731 lines
24 KiB
C++
731 lines
24 KiB
C++
#include "stdafx.h"
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#include "tunsafe_wg_plugin.h"
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#include "wireguard.h"
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#include "util.h"
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#include "crypto/curve25519/curve25519-donna.h"
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#include "crypto/sha/sha1.h"
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#include "crypto/chacha20poly1305.h"
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#include "crypto/siphash/siphash.h"
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#include "crypto/blake2s/blake2s.h"
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#include "tunsafe_endian.h"
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#include <algorithm>
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enum {
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WG_SESSION_ID_LEN = 32,
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WG_SESSION_AUTH_LEN = 16,
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};
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class PluginPeer;
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class TunsafePluginImpl;
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class ExtFieldWriter {
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public:
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ExtFieldWriter(uint8 *target, uint32 target_size) : target_(target), target_size_(target_size), target_pos_(0), fail_flag_(false) { }
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bool WriteField(uint8 code, const uint8 *data, uint32 size);
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void BlockLogin() { fail_flag_ = true; }
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bool fail_flag() { return fail_flag_; }
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uint32 length() {
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return target_pos_;
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}
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private:
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uint8 *target_;
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uint32 target_size_;
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uint32 target_pos_;
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bool fail_flag_;
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};
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bool ExtFieldWriter::WriteField(uint8 code, const uint8 *data, uint32 size) {
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assert(size < 256);
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uint8 *dst = &target_[target_pos_];
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if (target_pos_ + size + 2 > target_size_)
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return false;
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target_pos_ += size + 2;
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dst[0] = code;
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dst[1] = size;
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memcpy(dst + 2, data, size);
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return true;
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}
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enum {
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// The other peer has no way of identifying a specific instance of
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// a connection. There's no way to distinguish a periodic handshake from
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// a new client connection. Add a session ID to the Peer to solve this.
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// We don't send the actual session id, instead we send:
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// Hash(plaintext ephemeral public key, session id)
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kExtensionType_SessionIDAuth = 0x20,
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kExtensionType_SetSessionID = 0x21,
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// This is sent by the server to request an additional token to allow
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// login, for example a TOTP token, or a password.
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// By cleverly using session ids, the server can avoid having to request
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// this for every new handshake, even when roaming.
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kExtensionType_TokenRequest = 0x22,
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// This holds the token reply.
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kExtensionType_TokenReply = 0x23,
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};
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class TokenClientHandler {
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public:
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TokenClientHandler(PluginPeer *pp);
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~TokenClientHandler();
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void SetSessionId(const uint8 id[WG_SESSION_ID_LEN]);
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void SetToken(const uint8 *token, size_t token_size);
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void OnHandshakeCreate(WgPeer *peer, ExtFieldWriter &writer, const uint8 salt[WG_PUBLIC_KEY_LEN]);
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void OnTokenRequest(const uint8 *data, uint32 data_size);
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void OnHandshakeComplete();
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bool waiting_for_token() { return waiting_for_token_; }
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uint32 token_request() { return token_request_type_; }
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bool WantHandshake() { return !waiting_for_token_; }
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void WriteSessionId(ExtFieldWriter &writer, const uint8 salt[WG_PUBLIC_KEY_LEN]);
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private:
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PluginPeer *pp_;
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// Set to true if we're waiting for the UI to set the TOTP-token, so login can continue.
