sodium_crypto_secretstream_xchacha20poly1305_init_pull

    (PHP 7 >= 7.2.0, PHP 8)

    sodium_crypto_secretstream_xchacha20poly1305_init_pull — Initialize a secretstream context for decryption

    Description

    sodium_crypto_secretstream_xchacha20poly1305_init_pull(string$header, string$key): string

    Initialize a secretstream context for decryption.

    Parameters

    header

    The header of the secretstream. This should be one of the values produced by sodium_crypto_secretstream_xchacha20poly1305_init_push().

    key

    Encryption key (256-bit).

    Return Values

    Secretstream state.

    Examples

    Example #1 sodium_crypto_secretstream_xchacha20poly1305_init_pull() example

    <?php
    function decrypt_file(string $inputFilePath, string $outputFilePath, string $key): void
    {
    $inputFile = fopen($inputFilePath, 'rb');
    $outputFile = fopen($outputFilePath, 'wb');
    $header = fread($inputFile, 24);

    $state = sodium_crypto_secretstream_xchacha20poly1305_init_pull($header, $key);
    $inputFileSize = fstat($inputFile)['size'];

    // Decrypt the file and write its contents to the output file:
    for ($i = 24; $i < $inputFileSize; $i += 8192) {
    $ctxt_chunk = fread($inputFile, 8192);

    // We're not using $tag, but in real protocols you can use this on encrypt to e.g.

    The above example will output something similar to:

    string(12) "Hello world!"
    To Top