diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/otr')
| -rw-r--r-- | vendor/golang.org/x/crypto/otr/libotr_test_helper.c | 197 | ||||
| -rw-r--r-- | vendor/golang.org/x/crypto/otr/otr.go | 1415 | ||||
| -rw-r--r-- | vendor/golang.org/x/crypto/otr/otr_test.go | 470 | ||||
| -rw-r--r-- | vendor/golang.org/x/crypto/otr/smp.go | 572 |
4 files changed, 0 insertions, 2654 deletions
diff --git a/vendor/golang.org/x/crypto/otr/libotr_test_helper.c b/vendor/golang.org/x/crypto/otr/libotr_test_helper.c deleted file mode 100644 index b3ca072..0000000 --- a/vendor/golang.org/x/crypto/otr/libotr_test_helper.c +++ /dev/null @@ -1,197 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// This code can be compiled and used to test the otr package against libotr. -// See otr_test.go. - -// +build ignore - -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> - -#include <proto.h> -#include <message.h> -#include <privkey.h> - -static int g_session_established = 0; - -OtrlPolicy policy(void *opdata, ConnContext *context) { - return OTRL_POLICY_ALWAYS; -} - -int is_logged_in(void *opdata, const char *accountname, const char *protocol, - const char *recipient) { - return 1; -} - -void inject_message(void *opdata, const char *accountname, const char *protocol, - const char *recipient, const char *message) { - printf("%s\n", message); - fflush(stdout); - fprintf(stderr, "libotr helper sent: %s\n", message); -} - -void update_context_list(void *opdata) {} - -void new_fingerprint(void *opdata, OtrlUserState us, const char *accountname, - const char *protocol, const char *username, - unsigned char fingerprint[20]) { - fprintf(stderr, "NEW FINGERPRINT\n"); - g_session_established = 1; -} - -void write_fingerprints(void *opdata) {} - -void gone_secure(void *opdata, ConnContext *context) {} - -void gone_insecure(void *opdata, ConnContext *context) {} - -void still_secure(void *opdata, ConnContext *context, int is_reply) {} - -int max_message_size(void *opdata, ConnContext *context) { return 99999; } - -const char *account_name(void *opdata, const char *account, - const char *protocol) { - return "ACCOUNT"; -} - -void account_name_free(void *opdata, const char *account_name) {} - -const char *error_message(void *opdata, ConnContext *context, - OtrlErrorCode err_code) { - return "ERR"; -} - -void error_message_free(void *opdata, const char *msg) {} - -void resent_msg_prefix_free(void *opdata, const char *prefix) {} - -void handle_smp_event(void *opdata, OtrlSMPEvent smp_event, - ConnContext *context, unsigned short progress_event, - char *question) {} - -void handle_msg_event(void *opdata, OtrlMessageEvent msg_event, - ConnContext *context, const char *message, - gcry_error_t err) { - fprintf(stderr, "msg event: %d %s\n", msg_event, message); -} - -OtrlMessageAppOps uiops = { - policy, - NULL, - is_logged_in, - inject_message, - update_context_list, - new_fingerprint, - write_fingerprints, - gone_secure, - gone_insecure, - still_secure, - max_message_size, - account_name, - account_name_free, - NULL, /* received_symkey */ - error_message, - error_message_free, - NULL, /* resent_msg_prefix */ - resent_msg_prefix_free, - handle_smp_event, - handle_msg_event, - NULL /* create_instag */, - NULL /* convert_msg */, - NULL /* convert_free */, - NULL /* timer_control */, -}; - -static const char kPrivateKeyData[] = - "(privkeys (account (name \"account\") (protocol proto) (private-key (dsa " - "(p " - "#00FC07ABCF0DC916AFF6E9AE47BEF60C7AB9B4D6B2469E436630E36F8A489BE812486A09F" - "30B71224508654940A835301ACC525A4FF133FC152CC53DCC59D65C30A54F1993FE13FE63E" - "5823D4C746DB21B90F9B9C00B49EC7404AB1D929BA7FBA12F2E45C6E0A651689750E8528AB" - "8C031D3561FECEE72EBB4A090D450A9B7A857#) (q " - "#00997BD266EF7B1F60A5C23F3A741F2AEFD07A2081#) (g " - "#535E360E8A95EBA46A4F7DE50AD6E9B2A6DB785A66B64EB9F20338D2A3E8FB0E94725848F" - "1AA6CC567CB83A1CC517EC806F2E92EAE71457E80B2210A189B91250779434B41FC8A8873F" - "6DB94BEA7D177F5D59E7E114EE10A49CFD9CEF88AE43387023B672927BA74B04EB6BBB5E57" - "597766A2F9CE3857D7ACE3E1E3BC1FC6F26#) (y " - "#0AC8670AD767D7A8D9D14CC1AC6744CD7D76F993B77FFD9E39DF01E5A6536EF65E775FCEF" - "2A983E2A19BD6415500F6979715D9FD1257E1FE2B6F5E1E74B333079E7C880D39868462A93" - "454B41877BE62E5EF0A041C2EE9C9E76BD1E12AE25D9628DECB097025DD625EF49C3258A1A" - "3C0FF501E3DC673B76D7BABF349009B6ECF#) (x " - "#14D0345A3562C480A039E3C72764F72D79043216#)))))\n"; - -int main() { - OTRL_INIT; - - // We have to write the private key information to a file because the libotr - // API demands a filename to read from. - const char *tmpdir = "/tmp"; - if (getenv("TMP")) { - tmpdir = getenv("TMP"); - } - - char private_key_file[256]; - snprintf(private_key_file, sizeof(private_key_file), - "%s/libotr_test_helper_privatekeys-XXXXXX", tmpdir); - int fd = mkstemp(private_key_file); - if (fd == -1) { - perror("creating temp file"); - } - write(fd, kPrivateKeyData, sizeof(kPrivateKeyData) - 1); - close(fd); - - OtrlUserState userstate = otrl_userstate_create(); - otrl_privkey_read(userstate, private_key_file); - unlink(private_key_file); - - fprintf(stderr, "libotr helper started\n"); - - char buf[4096]; - - for (;;) { - char *message = fgets(buf, sizeof(buf), stdin); - if (strlen(message) == 0) { - break; - } - message[strlen(message) - 1] = 0; - fprintf(stderr, "libotr helper got: %s\n", message); - - char *newmessage = NULL; - OtrlTLV *tlvs; - int ignore_message = otrl_message_receiving( - userstate, &uiops, NULL, "account", "proto", "peer", message, - &newmessage, &tlvs, NULL, NULL, NULL); - if (tlvs) { - otrl_tlv_free(tlvs); - } - - if (newmessage != NULL) { - fprintf(stderr, "libotr got: %s\n", newmessage); - otrl_message_free(newmessage); - - gcry_error_t err; - char *newmessage = NULL; - - err = otrl_message_sending(userstate, &uiops, NULL, "account", "proto", - "peer", 0, "test message", NULL, &newmessage, - OTRL_FRAGMENT_SEND_SKIP, NULL, NULL, NULL); - if (newmessage == NULL) { - fprintf(stderr, "libotr didn't encrypt message\n"); - return 1; - } - write(1, newmessage, strlen(newmessage)); - write(1, "\n", 1); - fprintf(stderr, "libotr sent: %s\n", newmessage); - otrl_message_free(newmessage); - - g_session_established = 0; - write(1, "?OTRv2?