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. Perl

use chilkat();

$success = 0;

$crypt = chilkat::CkCrypt2->new();
$crypt->put_HashAlgorithm("sha256");
$crypt->put_Charset("utf-8");

$bd = chilkat::CkBinData->new();

$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");
$success = $crypt->HashBeginString($s);

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

# Get the hash in base64 format.
$crypt->put_EncodingMode("base64");

$encodedHash = $crypt->hashFinalENC();
print "Hash computed in chunks: " . $encodedHash . "\r\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 . "\r\n";

# Output:

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