text: #define COMMON_DIGEST_FOR_OPENSSL 1
  #include <CommonCrypto/CommonDigest.h>
  
  #define MD5_BLOCK_LENGTH	CC_MD5_BLOCK_BYTES
  
  static DEFINE_UPDATE_FUNC_FOR_UINT(MD5)
  static DEFINE_FINISH_FUNC_FROM_FINAL(MD5)
  
  #undef MD5_Update
  #undef MD5_Finish
  #define MD5_Update rb_digest_MD5_update
  #define MD5_Finish rb_digest_MD5_finish
  