/** @return 0 on success, -1 otherwise. */ int CryptoAuth_encrypt(struct CryptoAuth_Session* sessionPub, struct Message* msg) { struct CryptoAuth_Session_pvt* session = Identity_check((struct CryptoAuth_Session_pvt*) sessionPub); // If there has been no incoming traffic for a while, reset the connection to state 0. // This will prevent "connection in bad state" situations from lasting forever. // this will reset the session if it has timed out. resetIfTimeout(session); // If the nonce wraps, start over. if (session->nextNonce >= 0xfffffff0) { reset(session); } Assert_true(!((uintptr_t)msg->bytes % 4) || !"alignment fault"); // nextNonce 0: sending hello, we are initiating connection. // nextNonce 1: sending another hello, nothing received yet. // nextNonce 2: sending key, hello received. // nextNonce 3: sending key again, no data packet recieved yet. // nextNonce >3: handshake complete // // if it's a blind handshake, every message will be empty and nextNonce will remain // zero until the first message is received back. if (session->nextNonce < 5) { if (session->nextNonce < 4) { encryptHandshake(msg, session, 0); return 0; } else { cryptoAuthDebug0(session, "Doing final step to send message. nonce=4"); Assert_ifParanoid(!Bits_isZero(session->ourTempPrivKey, 32)); Assert_ifParanoid(!Bits_isZero(session->herTempPubKey, 32)); getSharedSecret(session->sharedSecret, session->ourTempPrivKey, session->herTempPubKey, NULL, session->context->logger); } } Assert_true(msg->length > 0 && "Empty packet during handshake"); Assert_true(msg->padding >= 36 || !"not enough padding"); encrypt(session->nextNonce, msg, session->sharedSecret, session->isInitiator); Message_push32(msg, session->nextNonce, NULL); session->nextNonce++; return 0; }
// connect an allocator to a new parent. static void connect(struct Allocator_pvt* parent, struct Allocator_pvt* child, const char* file, int line) { Assert_ifParanoid(child->parent == NULL); Assert_ifParanoid(child->lastSibling == NULL); Assert_ifParanoid(child->nextSibling == NULL); child->nextSibling = parent->firstChild; if (parent->firstChild) { parent->firstChild->lastSibling = child; } parent->firstChild = child; child->parent = parent; }
/** * If we don't know her key, the handshake has to be done backwards. * Reverse handshake requests are signaled by sending a non-obfuscated zero nonce. */ static uint8_t genReverseHandshake(struct Message* message, struct CryptoAuth_Wrapper* wrapper, union Headers_CryptoAuth* header) { reset(wrapper); Message_shift(message, -Headers_CryptoAuth_SIZE, NULL); // Buffer the packet so it can be sent ASAP if (wrapper->bufferedMessage != NULL) { // Not exactly a drop but a message is not going to reach the destination. cryptoAuthDebug0(wrapper, "DROP Expelled a message because a session has not yet been setup"); Allocator_free(wrapper->bufferedMessage->alloc); } cryptoAuthDebug0(wrapper, "Buffered a message"); struct Allocator* bmalloc = Allocator_child(wrapper->externalInterface.allocator); wrapper->bufferedMessage = Message_clone(message, bmalloc); Assert_ifParanoid(wrapper->nextNonce == 0); Message_shift(message, Headers_CryptoAuth_SIZE, NULL); header = (union Headers_CryptoAuth*) message->bytes; header->nonce = UINT32_MAX; message->length = Headers_CryptoAuth_SIZE; // sessionState must be 0, auth and 24 byte nonce are garbaged and public key is set // now garbage the authenticator and the encrypted key which are not used. Random_bytes(wrapper->context->rand, (uint8_t*) &header->handshake.authenticator, 48); // This is a special packet which the user should never see. Headers_setSetupPacket(&header->handshake.auth, 1); return wrapper->wrappedInterface->sendMessage(message, wrapper->wrappedInterface); }
static uint8_t sendMessage(struct Message* message, struct Interface* interface) { struct CryptoAuth_Wrapper* wrapper = Identity_check((struct CryptoAuth_Wrapper*) interface->senderContext); // If there has been no incoming traffic for a while, reset the connection to state 0. // This will prevent "connection in bad state" situations from lasting forever. // this will reset the session if it has timed out. CryptoAuth_resetIfTimeout(interface); // If the nonce wraps, start over. if (wrapper->nextNonce >= 0xfffffff0) { reset(wrapper); } Assert_true(!((uintptr_t)message->bytes % 4) || !"alignment fault"); // nextNonce 0: sending hello, we are initiating connection. // nextNonce 1: sending another hello, nothing received yet. // nextNonce 2: sending key, hello received. // nextNonce 3: sending key again, no data packet recieved yet. // nextNonce >3: handshake complete // // if it's a blind handshake, every message will be empty and nextNonce will remain // zero until the first message is received back. if (wrapper->nextNonce < 5) { if (wrapper->nextNonce < 4) { return encryptHandshake(message, wrapper, 0); } else { cryptoAuthDebug0(wrapper, "Doing final step to send message. nonce=4"); Assert_ifParanoid(!Bits_isZero(wrapper->ourTempPrivKey, 32)); Assert_ifParanoid(!Bits_isZero(wrapper->herTempPubKey, 32)); getSharedSecret(wrapper->sharedSecret, wrapper->ourTempPrivKey, wrapper->herTempPubKey, NULL, wrapper->context->logger); } } Assert_true(message->length > 0 && "Empty packet during handshake"); return encryptMessage(message, wrapper); }
static void sendMessageCallback(uv_write_t* uvReq, int error) { struct Pipe_WriteRequest_pvt* req = Identity_check((struct Pipe_WriteRequest_pvt*) uvReq); if (error) { Log_info(req->pipe->pub.logger, "Failed to write to pipe [%s] [%s]", req->pipe->pub.fullName, uv_strerror(error) ); } req->pipe->queueLen -= req->msg->length; Assert_ifParanoid(req->pipe->queueLen >= 0); Allocator_free(req->alloc); }