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bool waiting_for_token_;
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uint8 token_size_;
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bool has_session_id_;
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uint32 token_request_type_;
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// The session id
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uint8 session_id_[WG_SESSION_ID_LEN];
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// Crypto key for tokens
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uint8 token_crypto_key_[WG_SYMMETRIC_KEY_LEN];
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// This is set to the token given by the UI
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uint8 token_[TunsafePlugin::kMaxTokenLen];
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};
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class TotpTokenAuthenticator {
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public:
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TotpTokenAuthenticator() : secret_size_(0), window_size_(30), block_reuse_(false), digits_(6), precision_(0), next_allowed_code_(0) {}
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bool Initialize(const char *config);
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bool Authenticate(const uint8 *data, size_t size, uint64 *last_code);
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bool configured() { return secret_size_ != 0; }
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uint8 digits() { return digits_; }
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private:
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uint32 GetValueForTimestamp(uint64 now);
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uint16 window_size_;
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uint16 precision_;
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bool block_reuse_;
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uint8 digits_;
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uint8 secret_size_;
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uint64 next_allowed_code_;
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uint8 secret_[64];
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};
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class TokenServerHandler {
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public:
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TokenServerHandler();
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~TokenServerHandler();
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bool OnHandshake(uint8 *token_reply, int token_reply_size, bool has_valid_session_id, ExtFieldWriter &writer, const siphash_key_t *siphash_key);
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bool OnHandshake2(bool has_valid_session_id);
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bool OnUnknownPeerSetting(const char *key, const char *value);
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bool WantHandshake() { return !stop_reconnects_; }
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bool VerifySessionId(const uint8 session_id_auth[WG_SESSION_AUTH_LEN], const uint8 salt[WG_PUBLIC_KEY_LEN]);
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private:
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bool has_session_id_;
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bool is_session_id_authed_;
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bool stop_reconnects_;
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uint8 num_failures_;
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uint8 reset_recovery_counter_;
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uint8 token_bucket_;
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uint8 authentication_type_;
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uint8 last_login_status_;
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uint64 last_attempt_;
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uint64 reset_recovery_last_code_;
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uint64 last_cksum_;
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uint64 cksum_equal_timestamp_;
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enum {
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// Allow one token attempt every 30 seconds
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kTokenBucketCost = 30,
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// And the bucket size is 8, so you can perform 8 attempts
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// in a row.
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kTokenBucketFull = 240,
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// Failed attempts until lockout. When locked out, you need to
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// perform 3 successful 2fa attempts in a row before it's unlocked
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// for 3 different codes.
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kAttemptsUntilLockout = 10,
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kAttemptsUntilLockoutRemoved = 3,
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};
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TotpTokenAuthenticator token_authenticator_;
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uint8 session_id_[WG_SESSION_ID_LEN];
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uint8 token_crypto_key_[WG_SYMMETRIC_KEY_LEN];
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};
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class PluginPeer : public WgPeerExtraData {
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public:
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PluginPeer(TunsafePluginImpl *plugin, WgPeer *peer) : plugin(plugin), peer(peer), token_client_handler(this) {}
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~PluginPeer();
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virtual void OnPeerDestroy() override {
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delete this;
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}
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WgPeer *peer;
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TunsafePluginImpl *plugin;
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TokenClientHandler token_client_handler;
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TokenServerHandler token_server_handler;
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};
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// Toplevel wireguard plugin
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class TunsafePluginImpl : public TunsafePlugin {
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friend class PluginPeer;
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public:
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TunsafePluginImpl(PluginDelegate *del, WireguardProcessor *proc) {
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delegate_ = del;
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proc_ = proc;
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peer_doing_2fa_ = NULL;
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OsGetRandomBytes((uint8*)&siphash_key_, sizeof(siphash_key_));
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}
