl_MD5_final(struct MD5_context *context, unsigned char *result);
  
  #endif
  
  #endif /* HEADER_CURL_MD5_H */
  