aboutsummaryrefslogtreecommitdiffstats
path: root/Sources/WireGuardKitC
diff options
context:
space:
mode:
Diffstat (limited to 'Sources/WireGuardKitC')
-rw-r--r--Sources/WireGuardKitC/WireGuardKitC.h20
-rw-r--r--Sources/WireGuardKitC/key.c124
-rw-r--r--Sources/WireGuardKitC/key.h24
-rw-r--r--Sources/WireGuardKitC/module.modulemap4
-rw-r--r--Sources/WireGuardKitC/x25519.c178
-rw-r--r--Sources/WireGuardKitC/x25519.h7
6 files changed, 357 insertions, 0 deletions
diff --git a/Sources/WireGuardKitC/WireGuardKitC.h b/Sources/WireGuardKitC/WireGuardKitC.h
new file mode 100644
index 0000000..54e4783
--- /dev/null
+++ b/Sources/WireGuardKitC/WireGuardKitC.h
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2023 WireGuard LLC. All Rights Reserved.
+
+#include "key.h"
+#include "x25519.h"
+
+/* From <sys/kern_control.h> */
+#define CTLIOCGINFO 0xc0644e03UL
+struct ctl_info {
+ u_int32_t ctl_id;
+ char ctl_name[96];
+};
+struct sockaddr_ctl {
+ u_char sc_len;
+ u_char sc_family;
+ u_int16_t ss_sysaddr;
+ u_int32_t sc_id;
+ u_int32_t sc_unit;
+ u_int32_t sc_reserved[5];
+};
diff --git a/Sources/WireGuardKitC/key.c b/Sources/WireGuardKitC/key.c
new file mode 100644
index 0000000..84e7f16
--- /dev/null
+++ b/Sources/WireGuardKitC/key.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This is a specialized constant-time base64/hex implementation that resists side-channel attacks.
+ */
+
+#include <string.h>
+#include "key.h"
+
+static inline void encode_base64(char dest[static 4], const uint8_t src[static 3])
+{
+ const uint8_t input[] = { (src[0] >> 2) & 63, ((src[0] << 4) | (src[1] >> 4)) & 63, ((src[1] << 2) | (src[2] >> 6)) & 63, src[2] & 63 };
+
+ for (unsigned int i = 0; i < 4; ++i)
+ dest[i] = input[i] + 'A'
+ + (((25 - input[i]) >> 8) & 6)
+ - (((51 - input[i]) >> 8) & 75)
+ - (((61 - input[i]) >> 8) & 15)
+ + (((62 - input[i]) >> 8) & 3);
+
+}
+
+void key_to_base64(char base64[static WG_KEY_LEN_BASE64], const uint8_t key[static WG_KEY_LEN])
+{
+ unsigned int i;
+
+ for (i = 0; i < WG_KEY_LEN / 3; ++i)
+ encode_base64(&base64[i * 4], &key[i * 3]);
+ encode_base64(&base64[i * 4], (const uint8_t[]){ key[i * 3 + 0], key[i * 3 + 1], 0 });
+ base64[WG_KEY_LEN_BASE64 - 2] = '=';
+ base64[WG_KEY_LEN_BASE64 - 1] = '\0';
+}
+
+static inline int decode_base64(const char src[static 4])
+{
+ int val = 0;
+
+ for (unsigned int i = 0; i < 4; ++i)
+ val |= (-1
+ + ((((('A' - 1) - src[i]) & (src[i] - ('Z' + 1))) >> 8) & (src[i] - 64))
+ + ((((('a' - 1) - src[i]) & (src[i] - ('z' + 1))) >> 8) & (src[i] - 70))
+ + ((((('0' - 1) - src[i]) & (src[i] - ('9' + 1))) >> 8) & (src[i] + 5))
+ + ((((('+' - 1) - src[i]) & (src[i] - ('+' + 1))) >> 8) & 63)
+ + ((((('/' - 1) - src[i]) & (src[i] - ('/' + 1))) >> 8) & 64)
+ ) << (18 - 6 * i);
+ return val;
+}
+
+bool key_from_base64(uint8_t key[static WG_KEY_LEN], const char *base64)
+{
+ unsigned int i;
+ volatile uint8_t ret = 0;
+ int val;
+
+ if (strlen(base64) != WG_KEY_LEN_BASE64 - 1 || base64[WG_KEY_LEN_BASE64 - 2] != '=')
+ return false;
+
+ for (i = 0; i < WG_KEY_LEN / 3; ++i) {
+ val = decode_base64(&base64[i * 4]);
+ ret |= (uint32_t)val >> 31;
+ key[i * 3 + 0] = (val >> 16) & 0xff;
+ key[i * 3 + 1] = (val >> 8) & 0xff;
+ key[i * 3 + 2] = val & 0xff;
+ }
+ val = decode_base64((const char[]){ base64[i * 4 + 0], base64[i * 4 + 1], base64[i * 4 + 2], 'A' });
+ ret |= ((uint32_t)val >> 31) | (val & 0xff);
