<?php

/**
 * Class ParagonIE_Sodium_Core32_SecretStream_State
 */
class ParagonIE_Sodium_Core32_SecretStream_State
{
    /** @var string $key */
    protected $key;

    /** @var int $counter */
    protected $counter;

    /** @var string $nonce */
    protected $nonce;

    /** @var string $_pad */
    protected $_pad;

    /**
     * ParagonIE_Sodium_Core32_SecretStream_State constructor.
     * @param string $key
     * @param string|null $nonce
     */
    public function __construct($key, $nonce = null)
    {
        $this->key = $key;
        $this->counter = 1;
        if (is_null($nonce)) {
            $nonce = str_repeat("\0", 12);
        }
        $this->nonce = str_pad($nonce, 12, "\0", STR_PAD_RIGHT);;
        $this->_pad = str_repeat("\0", 4);
    }

    /**
     * @return self
     */
    public function counterReset()
    {
        $this->counter = 1;
        $this->_pad = str_repeat("\0", 4);
        return $this;
    }

    /**
     * @return string
     */
    public function getKey()
    {
        return $this->key;
    }

    /**
     * @return string
     */
    public function getCounter()
    {
        return ParagonIE_Sodium_Core32_Util::store32_le($this->counter);
    }

    /**
     * @return string
     */
    public function getNonce()
    {
        if (!is_string($this->nonce)) {
            $this->nonce = str_repeat("\0", 12);
        }
        if (ParagonIE_Sodium_Core32_Util::strlen($this->nonce) !== 12) {
            $this->nonce = str_pad($this->nonce, 12, "\0", STR_PAD_RIGHT);
        }
        return $this->nonce;
    }

    /**
     * @return string
     */
    public function getCombinedNonce()
    {
        return $this->getCounter() .
            ParagonIE_Sodium_Core32_Util::substr($this->getNonce(), 0, 8);
    }

    /**
     * @return self
     */
    public function incrementCounter()
    {
        ++$this->counter;
        return $this;
    }

    /**
     * @return bool
     */
    public function needsRekey()
    {
        return ($this->counter & 0xffff) === 0;
    }

    /**
     * @param string $newKeyAndNonce
     * @return self
     */
    public function rekey($newKeyAndNonce)
    {
        $this->key = ParagonIE_Sodium_Core32_Util::substr($newKeyAndNonce, 0, 32);
        $this->nonce = str_pad(
            ParagonIE_Sodium_Core32_Util::substr($newKeyAndNonce, 32),
            12,
            "\0",
            STR_PAD_RIGHT
        );
        return $this;
    }

    /**
     * @param string $str
     * @return self
     */
    public function xorNonce($str)
    {
        $this->nonce = ParagonIE_Sodium_Core32_Util::xorStrings(
            $this->getNonce(),
            str_pad(
                ParagonIE_Sodium_Core32_Util::substr($str, 0, 8),
                12,
                "\0",
                STR_PAD_RIGHT
            )
        );
        return $this;
    }

    /**
     * @param string $string
     * @return self
     */
    public static function fromString($string)
    {
        $state = new ParagonIE_Sodium_Core32_SecretStream_State(
            ParagonIE_Sodium_Core32_Util::substr($string, 0, 32)
        );
        $state->counter = ParagonIE_Sodium_Core32_Util::load_4(
            ParagonIE_Sodium_Core32_Util::substr($string, 32, 4)
        );
        $state->nonce = ParagonIE_Sodium_Core32_Util::substr($string, 36, 12);
        $state->_pad = ParagonIE_Sodium_Core32_Util::substr($string, 48, 8);
        return $state;
    }

    /**
     * @return string
     */
    public function toString()
    {
        return $this->key .
            $this->getCounter() .
            $this->nonce .
            $this->_pad;
    }
}

• [F] State.php
  Delete

Blog Section

Discover the Latest in Digital Payments and NFC Technology

Dive into our blog to explore the cutting-edge trends in digital payments and NFC technology. Stay updated on the innovations that are revolutionizing transactions, boosting security, and making payments quicker and more convenient. Learn how these advancements are shaping the future of financial interactions and driving the global transition towards a cashless world.

The Rise of Contactless Payments:...

In recent years, contactless payments have surged in popularity, driven...

Visit Blog

March 27, 2024

Enhancing Payment Security: The Role...

As digital transactions proliferate, ensuring robust payment security is more critical than ever. Two foundational...

Visit Blog

March 27, 2024

The Future of Digital Wallets:...

Digital wallets have fundamentally transformed how we manage money, offering a streamlined, secure, and highly...

Visit Blog

March 27, 2024