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authorJason A. Donenfeld <Jason@zx2c4.com>2019-02-08 00:44:14 +0100
committerJason A. Donenfeld <Jason@zx2c4.com>2019-02-08 03:23:15 +0100
commit05547861b65100279027a64f58793caea1143a30 (patch)
treec69303b55e68e93efc71d2b199119019f1199ff6 /WireGuard/Shared/Model/Key.swift
parentTunnelsManager: Ignore status changes on tunnel providers we don't have (diff)
downloadwireguard-apple-05547861b65100279027a64f58793caea1143a30.tar.xz
wireguard-apple-05547861b65100279027a64f58793caea1143a30.zip
Key: Constant time encoding
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to '')
-rw-r--r--WireGuard/Shared/Model/Key.swift148
1 files changed, 148 insertions, 0 deletions
diff --git a/WireGuard/Shared/Model/Key.swift b/WireGuard/Shared/Model/Key.swift
new file mode 100644
index 0000000..17e25a0
--- /dev/null
+++ b/WireGuard/Shared/Model/Key.swift
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+
+extension Data {
+ func isKey() -> Bool {
+ return self.count == 32
+ }
+
+ func hexKey() -> String? {
+ if self.count != 32 {
+ return nil
+ }
+ var nibble1, nibble2: UInt
+ var hex: [UInt8] = Array(repeating: 0, count: 64)
+
+ for i in 0..<32 {
+ let n = UInt(self[i])
+ nibble1 = 87 + (n >> 4)
+ nibble1 += (((UInt(bitPattern: Int(n >> 4) - 10)) >> 8) & 217)
+ nibble2 = 87 + (n & 0xf)
+ nibble2 += (((UInt(bitPattern: Int(n & 0xf) - 10)) >> 8) & 217)
+ hex[i * 2] = UInt8(truncatingIfNeeded: nibble1)
+ hex[i * 2 + 1] = UInt8(truncatingIfNeeded: nibble2)
+ }
+ return String(bytes: hex, encoding: .ascii)
+ }
+
+ private func decodeHex(c: UInt8) -> (UInt8, UInt8) {
+ var alpha0, alpha, num0, num, val, ret: UInt8
+
+ num = c ^ 48
+ num0 = UInt8(truncatingIfNeeded: UInt(bitPattern: Int(num) - 10) >> 8)
+
+ alpha = UInt8(truncatingIfNeeded: Int(c & 223) - 55)
+ alpha0 = UInt8(truncatingIfNeeded: (UInt(bitPattern: Int(alpha) - 10) ^ UInt(bitPattern: Int(alpha) - 16)) >> 8)
+
+ ret = UInt8(truncatingIfNeeded: UInt(bitPattern: Int(num0 | alpha0) - 1) >> 8)
+ val = (num0 & num) | (alpha0 & alpha)
+
+ return (val, ret)
+ }
+
+ init?(hexKey hexString: String) {
+ let hex = [UInt8](hexString.utf8)
+ if hex.count != 64 {
+ return nil
+ }
+ self.init(repeating: 0, count: 32)
+
+ var ret: UInt8 = 0
+ for i in stride(from: 0, to: 64, by: 2) {
+ var v1, v2, r: UInt8
+
+ (v1, r) = decodeHex(c: hex[i])
+ ret |= r
+
+ (v2, r) = decodeHex(c: hex[i + 1])
+ ret |= r
+
+ self[i / 2] = (v1 << 4) | v2
+ }
+
+ if 1 & (UInt8(truncatingIfNeeded: Int(ret) - 1) >> 8) != 0 {
+ return nil
+ }
+ }
+
+
+ private func encodeBase64<T: RandomAccessCollection>(dest: inout ArraySlice<UInt8>, src: T) where T.Index == Int, T.Element == UInt8 {
+ let a = Int((src[src.startIndex + 0] >> 2) & 63)
+ let b = Int(((src[src.startIndex + 0] << 4) | (src[src.startIndex + 1] >> 4)) & 63)
+ let c = Int(((src[src.startIndex + 1] << 2) | (src[src.startIndex + 2] >> 6)) & 63)
+ let d = Int(src[src.startIndex + 2] & 63)
+
+ for (i, x) in [a, b, c, d].enumerated() {
+ var y: Int = x + 65
+ y += ((25 - x) >> 8) & 6
+ y -= ((51 - x) >> 8) & 75
+ y -= ((61 - x) >> 8) & 15
+ y += ((62 - x) >> 8) & 3
+ dest[dest.startIndex + i] = UInt8(y)
+ }
+ }
+
+ func base64Key() -> String? {
+ if self.count != 32 {
+ return nil
+ }
+ var base64: [UInt8] = Array(repeating: 0, count: 44)
+
+ for i in 0..<(32 / 3) {
+ encodeBase64(dest: &base64[(i * 4)..<(i * 4 + 4)], src: self[(i * 3)..<(i * 3 + 3)])
+ }
+ encodeBase64(dest: &base64[40..<44], src: [self[30], self[31], 0])
+ base64[43] = 61
+
+ return String(bytes: base64, encoding: .ascii)
+ }
+
+ private func decodeBase64<T: RandomAccessCollection>(src: T) -> Int where T.Index == Int, T.Element == UInt8 {
+ var val: Int = 0
+ for i in 0..<4 {
+ let n = Int(src[src.startIndex + i])
+ var a: Int = -1
+ var b: Int
+ b = ((((65 - 1) - n) & (n - (90 + 1))) >> 8)
+ a += b & (n - 64)
+ b = ((((97 - 1) - n) & (n - (122 + 1))) >> 8)
+ a += b & (n - 70)
+ b = ((((48 - 1) - n) & (n - (57 + 1))) >> 8)
+ a += b & (n + 5)
+ b = ((((43 - 1) - n) & (n - (43 + 1))) >> 8)
+ a += b & 63
+ b = ((((47 - 1) - n) & (n - (47 + 1))) >> 8)
+ a += b & 64
+ val |= a << (18 - 6 * i)
+ }
+ return val
+ }
+
+ init?(base64Key base64String: String) {
+ let base64 = [UInt8](base64String.utf8)
+ if base64.count != 44 || base64[43] != 61 {
+ return nil
+ }
+ self.init(repeating: 0, count: 32)
+
+ var ret: UInt8 = 0
+ var val: Int
+ for i in 0..<(32/3) {
+ val = decodeBase64(src: base64[(i * 4)..<(i * 4 + 4)])
+ ret |= UInt8(UInt32(val) >> UInt32(31))
+ self[i * 3 + 0] = UInt8((val >> 16) & 0xff)
+ self[i * 3 + 1] = UInt8((val >> 8) & 0xff)
+ self[i * 3 + 2] = UInt8(val & 0xff)
+ }
+ val = decodeBase64(src: [base64[40], base64[41], base64[42], 65])
+ ret |= UInt8((UInt32(val) >> 31) | UInt32(val & 0xff))
+ self[30] = UInt8((val >> 16) & 0xff)
+ self[31] = UInt8((val >> 8) & 0xff)
+
+ if 1 & (UInt8(truncatingIfNeeded: Int(ret) - 1) >> 8) != 0 {
+ return nil
+ }
+ }
+}