+ key[i * 3 + 0] = (val >> 16) & 0xff;
+ key[i * 3 + 1] = (val >> 8) & 0xff;
+
+ return 1 & ((ret - 1) >> 8);
+}
+
+void key_to_hex(char hex[static WG_KEY_LEN_HEX], const uint8_t key[static WG_KEY_LEN])
+{
+ unsigned int i;
+
+ for (i = 0; i < WG_KEY_LEN; ++i) {
+ hex[i * 2] = 87U + (key[i] >> 4) + ((((key[i] >> 4) - 10U) >> 8) & ~38U);
+ hex[i * 2 + 1] = 87U + (key[i] & 0xf) + ((((key[i] & 0xf) - 10U) >> 8) & ~38U);
+ }
+ hex[i * 2] = '\0';
+}
+
+bool key_from_hex(uint8_t key[static WG_KEY_LEN], const char *hex)
+{
+ uint8_t c, c_acc, c_alpha0, c_alpha, c_num0, c_num, c_val;
+ volatile uint8_t ret = 0;
+
+ if (strlen(hex) != WG_KEY_LEN_HEX - 1)
+ return false;
+
+ for (unsigned int i = 0; i < WG_KEY_LEN_HEX - 1; i += 2) {
+ c = (uint8_t)hex[i];
+ c_num = c ^ 48U;
+ c_num0 = (c_num - 10U) >> 8;
+ c_alpha = (c & ~32U) - 55U;
+ c_alpha0 = ((c_alpha - 10U) ^ (c_alpha - 16U)) >> 8;
+ ret |= ((c_num0 | c_alpha0) - 1) >> 8;
+ c_val = (c_num0 & c_num) | (c_alpha0 & c_alpha);
+ c_acc = c_val * 16U;
+
+ c = (uint8_t)hex[i + 1];
+ c_num = c ^ 48U;
+ c_num0 = (c_num - 10U) >> 8;
+ c_alpha = (c & ~32U) - 55U;
+ c_alpha0 = ((c_alpha - 10U) ^ (c_alpha - 16U)) >> 8;
+ ret |= ((c_num0 | c_alpha0) - 1) >> 8;
+ c_val = (c_num0 & c_num) | (c_alpha0 & c_alpha);
+ key[i / 2] = c_acc | c_val;
+ }
+
+ return 1 & ((ret - 1) >> 8);
+}
+
+bool key_eq(const uint8_t key1[static WG_KEY_LEN], const uint8_t key2[static WG_KEY_LEN])
+{
+ volatile uint8_t acc = 0;
+ for (unsigned int i = 0; i < WG_KEY_LEN; ++i) {
+ acc |= key1[i] ^ key2[i];
+ asm volatile("" : "=r"(acc) : "0"(acc));
+ }
+ return 1 & ((acc - 1) >> 8);
+}
diff --git a/Sources/WireGuardKitC/key.h b/Sources/WireGuardKitC/key.h
new file mode 100644
index 0000000..5353ade
--- /dev/null
+++ b/Sources/WireGuardKitC/key.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef KEY_H
+#define KEY_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define WG_KEY_LEN (32)
+#define WG_KEY_LEN_BASE64 (45)
+#define WG_KEY_LEN_HEX (65)
+
+void key_to_base64(char base64[static WG_KEY_LEN_BASE64], const uint8_t key[static WG_KEY_LEN]);
+bool key_from_base64(uint8_t key[static WG_KEY_LEN], const char *base64);
+
+void key_to_hex(char hex[static WG_KEY_LEN_HEX], const uint8_t key[static WG_KEY_LEN]);
+bool key_from_hex(uint8_t key[static WG_KEY_LEN], const char *hex);
+
+bool key_eq(const uint8_t key1[static WG_KEY_LEN], const uint8_t key2[static WG_KEY_LEN]);
+
+#endif
diff --git a/Sources/WireGuardKitC/module.modulemap b/Sources/WireGuardKitC/module.modulemap
new file mode 100644
index 0000000..26b45bf
--- /dev/null
+++ b/Sources/WireGuardKitC/module.modulemap
@@ -0,0 +1,4 @@
+module WireGuardKitC {
+ umbrella header "WireGuardKitC.h"
+ export *
+}
diff --git a/Sources/WireGuardKitC/x25519.c b/Sources/WireGuardKitC/x25519.c
new file mode 100644
index 0000000..7793299
--- /dev/null
+++ b/Sources/WireGuardKitC/x25519.c
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * Curve25519 ECDH functions, based on TweetNaCl but cleaned up.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+#include <CommonCrypto/CommonRandom.h>
+
+#include "x25519.h"
+
+typedef int64_t fe[16];
+
+static inline void carry(fe o)
+{
+ int i;
+
+ for (i = 0; i < 16; ++i) {
+ o[(i + 1) % 16] += (i == 15 ? 38 : 1) * (o[i] >> 16);
+ o[i] &= 0xffff;
+ }
+}
+
+static inline void cswap(fe p, fe q, int b)
+{
+ int i;
+ int64_t t, c = ~(b - 1);