static int dhtModuleHandleOutgoing(struct DHTModule* module, struct DHTMessage* message) { Assert_ifParanoid(module); if (module->handleOutgoing) { DEBUG2(">> calling: %s->handleOutgoing\n", module->name); return module->handleOutgoing(message, module->context); } else { DEBUG2(">> skipping: %s->handleOutgoing\n", module->name); } return 0; }
// connect an allocator to a new parent. static void connect(struct Allocator_pvt* parent, struct Allocator_pvt* child, const char* file, int line) { Assert_ifParanoid(child->parent == NULL); Assert_ifParanoid(child->lastSibling == NULL); Assert_ifParanoid(child->nextSibling == NULL); Assert_true(parent != child); if (Defined(PARANOIA)) { for (struct Allocator_pvt* c = parent->firstChild; c; c = c->nextSibling) { Assert_true(child != c); } } child->nextSibling = parent->firstChild; if (parent->firstChild) { parent->firstChild->lastSibling = child; } parent->firstChild = child; child->parent = parent; }
// disconnect an allocator from it's parent. static void disconnect(struct Allocator_pvt* context) { // Remove this allocator from the sibling list. Assert_true(context->parent); if (context->lastSibling) { Assert_ifParanoid(context->lastSibling->nextSibling == context); Assert_ifParanoid(context->parent->firstChild != context); context->lastSibling->nextSibling = context->nextSibling; } else { // must be first in the list or a root allocator. Assert_ifParanoid(context->parent->firstChild == context || context->parent == context); Assert_ifParanoid(context->parent != context || !context->nextSibling); context->parent->firstChild = context->nextSibling; } if (context->nextSibling) { Assert_ifParanoid(context->nextSibling->lastSibling == context); context->nextSibling->lastSibling = context->lastSibling; } context->lastSibling = NULL; context->nextSibling = NULL; context->parent = NULL; }
// Shallow first search to prevent lots of flapping while we tear down the tree. static int pivotChildrenToAdoptedParents0(struct Allocator_pvt* context, int depth, int maxDepth, const char* file, int line) { int out = 0; if (depth == maxDepth) { if (context->pub.isFreeing) { return 0; } if (context->adoptions) { // Attempt to pivot around to a parent in order to save this allocator if (context->adoptions->parents) { Assert_true(!context->adoptions->parents->alloc->pub.isFreeing); disconnect(context); connect(context->adoptions->parents->alloc, context, file, line); disconnectAdopted(context->adoptions->parents->alloc, context); return 0; } // No saving it, drop it's adoptions. for (struct Allocator_List* c = context->adoptions->children; c; c = c->next) { Assert_true(!c->alloc->pub.isFreeing); disconnectAdopted(context, c->alloc); } } Assert_true(!context->pub.isFreeing); context->pub.isFreeing = 1; out++; } else { struct Allocator_pvt* child = context->firstChild; while (child) { Assert_ifParanoid(child != context); struct Allocator_pvt* nextChild = child->nextSibling; out += pivotChildrenToAdoptedParents0(child, depth+1, maxDepth, file, line); child = nextChild; } } return out; }
int main(int argc, char** argv) { #ifdef Log_KEYS fprintf(stderr, "Log_LEVEL = KEYS, EXPECT TO SEE PRIVATE KEYS IN YOUR LOGS!\n"); #endif if (argc < 2) { // Fall through. } else if (!CString_strcmp("angel", argv[1])) { return AngelInit_main(argc, argv); } else if (!CString_strcmp("core", argv[1])) { return Core_main(argc, argv); } Assert_ifParanoid(argc > 0); struct Except* eh = NULL; // Allow it to allocate 8MB struct Allocator* allocator = MallocAllocator_new(1<<23); struct Random* rand = Random_new(allocator, NULL, eh); struct EventBase* eventBase = EventBase_new(allocator); if (argc == 2) { // one argument if ((CString_strcmp(argv[1], "--help") == 0) || (CString_strcmp(argv[1], "-h") == 0)) { return usage(allocator, argv[0]); } else if (CString_strcmp(argv[1], "--genconf") == 0) { return genconf(rand); } else if (CString_strcmp(argv[1], "--pidfile") == 0) { // deprecated fprintf(stderr, "'--pidfile' option is deprecated.\n"); return 0; } else if (CString_strcmp(argv[1], "--reconf") == 0) { // Performed after reading the configuration } else if (CString_strcmp(argv[1], "--bench") == 0) { return benchmark(); } else if ((CString_strcmp(argv[1], "--version") == 0) || (CString_strcmp(argv[1], "-v") == 0)) { printf("Cjdns protocol version: %d\n", Version_CURRENT_PROTOCOL); return 0; } else if (CString_strcmp(argv[1], "--cleanconf") == 0) { // Performed after reading configuration } else if (CString_strcmp(argv[1], "--nobg") == 0) { // Performed while reading configuration } else { fprintf(stderr, "%s: unrecognized option '%s'\n", argv[0], argv[1]); fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]); return -1; } } else if (argc > 2) { // more than one argument? fprintf(stderr, "%s: too many arguments [%s]\n", argv[0], argv[1]); fprintf(stderr, "Try `%s --help' for more information.\n", argv[0]); // because of '--pidfile $filename'? if (CString_strcmp(argv[1], "--pidfile") == 0) { fprintf(stderr, "\n'--pidfile' option is deprecated.\n"); } return -1; } if (isatty(STDIN_FILENO)) { // We were started from a terminal // The chances an user wants to type in a configuration // bij hand are pretty slim so we show him the usage return usage(allocator, argv[0]); } else { // We assume stdin is a configuration file and that we should // start routing } struct Reader* stdinReader = FileReader_new(stdin, allocator); Dict config; if (JsonBencSerializer_get()->parseDictionary(stdinReader, allocator, &config)) { fprintf(stderr, "Failed to parse configuration.