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void DeletingPeer(PluginPeer *peer) {
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if (peer_doing_2fa_ == peer)
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peer_doing_2fa_ = NULL;
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}
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PluginDelegate *delegate() { return delegate_; }
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void OnTokenRequest(PluginPeer *peer);
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private:
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virtual bool HandleUnknownPeerId(uint8 public_key[WG_PUBLIC_KEY_LEN], Packet *packet) override { return false; }
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virtual bool OnUnknownInterfaceSetting(const char *key, const char *value) override;
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virtual bool OnUnknownPeerSetting(WgPeer *peer, const char *key, const char *value) override;
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virtual bool WantHandshake(WgPeer *peer) override;
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virtual uint32 OnHandshake0(WgPeer *peer, uint8 *extout, uint32 extout_size, const uint8 salt[WG_PUBLIC_KEY_LEN]) override;
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virtual uint32 OnHandshake1(WgPeer *peer, const uint8 *ext, uint32 ext_size, const uint8 salt_in[WG_PUBLIC_KEY_LEN], uint8 *extout, uint32 extout_size, const uint8 salt_out[WG_PUBLIC_KEY_LEN]) override;
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virtual uint32 OnHandshake2(WgPeer *peer, const uint8 *ext, uint32 ext_size, const uint8 salt[WG_PUBLIC_KEY_LEN]) override;
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virtual bool OnAfterSettingsParsed() override;
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virtual void OnOutgoingHandshakePacket(WgPeer *peer, Packet *packet) override;
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PluginPeer *GetPluginPeer(WgPeer *peer);
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virtual void SubmitToken(const uint8 *text, size_t text_len) override;
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WireguardProcessor *proc_;
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PluginPeer *peer_doing_2fa_;
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PluginDelegate *delegate_;
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siphash_key_t siphash_key_;
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};
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PluginPeer::~PluginPeer() {
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plugin->DeletingPeer(this);
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}
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TokenClientHandler::TokenClientHandler(PluginPeer *pp) {
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pp_ = pp;
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waiting_for_token_ = false;
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token_size_ = false;
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has_session_id_ = false;
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token_request_type_ = 0;
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memset(token_crypto_key_, 0, sizeof(token_crypto_key_));
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}
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TokenClientHandler::~TokenClientHandler() {
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}
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void TokenClientHandler::SetSessionId(const uint8 id[WG_SESSION_ID_LEN]) {
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has_session_id_ = true;
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memcpy(session_id_, id, WG_SESSION_ID_LEN);
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}
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void TokenClientHandler::SetToken(const uint8 *token, size_t token_size) {
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if (token_size > TunsafePlugin::kMaxTokenLen || !waiting_for_token_)
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return;
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waiting_for_token_ = false;
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token_size_ = (uint8)token_size;
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memcpy(token_, token, token_size);
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}
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void TokenClientHandler::WriteSessionId(ExtFieldWriter &writer, const uint8 salt[WG_PUBLIC_KEY_LEN]) {
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if (has_session_id_) {
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uint8 buf[WG_SESSION_AUTH_LEN];
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blake2s(buf, WG_SESSION_AUTH_LEN, salt, WG_PUBLIC_KEY_LEN, session_id_, sizeof(session_id_));
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writer.WriteField(kExtensionType_SessionIDAuth, buf, WG_SESSION_AUTH_LEN);
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}
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}
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// This is called to include a token (if the server has set one) in outgoing handshakes.
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void TokenClientHandler::OnHandshakeCreate(WgPeer *peer, ExtFieldWriter &writer, const uint8 salt[WG_PUBLIC_KEY_LEN]) {
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WriteSessionId(writer, salt);
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if (token_size_ && has_session_id_) {
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// Encrypt and include the token in the response
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// NOTE: Must not reuse the key to send different tokens, but we send
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// only one token as a reply to TokenRequest so that's fine.
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uint8 buf[TunsafePlugin::kMaxTokenLen + 16];
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chacha20poly1305_encrypt(buf, token_, token_size_, NULL, 0, 0, token_crypto_key_);
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writer.WriteField(kExtensionType_TokenReply, buf, 16 + token_size_);
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static const uint8 kPadding[16] = {0};
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writer.WriteField(kExtensionType_Padding, kPadding, -token_size_ & 0xF);
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}
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}
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// This runs on the initiator, after the handshake has been parsed
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void TokenClientHandler::OnHandshakeComplete() {
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// Forget an old token, we'll request it again if needed.
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token_size_ = 0;
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memset(token_crypto_key_, 0, sizeof(token_crypto_key_));
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}
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// This runs when backend requests a token, ask the user for the token
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// and then call SetToken.
