<?php
declare(strict_types=1);
if (class_exists('ParagonIE_Sodium_Core_Ed25519', false)) {
return;
}
if (!class_exists('ParagonIE_Sodium_Core_Curve25519', false)) {
require_once dirname(__FILE__) . '/Curve25519.php';
}
/**
* Class ParagonIE_Sodium_Core_Ed25519
*/
abstract class ParagonIE_Sodium_Core_Ed25519 extends ParagonIE_Sodium_Core_Curve25519
{
const KEYPAIR_BYTES = 96;
const SEED_BYTES = 32;
const SCALAR_BYTES = 32;
/**
* @internal You should not use this directly from another application
*
* @return string (96 bytes)
* @throws Exception
* @throws SodiumException
* @throws TypeError
*/
public static function keypair(): string
{
$seed = random_bytes(self::SEED_BYTES);
$pk = '';
$sk = '';
self::seed_keypair($pk, $sk, $seed);
return $sk . $pk;
}
/**
* @internal You should not use this directly from another application
*
* @param string $pk
* @param string $sk
* @param string $seed
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function seed_keypair(
string &$pk,
string &$sk,
#[SensitiveParameter]
string $seed
): string {
if (self::strlen($seed) !== self::SEED_BYTES) {
throw new RangeException('crypto_sign keypair seed must be 32 bytes long');
}
$pk = self::publickey_from_secretkey($seed);
$sk = $seed . $pk;
return $sk;
}
/**
* @internal You should not use this directly from another application
*
* @param string $keypair
* @return string
* @throws TypeError
*/
public static function secretkey(
#[SensitiveParameter]
string $keypair
): string {
if (self::strlen($keypair) !== self::KEYPAIR_BYTES) {
throw new RangeException('crypto_sign keypair must be 96 bytes long');
}
return self::substr($keypair, 0, 64);
}
/**
* @internal You should not use this directly from another application
*
* @param string $keypair
* @return string
* @throws TypeError
*/
public static function publickey(
#[SensitiveParameter]
string $keypair
): string {
if (self::strlen($keypair) !== self::KEYPAIR_BYTES) {
throw new RangeException('crypto_sign keypair must be 96 bytes long');
}
return self::substr($keypair, 64, 32);
}
/**
* @internal You should not use this directly from another application
*
* @param string $sk
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function publickey_from_secretkey(
#[SensitiveParameter]
string $sk
): string {
/** @var string $sk */
$sk = hash('sha512', self::substr($sk, 0, 32), true);
$sk[0] = self::intToChr(
self::chrToInt($sk[0]) & 248
);
$sk[31] = self::intToChr(
(self::chrToInt($sk[31]) & 63) | 64
);
return self::sk_to_pk($sk);
}
/**
* @param string $pk
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function pk_to_curve25519(
string $pk
): string {
if (self::small_order($pk)) {
throw new SodiumException('Public key is on a small order');
}
$A = self::ge_frombytes_negate_vartime(self::substr($pk, 0, 32));
$p1 = self::ge_mul_l($A);
if (!self::fe_isnonzero($p1->X)) {
throw new SodiumException('Unexpected zero result');
}
$one_minux_y = self::fe_invert(
self::fe_sub(
self::fe_1(),
$A->Y
)
);
$x = self::fe_mul(
self::fe_add(self::fe_1(), $A->Y),
$one_minux_y
);
return self::fe_tobytes($x);
}
/**
* @internal You should not use this directly from another application
*
* @param string $sk
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function sk_to_pk(
#[SensitiveParameter]
string $sk
): string {
return self::ge_p3_tobytes(
self::ge_scalarmult_base(
self::substr($sk, 0, 32)
)
);
}
/**
* @internal You should not use this directly from another application
*
* @param string $message
* @param string $sk
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function sign(
string $message,
#[SensitiveParameter]
string $sk
): string {
$signature = self::sign_detached($message, $sk);
return $signature . $message;
}
/**
* @internal You should not use this directly from another application
*
* @param string $message A signed message
* @param string $pk Public key