\n", 8); - fprintf(stderr, "libotr sent: ?OTRv2\n"); - } - } - - return 0; -} diff --git a/vendor/golang.org/x/crypto/otr/otr.go b/vendor/golang.org/x/crypto/otr/otr.go deleted file mode 100644 index 173b753..0000000 --- a/vendor/golang.org/x/crypto/otr/otr.go +++ /dev/null @@ -1,1415 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package otr implements the Off The Record protocol as specified in -// http://www.cypherpunks.ca/otr/Protocol-v2-3.1.0.html -package otr // import "golang.org/x/crypto/otr" - -import ( - "bytes" - "crypto/aes" - "crypto/cipher" - "crypto/dsa" - "crypto/hmac" - "crypto/rand" - "crypto/sha1" - "crypto/sha256" - "crypto/subtle" - "encoding/base64" - "encoding/hex" - "errors" - "hash" - "io" - "math/big" - "strconv" -) - -// SecurityChange describes a change in the security state of a Conversation. -type SecurityChange int - -const ( - NoChange SecurityChange = iota - // NewKeys indicates that a key exchange has completed. This occurs - // when a conversation first becomes encrypted, and when the keys are - // renegotiated within an encrypted conversation. - NewKeys - // SMPSecretNeeded indicates that the peer has started an - // authentication and that we need to supply a secret. Call SMPQuestion - // to get the optional, human readable challenge and then Authenticate - // to supply the matching secret. - SMPSecretNeeded - // SMPComplete indicates that an authentication completed. The identity - // of the peer has now been confirmed. - SMPComplete - // SMPFailed indicates that an authentication failed. - SMPFailed - // ConversationEnded indicates that the peer ended the secure - // conversation. - ConversationEnded -) - -// QueryMessage can be sent to a peer to start an OTR conversation. -var QueryMessage = "?OTRv2?" - -// ErrorPrefix can be used to make an OTR error by appending an error message -// to it. -var ErrorPrefix = "?OTR Error:" - -var ( - fragmentPartSeparator = []byte(",") - fragmentPrefix = []byte("?OTR,") - msgPrefix = []byte("?OTR:") - queryMarker = []byte("?OTR") -) - -// isQuery attempts to parse an OTR query from msg and returns the greatest -// common version, or 0 if msg is not an OTR query. -func isQuery(msg []byte) (greatestCommonVersion int) { - pos := bytes.Index(msg, queryMarker) - if pos == -1 { - return 0 - } - for i, c := range msg[pos+len(queryMarker):] { - if i == 0 { - if c == '?' { - // Indicates support for version 1, but we don't - // implement that. - continue - } - - if c != 'v' { - // Invalid message - return 0 - } - - continue - } - - if c == '?' { - // End of message - return - } - - if c == ' ' || c == '\t' { - // Probably an invalid message - return 0 - } - - if c == '2' { - greatestCommonVersion = 2 - } - } - - return 0 -} - -const ( - statePlaintext = iota - stateEncrypted - stateFinished -) - -const ( - authStateNone = iota - authStateAwaitingDHKey - authStateAwaitingRevealSig - authStateAwaitingSig -) - -const ( - msgTypeDHCommit = 2 - msgTypeData = 3 - msgTypeDHKey = 10 - msgTypeRevealSig = 17 - msgTypeSig = 18 -) - -const ( - // If the requested fragment size is less than this, it will be ignored. - minFragmentSize = 18 - // Messages are padded to a multiple of this number of bytes. - paddingGranularity = 256 - // The number of bytes in a Diffie-Hellman private value (320-bits). - dhPrivateBytes = 40 - // The number of bytes needed to represent an element of the DSA - // subgroup (160-bits). - dsaSubgroupBytes = 20 - // The number of bytes of the MAC that are sent on the wire (160-bits). - macPrefixBytes = 20 -) - -// These are the global, common group parameters for OTR. -var ( - p *big.Int // group prime - g *big.Int // group generator - q *big.Int // group order - pMinus2 *big.Int -) - -func init() { - p, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF", 16) - q, _ = new(big.Int).SetString("7FFFFFFFFFFFFFFFE487ED5110B4611A62633145C06E0E68948127044533E63A0105DF531D89CD9128A5043CC71A026EF7CA8CD9E69D218D98158536F92F8A1BA7F09AB6B6A8E122F242DABB312F3F637A262174D31BF6B585FFAE5B7A035BF6F71C35FDAD44CFD2D74F9208BE258FF324943328F6722D9EE1003E5C50B1DF82CC6D241B0E2AE9CD348B1FD47E9267AFC1B2AE91EE51D6CB0E3179AB1042A95DCF6A9483B84B4B36B3861AA7255E4C0278BA36046511B993FFFFFFFFFFFFFFFF", 16) - g = new(big.Int).SetInt64(2) - pMinus2 = new(big.Int).Sub(p, g) -} - -// Conversation represents a relation with a peer. The zero value is a valid -// Conversation, although PrivateKey must be set. -// -// When communicating with a peer, all inbound messages should be passed to -// Conversation.Receive and all outbound messages to Conversation.Send. The -// Conversation will take care of maintaining the encryption state and -// negotiating encryption as needed. -type Conversation struct { - // PrivateKey contains the private key to use to sign key exchanges. - PrivateKey *PrivateKey - - // Rand can be set to override the entropy source. Otherwise, - // crypto/rand will be used. - Rand io.Reader - // If FragmentSize is set, all messages produced by Receive and Send - // will be fragmented into messages of, at most, this number of bytes. - FragmentSize int - - // Once Receive has returned NewKeys once, the following fields are - // valid. - SSID [8]byte - TheirPublicKey PublicKey - - state, authState int - - r [16]byte - x, y *big.Int - gx, gy *big.Int - gxBytes []byte - digest [sha256.Size]byte - - revealKeys, sigKeys akeKeys - - myKeyId uint32 - myCurrentDHPub *big.Int - myCurrentDHPriv *big.Int - myLastDHPub *big.Int - myLastDHPriv *big.Int - - theirKeyId uint32 - theirCurrentDHPub *big.Int - theirLastDHPub *big.Int - - keySlots [4]keySlot - - myCounter [8]byte - theirLastCtr [8]byte - oldMACs []byte - - k, n int // fragment state - frag []byte - - smp smpState -} - -// A keySlot contains key material for a specific (their keyid, my keyid) pair. -type keySlot struct { - // used is true if this slot is valid. If false, it's free for reuse. - used bool - theirKeyId uint32 - myKeyId uint32 - sendAESKey, recvAESKey []byte - sendMACKey, recvMACKey []byte - theirLastCtr [8]byte -} - -// akeKeys are generated during key exchange. There's one set for the reveal -// signature message and another for the signature message. In the protocol -// spec the latter are indicated with a prime mark. -type akeKeys struct { - c [16]byte - m1, m2 [32]byte -} - -func (c *Conversation) rand() io.Reader { - if c.Rand != nil { - return c.Rand - } - return rand.Reader -} - -func (c *Conversation) randMPI(buf []byte) *big.Int { - _, err := io.ReadFull(c.rand(), buf) - if err != nil { - panic("otr: short read from random source") - } - - return new(big.Int).SetBytes(buf) -} - -// tlv represents the type-length value from the protocol. -type tlv struct { - typ, length uint16 - data []byte -} - -const ( - tlvTypePadding = 0 - tlvTypeDisconnected = 1 - tlvTypeSMP1 = 2 - tlvTypeSMP2 = 3 - tlvTypeSMP3 = 4 - tlvTypeSMP4 = 5 - tlvTypeSMPAbort = 6 - tlvTypeSMP1WithQuestion = 7 -) - -// Receive handles a message from a peer. It returns a human readable message, -// an indicator of whether that message was encrypted, a hint about the -// encryption state and zero or more messages to send back to the peer. -// These messages do not need to be passed to Send before transmission. -func (c *Conversation) Receive(in []byte) (out []byte, encrypted bool, change SecurityChange, toSend [][]byte, err error) { - if bytes.HasPrefix(in, fragmentPrefix) { - in, err = c.processFragment(in) - if in == nil || err != nil { - return - } - } - - if bytes.HasPrefix(in, msgPrefix) && in[len(in)-1] == '.' { - in = in[len(msgPrefix) : len(in)-1] - } else if version := isQuery(in); version > 0 { - c.authState = authStateAwaitingDHKey - c.reset() - toSend = c.encode(c.generateDHCommit()) - return - } else { - // plaintext message - out = in - return - } - - msg := make([]byte, base64.StdEncoding.DecodedLen(len(in))) - msgLen, err := base64.StdEncoding.Decode(msg, in) - if err != nil { - err = errors.New("otr: invalid base64 encoding in message") - return - } - msg = msg[:msgLen] - - // The first two bytes are the protocol version (2) - if len(msg) < 3 || msg[0] != 0 || msg[1] != 2 { - err = errors.New("otr: invalid OTR message") - return - } - - msgType := int(msg[2]) - msg = msg[3:] - - switch msgType { - case msgTypeDHCommit: - switch c.authState { - case authStateNone: - c.authState = authStateAwaitingRevealSig - if err = c.processDHCommit(msg); err != nil { - return - } - c.reset() - toSend = c.encode(c.generateDHKey()) - return - case authStateAwaitingDHKey: - // This is a 'SYN-crossing'. The greater digest wins. - var cmp int - if cmp, err = c.compareToDHCommit(msg); err != nil { - return - } - if cmp > 0 { - // We win. Retransmit DH commit. - toSend = c.encode(c.serializeDHCommit()) - return - } else { - // They win. We forget about our DH commit. - c.authState = authStateAwaitingRevealSig - if err = c.processDHCommit(msg); err != nil { - return - } - c.reset() - toSend = c.encode(c.generateDHKey()) - return - } - case authStateAwaitingRevealSig: - if err = c.processDHCommit(msg); err != nil { - return - } - toSend = c.encode(c.serializeDHKey()) - case authStateAwaitingSig: - if err = c.processDHCommit(msg); err != nil { - return - } - c.reset() - toSend = c.encode(c.generateDHKey()) - c.authState = authStateAwaitingRevealSig - default: - panic("bad state") - } - case msgTypeDHKey: - switch c.authState { - case authStateAwaitingDHKey: - var isSame bool - if isSame, err = c.processDHKey(msg); err != nil { - return - } - if isSame { - err = errors.New("otr: unexpected duplicate DH key") - return - } - toSend = c.encode(c.generateRevealSig()) - c.authState = authStateAwaitingSig - case authStateAwaitingSig: - var isSame bool - if isSame, err = c.processDHKey(msg); err != nil { - return - } - if isSame { - toSend = c.encode(c.serializeDHKey()) - } - } - case msgTypeRevealSig: - if c.authState != authStateAwaitingRevealSig { - return - } - if err = c.processRevealSig(msg); err != nil { - return - } - toSend = c.encode(c.generateSig()) - c.authState = authStateNone - c.state = stateEncrypted - change = NewKeys - case msgTypeSig: - if c.authState != authStateAwaitingSig { - return - } - if err = c.processSig(msg); err != nil { - return - } - c.authState = authStateNone - c.state = stateEncrypted - change = NewKeys - case msgTypeData: - if c.state != stateEncrypted { - err = errors.New("otr: encrypted message received without encrypted session established") - return - } - var tlvs []tlv - out, tlvs, err = c.processData(msg) - encrypted = true - - EachTLV: - for _, inTLV := range tlvs { - switch inTLV.typ { - case tlvTypeDisconnected: - change = ConversationEnded - c.state = stateFinished - break EachTLV - case tlvTypeSMP1, tlvTypeSMP2, tlvTypeSMP3, tlvTypeSMP4, tlvTypeSMPAbort, tlvTypeSMP1WithQuestion: - var reply tlv - var complete bool - reply, complete, err = c.processSMP(inTLV) - if err == smpSecretMissingError { - err = nil - change = SMPSecretNeeded - c.smp.saved = &inTLV - return - } - if err == smpFailureError { - err = nil - change = SMPFailed - } else if complete { - change = SMPComplete - } - if reply.typ != 0 { - toSend = c.encode(c.generateData(nil, &reply)) - } - break EachTLV - default: - // skip unknown TLVs - } - } - default: - err = errors.New("otr: unknown message type " + strconv.Itoa(msgType)) - } - - return -} - -// Send takes a human readable message from the local user, possibly encrypts -// it and returns zero one or more messages to send to the peer. -func (c *Conversation) Send(msg []byte) ([][]byte, error) { - switch c.state { - case statePlaintext: - return [][]byte{msg}, nil - case stateEncrypted: - return c.encode(c.generateData(msg, nil)), nil - case stateFinished: - return nil, errors.New("otr: cannot send message because secure conversation has finished") - } - - return nil, errors.New("otr: cannot send message in current state") -} - -// SMPQuestion returns the human readable challenge question from the peer. -// It's only valid after Receive has returned SMPSecretNeeded. -func (c *Conversation) SMPQuestion() string { - return c.smp.question -} - -// Authenticate begins an authentication with the peer. Authentication involves -// an optional challenge message and a shared secret. The authentication -// proceeds until either Receive returns SMPComplete, SMPSecretNeeded (which -// indicates that a new authentication is happening and thus this one was -// aborted) or SMPFailed. -func (c *Conversation) Authenticate(question string, mutualSecret []byte) (toSend [][]byte, err error) { - if c.state != stateEncrypted { - err = errors.New("otr: can't authenticate a peer without a secure conversation established") - return - } - - if c.smp.saved != nil { - c.calcSMPSecret(mutualSecret, false /* they started it */) - - var out tlv - var complete bool - out, complete, err = c.processSMP(*c.smp.saved) - if complete { - panic("SMP completed on the first message") - } - c.smp.saved = nil - if out.typ != 0 { - toSend = c.encode(c.generateData(nil, &out)) - } - return - } - - c.calcSMPSecret(mutualSecret, true /* we started it */) - outs := c.startSMP(question) - for _, out := range outs { - toSend = append(toSend, c.encode(c.generateData(nil, &out))...) - } - return -} - -// End ends a secure conversation by generating a termination message for -// the peer and switches to unencrypted communication. -func (c *Conversation) End() (toSend [][]byte) { - switch c.state { - case statePlaintext: - return nil - case stateEncrypted: - c.state = statePlaintext - return c.encode(c.generateData(nil, &tlv{typ: tlvTypeDisconnected})) - case stateFinished: - c.state = statePlaintext - return nil - } - panic("unreachable") -} - -// IsEncrypted returns true if a message passed to Send would be encrypted -// before transmission. This result remains valid until the next call to -// Receive or End, which may change the state of the Conversation. -func (c *Conversation) IsEncrypted() bool { - return c.state == stateEncrypted -} - -var fragmentError = errors.New("otr: invalid OTR fragment") - -// processFragment processes a fragmented OTR message and possibly returns a -// complete message. Fragmented messages look like "?OTR,k,n,msg," where k is -// the fragment number (starting from 1), n is the number of fragments in this -// message and msg is a substring of the base64 encoded message. -func (c *Conversation) processFragment(in []byte) (out []byte, err error) { - in = in[len(fragmentPrefix):] // remove "?OTR," - parts := bytes.Split(in, fragmentPartSeparator) - if len(parts) != 4 || len(parts[3]) != 0 { - return nil, fragmentError - } - - k, err := strconv.Atoi(string(parts[0])) - if err != nil { - return nil, fragmentError - } - - n, err := strconv.Atoi(string(parts[1])) - if err != nil { - return nil, fragmentError - } - - if k < 1 || n < 1 || k > n { - return nil, fragmentError - } - - if k == 1 { - c.frag = append(c.frag[:0], parts[2]...) - c.k, c.n = k, n - } else if n == c.n && k == c.k+1 { - c.frag = append(c.frag, parts[2]...) - c.k++ - } else { - c.frag = c.frag[:0] - c.n, c.k = 0, 0 - } - - if c.n > 0 && c.k == c.n { - c.n, c.k = 0, 0 - return c.frag, nil - } - - return nil, nil -} - -func (c *Conversation) generateDHCommit() []byte { - _, err := io.ReadFull(c.rand(), c.r[:]) - if err != nil { - panic("otr: short read from random source") - } - - var xBytes [dhPrivateBytes]byte - c.x = c.randMPI(xBytes[:]) - c.gx = new(big.Int).Exp(g, c.x, p) - c.gy = nil - c.gxBytes = appendMPI(nil, c.gx) - - h := sha256.New() - h.Write(c.gxBytes) - h.Sum(c.digest[:0]) - - aesCipher, err := aes.NewCipher(c.r[:]) - if err != nil { - panic(err.Error()) - } - - var iv [aes.BlockSize]byte - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(c.gxBytes, c.gxBytes) - - return c.serializeDHCommit() -} - -func (c *Conversation) serializeDHCommit() []byte { - var ret []byte - ret = appendU16(ret, 2) // protocol version - ret = append(ret, msgTypeDHCommit) - ret = appendData(ret, c.gxBytes) - ret = appendData(ret, c.digest[:]) - return ret -} - -func (c *Conversation) processDHCommit(in []byte) error { - var ok1, ok2 bool - c.gxBytes, in, ok1 = getData(in) - digest, in, ok2 := getData(in) - if !ok1 || !ok2 || len(in) > 0 { - return errors.New("otr: corrupt DH commit message") - } - copy(c.digest[:], digest) - return nil -} - -func (c *Conversation) compareToDHCommit(in []byte) (int, error) { - _, in, ok1 := getData(in) - digest, in, ok2 := getData(in) - if !ok1 || !ok2 || len(in) > 0 { - return 0, errors.New("otr: corrupt DH commit message") - } - return bytes.Compare(c.digest[:], digest), nil -} - -func (c *Conversation) generateDHKey() []byte { - var yBytes [dhPrivateBytes]byte - c.y = c.randMPI(yBytes[:]) - c.gy = new(big.Int).Exp(g, c.y, p) - return c.serializeDHKey() -} - -func (c *Conversation) serializeDHKey() []byte { - var ret []byte - ret = appendU16(ret, 2) // protocol version - ret = append(ret, msgTypeDHKey) - ret = appendMPI(ret, c.gy) - return ret -} - -func (c *Conversation) processDHKey(in []byte) (isSame bool, err error) { - gy, in, ok := getMPI(in) - if !ok { - err = errors.New("otr: corrupt DH key message") - return - } - if gy.Cmp(g) < 0 || gy.Cmp(pMinus2) > 0 { - err = errors.New("otr: DH value out of range") - return - } - if c.gy != nil { - isSame = c.gy.Cmp(gy) == 0 - return - } - c.gy = gy - return -} - -func (c *Conversation) generateEncryptedSignature(keys *akeKeys, xFirst bool) ([]byte, []byte) { - var xb []byte - xb = c.PrivateKey.PublicKey.Serialize(xb) - - var verifyData []byte - if xFirst { - verifyData = appendMPI(verifyData, c.gx) - verifyData = appendMPI(verifyData, c.gy) - } else { - verifyData = appendMPI(verifyData, c.gy) - verifyData = appendMPI(verifyData, c.gx) - } - verifyData = append(verifyData, xb...) - verifyData = appendU32(verifyData, c.myKeyId) - - mac := hmac.New(sha256.New, keys.m1[:]) - mac.Write(verifyData) - mb := mac.Sum(nil) - - xb = appendU32(xb, c.myKeyId) - xb = append(xb, c.PrivateKey.Sign(c.rand(), mb)...) - - aesCipher, err := aes.NewCipher(keys.c[:]) - if err != nil { - panic(err.Error()) - } - var iv [aes.BlockSize]byte - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(xb, xb) - - mac = hmac.New(sha256.New, keys.m2[:]) - encryptedSig := appendData(nil, xb) - mac.Write(encryptedSig) - - return encryptedSig, mac.Sum(nil) -} - -func (c *Conversation) generateRevealSig() []byte { - s := new(big.Int).Exp(c.gy, c.x, p) - c.calcAKEKeys(s) - c.myKeyId++ - - encryptedSig, mac := c.generateEncryptedSignature(&c.revealKeys, true /* gx comes first */) - - c.myCurrentDHPub = c.gx - c.myCurrentDHPriv = c.x - c.rotateDHKeys() - incCounter(&c.myCounter) - - var ret []byte - ret = appendU16(ret, 2) - ret = append(ret, msgTypeRevealSig) - ret = appendData(ret, c.r[:]) - ret = append(ret, encryptedSig...) - ret = append(ret, mac[:20]...) - return ret -} - -func (c *Conversation) processEncryptedSig(encryptedSig, theirMAC []byte, keys *akeKeys, xFirst bool) error { - mac := hmac.New(sha256.New, keys.m2[:]) - mac.Write(appendData(nil, encryptedSig)) - myMAC := mac.Sum(nil)[:20] - - if len(myMAC) != len(theirMAC) || subtle.ConstantTimeCompare(myMAC, theirMAC) == 0 { - return errors.New("bad signature MAC in encrypted signature") - } - - aesCipher, err := aes.NewCipher(keys.c[:]) - if err != nil { - panic(err.Error()) - } - var iv [aes.BlockSize]byte - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(encryptedSig, encryptedSig) - - sig := encryptedSig - sig, ok1 := c.TheirPublicKey.Parse(sig) - keyId, sig, ok2 := getU32(sig) - if !ok1 || !ok2 { - return errors.New("otr: corrupt encrypted signature") - } - - var verifyData []byte - if xFirst { - verifyData = appendMPI(verifyData, c.gx) - verifyData = appendMPI(verifyData, c.gy) - } else { - verifyData = appendMPI(verifyData, c.gy) - verifyData = appendMPI(verifyData, c.gx) - } - verifyData = c.TheirPublicKey.Serialize(verifyData) - verifyData = appendU32(verifyData, keyId) - - mac = hmac.New(sha256.New, keys.m1[:]) - mac.Write(verifyData) - mb := mac.Sum(nil) - - sig, ok1 = c.TheirPublicKey.Verify(mb, sig) - if !ok1 { - return errors.New("bad signature in encrypted signature") - } - if len(sig) > 0 { - return errors.New("corrupt encrypted signature") - } - - c.theirKeyId = keyId - zero(c.theirLastCtr[:]) - return nil -} - -func (c *Conversation) processRevealSig(in []byte) error { - r, in, ok1 := getData(in) - encryptedSig, in, ok2 := getData(in) - theirMAC := in - if !ok1 || !ok2 || len(theirMAC) != 20 { - return errors.New("otr: corrupt reveal signature message") - } - - aesCipher, err := aes.NewCipher(r) - if err != nil { - return errors.New("otr: cannot create AES cipher from reveal signature message: " + err.Error()) - } - var iv [aes.BlockSize]byte - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(c.gxBytes, c.gxBytes) - h := sha256.New() - h.Write(c.gxBytes) - digest := h.Sum(nil) - if len(digest) != len(c.digest) || subtle.ConstantTimeCompare(digest, c.digest[:]) == 0 { - return errors.New("otr: bad commit MAC in reveal signature message") - } - var rest []byte - c.gx, rest, ok1 = getMPI(c.gxBytes) - if !ok1 || len(rest) > 0 { - return errors.New("otr: gx corrupt after decryption") - } - if c.gx.Cmp(g) < 0 || c.gx.Cmp(pMinus2) > 0 { - return errors.New("otr: DH value out of range") - } - s := new(big.Int).Exp(c.gx, c.y, p) - c.calcAKEKeys(s) - - if err := c.processEncryptedSig(encryptedSig, theirMAC, &c.revealKeys, true /* gx comes first */); err != nil { - return errors.New("otr: in reveal signature message: " + err.Error()) - } - - c.theirCurrentDHPub = c.gx - c.theirLastDHPub = nil - - return nil -} - -func (c *Conversation) generateSig() []byte { - c.myKeyId++ - - encryptedSig, mac := c.generateEncryptedSignature(&c.sigKeys, false /* gy comes first */) - - c.myCurrentDHPub = c.gy - c.myCurrentDHPriv = c.y - c.rotateDHKeys() - incCounter(&c.myCounter) - - var ret []byte - ret = appendU16(ret, 2) - ret = append(ret, msgTypeSig) - ret = append(ret, encryptedSig...) - ret = append(ret, mac[:macPrefixBytes]...) - return ret -} - -func (c *Conversation) processSig(in []byte) error { - encryptedSig, in, ok1 := getData(in) - theirMAC := in - if !ok1 || len(theirMAC) != macPrefixBytes { - return errors.New("otr: corrupt signature message") - } - - if err := c.processEncryptedSig(encryptedSig, theirMAC, &c.sigKeys, false /* gy comes first */); err != nil { - return errors.New("otr: in signature message: " + err.Error()) - } - - c.theirCurrentDHPub = c.gy - c.theirLastDHPub = nil - - return nil -} - -func (c *Conversation) rotateDHKeys() { - // evict slots using our retired key id - for i := range c.keySlots { - slot := &c.keySlots[i] - if slot.used && slot.myKeyId == c.myKeyId-1 { - slot.used = false - c.oldMACs = append(c.oldMACs, slot.recvMACKey...) - } - } - - c.myLastDHPriv = c.myCurrentDHPriv - c.myLastDHPub = c.myCurrentDHPub - - var xBytes [dhPrivateBytes]byte - c.myCurrentDHPriv = c.randMPI(xBytes[:]) - c.myCurrentDHPub = new(big.Int).Exp(g, c.myCurrentDHPriv, p) - c.myKeyId++ -} - -func (c *Conversation) processData(in []byte) (out []byte, tlvs []tlv, err error) { - origIn := in - flags, in, ok1 := getU8(in) - theirKeyId, in, ok2 := getU32(in) - myKeyId, in, ok3 := getU32(in) - y, in, ok4 := getMPI(in) - counter, in, ok5 := getNBytes(in, 8) - encrypted, in, ok6 := getData(in) - macedData := origIn[:len(origIn)-len(in)] - theirMAC, in, ok7 := getNBytes(in, macPrefixBytes) - _, in, ok8 := getData(in) - if !ok1 || !ok2 || !ok3 || !ok4 || !ok5 || !ok6 || !ok7 || !ok8 || len(in) > 0 { - err = errors.New("otr: corrupt data message") - return - } - - ignoreErrors := flags&1 != 0 - - slot, err := c.calcDataKeys(myKeyId, theirKeyId) - if err != nil { - if ignoreErrors { - err = nil - } - return - } - - mac := hmac.New(sha1.New, slot.recvMACKey) - mac.Write([]byte{0, 2, 3}) - mac.Write(macedData) - myMAC := mac.Sum(nil) - if len(myMAC) != len(theirMAC) || subtle.ConstantTimeCompare(myMAC, theirMAC) == 0 { - if !ignoreErrors { - err = errors.New("otr: bad MAC on data message") - } - return - } - - if bytes.Compare(counter, slot.theirLastCtr[:]) <= 0 { - err = errors.New("otr: counter regressed") - return - } - copy(slot.theirLastCtr[:], counter) - - var iv [aes.BlockSize]byte - copy(iv[:], counter) - aesCipher, err := aes.NewCipher(slot.recvAESKey) - if err != nil { - panic(err.Error()) - } - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(encrypted, encrypted) - decrypted := encrypted - - if myKeyId == c.myKeyId { - c.rotateDHKeys() - } - if theirKeyId == c.theirKeyId { - // evict slots using their retired key id - for i := range c.keySlots { - slot := &c.keySlots[i] - if slot.used && slot.theirKeyId == theirKeyId-1 { - slot.used = false - c.oldMACs = append(c.oldMACs, slot.recvMACKey...) - } - } - - c.theirLastDHPub = c.theirCurrentDHPub - c.theirKeyId++ - c.theirCurrentDHPub = y - } - - if nulPos := bytes.IndexByte(decrypted, 0); nulPos >= 0 { - out = decrypted[:nulPos] - tlvData := decrypted[nulPos+1:] - for len(tlvData) > 0 { - var t tlv - var ok1, ok2, ok3 bool - - t.typ, tlvData, ok1 = getU16(tlvData) - t.length, tlvData, ok2 = getU16(tlvData) - t.data, tlvData, ok3 = getNBytes(tlvData, int(t.length)) - if !ok1 || !ok2 || !ok3 { - err = errors.New("otr: corrupt tlv data") - return - } - tlvs = append(tlvs, t) - } - } else { - out = decrypted - } - - return -} - -func (c *Conversation) generateData(msg []byte, extra *tlv) []byte { - slot, err := c.calcDataKeys(c.myKeyId-1, c.theirKeyId) - if err != nil { - panic("otr: failed to generate sending keys: " + err.Error()) - } - - var plaintext []byte - plaintext = append(plaintext, msg...) - plaintext = append(plaintext, 0) - - padding := paddingGranularity - ((len(plaintext) + 4) % paddingGranularity) - plaintext = appendU16(plaintext, tlvTypePadding) - plaintext = appendU16(plaintext, uint16(padding)) - for i := 0; i < padding; i++ { - plaintext = append(plaintext, 0) - } - - if extra != nil { - plaintext = appendU16(plaintext, extra.typ) - plaintext = appendU16(plaintext, uint16(len(extra.data))) - plaintext = append(plaintext, extra.data...) - } - - encrypted := make([]byte, len(plaintext)) - - var iv [aes.BlockSize]byte - copy(iv[:], c.myCounter[:]) - aesCipher, err := aes.NewCipher(slot.sendAESKey) - if err != nil { - panic(err.Error()) - } - ctr := cipher.NewCTR(aesCipher, iv[:]) - ctr.XORKeyStream(encrypted, plaintext) - - var ret []byte - ret = appendU16(ret, 2) - ret = append(ret, msgTypeData) - ret = append(ret, 0 /* flags */) - ret = appendU32(ret, c.myKeyId-1) - ret = appendU32(ret, c.theirKeyId) - ret = appendMPI(ret, c.myCurrentDHPub) - ret = append(ret, c.myCounter[:]...) - ret = appendData(ret, encrypted) - - mac := hmac.New(sha1.New, slot.sendMACKey) - mac.Write(ret) - ret = append(ret, mac.Sum(nil)[:macPrefixBytes]...) - ret = appendData(ret, c.oldMACs) - c.oldMACs = nil - incCounter(&c.myCounter) - - return ret -} - -func incCounter(counter *[8]byte) { - for i := 7; i >= 0; i-- { - counter[i]++ - if counter[i] > 0 { - break - } - } -} - -// calcDataKeys computes the keys used to encrypt a data message given the key -// IDs. -func (c *Conversation) calcDataKeys(myKeyId, theirKeyId uint32) (slot *keySlot, err error) { - // Check for a cache hit. - for i := range c.keySlots { - slot = &c.keySlots[i] - if slot.used && slot.theirKeyId == theirKeyId && slot.myKeyId == myKeyId { - return - } - } - - // Find an empty slot to write into. - slot = nil - for i := range c.keySlots { - if !c.keySlots[i].used { - slot = &c.keySlots[i] - break - } - } - if slot == nil { - return nil, errors.New("otr: internal error: no more key slots") - } - - var myPriv, myPub, theirPub *big.Int - - if myKeyId == c.myKeyId { - myPriv = c.myCurrentDHPriv - myPub = c.myCurrentDHPub - } else if myKeyId == c.myKeyId-1 { - myPriv = c.myLastDHPriv - myPub = c.myLastDHPub - } else { - err = errors.New("otr: peer requested keyid " + strconv.FormatUint(uint64(myKeyId), 10) + " when I'm on " + strconv.FormatUint(uint64(c.myKeyId), 10)) - return - } - - if theirKeyId == c.theirKeyId { - theirPub = c.theirCurrentDHPub - } else if theirKeyId == c.theirKeyId-1 && c.theirLastDHPub != nil { - theirPub = c.theirLastDHPub - } else { - err = errors.New("otr: peer requested keyid " + strconv.FormatUint(uint64(myKeyId), 10) + " when they're on " + strconv.FormatUint(uint64(c.myKeyId), 10)) - return - } - - var sendPrefixByte, recvPrefixByte [1]byte - - if myPub.Cmp(theirPub) > 0 { - // we're the high end - sendPrefixByte[0], recvPrefixByte[0] = 1, 2 - } else { - // we're the low end - sendPrefixByte[0], recvPrefixByte[0] = 2, 1 - } - - s := new(big.Int).Exp(theirPub, myPriv, p) - sBytes := appendMPI(nil, s) - - h := sha1.New() - h.Write(sendPrefixByte[:]) - h.Write(sBytes) - slot.sendAESKey = h.Sum(slot.sendAESKey[:0])[:16] - - h.Reset() - h.Write(slot.sendAESKey) - slot.sendMACKey = h.Sum(slot.sendMACKey[:0]) - - h.Reset() - h.Write(recvPrefixByte[:]) - h.Write(sBytes) - slot.recvAESKey = h.Sum(slot.recvAESKey[:0])[:16] - - h.Reset() - h.Write(slot.recvAESKey) - slot.recvMACKey = h.Sum(slot.recvMACKey[:0]) - - slot.theirKeyId = theirKeyId - slot.myKeyId = myKeyId - slot.used = true - - zero(slot.theirLastCtr[:]) - return -} - -func (c *Conversation) calcAKEKeys(s *big.Int) { - mpi := appendMPI(nil, s) - h := sha256.New() - - var cBytes [32]byte - hashWithPrefix(c.SSID[:], 0, mpi, h) - - hashWithPrefix(cBytes[:], 1, mpi, h) - copy(c.revealKeys.c[:], cBytes[:16]) - copy(c.sigKeys.c[:], cBytes[16:]) - - hashWithPrefix(c.revealKeys.m1[:], 2, mpi, h) - hashWithPrefix(c.revealKeys.m2[:], 3, mpi, h) - hashWithPrefix(c.sigKeys.m1[:], 4, mpi, h) - hashWithPrefix(c.sigKeys.m2[:], 5, mpi, h) -} - -func hashWithPrefix(out []byte, prefix byte, in []byte, h hash.Hash) { - h.Reset() - var p [1]byte - p[0] = prefix - h.Write(p[:]) - h.Write(in) - if len(out) == h.Size() { - h.Sum(out[:0]) - } else { - digest := h.Sum(nil) - copy(out, digest) - } -} - -func (c *Conversation) encode(msg []byte) [][]byte { - b64 := make([]byte, base64.StdEncoding.EncodedLen(len(msg))+len(msgPrefix)+1) - base64.StdEncoding.Encode(b64[len(msgPrefix):], msg) - copy(b64, msgPrefix) - b64[len(b64)-1] = '.' - - if c.FragmentSize < minFragmentSize || len(b64) <= c.FragmentSize { - // We can encode this in a single fragment. - return [][]byte{b64} - } - - // We have to fragment this message. - var ret [][]byte - bytesPerFragment := c.FragmentSize - minFragmentSize - numFragments := (len(b64) + bytesPerFragment) / bytesPerFragment - - for i := 0; i < numFragments; i++ { - frag := []byte("?OTR," + strconv.Itoa(i+1) + "," + strconv.Itoa(numFragments) + ",") - todo := bytesPerFragment - if todo > len(b64) { - todo = len(b64) - } - frag = append(frag, b64[:todo]...) - b64 = b64[todo:] - frag = append(frag, ',') - ret = append(ret, frag) - } - - return ret -} - -func (c *Conversation) reset() { - c.myKeyId = 0 - - for i := range c.keySlots { - c.keySlots[i].used = false - } -} - -type PublicKey struct { - dsa.PublicKey -} - -func (pk *PublicKey) Parse(in []byte) ([]byte, bool) { - var ok bool - var pubKeyType uint16 - - if pubKeyType, in, ok = getU16(in); !ok || pubKeyType != 0 { - return nil, false - } - if pk.P, in, ok = getMPI(in); !ok { - return nil, false - } - if pk.Q, in, ok = getMPI(in); !ok { - return nil, false - } - if pk.G, in, ok = getMPI(in); !ok { - return nil, false - } - if pk.Y, in, ok = getMPI(in); !ok { - return nil, false - } - - return in, true -} - -func (pk *PublicKey) Serialize(in []byte) []byte { - in = appendU16(in, 0) - in = appendMPI(in, pk.P) - in = appendMPI(in, pk.Q) - in = appendMPI(in, pk.G) - in = appendMPI(in, pk.Y) - return in -} - -// Fingerprint returns the 20-byte, binary fingerprint of the PublicKey. -func (pk *PublicKey) Fingerprint() []byte { - b := pk.Serialize(nil) - h := sha1.New() - h.Write(b[2:]) - return h.Sum(nil) -} - -func (pk *PublicKey) Verify(hashed, sig []byte) ([]byte, bool) { - if len(sig) != 2*dsaSubgroupBytes { - return nil, false - } - r := new(big.Int).SetBytes(sig[:dsaSubgroupBytes]) - s := new(big.Int).SetBytes(sig[dsaSubgroupBytes:]) - ok := dsa.Verify(&pk.PublicKey, hashed, r, s) - return sig[dsaSubgroupBytes*2:], ok -} - -type PrivateKey struct { - PublicKey - dsa.PrivateKey -} - -func (priv *PrivateKey) Sign(rand io.Reader, hashed []byte) []byte { - r, s, err := dsa.Sign(rand, &priv.PrivateKey, hashed) - if err != nil { - panic(err.Error()) - } - rBytes := r.Bytes() - sBytes := s.Bytes() - if len(rBytes) > dsaSubgroupBytes || len(sBytes) > dsaSubgroupBytes { - panic("DSA signature too large") - } - - out := make([]byte, 2*dsaSubgroupBytes) - copy(out[dsaSubgroupBytes-len(rBytes):], rBytes) - copy(out[len(out)-len(sBytes):], sBytes) - return out -} - -func (priv *PrivateKey) Serialize(in []byte) []byte { - in = priv.PublicKey.Serialize(in) - in = appendMPI(in, priv.PrivateKey.X) - return in -} - -func (priv *PrivateKey) Parse(in []byte) ([]byte, bool) { - in, ok := priv.PublicKey.Parse(in) - if !ok { - return in, ok - } - priv.PrivateKey.PublicKey = priv.PublicKey.PublicKey - priv.PrivateKey.X, in, ok = getMPI(in) - return in, ok -} - -func (priv *PrivateKey) Generate(rand io.Reader) { - if err := dsa.GenerateParameters(&priv.PrivateKey.PublicKey.Parameters, rand, dsa.L1024N160); err != nil { - panic(err.Error()) - } - if err := dsa.GenerateKey(&priv.PrivateKey, rand); err != nil { - panic(err.Error()) - } - priv.PublicKey.PublicKey = priv.PrivateKey.PublicKey -} - -func notHex(r rune) bool { - if r >= '0' && r <= '9' || - r >= 'a' && r <= 'f' || - r >= 'A' && r <= 'F' { - return false - } - - return true -} - -// Import parses the contents of a libotr private key file. -func (priv *PrivateKey) Import(in []byte) bool { - mpiStart := []byte(" #") - - mpis := make([]*big.Int, 5) - - for i := 0; i < len(mpis); i++ { - start := bytes.Index(in, mpiStart) - if start == -1 { - return false - } - in = in[start+len(mpiStart):] - end := bytes.IndexFunc(in, notHex) - if end == -1 { - return false - } - hexBytes := in[:end] - in = in[end:] - - if len(hexBytes)&1 != 0 { - return false - } - - mpiBytes := make([]byte, len(hexBytes)/2) - if _, err := hex.Decode(mpiBytes, hexBytes); err != nil { - return false - } - - mpis[i] = new(big.Int).SetBytes(mpiBytes) - } - - for _, mpi := range mpis { - if mpi.Sign() <= 0 { - return false - } - } - - priv.PrivateKey.P = mpis[0] - priv.PrivateKey.Q = mpis[1] - priv.PrivateKey.G = mpis[2] - priv.PrivateKey.Y = mpis[3] - priv.PrivateKey.X = mpis[4] - priv.PublicKey.PublicKey = priv.PrivateKey.PublicKey - - a := new(big.Int).Exp(priv.PrivateKey.G, priv.PrivateKey.X, priv.PrivateKey.P) - return a.Cmp(priv.PrivateKey.Y) == 0 -} - -func getU8(in []byte) (uint8, []byte, bool) { - if len(in) < 1 { - return 0, in, false - } - return in[0], in[1:], true -} - -func getU16(in []byte) (uint16, []byte, bool) { - if len(in) < 2 { - return 0, in, false - } - r := uint16(in[0])<<8 | uint16(in[1]) - return r, in[2:], true -} - -func getU32(in []byte) (uint32, []byte, bool) { - if