\n"); return -1; } if (argc == 2 && CString_strcmp(argv[1], "--cleanconf") == 0) { struct Writer* stdoutWriter = FileWriter_new(stdout, allocator); JsonBencSerializer_get()->serializeDictionary(stdoutWriter, &config); printf("\n"); return 0; } int forceNoBackground = 0; if (argc == 2 && CString_strcmp(argv[1], "--nobg") == 0) { forceNoBackground = 1; } struct Writer* logWriter = FileWriter_new(stdout, allocator); struct Log* logger = WriterLog_new(logWriter, allocator); // --------------------- Get Admin --------------------- // Dict* configAdmin = Dict_getDict(&config, String_CONST("admin")); String* adminPass = Dict_getString(configAdmin, String_CONST("password")); String* adminBind = Dict_getString(configAdmin, String_CONST("bind")); if (!adminPass) { adminPass = String_newBinary(NULL, 32, allocator); Random_base32(rand, (uint8_t*) adminPass->bytes, 32); adminPass->len = CString_strlen(adminPass->bytes); } if (!adminBind) { Except_throw(eh, "You must specify admin.bind in the cjdroute.conf file."); } // --------------------- Welcome to cjdns ---------------------- // char* archInfo = ArchInfo_describe(ArchInfo_detect(), allocator); char* sysInfo = SysInfo_describe(SysInfo_detect(), allocator); Log_info(logger, "Cjdns %s %s", archInfo, sysInfo); // --------------------- Check for running instance --------------------- // Log_info(logger, "Checking for running instance..."); checkRunningInstance(allocator, eventBase, adminBind, adminPass, logger, eh); // --------------------- Setup Pipes to Angel --------------------- // char angelPipeName[64] = "client-angel-"; Random_base32(rand, (uint8_t*)angelPipeName+13, 31); Assert_ifParanoid(EventBase_eventCount(eventBase) == 0); struct Pipe* angelPipe = Pipe_named(angelPipeName, eventBase, eh, allocator); Assert_ifParanoid(EventBase_eventCount(eventBase) == 2); angelPipe->logger = logger; char* args[] = { "angel", angelPipeName, NULL }; // --------------------- Spawn Angel --------------------- // String* privateKey = Dict_getString(&config, String_CONST("privateKey")); char* corePath = Process_getPath(allocator); if (!corePath) { Except_throw(eh, "Can't find a usable cjdns core executable, " "make sure it is in the same directory as cjdroute"); } if (!privateKey) { Except_throw(eh, "Need to specify privateKey."); } Log_info(logger, "Forking angel to background."); Process_spawn(corePath, args, eventBase, allocator); // --------------------- Get user for angel to setuid() ---------------------- // String* securityUser = NULL; List* securityConf = Dict_getList(&config, String_CONST("security")); for (int i = 0; securityConf && i < List_size(securityConf); i++) { securityUser = Dict_getString(List_getDict(securityConf, i), String_CONST("setuser")); if (securityUser) { int64_t* ea = Dict_getInt(List_getDict(securityConf, i), String_CONST("exemptAngel")); if (ea && *ea) { securityUser = NULL; } break; } } // --------------------- Pre-Configure Angel ------------------------- // Dict* preConf = Dict_new(allocator); Dict* adminPreConf = Dict_new(allocator); Dict_putDict(preConf, String_CONST("admin"), adminPreConf, allocator); Dict_putString(adminPreConf, String_CONST("core"), String_new(corePath, allocator), allocator); Dict_putString(preConf, String_CONST("privateKey"), privateKey, allocator); Dict_putString(adminPreConf, String_CONST("bind"), adminBind, allocator); Dict_putString(adminPreConf, String_CONST("pass"), adminPass, allocator); if (securityUser) { Dict_putString(adminPreConf, String_CONST("user"), securityUser, allocator); } Dict* logging = Dict_getDict(&config, String_CONST("logging")); if (logging) { Dict_putDict(preConf, String_CONST("logging"), logging, allocator); } struct Message* toAngelMsg = Message_new(0, 1024, allocator); BencMessageWriter_write(preConf, toAngelMsg, eh); Interface_sendMessage(&angelPipe->iface, toAngelMsg); Log_debug(logger, "Sent [%d] bytes to angel process", toAngelMsg->length); // --------------------- Get Response from Angel --------------------- // struct Message* fromAngelMsg = InterfaceWaiter_waitForData(&angelPipe->iface, eventBase, allocator, eh); Dict* responseFromAngel = BencMessageReader_read(fromAngelMsg, allocator, eh); // --------------------- Get Admin Addr/Port/Passwd --------------------- // Dict* responseFromAngelAdmin = Dict_getDict(responseFromAngel, String_CONST("admin")); adminBind = Dict_getString(responseFromAngelAdmin, String_CONST("bind")); if (!adminBind) { Except_throw(eh, "didn't get address and port back from angel"); } struct Sockaddr_storage adminAddr; if (Sockaddr_parse(adminBind->bytes, &adminAddr)) { Except_throw(eh, "Unable to parse [%s] as an ip address port, eg: 127.0.0.1:11234", adminBind->bytes); } // sanity check, Pipe_named() creates 2 events, see above. Assert_ifParanoid(EventBase_eventCount(eventBase) == 2); // --------------------- Configuration ------------------------- // Configurator_config(&config, &adminAddr.addr, adminPass, eventBase, logger, allocator); // --------------------- noBackground ------------------------ // int64_t* noBackground = Dict_getInt(&config, String_CONST("noBackground")); if (forceNoBackground || (noBackground && *noBackground)) { EventBase_beginLoop(eventBase); } //Allocator_free(allocator); return 0; }