* @return string Message (without signature)
* @throws SodiumException
* @throws TypeError
*/
public static function sign_open(
string $message,
string $pk
): string {
$signature = self::substr($message, 0, 64);
/** @var string $message */
$message = self::substr($message, 64);
if (self::verify_detached($signature, $message, $pk)) {
return $message;
}
throw new SodiumException('Invalid signature');
}
/**
* @internal You should not use this directly from another application
*
* @param string $message
* @param string $sk
* @return string
* @throws SodiumException
* @throws TypeError
*/
public static function sign_detached(
string $message,
#[SensitiveParameter]
string $sk
): string {
$az = hash('sha512', self::substr($sk, 0, 32), true);
$az[0] = self::intToChr(self::chrToInt($az[0]) & 248);
$az[31] = self::intToChr((self::chrToInt($az[31]) & 63) | 64);
$hs = hash_init('sha512');
hash_update($hs, self::substr($az, 32, 32));
hash_update($hs, $message);
$nonceHash = hash_final($hs, true);
$pk = self::substr($sk, 32, 32);
$nonce = self::sc_reduce($nonceHash) . self::substr($nonceHash, 32);
$sig = self::ge_p3_tobytes(
self::ge_scalarmult_base($nonce)
);
$hs = hash_init('sha512');
hash_update($hs, self::substr($sig, 0, 32));
hash_update($hs, self::substr($pk, 0, 32));
hash_update($hs, $message);
$hramHash = hash_final($hs, true);
$hram = self::sc_reduce($hramHash);
$sigAfter = self::sc_muladd($hram, $az, $nonce);
$sig = self::substr($sig, 0, 32) . self::substr($sigAfter, 0, 32);
try {
ParagonIE_Sodium_Compat::memzero($az);
} catch (SodiumException) {
$az = null;
}
return $sig;
}
/**
* @internal You should not use this directly from another application
*
* @param string $sig
* @param string $message
* @param string $pk
* @return bool
* @throws SodiumException
* @throws TypeError
*/
public static function verify_detached(
string $sig,
string $message,
string $pk
): bool {
if (self::strlen($sig) < 64) {
throw new SodiumException('Signature is too short');
}
if ((self::chrToInt($sig[63]) & 240) && self::check_S_lt_L(self::substr($sig, 32, 32))) {
throw new SodiumException('S < L - Invalid signature');
}
if (self::small_order($sig)) {
throw new SodiumException('Signature is on too small of an order');
}
if ((self::chrToInt($sig[63]) & 224) !== 0) {
throw new SodiumException('Invalid signature');
}
$d = 0;
for ($i = 0; $i < 32; ++$i) {
$d |= self::chrToInt($pk[$i]);
}
if ($d === 0) {
throw new SodiumException('All zero public key');
}
/* The original value of ParagonIE_Sodium_Compat::$fastMult */
$orig = ParagonIE_Sodium_Compat::$fastMult;
// Set ParagonIE_Sodium_Compat::$fastMult to true to speed up verification.
ParagonIE_Sodium_Compat::$fastMult = true;
$A = self::ge_frombytes_negate_vartime($pk);
$hDigest = hash(
'sha512',
self::substr($sig, 0, 32) .
self::substr($pk, 0, 32) .
$message,
true
);
$h = self::sc_reduce($hDigest) . self::substr($hDigest, 32);
$R = self::ge_double_scalarmult_vartime(
$h,
$A,
self::substr($sig, 32)
);
$rcheck = self::ge_tobytes($R);
// Reset ParagonIE_Sodium_Compat::$fastMult to what it was before.
ParagonIE_Sodium_Compat::$fastMult = $orig;
return self::verify_32($rcheck, self::substr($sig, 0, 32));
}
/**
* @internal You should not use this directly from another application
*
* @param string $S
* @return bool
* @throws SodiumException
* @throws TypeError
*/
public static function check_S_lt_L(string $S): bool
{
if (self::strlen($S) < 32) {
throw new SodiumException('Signature must be 32 bytes');
}
$L = array(
0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10
);
$c = 0;
$n = 1;
$i = 32;
/** @var array<int, int> $L */
do {
--$i;
$x = self::chrToInt($S[$i]);
$c |= (
(($x - $L[$i]) >> 8) & $n
);
$n &= (
(($x ^ $L[$i]) - 1) >> 8
);
} while ($i !== 0);
return $c === 0;
}
/**
* @param string $R
* @return bool
* @throws SodiumException
* @throws TypeError
*/