+
+ for (i = 0; i < 16; ++i) {
+ t = c & (p[i] ^ q[i]);
+ p[i] ^= t;
+ q[i] ^= t;
+ }
+}
+
+static inline void pack(uint8_t *o, const fe n)
+{
+ int i, j, b;
+ fe m, t;
+
+ memcpy(t, n, sizeof(t));
+ carry(t);
+ carry(t);
+ carry(t);
+ for (j = 0; j < 2; ++j) {
+ m[0] = t[0] - 0xffed;
+ for (i = 1; i < 15; ++i) {
+ m[i] = t[i] - 0xffff - ((m[i - 1] >> 16) & 1);
+ m[i - 1] &= 0xffff;
+ }
+ m[15] = t[15] - 0x7fff - ((m[14] >> 16) & 1);
+ b = (m[15] >> 16) & 1;
+ m[14] &= 0xffff;
+ cswap(t, m, 1 - b);
+ }
+ for (i = 0; i < 16; ++i) {
+ o[2 * i] = t[i] & 0xff;
+ o[2 * i + 1] = t[i] >> 8;
+ }
+}
+
+static inline void unpack(fe o, const uint8_t *n)
+{
+ int i;
+
+ for (i = 0; i < 16; ++i)
+ o[i] = n[2 * i] + ((int64_t)n[2 * i + 1] << 8);
+ o[15] &= 0x7fff;
+}
+
+static inline void add(fe o, const fe a, const fe b)
+{
+ int i;
+
+ for (i = 0; i < 16; ++i)
+ o[i] = a[i] + b[i];
+}
+
+static inline void subtract(fe o, const fe a, const fe b)
+{
+ int i;
+
+ for (i = 0; i < 16; ++i)
+ o[i] = a[i] - b[i];
+}
+
+static inline void multmod(fe o, const fe a, const fe b)
+{
+ int i, j;
+ int64_t t[31] = { 0 };
+
+ for (i = 0; i < 16; ++i) {
+ for (j = 0; j < 16; ++j)
+ t[i + j] += a[i] * b[j];
+ }
+ for (i = 0; i < 15; ++i)
+ t[i] += 38 * t[i + 16];
+ memcpy(o, t, sizeof(fe));
+ carry(o);
+ carry(o);
+}
+
+static inline void invert(fe o, const fe i)
+{
+ fe c;
+ int a;
+
+ memcpy(c, i, sizeof(c));
+ for (a = 253; a >= 0; --a) {
+ multmod(c, c, c);
+ if (a != 2 && a != 4)
+ multmod(c, c, i);
+ }
+ memcpy(o, c, sizeof(fe));
+}
+
+static void curve25519_shared_secret(uint8_t shared_secret[32], const uint8_t private_key[32], const uint8_t public_key[32])
+{
+ static const fe a24 = { 0xdb41, 1 };
+ uint8_t z[32];
+ int64_t r;
+ int i;
+ fe a = { 1 }, b, c = { 0 }, d = { 1 }, e, f, x;
+
+ memcpy(z, private_key, sizeof(z));
+
+ z[31] = (z[31] & 127) | 64;
+ z[0] &= 248;
+
+ unpack(x, public_key);
+ memcpy(b, x, sizeof(b));
+
+ for (i = 254; i >= 0; --i) {
+ r = (z[i >> 3] >> (i & 7)) & 1;
+ cswap(a, b, (int)r);
+ cswap(c, d, (int)r);
+ add(e, a, c);
+ subtract(a, a, c);
+ add(c, b, d);
+ subtract(b, b, d);
+ multmod(d, e, e);
+ multmod(f, a, a);
+ multmod(a, c, a);
+ multmod(c, b, e);
+ add(e, a, c);
+ subtract(a, a, c);
+ multmod(b, a, a);
+ subtract(c, d, f);
+ multmod(a, c, a24);
+ add(a, a, d);
+ multmod(c, c, a);
+ multmod(a, d, f);
+ multmod(d, b, x);
+ multmod(b, e, e);
+ cswap(a, b, (int)r);
+ cswap(c, d, (int)r);
+ }
+ invert(c, c);
+ multmod(a, a, c);
+ pack(shared_secret, a);
+}
+
+void curve25519_derive_public_key(uint8_t public_key[32], const uint8_t private_key[32])
+{
+ static const uint8_t basepoint[32] = { 9 };
+
+ curve25519_shared_secret(public_key, private_key, basepoint);
+}
+
+void curve25519_generate_private_key(uint8_t private_key[32])
+{
+ assert(CCRandomGenerateBytes(private_key, 32) == kCCSuccess);
+ private_key[31] = (private_key[31] & 127) | 64;
+ private_key[0] &= 248;
+}
diff --git a/Sources/WireGuardKitC/x25519.h b/Sources/WireGuardKitC/x25519.h
new file mode 100644
index 0000000..7d8440d
--- /dev/null
+++ b/Sources/WireGuardKitC/x25519.h
@@ -0,0 +1,7 @@
+#ifndef X25519_H
+#define X25519_H
+
+void curve25519_derive_public_key(unsigned char public_key[32], const unsigned char private_key[32]);
+void curve25519_generate_private_key(unsigned char private_key[32]);
+
+#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.