static uint8_t receiveMessage(struct Message* received, struct Interface* interface) { struct CryptoAuth_Wrapper* wrapper = Identity_check((struct CryptoAuth_Wrapper*) interface->receiverContext); union Headers_CryptoAuth* header = (union Headers_CryptoAuth*) received->bytes; if (received->length < 20) { cryptoAuthDebug0(wrapper, "DROP runt"); return Error_UNDERSIZE_MESSAGE; } Assert_true(received->padding >= 12 || "need at least 12 bytes of padding in incoming message"); Assert_true(!((uintptr_t)received->bytes % 4) || !"alignment fault"); Message_shift(received, -4, NULL); uint32_t nonce = Endian_bigEndianToHost32(header->nonce); if (!wrapper->established) { if (nonce > 3 && nonce != UINT32_MAX) { if (wrapper->nextNonce < 3) { // This is impossible because we have not exchanged hello and key messages. cryptoAuthDebug0(wrapper, "DROP Received a run message to an un-setup session"); return Error_UNDELIVERABLE; } cryptoAuthDebug(wrapper, "Trying final handshake step, nonce=%u\n", nonce); uint8_t secret[32]; Assert_ifParanoid(!Bits_isZero(wrapper->ourTempPrivKey, 32)); Assert_ifParanoid(!Bits_isZero(wrapper->herTempPubKey, 32)); getSharedSecret(secret, wrapper->ourTempPrivKey, wrapper->herTempPubKey, NULL, wrapper->context->logger); // We'll optimistically advance the nextNonce value because decryptMessage() // passes the message on to the upper level and if this message causes a // response, we want the CA to be in ESTABLISHED state. // if the decryptMessage() call fails, we CryptoAuth_reset() it back. wrapper->nextNonce += 3; if (decryptMessage(wrapper, nonce, received, secret)) { cryptoAuthDebug0(wrapper, "Final handshake step succeeded"); Bits_memcpyConst(wrapper->sharedSecret, secret, 32); // Now we're in run mode, no more handshake packets will be accepted Bits_memset(wrapper->ourTempPrivKey, 0, 32); Bits_memset(wrapper->ourTempPubKey, 0, 32); Bits_memset(wrapper->herTempPubKey, 0, 32); wrapper->established = true; return callReceivedMessage(wrapper, received); } CryptoAuth_reset(&wrapper->externalInterface); cryptoAuthDebug0(wrapper, "DROP Final handshake step failed"); return Error_UNDELIVERABLE; } Message_shift(received, 4, NULL); return decryptHandshake(wrapper, nonce, received, header); } else if (nonce > 3 && nonce != UINT32_MAX) { Assert_ifParanoid(!Bits_isZero(wrapper->sharedSecret, 32)); if (decryptMessage(wrapper, nonce, received, wrapper->sharedSecret)) { return callReceivedMessage(wrapper, received); } else { cryptoAuthDebug0(wrapper, "DROP Failed to decrypt message"); return Error_UNDELIVERABLE; } } else if (nonce < 2) { cryptoAuthDebug(wrapper, "hello packet during established session nonce=[%d]", nonce); Message_shift(received, 4, NULL); return decryptHandshake(wrapper, nonce, received, header); } else { // setup keys are already zeroed, not much we can do here. cryptoAuthDebug(wrapper, "DROP key packet during established session nonce=[%d]", nonce); return Error_UNDELIVERABLE; } Assert_true(0); }
static uint8_t decryptHandshake(struct CryptoAuth_Wrapper* wrapper, const uint32_t nonce, struct Message* message, union Headers_CryptoAuth* header) { if (message->length < Headers_CryptoAuth_SIZE) { cryptoAuthDebug0(wrapper, "DROP runt"); return Error_UNDERSIZE_MESSAGE; } // handshake // nextNonce 0: recieving hello. // nextNonce 1: recieving key, we sent hello. // nextNonce 2: recieving first data packet or duplicate hello. // nextNonce 3: recieving first data packet. // nextNonce >3: handshake complete if (knowHerKey(wrapper)) { if (Bits_memcmp(wrapper->herPerminentPubKey, header->handshake.publicKey, 32)) { cryptoAuthDebug0(wrapper, "DROP a packet with different public key than this session"); return Error_AUTHENTICATION; } } else if (!Bits_isZero(wrapper->herIp6, 16)) { uint8_t calculatedIp6[16]; AddressCalc_addressForPublicKey(calculatedIp6, header->handshake.publicKey); if (Bits_memcmp(wrapper->herIp6, calculatedIp6, 16)) { cryptoAuthDebug0(wrapper, "DROP packet with public key not matching ip6 for session"); return Error_AUTHENTICATION; } } if (wrapper->nextNonce < 2 && nonce == UINT32_MAX && !wrapper->requireAuth) { // Reset without knowing key is allowed until state reaches 2. // this is because we don't know that the other end knows our key until we // have received a valid packet from them. // We can't allow the upper layer to see this message because it's not authenticated. if (!knowHerKey(wrapper)) { Bits_memcpyConst(wrapper->herPerminentPubKey, header->handshake.publicKey, 32); } Message_shift(message, -Headers_CryptoAuth_SIZE, NULL); message->length = 0; reset(wrapper); wrapper->user = NULL; cryptoAuthDebug0(wrapper, "Got a connect-to-me message, sending a hello"); // Send an empty response (to initiate the connection). encryptHandshake(message, wrapper, 1); return Error_NONE; } String* user = NULL; uint8_t passwordHashStore[32]; uint8_t* passwordHash = tryAuth(header, passwordHashStore, wrapper, &user); if (wrapper->requireAuth && !user) { cryptoAuthDebug0(wrapper, "DROP message because auth was not given"); return Error_AUTHENTICATION; } if (passwordHash == NULL && header->handshake.auth.challenge.type != 0) { cryptoAuthDebug0(wrapper, "DROP message with unrecognized authenticator"); return Error_AUTHENTICATION; } // What the nextNonce will become if this packet is valid. uint32_t nextNonce; // The secret for decrypting this message. uint8_t sharedSecret[32]; uint8_t* herPermKey = NULL; if (nonce < 2) { if (nonce == 0) { cryptoAuthDebug(wrapper, "Received a hello packet, using auth: %d", (passwordHash != NULL)); } else { cryptoAuthDebug0(wrapper, "Received a repeat hello packet"); } // Decrypt message with perminent keys. if (!knowHerKey(wrapper) || wrapper->nextNonce == 0) { herPermKey = header->handshake.publicKey; #ifdef