len(in) < 4 { - return 0, in, false - } - r := uint32(in[0])<<24 | uint32(in[1])<<16 | uint32(in[2])<<8 | uint32(in[3]) - return r, in[4:], true -} - -func getMPI(in []byte) (*big.Int, []byte, bool) { - l, in, ok := getU32(in) - if !ok || uint32(len(in)) < l { - return nil, in, false - } - r := new(big.Int).SetBytes(in[:l]) - return r, in[l:], true -} - -func getData(in []byte) ([]byte, []byte, bool) { - l, in, ok := getU32(in) - if !ok || uint32(len(in)) < l { - return nil, in, false - } - return in[:l], in[l:], true -} - -func getNBytes(in []byte, n int) ([]byte, []byte, bool) { - if len(in) < n { - return nil, in, false - } - return in[:n], in[n:], true -} - -func appendU16(out []byte, v uint16) []byte { - out = append(out, byte(v>>8), byte(v)) - return out -} - -func appendU32(out []byte, v uint32) []byte { - out = append(out, byte(v>>24), byte(v>>16), byte(v>>8), byte(v)) - return out -} - -func appendData(out, v []byte) []byte { - out = appendU32(out, uint32(len(v))) - out = append(out, v...) - return out -} - -func appendMPI(out []byte, v *big.Int) []byte { - vBytes := v.Bytes() - out = appendU32(out, uint32(len(vBytes))) - out = append(out, vBytes...) - return out -} - -func appendMPIs(out []byte, mpis ...*big.Int) []byte { - for _, mpi := range mpis { - out = appendMPI(out, mpi) - } - return out -} - -func zero(b []byte) { - for i := range b { - b[i] = 0 - } -} diff --git a/vendor/golang.org/x/crypto/otr/otr_test.go b/vendor/golang.org/x/crypto/otr/otr_test.go deleted file mode 100644 index cfcd062..0000000 --- a/vendor/golang.org/x/crypto/otr/otr_test.go +++ /dev/null @@ -1,470 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package otr - -import ( - "bufio" - "bytes" - "crypto/rand" - "encoding/hex" - "math/big" - "os" - "os/exec" - "testing" -) - -var isQueryTests = []struct { - msg string - expectedVersion int -}{ - {"foo", 0}, - {"?OtR", 0}, - {"?OtR?", 0}, - {"?OTR?", 0}, - {"?OTRv?", 0}, - {"?OTRv1?", 0}, - {"?OTR?v1?", 0}, - {"?OTR?v?", 0}, - {"?OTR?v2?", 2}, - {"?OTRv2?", 2}, - {"?OTRv23?", 2}, - {"?OTRv23 ?", 0}, -} - -func TestIsQuery(t *testing.T) { - for i, test := range isQueryTests { - version := isQuery([]byte(test.msg)) - if version != test.expectedVersion { - t.Errorf("#%d: got %d, want %d", i, version, test.expectedVersion) - } - } -} - -var alicePrivateKeyHex = "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" - -var aliceFingerprintHex = "0bb01c360424522e94ee9c346ce877a1a4288b2f" - -var bobPrivateKeyHex = "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" - -func TestKeySerialization(t *testing.T) { - var priv PrivateKey - alicePrivateKey, _ := hex.DecodeString(alicePrivateKeyHex) - rest, ok := priv.Parse(alicePrivateKey) - if !ok { - t.Error("failed to parse private key") - } - if len(rest) > 0 { - t.Error("data remaining after parsing private key") - } - - out := priv.Serialize(nil) - if !bytes.Equal(alicePrivateKey, out) { - t.Errorf("serialization (%x) is not equal to original (%x)", out, alicePrivateKey) - } - - aliceFingerprint, _ := hex.DecodeString(aliceFingerprintHex) - fingerprint := priv.PublicKey.Fingerprint() - if !bytes.Equal(aliceFingerprint, fingerprint) { - t.Errorf("fingerprint (%x) is not equal to expected value (%x)", fingerprint, aliceFingerprint) - } -} - -const libOTRPrivateKey = `(privkeys - (account -(name "foo@example.com") -(protocol prpl-jabber) -(private-key - (dsa - (p #00FC07ABCF0DC916AFF6E9AE47BEF60C7AB9B4D6B2469E436630E36F8A489BE812486A09F30B71224508654940A835301ACC525A4FF133FC152CC53DCC59D65C30A54F1993FE13FE63E5823D4C746DB21B90F9B9C00B49EC7404AB1D929BA7FBA12F2E45C6E0A651689750E8528AB8C031D3561FECEE72EBB4A090D450A9B7A857#) - (q #00997BD266EF7B1F60A5C23F3A741F2AEFD07A2081#) - (g #535E360E8A95EBA46A4F7DE50AD6E9B2A6DB785A66B64EB9F20338D2A3E8FB0E94725848F1AA6CC567CB83A1CC517EC806F2E92EAE71457E80B2210A189B91250779434B41FC8A8873F6DB94BEA7D177F5D59E7E114EE10A49CFD9CEF88AE43387023B672927BA74B04EB6BBB5E57597766A2F9CE3857D7ACE3E1E3BC1FC6F26#) - (y #0AC8670AD767D7A8D9D14CC1AC6744CD7D76F993B77FFD9E39DF01E5A6536EF65E775FCEF2A983E2A19BD6415500F6979715D9FD1257E1FE2B6F5E1E74B333079E7C880D39868462A93454B41877BE62E5EF0A041C2EE9C9E76BD1E12AE25D9628DECB097025DD625EF49C3258A1A3C0FF501E3DC673B76D7BABF349009B6ECF#) - (x #14D0345A3562C480A039E3C72764F72D79043216#) - ) - ) - ) -)` - -func TestParseLibOTRPrivateKey(t *testing.T) { - var priv PrivateKey - - if !priv.Import([]byte(libOTRPrivateKey)) { - t.Fatalf("Failed to import sample private key") - } -} - -func TestSignVerify(t *testing.T) { - var priv PrivateKey - alicePrivateKey, _ := hex.DecodeString(alicePrivateKeyHex) - _, ok := priv.Parse(alicePrivateKey) - if !ok { - t.Error("failed to parse private key") - } - - var msg [32]byte - rand.Reader.Read(msg[:]) - - sig := priv.Sign(rand.Reader, msg[:]) - rest, ok := priv.PublicKey.Verify(msg[:], sig) - if !ok { - t.Errorf("signature (%x) of %x failed to verify", sig, msg[:]) - } else if len(rest) > 0 { - t.Error("signature data remains after verification") - } - - sig[10] ^= 80 - _, ok = priv.PublicKey.Verify(msg[:], sig) - if ok { - t.Errorf("corrupted signature (%x) of %x verified", sig, msg[:]) - } -} - -func setupConversation(t *testing.T) (alice, bob *Conversation) { - alicePrivateKey, _ := hex.DecodeString(alicePrivateKeyHex) - bobPrivateKey, _ := hex.DecodeString(bobPrivateKeyHex) - - alice, bob = new(Conversation), new(Conversation) - - alice.PrivateKey = new(PrivateKey) - bob.PrivateKey = new(PrivateKey) - alice.PrivateKey.Parse(alicePrivateKey) - bob.PrivateKey.Parse(bobPrivateKey) - alice.FragmentSize = 100 - bob.FragmentSize = 100 - - if alice.IsEncrypted() { - t.Error("Alice believes that the conversation is secure before we've started") - } - if bob.IsEncrypted() { - t.Error("Bob believes that the conversation is secure before we've started") - } - - performHandshake(t, alice, bob) - return alice, bob -} - -func performHandshake(t *testing.T, alice, bob *Conversation) { - var alicesMessage, bobsMessage [][]byte - var out []byte - var aliceChange, bobChange SecurityChange - var err error - alicesMessage = append(alicesMessage, []byte(QueryMessage)) - - for round := 0; len(alicesMessage) > 0 || len(bobsMessage) > 0; round++ { - bobsMessage = nil - for i, msg := range alicesMessage { - out, _, bobChange, bobsMessage, err = bob.Receive(msg) - if len(out) > 0 { - t.Errorf("Bob generated output during key exchange, round %d, message %d", round, i) - } - if err != nil { - t.Fatalf("Bob returned an error, round %d, message %d (%x): %s", round, i, msg, err) - } - if len(bobsMessage) > 0 && i != len(alicesMessage)-1 { - t.Errorf("Bob produced output while processing a fragment, round %d, message %d", round, i) - } - } - - alicesMessage = nil - for i, msg := range bobsMessage { - out, _, aliceChange, alicesMessage, err = alice.Receive(msg) - if len(out) > 0 { - t.Errorf("Alice