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void TokenClientHandler::OnTokenRequest(const uint8 *data, uint32 data_size) {
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if (data_size >= WG_SYMMETRIC_KEY_LEN + 2 && !waiting_for_token_) {
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memcpy(token_crypto_key_, data, WG_SYMMETRIC_KEY_LEN);
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token_request_type_ = ReadLE16(data + WG_SYMMETRIC_KEY_LEN);
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if (token_size_ && (token_request_type_ & kTokenRequestStatus_Mask) == kTokenRequestStatus_None)
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token_request_type_ |= kTokenRequestStatus_NotAccepted;
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waiting_for_token_ = true;
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pp_->plugin->OnTokenRequest(pp_);
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}
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}
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// Decode a base32 string, skip whitespace and =.
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// returns 0 on failure.
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static size_t DecodeBase32String(const char *string, size_t string_len, uint8 *output, size_t output_len) {
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// static const char kBase32Charset[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
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size_t n = 0;
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uint32 bitbuff = 0, nbits = 0, v;
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for (size_t i = 0; i < string_len; i++) {
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uint8 c = string[i];
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if (c >= '2' && c <= '7') {
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v = c - '2' + 26;
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} else if ((c | 32) >= 'a' && (c | 32) <= 'z') {
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v = (c | 32) - 'a';
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} else if (c == ' ' || c == '=' || c == '\t') {
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continue;
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} else {
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return 0;
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}
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bitbuff = bitbuff * 32 + v;
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nbits += 5;
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if (nbits >= 8) {
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nbits -= 8;
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if (n == output_len)
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return 0;
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output[n++] = (uint8)(bitbuff >> nbits);
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}
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}
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return n;
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}
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// RequireToken=totp-sha1:ALPHABETAGAMMAOSCAR,digits=6,period=30,precision=15
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bool TotpTokenAuthenticator::Initialize(const char *config) {
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const char *end = config + strlen(config);
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const char *comma = strchr(config, ',');
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size_t rv = DecodeBase32String(config, (comma ? comma : end) - config, secret_, sizeof(secret_));
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if (!rv)
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return false;
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secret_size_ = (uint8)rv;
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bool has_precision = false;
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while (comma) {
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comma += 1;
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while (*comma == ' ') comma++;
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if (strncmp(comma, "digits=", 7) == 0) {
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int v = atoi(comma + 7);
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if (v < 6 || v > 8)
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return false;
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digits_ = (uint8)v;
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} else if (strncmp(comma, "period=", 7) == 0) {
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int v = atoi(comma + 7);
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if (v < 1 || v > 3600)
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return false;
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window_size_ = (uint16)v;
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} else if (strncmp(comma, "precision=", 10) == 0) {
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int v = atoi(comma + 10);
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if (v < 0 || v > 3600)
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return false;
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has_precision = true;
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precision_ = (uint16)v;
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} else if (strncmp(comma, "reuse=0", 7) == 0) {
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block_reuse_ = true;
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} else {
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return false;
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}
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comma = strchr(comma, ',');
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}
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if (!has_precision)
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precision_ = window_size_ >> 1;
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return true;
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}
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extern int memcmp_crypto(const uint8 *a, const uint8 *b, size_t n);
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uint32 TotpTokenAuthenticator::GetValueForTimestamp(uint64 now) {
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uint8 hmacbuf[20];
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SHA1HmacContext hmac;
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SHA1HmacReset(&hmac, secret_, secret_size_);
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uint8 timebuf[8];
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WriteBE64(timebuf, now);
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SHA1HmacInput(&hmac, timebuf, 8);
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SHA1HmacFinish(&hmac, hmacbuf);
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uint32 tmp;
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memcpy(&tmp, hmacbuf + (hmacbuf[19] & 0xF), 4);
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uint32 value = ReadBE32(&tmp) & 0x7FFFFFFF;
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switch (digits_) {
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case 6: value %= 1000000; break;
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case 7: value %= 10000000; break;
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case 8: value %= 100000000; break;
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}
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return value;
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}
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bool TotpTokenAuthenticator::Authenticate(const uint8 *data, size_t size, uint64 *code_out) {
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uint64 now = time(NULL);
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uint64 first_period = (now - precision_) / window_size_;
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uint64 last_period = (now + precision_) / window_size_;
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for (; first_period <= last_period; first_period++) {
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char buf[16];
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int r = snprintf(buf, sizeof(buf), "%.*u", digits_, GetValueForTimestamp(first_period));
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// RINFO("Checking if %.*s equals %s", (int)size, data, buf);
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if (r == size && memcmp_crypto((uint8*)buf, data, size) == 0) {
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// Disable code reuse if requested.
