Perl

Example: Hash Text in Chunks

Shows how to generate a final hash, like SHA-256, for a large text by processing it in chunks. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

my $crypt = Chilkat2::Crypt2->new;
$crypt->HashAlgorithm('sha256');
$crypt->Charset('utf-8');

my $bd = Chilkat2::BinData->new;

my $s = "The quick brown fox jumped over the lazy dog.\r\n";

# Accumulate the text in a StringBuilder.  We'll demonstrate hashing the text in chunks,
# and then also hashing the entire text at once to show the results are the same.

$bd->AppendString($s, 'utf-8');
my $success = $crypt->HashBeginString($s);

my $i = 0;
while ($i < 200) {
    $bd->AppendString($s, 'utf-8');
    $crypt->HashMoreString($s);
    $i = $i + 1;
}

# Get the hash in base64 format.
$crypt->EncodingMode('base64');

my $encodedHash = $crypt->HashFinalENC();
print 'Hash computed in chunks: ', $encodedHash, "\n";

# Let's alternatively compute the hash of the entire amount of data at once,
# to show the hash computation is the same:
$encodedHash = $crypt->HashBdENC($bd);
print 'Hash computed in 1 step: ', $encodedHash, "\n";

# Output:

# Hash computed in chunks: unwkVff61k40roRIJizaknreScHaL6frWe37kydXbZQ=
# Hash computed in 1 step: unwkVff61k40roRIJizaknreScHaL6frWe37kydXbZQ=