public static function small_order(string $R): bool
{
/** @var array<int, array<int, int>> $blocklist */
$blocklist = array(
/* 0 (order 4) */
array(
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
),
/* 1 (order 1) */
array(
0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
),
/* 2707385501144840649318225287225658788936804267575313519463743609750303402022 (order 8) */
array(
0x26, 0xe8, 0x95, 0x8f, 0xc2, 0xb2, 0x27, 0xb0,
0x45, 0xc3, 0xf4, 0x89, 0xf2, 0xef, 0x98, 0xf0,
0xd5, 0xdf, 0xac, 0x05, 0xd3, 0xc6, 0x33, 0x39,
0xb1, 0x38, 0x02, 0x88, 0x6d, 0x53, 0xfc, 0x05
),
/* 55188659117513257062467267217118295137698188065244968500265048394206261417927 (order 8) */
array(
0xc7, 0x17, 0x6a, 0x70, 0x3d, 0x4d, 0xd8, 0x4f,
0xba, 0x3c, 0x0b, 0x76, 0x0d, 0x10, 0x67, 0x0f,
0x2a, 0x20, 0x53, 0xfa, 0x2c, 0x39, 0xcc, 0xc6,
0x4e, 0xc7, 0xfd, 0x77, 0x92, 0xac, 0x03, 0x7a
),
/* p-1 (order 2) */
array(
0x13, 0xe8, 0x95, 0x8f, 0xc2, 0xb2, 0x27, 0xb0,
0x45, 0xc3, 0xf4, 0x89, 0xf2, 0xef, 0x98, 0xf0,
0xd5, 0xdf, 0xac, 0x05, 0xd3, 0xc6, 0x33, 0x39,
0xb1, 0x38, 0x02, 0x88, 0x6d, 0x53, 0xfc, 0x85
),
/* p (order 4) */
array(
0xb4, 0x17, 0x6a, 0x70, 0x3d, 0x4d, 0xd8, 0x4f,
0xba, 0x3c, 0x0b, 0x76, 0x0d, 0x10, 0x67, 0x0f,
0x2a, 0x20, 0x53, 0xfa, 0x2c, 0x39, 0xcc, 0xc6,
0x4e, 0xc7, 0xfd, 0x77, 0x92, 0xac, 0x03, 0xfa
),
/* p+1 (order 1) */
array(
0xec, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
),
/* p+2707385501144840649318225287225658788936804267575313519463743609750303402022 (order 8) */
array(
0xed, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
),
/* p+55188659117513257062467267217118295137698188065244968500265048394206261417927 (order 8) */
array(
0xee, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
),
/* 2p-1 (order 2) */
array(
0xd9, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
),
/* 2p (order 4) */
array(
0xda, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
),
/* 2p+1 (order 1) */
array(
0xdb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
)
);
$countBlocklist = count($blocklist);
for ($i = 0; $i < $countBlocklist; ++$i) {
$c = 0;
for ($j = 0; $j < 32; ++$j) {
$c |= self::chrToInt($R[$j]) ^ $blocklist[$i][$j];
}
if ($c === 0) {
return true;
}
}
return false;
}
/**
* @param string $s
* @return string
* @throws SodiumException
*/
public static function scalar_complement(
#[SensitiveParameter]
string $s
): string {
$t_ = self::L . str_repeat("\x00", 32);
sodium_increment($t_);
$s_ = $s . str_repeat("\x00", 32);
ParagonIE_Sodium_Compat::sub($t_, $s_);
return self::sc_reduce($t_);
}
/**
* @return string
* @throws SodiumException
*/
public static function scalar_random(): string
{
do {
$r = ParagonIE_Sodium_Compat::randombytes_buf(self::SCALAR_BYTES);
$r[self::SCALAR_BYTES - 1] = self::intToChr(
self::chrToInt($r[self::SCALAR_BYTES - 1]) & 0x1f
);
} while (
!self::check_S_lt_L($r) || ParagonIE_Sodium_Compat::is_zero($r)
);
return $r;
}
/**
* @param string $s
* @return string
* @throws SodiumException
*/
public static function scalar_negate(
#[SensitiveParameter]
string $s
): string {
$t_ = self::L . str_repeat("\x00", 32) ;
$s_ = $s . str_repeat("\x00", 32) ;
ParagonIE_Sodium_Compat::sub($t_, $s_);
return self::sc_reduce($t_);
}
/**
* @param string $a
* @param string $b
* @return string
* @throws SodiumException
*/
public static function scalar_add(
#[SensitiveParameter]
string $a,
#[SensitiveParameter]
string $b
): string {
$a_ = $a . str_repeat("\x00", 32);
$b_ = $b . str_repeat("\x00", 32);
ParagonIE_Sodium_Compat::add($a_, $b_);
return self::sc_reduce($a_);
}
/**
* @param string $x
* @param string $y
* @return string
* @throws SodiumException
*/
public static function scalar_sub(
#[SensitiveParameter]
string $x,
#[SensitiveParameter]
string $y
): string {
return self::scalar_add($x, self::scalar_negate($y));
}
}
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