> 31) & 1; } /** * @param ParagonIE_Sodium_Core_Curve25519_Fe $u * @param ParagonIE_Sodium_Core_Curve25519_Fe $v * @return array{x: ParagonIE_Sodium_Core_Curve25519_Fe, nonsquare: int} * * @throws SodiumException */ public static function ristretto255_sqrt_ratio_m1( ParagonIE_Sodium_Core_Curve25519_Fe $u, ParagonIE_Sodium_Core_Curve25519_Fe $v ) { $sqrtm1 = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqrtm1); $v3 = self::fe_mul( self::fe_sq($v), $v ); /* v3 = v^3 */ $x = self::fe_mul( self::fe_mul( self::fe_sq($v3), $u ), $v ); /* x = uv^7 */ $x = self::fe_mul( self::fe_mul( self::fe_pow22523($x), /* x = (uv^7)^((q-5)/8) */ $v3 ), $u ); /* x = uv^3(uv^7)^((q-5)/8) */ $vxx = self::fe_mul( self::fe_sq($x), $v ); /* vx^2 */ $m_root_check = self::fe_sub($vxx, $u); /* vx^2-u */ $p_root_check = self::fe_add($vxx, $u); /* vx^2+u */ $f_root_check = self::fe_mul($u, $sqrtm1); /* u*sqrt(-1) */ $f_root_check = self::fe_add($vxx, $f_root_check); /* vx^2+u*sqrt(-1) */ $has_m_root = self::fe_iszero($m_root_check); $has_p_root = self::fe_iszero($p_root_check); $has_f_root = self::fe_iszero($f_root_check); $x_sqrtm1 = self::fe_mul($x, $sqrtm1); /* x*sqrt(-1) */ $x = self::fe_abs( self::fe_cmov($x, $x_sqrtm1, $has_p_root | $has_f_root) ); return array( 'x' => $x, 'nonsquare' => $has_m_root | $has_p_root ); } /** * @param string $s * @return int * @throws SodiumException */ public static function ristretto255_point_is_canonical($s) { $c = (self::chrToInt($s[31]) & 0x7f) ^ 0x7f; for ($i = 30; $i > 0; --$i) { $c |= self::chrToInt($s[$i]) ^ 0xff; } $c = ($c - 1) >> 8; $d = (0xed - 1 - self::chrToInt($s[0])) >> 8; $e = self::chrToInt($s[31]) >> 7; return 1 - ((($c & $d) | $e | self::chrToInt($s[0])) & 1); } /** * @param string $s * @param bool $skipCanonicalCheck * @return array{h: ParagonIE_Sodium_Core_Curve25519_Ge_P3, res: int} * @throws SodiumException */ public static function ristretto255_frombytes($s, $skipCanonicalCheck = false) { if (!$skipCanonicalCheck) { if (!self::ristretto255_point_is_canonical($s)) { throw new SodiumException('S is not canonical'); } } $s_ = self::fe_frombytes($s); $ss = self::fe_sq($s_); /* ss = s^2 */ $u1 = self::fe_sub(self::fe_1(), $ss); /* u1 = 1-ss */ $u1u1 = self::fe_sq($u1); /* u1u1 = u1^2 */ $u2 = self::fe_add(self::fe_1(), $ss); /* u2 = 1+ss */ $u2u2 = self::fe_sq($u2); /* u2u2 = u2^2 */ $v = self::fe_mul( ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$d), $u1u1 ); /* v = d*u1^2 */ $v = self::fe_neg($v); /* v = -d*u1^2 */ $v = self::fe_sub($v, $u2u2); /* v = -(d*u1^2)-u2^2 */ $v_u2u2 = self::fe_mul($v, $u2u2); /* v_u2u2 = v*u2^2 */ // fe25519_1(one); // notsquare = ristretto255_sqrt_ratio_m1(inv_sqrt, one, v_u2u2); $one = self::fe_1(); $result = self::ristretto255_sqrt_ratio_m1($one, $v_u2u2); $inv_sqrt = $result['x']; $notsquare = $result['nonsquare']; $h = new ParagonIE_Sodium_Core_Curve25519_Ge_P3(); $h->X = self::fe_mul($inv_sqrt, $u2); $h->Y = self::fe_mul(self::fe_mul($inv_sqrt, $h->X), $v); $h->X = self::fe_mul($h->X, $s_); $h->X = self::fe_abs( self::fe_add($h->X, $h->X) ); $h->Y = self::fe_mul($u1, $h->Y); $h->Z = self::fe_1(); $h->T = self::fe_mul($h->X, $h->Y); $res = - ((1 - $notsquare) | self::fe_isnegative($h->T) | self::fe_iszero($h->Y)); return array('h' => $h, 'res' => $res); } /** * @param ParagonIE_Sodium_Core_Curve25519_Ge_P3 $h * @return string * @throws SodiumException */ public static function ristretto255_p3_tobytes(ParagonIE_Sodium_Core_Curve25519_Ge_P3 $h) { $sqrtm1 = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqrtm1); $invsqrtamd = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$invsqrtamd); $u1 = self::fe_add($h->Z, $h->Y); /* u1 = Z+Y */ $zmy = self::fe_sub($h->Z, $h->Y); /* zmy = Z-Y */ $u1 = self::fe_mul($u1, $zmy); /* u1 = (Z+Y)*(Z-Y) */ $u2 = self::fe_mul($h->X, $h->Y); /* u2 = X*Y */ $u1_u2u2 = self::fe_mul(self::fe_sq($u2), $u1); /* u1_u2u2 = u1*u2^2 */ $one = self::fe_1(); // fe25519_1(one); // (void) ristretto255_sqrt_ratio_m1(inv_sqrt, one, u1_u2u2); $result = self::ristretto255_sqrt_ratio_m1($one, $u1_u2u2); $inv_sqrt = $result['x']; $den1 = self::fe_mul($inv_sqrt, $u1); /* den1 = inv_sqrt*u1 */ $den2 = self::fe_mul($inv_sqrt, $u2); /* den2 = inv_sqrt*u2 */ $z_inv = self::fe_mul($h->T, self::fe_mul($den1, $den2)); /* z_inv = den1*den2*T */ $ix = self::fe_mul($h->X, $sqrtm1); /* ix = X*sqrt(-1) */ $iy = self::fe_mul($h->Y, $sqrtm1); /* iy = Y*sqrt(-1) */ $eden = self::fe_mul($den1, $invsqrtamd); $t_z_inv = self::fe_mul($h->T, $z_inv); /* t_z_inv = T*z_inv */ $rotate = self::fe_isnegative($t_z_inv); $x_ = self::fe_copy($h->X); $y_ = self::fe_copy($h->Y); $den_inv = self::fe_copy($den2); $x_ = self::fe_cmov($x_, $iy, $rotate); $y_ = self::fe_cmov($y_, $ix, $rotate); $den_inv = self::fe_cmov($den_inv, $eden, $rotate); $x_z_inv = self::fe_mul($x_, $z_inv); $y_ = self::fe_cneg($y_, self::fe_isnegative($x_z_inv)); // fe25519_sub(s_, h->Z, y_); // fe25519_mul(s_, den_inv, s_); // fe25519_abs(s_, s_); // fe25519_tobytes(s, s_); return self::fe_tobytes( self::fe_abs( self::fe_mul( $den_inv, self::fe_sub($h->Z, $y_) ) ) ); } /** * @param ParagonIE_Sodium_Core_Curve25519_Fe $t * @return ParagonIE_Sodium_Core_Curve25519_Ge_P3 * * @throws SodiumException */ public static function ristretto255_elligator(ParagonIE_Sodium_Core_Curve25519_Fe $t) { $sqrtm1 = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqrtm1); $onemsqd = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$onemsqd); $d = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$d); $sqdmone = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqdmone); $sqrtadm1 = ParagonIE_Sodium_Core_Curve25519_Fe::fromArray(self::$sqrtadm1); $one = self::fe_1(); $r = self::fe_mul($sqrtm1, self::fe_sq($t)); /* r = sqrt(-1)*t^2 */ $u = self::fe_mul(self::fe_add($r, $one), $onemsqd); /* u = (r+1)*(1-d^2) */ $c = self::fe_neg(self::fe_1()); /* c = -1 */ $rpd = self::fe_add($r, $d); /* rpd = r+d */ $v = self::fe_mul( self::fe_sub( $c, self::fe_mul($r, $d) ), $rpd ); /* v = (c-r*d)*(r+d) */ $result = self::ristretto255_sqrt_ratio_m1($u, $v); $s = $result['x']; $wasnt_square = 1 - $result['nonsquare']; $s_prime = self::fe_neg( self::fe_abs( self::fe_mul($s, $t) ) ); /* s_prime = -|s*t| */ $s = self::fe_cmov($s, $s_prime, $wasnt_square); $c = self::fe_cmov($c, $r, $wasnt_square); // fe25519_sub(n, r, one); /* n = r-1 */ // fe25519_mul(n, n, c); /* n = c*(r-1) */ // fe25519_mul(n, n, ed25519_sqdmone); /* n = c*(r-1)*(d-1)^2 */ // fe25519_sub(n, n, v); /* n = c*(r-1)*(d-1)^2-v */ $n = self::fe_sub( self::fe_mul( self::fe_mul( self::fe_sub($r, $one), $c ), $sqdmone ), $v ); /* n = c*(r-1)*(d-1)^2-v */ $w0 = self::fe_mul( self::fe_add($s, $s), $v ); /* w0 = 2s*v */ $w1 = self::fe_mul($n, $sqrtadm1); /* w1 = n*sqrt(ad-1) */ $ss = self::fe_sq($s); /* ss = s^2 */ $w2 = self::fe_sub($one, $ss); /* w2 = 1-s^2 */ $w3 = self::fe_add($one, $ss); /* w3 = 1+s^2 */ return new ParagonIE_Sodium_Core_Curve25519_Ge_P3( self::fe_mul($w0, $w3), self::fe_mul($w2, $w1), self::fe_mul($w1, $w3), self::fe_mul($w0, $w2) ); } /** * @param string $h * @return string * @throws SodiumException */ public static function ristretto255_from_hash($h) { if (self::strlen($h) !== 64) { throw new SodiumException('Hash must be 64 bytes'); } //fe25519_frombytes(r0, h); //fe25519_frombytes(r1, h + 32); $r0 = self::fe_frombytes(self::substr($h, 0, 32)); $r1 = self::fe_frombytes(self::substr($h, 32, 32)); //ristretto255_elligator(&p0, r0); //ristretto255_elligator(&p1, r1); $p0 = self::ristretto255_elligator($r0); $p1 = self::ristretto255_elligator($r1); //ge25519_p3_to_cached(&p1_cached, &p1); //ge25519_add_cached(&p_p1p1, &p0, &p1_cached); $p_p1p1 = self::ge_add( $p0, self::ge_p3_to_cached($p1) ); //ge25519_p1p1_to_p3(&p, &p_p1p1); //ristretto255_p3_tobytes(s, &p); return self::ristretto255_p3_tobytes( self::ge_p1p1_to_p3($p_p1p1) ); } /** * @param string $p * @return int * @throws SodiumException */ public static function is_valid_point($p) { $result = self::ristretto255_frombytes($p); if ($result['res'] !== 0) { return 0; } return 1; } /** * @param string $p * @param string $q * @return string * @throws SodiumException */ public static function ristretto255_add($p, $q) { $p_res = self::ristretto255_frombytes($p); $q_res = self::ristretto255_frombytes($q); if ($p_res['res'] !== 0 || $q_res['res'] !== 0) { throw new SodiumException('Could not add points'); } $p_p3 = $p_res['h']; $q_p3 = $q_res['h']; $q_cached = self::ge_p3_to_cached($q_p3); $r_p1p1 = self::ge_add($p_p3, $q_cached); $r_p3 = self::ge_p1p1_to_p3($r_p1p1); return self::ristretto255_p3_tobytes($r_p3); } /** * @param string $p * @param string $q * @return string * @throws SodiumException */ public static function ristretto255_sub($p, $q) { $p_res = self::ristretto255_frombytes($p); $q_res = self::ristretto255_frombytes($q); if ($p_res['res'] !== 0 || $q_res['res'] !== 0) { throw new SodiumException('Could not add points'); } $p_p3 = $p_res['h']; $q_p3 = $q_res['h']; $q_cached = self::ge_p3_to_cached($q_p3); $r_p1p1 = self::ge_sub($p_p3, $q_cached); $r_p3 = self::ge_p1p1_to_p3($r_p1p1); return self::ristretto255_p3_tobytes($r_p3); } /** * @param int $hLen * @param ?string $ctx * @param string $msg * @return string * @throws SodiumException * @psalm-suppress PossiblyInvalidArgument hash API */ protected static function h2c_string_to_hash_sha256($hLen, $ctx, $msg) { $h = array_fill(0, $hLen, 0); $ctx_len = !is_null($ctx) ? self::strlen($ctx) : 0; if ($hLen > 0xff) { throw new SodiumException('Hash must be less than 256 bytes'); } if ($ctx_len > 0xff) { $st = hash_init('sha256'); self::hash_update($st, "H2C-OVERSIZE-DST-"); self::hash_update($st, $ctx); $ctx = hash_final($st, true); $ctx_len = 32; } $t = array(0, $hLen, 0); $ux = str_repeat("\0", 64); $st = hash_init('sha256'); self::hash_update($st, $ux); self::hash_update($st, $msg); self::hash_update($st, self::intArrayToString($t)); self::hash_update($st, $ctx); self::hash_update($st, self::intToChr($ctx_len)); $u0 = hash_final($st, true); for ($i = 0; $i < $hLen; $i += 64) { $ux = self::xorStrings($ux, $u0); ++$t[2]; $st = hash_init('sha256'); self::hash_update($st, $ux); self::hash_update($st, self::intToChr($t[2])); self::hash_update($st, $ctx); self::hash_update($st, self::intToChr($ctx_len)); $ux = hash_final($st, true); $amount = min($hLen - $i, 64); for ($j = 0; $j < $amount; ++$j) { $h[$i + $j] = self::chrToInt($ux[$i]); } } return self::intArrayToString(array_slice($h, 0, $hLen)); } /** * @param int $hLen * @param ?string $ctx * @param string $msg * @return string * @throws SodiumException * @psalm-suppress PossiblyInvalidArgument hash API */ protected static function h2c_string_to_hash_sha512($hLen, $ctx, $msg) { $h = array_fill(0, $hLen, 0); $ctx_len = !is_null($ctx) ? self::strlen($ctx) : 0; if ($hLen > 0xff) { throw new SodiumException('Hash must be less than 256 bytes'); } if ($ctx_len > 0xff) { $st = hash_init('sha256'); self::hash_update($st, "H2C-OVERSIZE-DST-"); self::hash_update($st, $ctx); $ctx = hash_final($st, true); $ctx_len = 32; } $t = array(0, $hLen, 0); $ux = str_repeat("\0", 128); $st = hash_init('sha512'); self::hash_update($st, $ux); self::hash_update($st, $msg); self::hash_update($st, self::intArrayToString($t)); self::hash_update($st, $ctx); self::hash_update($st, self::intToChr($ctx_len)); $u0 = hash_final($st, true); for ($i = 0; $i < $hLen; $i += 128) { $ux = self::xorStrings($ux, $u0); ++$t[2]; $st = hash_init('sha512'); self::hash_update($st, $ux); self::hash_update($st, self::intToChr($t[2])); self::hash_update($st, $ctx); self::hash_update($st, self::intToChr($ctx_len)); $ux = hash_final($st, true); $amount = min($hLen - $i, 128); for ($j = 0; $j < $amount; ++$j) { $h[$i + $j] = self::chrToInt($ux[$i]); } } return self::intArrayToString(array_slice($h, 0, $hLen)); } /** * @param int $hLen * @param ?string $ctx * @param string $msg * @param int $hash_alg * @return string * @throws SodiumException */ public static function h2c_string_to_hash($hLen, $ctx, $msg, $hash_alg) { switch ($hash_alg) { case self::CORE_H2C_SHA256: return self::h2c_string_to_hash_sha256($hLen, $ctx, $msg); case self::CORE_H2C_SHA512: return self::h2c_string_to_hash_sha512($hLen, $ctx, $msg); default: throw new SodiumException('Invalid H2C hash algorithm'); } } /** * @param ?string $ctx * @param string $msg * @param int $hash_alg * @return string * @throws SodiumException */ protected static function _string_to_element($ctx, $msg, $hash_alg) { return self::ristretto255_from_hash( self::h2c_string_to_hash(self::crypto_core_ristretto255_HASHBYTES, $ctx, $msg, $hash_alg) ); } /** * @return