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if (block_reuse_ && first_period < next_allowed_code_)
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return false;
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next_allowed_code_ = first_period + 1;
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*code_out = first_period;
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return true;
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}
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}
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return false;
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}
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////////////////////////////////////////////////////////////////////////////////////////////////////////////////
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TokenServerHandler::TokenServerHandler() {
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num_failures_ = 0;
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has_session_id_ = false;
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is_session_id_authed_ = false;
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stop_reconnects_ = false;
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last_attempt_ = 0;
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token_bucket_ = kTokenBucketFull;
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reset_recovery_counter_ = 0;
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reset_recovery_last_code_ = 0;
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last_cksum_ = 0;
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cksum_equal_timestamp_ = 0;
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last_login_status_ = 0;
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}
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TokenServerHandler::~TokenServerHandler() {
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}
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bool TokenServerHandler::OnHandshake(uint8 *token_reply, int token_reply_size, bool has_valid_session_id, ExtFieldWriter &writer, const siphash_key_t *siphash_key) {
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// Tokens not required for this peer?
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if (!token_authenticator_.configured())
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return true;
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// check that the client has a valid token session, otherwise block login.
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if (!has_valid_session_id) {
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OsGetRandomBytes(session_id_, sizeof(session_id_));
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writer.WriteField(kExtensionType_SetSessionID, session_id_, WG_SESSION_ID_LEN);
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is_session_id_authed_ = false;
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has_session_id_ = true;
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request_token:
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// TODO: Make it optional to reveal last_login_status_
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uint8 data[WG_SYMMETRIC_KEY_LEN + 2];
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OsGetRandomBytes(token_crypto_key_, sizeof(token_crypto_key_));
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data[WG_SYMMETRIC_KEY_LEN] = authentication_type_;
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data[WG_SYMMETRIC_KEY_LEN + 1] = last_login_status_;
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memcpy(data, token_crypto_key_, WG_SYMMETRIC_KEY_LEN);
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writer.WriteField(kExtensionType_TokenRequest, data, sizeof(data));
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writer.BlockLogin();
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return true;
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}
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if (!is_session_id_authed_ && token_reply && token_reply_size >= 16) {
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// allow only so many attempts per second
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uint64 now = OsGetMilliseconds(), code_out;
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uint64 secs = (now - last_attempt_) >> 10;
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last_attempt_ += secs << 10;
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token_bucket_ = (uint8)std::min<uint64>(token_bucket_ + secs, kTokenBucketFull);
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bool authenticated = false;
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// Decrypt and verify the supplied key. If this fails, we're likely using an old key.
