# phpman > perldoc > Crypt::Digest::SHA256

## NAME
    [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown) - Hash function SHA-256 [size: 256 bits]

## SYNOPSIS
       ### Functional interface:
       use [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown) qw( sha256 sha256_hex sha256_b64 sha256_b64u
                                    sha256_file sha256_file_hex sha256_file_b64 sha256_file_b64u );

       # calculate digest from string/buffer
       $sha256_raw  = sha256('data string');
       $sha256_hex  = sha256_hex('data string');
       $sha256_b64  = sha256_b64('data string');
       $sha256_b64u = sha256_b64u('data string');
       # calculate digest from file
       $sha256_raw  = sha256_file('filename.dat');
       $sha256_hex  = sha256_file_hex('filename.dat');
       $sha256_b64  = sha256_file_b64('filename.dat');
       $sha256_b64u = sha256_file_b64u('filename.dat');
       # calculate digest from filehandle
       $sha256_raw  = sha256_file(*FILEHANDLE);
       $sha256_hex  = sha256_file_hex(*FILEHANDLE);
       $sha256_b64  = sha256_file_b64(*FILEHANDLE);
       $sha256_b64u = sha256_file_b64u(*FILEHANDLE);

       ### OO interface:
       use [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown);

       $d = [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown)->new;
       $d->add('any data');
       $d->addfile('filename.dat');
       $d->addfile(*FILEHANDLE);
       $result_raw  = $d->digest;     # raw bytes
       $result_hex  = $d->hexdigest;  # hexadecimal form
       $result_b64  = $d->b64digest;  # Base64 form
       $result_b64u = $d->b64udigest; # Base64 URL Safe form

## DESCRIPTION
    Provides an interface to the SHA256 digest algorithm.

## EXPORT
    Nothing is exported by default.

    You can export selected functions:

      use [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown) qw(sha256 sha256_hex sha256_b64 sha256_b64u
                                          sha256_file sha256_file_hex sha256_file_b64 sha256_file_b64u);

    Or all of them at once:

      use [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown) ':all';

## FUNCTIONS
  sha256
    Logically joins all arguments into a single string, and returns its SHA256 digest encoded as a
    binary string.

     $sha256_raw = sha256('data string');
     #or
     $sha256_raw = sha256('any data', 'more data', 'even more data');

  sha256_hex
    Logically joins all arguments into a single string, and returns its SHA256 digest encoded as a
    hexadecimal string.

     $sha256_hex = sha256_hex('data string');
     #or
     $sha256_hex = sha256_hex('any data', 'more data', 'even more data');

  sha256_b64
    Logically joins all arguments into a single string, and returns its SHA256 digest encoded as a
    Base64 string, with trailing '=' padding.

     $sha256_b64 = sha256_b64('data string');
     #or
     $sha256_b64 = sha256_b64('any data', 'more data', 'even more data');

  sha256_b64u
    Logically joins all arguments into a single string, and returns its SHA256 digest encoded as a
    Base64 URL Safe string (see RFC 4648 section 5).

     $sha256_b64url = sha256_b64u('data string');
     #or
     $sha256_b64url = sha256_b64u('any data', 'more data', 'even more data');

  sha256_file
    Reads file (defined by filename or filehandle) content, and returns its SHA256 digest encoded as
    a binary string.

     $sha256_raw = sha256_file('filename.dat');
     #or
     $sha256_raw = sha256_file(*FILEHANDLE);

  sha256_file_hex
    Reads file (defined by filename or filehandle) content, and returns its SHA256 digest encoded as
    a hexadecimal string.

     $sha256_hex = sha256_file_hex('filename.dat');
     #or
     $sha256_hex = sha256_file_hex(*FILEHANDLE);

    BEWARE: You have to make sure that the filehandle is in binary mode before you pass it as
    argument to the addfile() method.

  sha256_file_b64
    Reads file (defined by filename or filehandle) content, and returns its SHA256 digest encoded as
    a Base64 string, with trailing '=' padding.

     $sha256_b64 = sha256_file_b64('filename.dat');
     #or
     $sha256_b64 = sha256_file_b64(*FILEHANDLE);

  sha256_file_b64u
    Reads file (defined by filename or filehandle) content, and returns its SHA256 digest encoded as
    a Base64 URL Safe string (see RFC 4648 section 5).

     $sha256_b64url = sha256_file_b64u('filename.dat');
     #or
     $sha256_b64url = sha256_file_b64u(*FILEHANDLE);

## METHODS
    The OO interface provides the same set of functions as [Crypt::Digest](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest/markdown).

  new
     $d = [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown)->new();

  clone
     $d->clone();

  reset
     $d->reset();

  add
     $d->add('any data');
     #or
     $d->add('any data', 'more data', 'even more data');

  addfile
     $d->addfile('filename.dat');
     #or
     $d->addfile(*FILEHANDLE);

  add_bits
     $d->add_bits($bit_string);   # e.g. $d->add_bits("111100001010");
     #or
     $d->add_bits($data, $nbits); # e.g. $d->add_bits("\xF0\xA0", 16);

  hashsize
     $d->hashsize;
     #or
     [Crypt::Digest::SHA256](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256/markdown)->hashsize();
     #or
     [Crypt::Digest::SHA256::hashsize](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest%3A%3ASHA256%3A%3Ahashsize/markdown)();

  digest
     $result_raw = $d->digest();

  hexdigest
     $result_hex = $d->hexdigest();

  b64digest
     $result_b64 = $d->b64digest();

  b64udigest
     $result_b64url = $d->b64udigest();

## SEE ALSO
    *   CryptX, [Crypt::Digest](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ADigest/markdown)

    *   <<https://en.wikipedia.org/wiki/SHA-2>>