ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_pull

Advertisement

Syntax Syntax

ParagonIE_Sodium_Crypto::secretstream_xchacha20poly1305_pull( string $state, string $cipher, string $aad = '' )

Parameters Parameters

$state

(string) (Required)

$cipher

(string) (Required)

$aad

(string) (Optional)

Default value: ''

Return Return

(bool|array{0:) string, 1: int}

Source Source

File: wp-includes/sodium_compat/src/Crypto.php

    public static function secretstream_xchacha20poly1305_pull(&$state, $cipher, $aad = '')
    {
        $st = ParagonIE_Sodium_Core_SecretStream_State::fromString($state);

        $cipherlen = ParagonIE_Sodium_Core_Util::strlen($cipher);
        #     mlen = inlen - crypto_secretstream_xchacha20poly1305_ABYTES;
        $msglen = $cipherlen - ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_ABYTES;
        $aadlen = ParagonIE_Sodium_Core_Util::strlen($aad);

        #     if (mlen > crypto_secretstream_xchacha20poly1305_MESSAGEBYTES_MAX) {
        #         sodium_misuse();
        #     }
        if ((($msglen + 63) >> 6) > 0xfffffffe) {
            throw new SodiumException(
                'message cannot be larger than SODIUM_CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_MESSAGEBYTES_MAX bytes'
            );
        }

        #     crypto_stream_chacha20_ietf(block, sizeof block, state->nonce, state->k);
        #     crypto_onetimeauth_poly1305_init(&poly1305_state, block);
        #     sodium_memzero(block, sizeof block);
        $auth = new ParagonIE_Sodium_Core_Poly1305_State(
            ParagonIE_Sodium_Core_ChaCha20::ietfStream(32, $st->getCombinedNonce(), $st->getKey())
        );

        #     crypto_onetimeauth_poly1305_update(&poly1305_state, ad, adlen);
        $auth->update($aad);

        #     crypto_onetimeauth_poly1305_update(&poly1305_state, _pad0,
        #         (0x10 - adlen) & 0xf);
        $auth->update(str_repeat("\0", ((0x10 - $aadlen) & 0xf)));


        #     memset(block, 0, sizeof block);
        #     block[0] = in[0];
        #     crypto_stream_chacha20_ietf_xor_ic(block, block, sizeof block,
        #                                        state->nonce, 1U, state->k);
        $block = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
            $cipher[0] . str_repeat("\0", 63),
            $st->getCombinedNonce(),
            $st->getKey(),
            ParagonIE_Sodium_Core_Util::store64_le(1)
        );
        #     tag = block[0];
        #     block[0] = in[0];
        #     crypto_onetimeauth_poly1305_update(&poly1305_state, block, sizeof block);
        $tag = ParagonIE_Sodium_Core_Util::chrToInt($block[0]);
        $block[0] = $cipher[0];
        $auth->update($block);


        #     c = in + (sizeof tag);
        #     crypto_onetimeauth_poly1305_update(&poly1305_state, c, mlen);
        $auth->update(ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen));

        #     crypto_onetimeauth_poly1305_update
        #     (&poly1305_state, _pad0, (0x10 - (sizeof block) + mlen) & 0xf);
        $auth->update(str_repeat("\0", ((0x10 - 64 + $msglen) & 0xf)));

        #     STORE64_LE(slen, (uint64_t) adlen);
        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
        $slen = ParagonIE_Sodium_Core_Util::store64_le($aadlen);
        $auth->update($slen);

        #     STORE64_LE(slen, (sizeof block) + mlen);
        #     crypto_onetimeauth_poly1305_update(&poly1305_state, slen, sizeof slen);
        $slen = ParagonIE_Sodium_Core_Util::store64_le(64 + $msglen);
        $auth->update($slen);

        #     crypto_onetimeauth_poly1305_final(&poly1305_state, mac);
        #     sodium_memzero(&poly1305_state, sizeof poly1305_state);
        $mac = $auth->finish();

        #     stored_mac = c + mlen;
        #     if (sodium_memcmp(mac, stored_mac, sizeof mac) != 0) {
        #     sodium_memzero(mac, sizeof mac);
        #         return -1;
        #     }

        $stored = ParagonIE_Sodium_Core_Util::substr($cipher, $msglen + 1, 16);
        if (!ParagonIE_Sodium_Core_Util::hashEquals($mac, $stored)) {
            return false;
        }

        #     crypto_stream_chacha20_ietf_xor_ic(m, c, mlen, state->nonce, 2U, state->k);
        $out = ParagonIE_Sodium_Core_ChaCha20::ietfStreamXorIc(
            ParagonIE_Sodium_Core_Util::substr($cipher, 1, $msglen),
            $st->getCombinedNonce(),
            $st->getKey(),
            ParagonIE_Sodium_Core_Util::store64_le(2)
        );

        #     XOR_BUF(STATE_INONCE(state), mac,
        #         crypto_secretstream_xchacha20poly1305_INONCEBYTES);
        $st->xorNonce($mac);

        #     sodium_increment(STATE_COUNTER(state),
        #         crypto_secretstream_xchacha20poly1305_COUNTERBYTES);
        $st->incrementCounter();

        #     if ((tag & crypto_secretstream_xchacha20poly1305_TAG_REKEY) != 0 ||
        #         sodium_is_zero(STATE_COUNTER(state),
        #             crypto_secretstream_xchacha20poly1305_COUNTERBYTES)) {
        #         crypto_secretstream_xchacha20poly1305_rekey(state);
        #     }

        // Overwrite by reference:
        $state = $st->toString();

        /** @var bool $rekey */
        $rekey = ($tag & ParagonIE_Sodium_Compat::CRYPTO_SECRETSTREAM_XCHACHA20POLY1305_TAG_REKEY) !== 0;
        if ($rekey || $st->needsRekey()) {
            // DO REKEY
            self::secretstream_xchacha20poly1305_rekey($state);
        }
        return array($out, $tag);
    }

Advertisement

Advertisement

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.