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if (chacha20poly1305_decrypt(token_reply, token_reply, token_reply_size, NULL, 0, 0, token_crypto_key_)) {
|
|
authenticated = token_authenticator_.Authenticate(token_reply, token_reply_size - 16, &code_out);
|
|
|
|
// Account is locked after 10 failed attempts. To unlock the account, you need to login 3 times successfully
|
|
// in a row, with distincts, increasing codes, with no failed attempts in between.
|
|
if (num_failures_ >= kAttemptsUntilLockout) {
|
|
if (authenticated && code_out > reset_recovery_last_code_) {
|
|
reset_recovery_last_code_ = code_out;
|
|
if (reset_recovery_counter_++ == kAttemptsUntilLockoutRemoved - 1) {
|
|
RINFO("Account unlocked.");
|
|
num_failures_ = 0;
|
|
reset_recovery_counter_ = 0;
|
|
token_bucket_ = kTokenBucketFull;
|
|
} else {
|
|
authenticated = false;
|
|
}
|
|
} else {
|
|
reset_recovery_counter_ = 0;
|
|
authenticated = false;
|
|
}
|
|
} else {
|
|
// Check if the password is the same as the previous attempt, this could indicate a retransmission of the packet.
|
|
// Don't increase num_failures_ based on this, but after a minute, force authenticated to false.
|
|
uint64 cksum = siphash(token_reply, token_reply_size - 16, siphash_key);
|
|
if (cksum == last_cksum_) {
|
|
if (now >= cksum_equal_timestamp_ + 60000) {
|
|
authenticated = false;
|
|
} else {
|
|
if (authenticated)
|
|
num_failures_ = 0;
|
|
}
|
|
} else {
|
|
cksum_equal_timestamp_ = now;
|
|
last_cksum_ = cksum;
|
|
num_failures_ = authenticated ? 0 : num_failures_ + 1;
|
|
if (num_failures_ == kAttemptsUntilLockout)
|
|
RINFO("Account locked because of %d failed login attempts.", num_failures_);
|
|
}
|
|
}
|
|
}
|
|
last_login_status_ = (num_failures_ >= kAttemptsUntilLockout) ? (kTokenRequestStatus_Locked >> 8) :
|
|
(token_bucket_ >= kTokenBucketCost) ? (kTokenRequestStatus_Wrong >> 8) :
|
|
(kTokenRequestStatus_Ratelimit >> 8);
|
|
// Fail when toket bucket is exceeded
|
|
if (token_bucket_ >= kTokenBucketCost) {
|
|
token_bucket_ -= kTokenBucketCost;
|
|
} else {
|
|
authenticated = false;
|
|
}
|
|
is_session_id_authed_ = authenticated;
|
|
}
|
|
|
|
if (!is_session_id_authed_)
|
|
goto request_token;
|
|
|
|
last_login_status_ = 0;
|
|
stop_reconnects_ = false;
|
|
return true;
|
|
}
|
|
|
|
bool TokenServerHandler::OnHandshake2(bool has_valid_session_id) {
|
|
// Tokens not required for this peer?
|
|
if (!token_authenticator_.configured())
|
|
return true;
|
|
// Only allow configuration in this direction if a valid session key was provided.
|
|
if (has_valid_session_id && is_session_id_authed_)
|
|
return true;
|
|
|
|
// Stop further reconnections to this peer until further notice.