string * @throws SodiumException * @throws Exception */ public static function ristretto255_random() { return self::ristretto255_from_hash( ParagonIE_Sodium_Compat::randombytes_buf(self::crypto_core_ristretto255_HASHBYTES) ); } /** * @return string * @throws SodiumException */ public static function ristretto255_scalar_random() { return self::scalar_random(); } /** * @param string $s * @return string * @throws SodiumException */ public static function ristretto255_scalar_complement($s) { return self::scalar_complement($s); } /** * @param string $s * @return string */ public static function ristretto255_scalar_invert($s) { return self::sc25519_invert($s); } /** * @param string $s * @return string * @throws SodiumException */ public static function ristretto255_scalar_negate($s) { return self::scalar_negate($s); } /** * @param string $x * @param string $y * @return string */ public static function ristretto255_scalar_add($x, $y) { return self::scalar_add($x, $y); } /** * @param string $x * @param string $y * @return string */ public static function ristretto255_scalar_sub($x, $y) { return self::scalar_sub($x, $y); } /** * @param string $x * @param string $y * @return string */ public static function ristretto255_scalar_mul($x, $y) { return self::sc25519_mul($x, $y); } /** * @param string $ctx * @param string $msg * @param int $hash_alg * @return string * @throws SodiumException */ public static function ristretto255_scalar_from_string($ctx, $msg, $hash_alg) { $h = array_fill(0, 64, 0); $h_be = self::stringToIntArray( self::h2c_string_to_hash( self::HASH_SC_L, $ctx, $msg, $hash_alg ) ); for ($i = 0; $i < self::HASH_SC_L; ++$i) { $h[$i] = $h_be[self::HASH_SC_L - 1 - $i]; } return self::ristretto255_scalar_reduce(self::intArrayToString($h)); } /** * @param string $s * @return string */ public static function ristretto255_scalar_reduce($s) { return self::sc_reduce($s); } /** * @param string $n * @param string $p * @return string * @throws SodiumException */ public static function scalarmult_ristretto255($n, $p) { if (self::strlen($n) !== 32) { throw new SodiumException('Scalar must be 32 bytes, ' . self::strlen($p) . ' given.'); } if (self::strlen($p) !== 32) { throw new SodiumException('Point must be 32 bytes, ' . self::strlen($p) . ' given.'); } $result = self::ristretto255_frombytes($p); if ($result['res'] !== 0) { throw new SodiumException('Could not multiply points'); } $P = $result['h']; $t = self::stringToIntArray($n); $t[31] &= 0x7f; $Q = self::ge_scalarmult(self::intArrayToString($t), $P); $q = self::ristretto255_p3_tobytes($Q); if (ParagonIE_Sodium_Compat::is_zero($q)) { throw new SodiumException('An unknown error has occurred'); } return $q; } /** * @param string $n * @return string * @throws SodiumException */ public static function scalarmult_ristretto255_base($n) { $t = self::stringToIntArray($n); $t[31] &= 0x7f; $Q = self::ge_scalarmult_base(self::intArrayToString($t)); $q = self::ristretto255_p3_tobytes($Q); if (ParagonIE_Sodium_Compat::is_zero($q)) { throw new SodiumException('An unknown error has occurred'); } return $q; } }