Log_DEBUG if (Bits_isZero(header->handshake.publicKey, 32)) { cryptoAuthDebug0(wrapper, "Node sent public key of ZERO!"); } #endif } else { herPermKey = wrapper->herPerminentPubKey; if (Bits_memcmp(header->handshake.publicKey, herPermKey, 32)) { cryptoAuthDebug0(wrapper, "DROP packet contains different perminent key"); return Error_AUTHENTICATION; } } getSharedSecret(sharedSecret, wrapper->context->privateKey, herPermKey, passwordHash, wrapper->context->logger); nextNonce = 2; } else { if (nonce == 2) { cryptoAuthDebug0(wrapper, "Received a key packet"); } else if (nonce == 3) { cryptoAuthDebug0(wrapper, "Received a repeat key packet"); } else { cryptoAuthDebug(wrapper, "Received a packet of unknown type! nonce=%u", nonce); } if (Bits_memcmp(header->handshake.publicKey, wrapper->herPerminentPubKey, 32)) { cryptoAuthDebug0(wrapper, "DROP packet contains different perminent key"); return Error_AUTHENTICATION; } if (!wrapper->isInitiator) { cryptoAuthDebug0(wrapper, "DROP a stray key packet"); return Error_AUTHENTICATION; } // We sent the hello, this is a key getSharedSecret(sharedSecret, wrapper->ourTempPrivKey, wrapper->herPerminentPubKey, passwordHash, wrapper->context->logger); nextNonce = 4; } // Shift it on top of the authenticator before the encrypted public key Message_shift(message, 48 - Headers_CryptoAuth_SIZE, NULL); #ifdef Log_KEYS uint8_t sharedSecretHex[65]; printHexKey(sharedSecretHex, sharedSecret); uint8_t nonceHex[49]; Hex_encode(nonceHex, 49, header->handshake.nonce, 24); uint8_t cipherHex[65]; printHexKey(cipherHex, message->bytes); Log_keys(wrapper->context->logger, "Decrypting message with:\n" " nonce: %s\n" " secret: %s\n" " cipher: %s\n", nonceHex, sharedSecretHex, cipherHex); #endif // Decrypt her temp public key and the message. if (decryptRndNonce(header->handshake.nonce, message, sharedSecret) != 0) { // just in case Bits_memset(header, 0, Headers_CryptoAuth_SIZE); cryptoAuthDebug(wrapper, "DROP message with nonce [%d], decryption failed", nonce); return Error_AUTHENTICATION; } Assert_ifParanoid(!Bits_isZero(header->handshake.encryptedTempKey, 32)); #ifdef Log_KEYS uint8_t tempKeyHex[65]; Hex_encode(tempKeyHex, 65, header->handshake.encryptedTempKey, 32); Log_keys(wrapper->context->logger, "Unwrapping temp public key:\n" " %s\n", tempKeyHex); #endif Message_shift(message, -32, NULL); // Post-decryption checking if (nonce == 0) { // A new hello packet if (!Bits_memcmp(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32)) { // possible replay attack or duped packet cryptoAuthDebug0(wrapper, "DROP dupe hello packet with same temp key"); return Error_AUTHENTICATION; } } else if (nonce == 2 && wrapper->nextNonce >= 4) { // we accept a new key packet and let it change the session since the other end might have // killed off the session while it was in the midst of setting up. if (!Bits_memcmp(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32)) { Assert_true(!Bits_isZero(wrapper->herTempPubKey, 32)); cryptoAuthDebug0(wrapper, "DROP dupe key packet with same temp key"); return Error_AUTHENTICATION; } } else if (nonce == 3 && wrapper->nextNonce >= 4) { // Got a repeat key packet, make sure the temp key is the same as the one we know. if (Bits_memcmp(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32)) { Assert_true(!Bits_isZero(wrapper->herTempPubKey, 32)); cryptoAuthDebug0(wrapper, "DROP repeat key packet with different temp key"); return Error_AUTHENTICATION; } } // If Alice sent a hello packet then Bob sent a hello packet and they crossed on the wire, // somebody has to yield and the other has to stand firm otherwise they will either deadlock // each believing their hello packet is superior or they will livelock, each switching to the // other's session and never synchronizing. // In this event whoever has the lower permanent public key wins. // If we receive a (possibly repeat) key packet if (nextNonce == 4) { if (wrapper->nextNonce <= 4) { // and have not yet begun sending "run" data Assert_true(wrapper->nextNonce <= nextNonce); wrapper->nextNonce = nextNonce; wrapper->user = user; Bits_memcpyConst(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32); } else { // It's a (possibly repeat) key packet and we have begun sending run data. // We will change the shared secret to the one specified in the new key packet but // intentionally avoid de-incrementing the nonce just in case getSharedSecret(wrapper->sharedSecret, wrapper->ourTempPrivKey, header->handshake.encryptedTempKey, NULL, wrapper->context->logger); cryptoAuthDebug0(wrapper, "New key packet but we are already sending data"); } } else if (nextNonce == 2 && (!wrapper->isInitiator || wrapper->established)) { // This is a hello packet and we are either in ESTABLISHED state or we are // not the initiator of the connection. // If the case is that we are in ESTABLISHED state, the other side tore down the session // and we have not so lets tear it down. // If we are not in ESTABLISHED state then we don't allow resetting of the session unless // they are the sender of the hello packet or their permanent public key is lower. // this is a tie-breaker in case hello packets cross on the wire. if (wrapper->established) { reset(wrapper); } // We got a (possibly repeat) hello packet and we have not sent any hello packet, // new session. if (wrapper->nextNonce == 3 && nextNonce == 2) { // We sent a key packet so the next packet is a repeat key but we got another hello // We'll just keep steaming along sending repeat key packets nextNonce = 3; } Assert_true(wrapper->nextNonce <= nextNonce); wrapper->nextNonce = nextNonce; wrapper->user = user; Bits_memcpyConst(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32); } else if (nextNonce == 2 && Bits_memcmp(header->handshake.publicKey, wrapper->context->pub.publicKey, 32) < 0) { // It's a hello and we are the initiator but their permant public key is numerically lower // than ours, this is so that in the event of two hello packets crossing on the wire, the // nodes will agree on who is the initiator. cryptoAuthDebug0(wrapper, "Incoming hello from node with lower key, resetting"); reset(wrapper); Assert_true(wrapper->nextNonce <= nextNonce); wrapper->nextNonce = nextNonce; wrapper->user = user; Bits_memcpyConst(wrapper->herTempPubKey, header->handshake.encryptedTempKey, 32); } else { cryptoAuthDebug0(wrapper, "Incoming hello from node with higher key, not resetting"); } if (herPermKey && herPermKey != wrapper->herPerminentPubKey) { Bits_memcpyConst(wrapper->herPerminentPubKey, herPermKey, 32); } // If this is a handshake which was initiated in reverse because we // didn't know the other node's key, now send what we were going to send. if (wrapper->bufferedMessage) { // This can only happen when we have received a (maybe repeat) hello packet. Assert_true(wrapper->nextNonce == 2); struct Message* bm = wrapper->bufferedMessage; wrapper->bufferedMessage = NULL; cryptoAuthDebug0(wrapper, "Sending buffered message"); sendMessage(bm, &wrapper->externalInterface); Allocator_free(bm->alloc); } if (message->length == 0 && Headers_isSetupPacket(&header->handshake.auth)) { return Error_NONE; } Bits_memset(&wrapper->replayProtector, 0, sizeof(struct ReplayProtector)); setRequiredPadding(wrapper); return callReceivedMessage(wrapper, message); }
static uint8_t encryptHandshake(struct Message* message, struct CryptoAuth_Wrapper* wrapper, int setupMessage) { Message_shift(message, sizeof(union Headers_CryptoAuth), NULL); union Headers_CryptoAuth* header = (union Headers_CryptoAuth*) message->bytes; // garbage the auth challenge and set the nonce which follows it Random_bytes(wrapper->context->rand, (uint8_t*) &header->handshake.auth, sizeof(union Headers_AuthChallenge) + 24); // set the permanent key Bits_memcpyConst(&header->handshake.publicKey, wrapper->context->pub.publicKey, 32); if (!knowHerKey(wrapper)) { return genReverseHandshake(message, wrapper, header); } else if (!Bits_isZero(wrapper->herIp6, 16)) { // If someone starts a CA session and then discovers the key later and memcpy's it into the // result of getHerPublicKey() then we want to make sure they didn't memcpy in an invalid // key. uint8_t calculatedIp6[16]; AddressCalc_addressForPublicKey(calculatedIp6, wrapper->herPerminentPubKey); Assert_true(!Bits_memcmp(wrapper->herIp6, calculatedIp6, 16)); } if (wrapper->bufferedMessage) { // We wanted to send a message but we didn't know the peer's key so we buffered it // and sent a connectToMe. // Now we just discovered their key and we're sending a hello packet. // Lets send 2 hello packets instead and on one will attach our buffered message. // This can never happen when the machine is beyond the first hello packet because // it should have been sent either by this or in the recipet of a hello packet from // the other node. Assert_true(wrapper->nextNonce == 0); struct Message* bm = wrapper->bufferedMessage; wrapper->bufferedMessage = NULL; cryptoAuthDebug0(wrapper, "Sending buffered message"); sendMessage(bm, &wrapper->externalInterface); Allocator_free(bm->alloc); } // Password auth uint8_t* passwordHash = NULL; struct CryptoAuth_Auth auth; if (wrapper->password != NULL) { passwordHash = hashPassword(&auth, wrapper->password, wrapper->authType); Bits_memcpyConst(header->handshake.auth.bytes, &auth.challenge, sizeof(union Headers_AuthChallenge)); } header->handshake.auth.challenge.type = wrapper->authType; // Packet authentication option is deprecated, it must always be enabled. Headers_setPacketAuthRequired(&header->handshake.auth, 1); // This is a special packet which the user should never see. Headers_setSetupPacket(&header->handshake.auth, setupMessage); // Set the session state uint32_t sessionState_be = Endian_hostToBigEndian32(wrapper->nextNonce); header->nonce = sessionState_be; if (wrapper->nextNonce == 0 || wrapper->nextNonce == 2) { // If we're sending a hello or a key // Here we make up a temp keypair Random_bytes(wrapper->context->rand, wrapper->ourTempPrivKey, 32); crypto_scalarmult_curve25519_base(wrapper->ourTempPubKey, wrapper->ourTempPrivKey); #ifdef Log_KEYS uint8_t tempPrivateKeyHex[65]; Hex_encode(tempPrivateKeyHex, 65, wrapper->ourTempPrivKey, 32); uint8_t tempPubKeyHex[65]; Hex_encode(tempPubKeyHex, 65, header->handshake.encryptedTempKey, 32); Log_keys(wrapper->context->logger, "Generating temporary keypair\n" " myTempPrivateKey=%s\n" " myTempPublicKey=%s\n", tempPrivateKeyHex, tempPubKeyHex); #endif } Bits_memcpyConst(header->handshake.encryptedTempKey, wrapper->ourTempPubKey, 32); #ifdef Log_KEYS uint8_t tempKeyHex[65]; Hex_encode(tempKeyHex, 65, header->handshake.encryptedTempKey, 32); Log_keys(wrapper->context->logger, "Wrapping temp public key:\n" " %s\n", tempKeyHex); #endif cryptoAuthDebug(wrapper, "Sending %s%s packet", ((wrapper->nextNonce & 1) ? "repeat " : ""), ((wrapper->nextNonce < 2) ? "hello" : "key")); uint8_t sharedSecret[32]; if (wrapper->nextNonce < 2) { getSharedSecret(sharedSecret, wrapper->context->privateKey, wrapper->herPerminentPubKey, passwordHash, wrapper->context->logger); wrapper->isInitiator = true; Assert_true(wrapper->nextNonce <= 1); wrapper->nextNonce = 1; } else { // Handshake2 // herTempPubKey was set by receiveMessage() Assert_ifParanoid(!Bits_isZero(wrapper->herTempPubKey, 32)); getSharedSecret(sharedSecret, wrapper->context->privateKey, wrapper->herTempPubKey, passwordHash, wrapper->context->logger); Assert_true(wrapper->nextNonce <= 3); wrapper->nextNonce = 3; #ifdef Log_KEYS uint8_t tempKeyHex[65]; Hex_encode(tempKeyHex, 65, wrapper->herTempPubKey, 32); Log_keys(wrapper->context->logger, "Using their temp public key:\n" " %s\n", tempKeyHex); #endif } // Shift message over the encryptedTempKey field. Message_shift(message, 32 - Headers_CryptoAuth_SIZE, NULL); encryptRndNonce(header->handshake.nonce, message, sharedSecret); #ifdef Log_KEYS uint8_t sharedSecretHex[65]; printHexKey(sharedSecretHex, sharedSecret); uint8_t nonceHex[49]; Hex_encode(nonceHex, 49, header->handshake.nonce, 24); uint8_t cipherHex[65]; printHexKey(cipherHex, message->bytes); Log_keys(wrapper->context->logger, "Encrypting message with:\n" " nonce: %s\n" " secret: %s\n" " cipher: %s\n", nonceHex, sharedSecretHex, cipherHex); #endif // Shift it back -- encryptRndNonce adds 16 bytes of authenticator. Message_shift(message, Headers_CryptoAuth_SIZE - 32 - 16, NULL); return wrapper->wrappedInterface->sendMessage(message, wrapper->wrappedInterface); }
/** @return 0 on success, -1 otherwise. */ int CryptoAuth_decrypt(struct CryptoAuth_Session* sessionPub, struct Message* msg) { struct CryptoAuth_Session_pvt* session = Identity_check((struct CryptoAuth_Session_pvt*) sessionPub); union CryptoHeader* header = (union CryptoHeader*) msg->bytes; if (msg->length < 20) { cryptoAuthDebug0(session, "DROP runt"); return -1; } Assert_true(msg->padding >= 12 || "need at least 12 bytes of padding in incoming message"); Assert_true(!((uintptr_t)msg->bytes % 4) || !"alignment fault"); Assert_true(!(msg->capacity % 4) || !"length fault"); Message_shift(msg, -4, NULL); uint32_t nonce = Endian_bigEndianToHost32(header->nonce); if (!session->established) { if (nonce > 3) { if (session->nextNonce < 3) { // This is impossible because we have not exchanged hello and key messages. cryptoAuthDebug0(session, "DROP Received a run message to an un-setup session"); return -1; } cryptoAuthDebug(session, "Trying final handshake step, nonce=%u\n", nonce); uint8_t secret[32]; Assert_ifParanoid(!Bits_isZero(session->ourTempPrivKey, 32)); Assert_ifParanoid(!Bits_isZero(session->herTempPubKey, 32)); getSharedSecret(secret, session->ourTempPrivKey, session->herTempPubKey, NULL, session->context->logger); if (decryptMessage(session, nonce, msg, secret)) { cryptoAuthDebug0(session, "Final handshake step succeeded"); Bits_memcpyConst(session->sharedSecret, secret, 32); // Now we're in run mode, no more handshake packets will be accepted Bits_memset(session->ourTempPrivKey, 0, 32); Bits_memset(session->ourTempPubKey, 0, 32); Bits_memset(session->herTempPubKey, 0, 32); session->established = true; session->nextNonce += 3; updateTime(session, msg); return 0; } cryptoAuthDebug0(session, "DROP Final handshake step failed"); return -1; } Message_shift(msg, 4, NULL); return decryptHandshake(session, nonce, msg, header); } else if (nonce > 3) { Assert_ifParanoid(!Bits_isZero(session->sharedSecret, 32)); if (decryptMessage(session, nonce, msg, session->sharedSecret)) { updateTime(session, msg); return 0; } else { cryptoAuthDebug0(session, "DROP Failed to decrypt message"); return -1; } } else if (nonce < 2) { cryptoAuthDebug(session, "hello packet during established session nonce=[%d]", nonce); Message_shift(msg, 4, NULL); return decryptHandshake(session, nonce, msg, header); } else { // setup keys are already zeroed, not much we can do here. cryptoAuthDebug(session, "DROP key packet during established session nonce=[%d]", nonce); return -1; } Assert_true(0); }
static void encryptHandshake(struct Message* message, struct CryptoAuth_Session_pvt* session, int setupMessage) { Message_shift(message, sizeof(union CryptoHeader), NULL); union CryptoHeader* header = (union CryptoHeader*) message->bytes; // garbage the auth challenge and set the nonce which follows it Random_bytes(session->context->rand, (uint8_t*) &header->handshake.auth, sizeof(union CryptoHeader_Challenge) + 24); // set the permanent key Bits_memcpyConst(&header->handshake.publicKey, session->context->pub.publicKey, 32); Assert_true(knowHerKey(session)); uint8_t calculatedIp6[16]; AddressCalc_addressForPublicKey(calculatedIp6, session->pub.herPublicKey); if (!Bits_isZero(session->pub.herIp6, 16)) { // If someone starts a CA session and then discovers the key later and memcpy's it into the // result of getHerPublicKey() then we want to make sure they didn't memcpy in an invalid // key. Assert_true(!Bits_memcmp(session->pub.herIp6, calculatedIp6, 16)); } // Password auth uint8_t* passwordHash = NULL; uint8_t passwordHashStore[32]; if (session->password != NULL) { hashPassword(passwordHashStore, &header->handshake.auth, session->login, session->password, session->authType); passwordHash = passwordHashStore; } else { header->handshake.auth.challenge.type = session->authType; header->handshake.auth.challenge.additional = 0; } // Set the session state header->nonce = Endian_hostToBigEndian32(session->nextNonce); if (session->nextNonce == 0 || session->nextNonce == 2) { // If we're sending a hello or a key // Here we make up a temp keypair Random_bytes(session->context->rand, session->ourTempPrivKey, 32); crypto_scalarmult_curve25519_base(session->ourTempPubKey, session->ourTempPrivKey); if (Defined(Log_KEYS)) { uint8_t tempPrivateKeyHex[65]; Hex_encode(tempPrivateKeyHex, 65, session->ourTempPrivKey, 32); uint8_t tempPubKeyHex[65]; Hex_encode(tempPubKeyHex, 65, session->ourTempPubKey, 32); Log_keys(session->context->logger, "Generating temporary keypair\n" " myTempPrivateKey=%s\n" " myTempPublicKey=%s\n", tempPrivateKeyHex, tempPubKeyHex); } } Bits_memcpyConst(header->handshake.encryptedTempKey, session->ourTempPubKey, 32); if (Defined(Log_KEYS)) { uint8_t tempKeyHex[65]; Hex_encode(tempKeyHex, 65, header->handshake.encryptedTempKey, 32); Log_keys(session->context->logger, "Wrapping temp public key:\n" " %s\n", tempKeyHex); } cryptoAuthDebug(session, "Sending %s%s packet", ((session->nextNonce & 1) ? "repeat " : ""), ((session->nextNonce < 2) ? "hello" : "key")); uint8_t sharedSecret[32]; if (session->nextNonce < 2) { getSharedSecret(sharedSecret, session->context->privateKey, session->pub.herPublicKey, passwordHash, session->context->logger); session->isInitiator = true; Assert_true(session->nextNonce <= 1); session->nextNonce = 1; } else { // Handshake2 // herTempPubKey was set by decryptHandshake() Assert_ifParanoid(!Bits_isZero(session->herTempPubKey, 32)); getSharedSecret(sharedSecret, session->context->privateKey, session->herTempPubKey, passwordHash, session->context->logger); Assert_true(session->nextNonce <= 3); session->nextNonce = 3; if (Defined(Log_KEYS)) { uint8_t tempKeyHex[65]; Hex_encode(tempKeyHex, 65, session->herTempPubKey, 32); Log_keys(session->context->logger, "Using their temp public key:\n" " %s\n", tempKeyHex); } } // Shift message over the encryptedTempKey field. Message_shift(message, 32 - CryptoHeader_SIZE, NULL); encryptRndNonce(header->handshake.nonce, message, sharedSecret); if (Defined(Log_KEYS)) { uint8_t sharedSecretHex[65]; printHexKey(sharedSecretHex, sharedSecret); uint8_t nonceHex[49]; Hex_encode(nonceHex, 49, header->handshake.nonce, 24); uint8_t cipherHex[65]; printHexKey(cipherHex, message->bytes); Log_keys(session->context->logger, "Encrypting message with:\n" " nonce: %s\n" " secret: %s\n" " cipher: %s\n", nonceHex, sharedSecretHex, cipherHex); } // Shift it back -- encryptRndNonce adds 16 bytes of authenticator. Message_shift(message, CryptoHeader_SIZE - 32 - 16, NULL); }
int main(int argc, char** argv) { Assert_ifParanoid(argc > 0); struct Allocator* allocator = MallocAllocator_new(1<<23); if (argc != 6 || (argc == 2 && (!(CString_strcmp(argv[1], "--help") == 0) || (CString_strcmp(argv[1], "-h") == 0)))) { return usage(allocator, argv[0]); } struct Except* eh = NULL; struct EventBase* eventBase = EventBase_new(allocator); struct Log* logger = FileWriterLog_new(stdout, allocator); String* privateKey = String_new(argv[3], allocator); String* adminBind = String_new(argv[4], allocator); String* adminPass = String_new(argv[5], allocator); String* logTo = String_new("stdout", allocator); // --------------------- Welcome to cjdns ---------------------- // char* sysInfo = SysInfo_describe(SysInfo_detect(), allocator); Log_info(logger, "Cjdns %s %s", ArchInfo_getArchStr(), sysInfo); // --------------------- Setup Pipes to Angel --------------------- // struct Allocator* corePipeAlloc = Allocator_child(allocator); String* corePipeDir = String_new(argv[1], allocator); String* corePipeName = String_new(argv[2], allocator); if (!Defined(win32) && access(corePipeDir->bytes, W_OK)) { Except_throw(eh, "Don't have write permission to [%s].", corePipeDir->bytes); } Assert_ifParanoid(EventBase_eventCount(eventBase) == 0); struct Pipe* corePipe = Pipe_named(corePipeDir->bytes, corePipeName->bytes, eventBase, eh, corePipeAlloc); Assert_ifParanoid(EventBase_eventCount(eventBase) == 2); corePipe->logger = logger; // --------------------- Pre-Configure Core ------------------------- // Dict* preConf = Dict_new(allocator); Dict* adminPreConf = Dict_new(allocator); Dict* logPreConf = Dict_new(allocator); Dict_putDict(preConf, String_CONST("admin"), adminPreConf, allocator); Dict_putDict(preConf, String_CONST("logging"), logPreConf, allocator); Dict_putString(preConf, String_CONST("privateKey"), privateKey, allocator); Dict_putString(adminPreConf, String_CONST("bind"), adminBind, allocator); Dict_putString(adminPreConf, String_CONST("pass"), adminPass, allocator); Dict_putString(logPreConf, String_CONST("logTo"), logTo, allocator); struct Message* toCoreMsg = Message_new(0, 1024, allocator); BencMessageWriter_write(preConf, toCoreMsg, eh); Iface_CALL(corePipe->iface.send, toCoreMsg, &corePipe->iface); Log_debug(logger, "Sent [%d] bytes to core.", toCoreMsg->length); // --------------------- Get Response from Core --------------------- // struct Message* fromCoreMsg = InterfaceWaiter_waitForData(&corePipe->iface, eventBase, allocator, eh); Dict* responseFromCore = BencMessageReader_read(fromCoreMsg, allocator, eh); // --------------------- Close the Core Pipe --------------------- // Allocator_free(corePipeAlloc); corePipe = NULL; // --------------------- Get Admin Addr/Port/Passwd --------------------- // Dict* responseFromCoreAdmin = Dict_getDict(responseFromCore, String_CONST("admin")); adminBind = Dict_getString(responseFromCoreAdmin, String_CONST("bind")); if (!adminBind) { Except_throw(eh, "Didn't get ADMIN_BIND back from cjdroute."); } struct Sockaddr_storage adminAddr; if (Sockaddr_parse(adminBind->bytes, &adminAddr)) { Except_throw(eh, "Unable to parse [%s] as an IP address:port.", adminBind->bytes); } Assert_ifParanoid(EventBase_eventCount(eventBase) == 0); Log_info(logger, "Admin API ready at [%s].", adminBind->bytes); return 0; }