|
|
stop_reconnects_ = true;
|
|
return false;
|
|
}
|
|
|
|
|
|
bool TokenServerHandler::OnUnknownPeerSetting(const char *key, const char *value) {
|
|
if (strcmp(key, "RequireToken") != 0)
|
|
return false;
|
|
|
|
if (strncmp(value, "totp-sha1:", 10) != 0)
|
|
return false;
|
|
|
|
if (!token_authenticator_.Initialize(value + 10))
|
|
return false;
|
|
authentication_type_ = kTokenRequestType_6digits + (token_authenticator_.digits() - 6);
|
|
return true;
|
|
}
|
|
|
|
bool TokenServerHandler::VerifySessionId(const uint8 session_id_auth[WG_SESSION_AUTH_LEN], const uint8 salt[WG_PUBLIC_KEY_LEN]) {
|
|
if (!has_session_id_)
|
|
return false;
|
|
uint8 buf[WG_SESSION_AUTH_LEN];
|
|
blake2s(buf, WG_SESSION_AUTH_LEN, salt, WG_PUBLIC_KEY_LEN, session_id_, sizeof(session_id_));
|
|
return memcmp_crypto(buf, session_id_auth, WG_SESSION_AUTH_LEN) == 0;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
PluginPeer *TunsafePluginImpl::GetPluginPeer(WgPeer *peer) {
|
|
PluginPeer *rv = (PluginPeer *)peer->extradata();
|
|
if (!rv) {
|
|
rv = new PluginPeer(this, peer);
|
|
peer->SetExtradata(rv);
|
|
}
|
|
return rv;
|
|
}
|
|
|
|
bool TunsafePluginImpl::WantHandshake(WgPeer *peer) {
|
|
PluginPeer *pp = GetPluginPeer(peer);
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION) {
|
|
return pp->token_server_handler.WantHandshake() &&
|
|
pp->token_client_handler.WantHandshake();
|
|
} else {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// This runs on client and appends data
|
|
uint32 TunsafePluginImpl::OnHandshake0(WgPeer *peer, uint8 *extout, uint32 extout_size, const uint8 salt[WG_PUBLIC_KEY_LEN]) {
|
|
PluginPeer *pp = GetPluginPeer(peer);
|
|
ExtFieldWriter writer(extout, extout_size);
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION)
|
|
pp->token_client_handler.OnHandshakeCreate(peer, writer, salt);
|
|
return writer.length();
|
|
}
|
|
|
|
// This runs on the server to parse init and send response
|
|
uint32 TunsafePluginImpl::OnHandshake1(WgPeer *peer, const uint8 *ext, uint32 ext_size, const uint8 salt_in[WG_PUBLIC_KEY_LEN], uint8 *extout, uint32 extout_size, const uint8 salt_out[WG_PUBLIC_KEY_LEN]) {
|
|
PluginPeer *pp = GetPluginPeer(peer);
|
|
ExtFieldWriter writer(extout, extout_size);
|
|
|
|
// Skip the version
|
|
if (ext_size >= 4)
|
|
ext += 4, ext_size -= 4;
|
|
|
|
bool has_valid_session_id = false;
|
|
uint8 *token_reply = NULL;
|
|
uint8 token_reply_size = 0;
|
|
|
|
while (ext_size >= 2) {
|
|
uint8 type = ext[0], size = ext[1];
|
|
ext += 2, ext_size -= 2;
|
|
if (size > ext_size)
|
|
return false;
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION) {
|
|
switch (type) {
|
|
case kExtensionType_SessionIDAuth:
|
|
if (size == WG_SESSION_AUTH_LEN)
|
|
has_valid_session_id = pp->token_server_handler.VerifySessionId(ext, salt_in);
|
|
break;
|
|
|
|
case kExtensionType_TokenReply:
|
|
token_reply = (uint8*)ext;
|
|
token_reply_size = size;
|
|
break;
|
|
}
|
|
}
|
|
ext += size, ext_size -= size;
|
|
}
|
|
if (ext_size != 0)
|
|
return kHandshakeResponseDrop;
|
|
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION) {
|
|
// If this is a handshake in the other direction, also include session id.
|
|
pp->token_client_handler.WriteSessionId(writer, salt_out);
|
|
|
|
if (!pp->token_server_handler.OnHandshake(token_reply, token_reply_size, has_valid_session_id, writer, &siphash_key_))
|
|
return kHandshakeResponseDrop;
|
|
}
|
|
|
|
return writer.length() + writer.fail_flag() * WgPlugin::kHandshakeResponseFail;
|
|
}
|
|
|
|
// This runs on client and parses response
|
|
uint32 TunsafePluginImpl::OnHandshake2(WgPeer *peer, const uint8 *ext, uint32 ext_size, const uint8 salt[WG_PUBLIC_KEY_LEN]) {
|
|
PluginPeer *pp = GetPluginPeer(peer);
|
|
|
|
// Skip the version
|
|
if (ext_size >= 4)
|
|
ext += 4, ext_size -= 4;
|
|
|
|
bool has_valid_session_id = false;
|
|
|
|
while (ext_size >= 2) {
|
|
uint8 type = ext[0], size = ext[1];
|
|
ext += 2, ext_size -= 2;
|
|
if (size > ext_size)
|
|
return false;
|
|
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION) {
|
|
switch (type) {
|
|
case kExtensionType_SessionIDAuth:
|
|
if (size == WG_SESSION_AUTH_LEN)
|
|
has_valid_session_id = pp->token_server_handler.VerifySessionId(ext, salt);
|
|
break;
|
|
// All token requests mean that handshake has failed.
|
|
case kExtensionType_TokenRequest:
|
|
pp->token_client_handler.OnTokenRequest(ext, size);
|
|
return kHandshakeResponseDrop;
|
|
case kExtensionType_SetSessionID:
|
|
if (size == WG_SESSION_ID_LEN)
|
|
pp->token_client_handler.SetSessionId(ext);
|
|
break;
|
|
}
|
|
}
|
|
ext += size, ext_size -= size;
|
|
}
|
|
if (ext_size != 0)
|
|
return kHandshakeResponseDrop;
|
|
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION) {
|
|
// Stop outgoing handshakes if client didn't supply a valid session id.
|
|
if (!pp->token_server_handler.OnHandshake2(has_valid_session_id))
|
|
return kHandshakeResponseDrop;
|
|
pp->token_client_handler.OnHandshakeComplete();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
bool TunsafePluginImpl::OnUnknownInterfaceSetting(const char *key, const char *value) {
|
|
return false;
|
|
}
|
|
|
|
bool TunsafePluginImpl::OnUnknownPeerSetting(WgPeer *peer, const char *key, const char *value) {
|
|
PluginPeer *pp = GetPluginPeer(peer);
|
|
if (WITH_TWO_FACTOR_AUTHENTICATION && pp->token_server_handler.OnUnknownPeerSetting(key, value))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
void TunsafePluginImpl::OnTokenRequest(PluginPeer *peer) {
|
|
if (!WITH_TWO_FACTOR_AUTHENTICATION || peer_doing_2fa_ != NULL)
|
|
return;
|
|
peer_doing_2fa_ = peer;
|
|
delegate_->OnRequestToken(peer->peer, peer->token_client_handler.token_request());
|
|
}
|
|
|
|
void TunsafePluginImpl::SubmitToken(const uint8 *text, size_t text_len) {
|
|
if (!WITH_TWO_FACTOR_AUTHENTICATION || peer_doing_2fa_ == NULL)
|
|
return;
|
|
assert(peer_doing_2fa_->peer->dev()->IsMainThread());
|
|
peer_doing_2fa_->token_client_handler.SetToken(text, text_len);
|
|
proc_->ForceSendHandshakeInitiation(peer_doing_2fa_->peer);
|
|
peer_doing_2fa_ = NULL;
|
|
|
|
// Find the next peer requiring a token
|
|
for (WgPeer *peer = proc_->dev().first_peer(); peer; peer = peer->next_peer()) {
|
|
PluginPeer *pp = (PluginPeer *)peer->extradata();
|
|
if (!pp)
|
|
continue;
|
|
if (pp->token_client_handler.waiting_for_token()) {
|
|
OnTokenRequest(pp);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool TunsafePluginImpl::OnAfterSettingsParsed() {
|
|
return true;
|
|
}
|
|
|
|
void TunsafePluginImpl::OnOutgoingHandshakePacket(WgPeer *peer, Packet *packet) {
|
|
}
|
|
|
|
TunsafePlugin *CreateTunsafePlugin(PluginDelegate *delegate, WireguardProcessor *wgp) {
|
|
return new TunsafePluginImpl(delegate, wgp);
|
|
}
|
|
|