generated output during key exchange, round %d, message %d", round, i) - } - if err != nil { - t.Fatalf("Alice returned an error, round %d, message %d (%x): %s", round, i, msg, err) - } - if len(alicesMessage) > 0 && i != len(bobsMessage)-1 { - t.Errorf("Alice produced output while processing a fragment, round %d, message %d", round, i) - } - } - } - - if aliceChange != NewKeys { - t.Errorf("Alice terminated without signaling new keys") - } - if bobChange != NewKeys { - t.Errorf("Bob terminated without signaling new keys") - } - - if !bytes.Equal(alice.SSID[:], bob.SSID[:]) { - t.Errorf("Session identifiers don't match. Alice has %x, Bob has %x", alice.SSID[:], bob.SSID[:]) - } - - if !alice.IsEncrypted() { - t.Error("Alice doesn't believe that the conversation is secure") - } - if !bob.IsEncrypted() { - t.Error("Bob doesn't believe that the conversation is secure") - } -} - -const ( - firstRoundTrip = iota - subsequentRoundTrip - noMACKeyCheck -) - -func roundTrip(t *testing.T, alice, bob *Conversation, message []byte, macKeyCheck int) { - alicesMessage, err := alice.Send(message) - if err != nil { - t.Errorf("Error from Alice sending message: %s", err) - } - - if len(alice.oldMACs) != 0 { - t.Errorf("Alice has not revealed all MAC keys") - } - - for i, msg := range alicesMessage { - out, encrypted, _, _, err := bob.Receive(msg) - - if err != nil { - t.Errorf("Error generated while processing test message: %s", err.Error()) - } - if len(out) > 0 { - if i != len(alicesMessage)-1 { - t.Fatal("Bob produced a message while processing a fragment of Alice's") - } - if !encrypted { - t.Errorf("Message was not marked as encrypted") - } - if !bytes.Equal(out, message) { - t.Errorf("Message corrupted: got %x, want %x", out, message) - } - } - } - - switch macKeyCheck { - case firstRoundTrip: - if len(bob.oldMACs) != 0 { - t.Errorf("Bob should not have MAC keys to reveal") - } - case subsequentRoundTrip: - if len(bob.oldMACs) != 40 { - t.Errorf("Bob has %d bytes of MAC keys to reveal, but should have 40", len(bob.oldMACs)) - } - } - - bobsMessage, err := bob.Send(message) - if err != nil { - t.Errorf("Error from Bob sending message: %s", err) - } - - if len(bob.oldMACs) != 0 { - t.Errorf("Bob has not revealed all MAC keys") - } - - for i, msg := range bobsMessage { - out, encrypted, _, _, err := alice.Receive(msg) - - if err != nil { - t.Errorf("Error generated while processing test message: %s", err.Error()) - } - if len(out) > 0 { - if i != len(bobsMessage)-1 { - t.Fatal("Alice produced a message while processing a fragment of Bob's") - } - if !encrypted { - t.Errorf("Message was not marked as encrypted") - } - if !bytes.Equal(out, message) { - t.Errorf("Message corrupted: got %x, want %x", out, message) - } - } - } - - switch macKeyCheck { - case firstRoundTrip: - if len(alice.oldMACs) != 20 { - t.Errorf("Alice has %d bytes of MAC keys to reveal, but should have 20", len(alice.oldMACs)) - } - case subsequentRoundTrip: - if len(alice.oldMACs) != 40 { - t.Errorf("Alice has %d bytes of MAC keys to reveal, but should have 40", len(alice.oldMACs)) - } - } -} - -func TestConversation(t *testing.T) { - alice, bob := setupConversation(t) - - var testMessages = [][]byte{ - []byte("hello"), []byte("bye"), - } - - roundTripType := firstRoundTrip - - for _, testMessage := range testMessages { - roundTrip(t, alice, bob, testMessage, roundTripType) - roundTripType = subsequentRoundTrip - } -} - -func TestGoodSMP(t *testing.T) { - var alice, bob Conversation - - alice.smp.secret = new(big.Int).SetInt64(42) - bob.smp.secret = alice.smp.secret - - var alicesMessages, bobsMessages []tlv - var aliceComplete, bobComplete bool - var err error - var out tlv - - alicesMessages = alice.startSMP("") - for round := 0; len(alicesMessages) > 0 || len(bobsMessages) > 0; round++ { - bobsMessages = bobsMessages[:0] - for i, msg := range alicesMessages { - out, bobComplete, err = bob.processSMP(msg) - if err != nil { - t.Errorf("Error from Bob in round %d: %s", round, err) - } - if bobComplete && i != len(alicesMessages)-1 { - t.Errorf("Bob returned a completed signal before processing all of Alice's messages in round %d", round) - } - if out.typ != 0 { - bobsMessages = append(bobsMessages, out) - } - } - - alicesMessages = alicesMessages[:0] - for i, msg := range bobsMessages { - out, aliceComplete, err = alice.processSMP(msg) - if err != nil { - t.Errorf("Error from Alice in round %d: %s", round, err) - } - if aliceComplete && i != len(bobsMessages)-1 { - t.Errorf("Alice returned a completed signal before processing all of Bob's messages in round %d", round) - } - if out.typ != 0 { - alicesMessages = append(alicesMessages, out) - } - } - } - - if !aliceComplete || !bobComplete { - t.Errorf("SMP completed without both sides reporting success: alice: %v, bob: %v\n", aliceComplete, bobComplete) - } -} - -func TestBadSMP(t *testing.T) { - var alice, bob Conversation - - alice.smp.secret = new(big.Int).SetInt64(42) - bob.smp.secret = new(big.Int).SetInt64(43) - - var alicesMessages, bobsMessages []tlv - - alicesMessages = alice.startSMP("") - for round := 0; len(alicesMessages) > 0 || len(bobsMessages) > 0; round++ { - bobsMessages = bobsMessages[:0] - for _, msg := range alicesMessages { - out, complete, _ := bob.processSMP(msg) - if complete { - t.Errorf("Bob signaled completion in round %d", round) - } - if out.typ != 0 { - bobsMessages = append(bobsMessages, out) - } - } - - alicesMessages = alicesMessages[:0] - for _, msg := range bobsMessages { - out, complete, _ := alice.processSMP(msg) - if complete { - t.Errorf("Alice signaled completion in round %d", round) - } - if out.typ != 0 { - alicesMessages = append(alicesMessages, out) - } - } - } -} - -func TestRehandshaking(t *testing.T) { - alice, bob := setupConversation(t) - roundTrip(t, alice, bob, []byte("test"), firstRoundTrip) - roundTrip(t, alice, bob, []byte("test 2"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 3"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 4"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 5"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 6"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 7"), subsequentRoundTrip) - roundTrip(t, alice, bob, []byte("test 8"), subsequentRoundTrip) - performHandshake(t, alice, bob) - roundTrip(t, alice, bob, []byte("test"), noMACKeyCheck) - roundTrip(t, alice, bob, []byte("test 2"), noMACKeyCheck) -} - -func TestAgainstLibOTR(t *testing.T) { - // This test requires otr.c.test to be built as /tmp/a.out. - // If enabled, this tests runs forever performing OTR handshakes in a - // loop. - return - - alicePrivateKey, _ := hex.DecodeString(alicePrivateKeyHex) - var alice Conversation - alice.PrivateKey = new(PrivateKey) - alice.PrivateKey.Parse(alicePrivateKey) - - cmd := exec.Command("/tmp/a.out") - cmd.Stderr = os.Stderr - - out, err := cmd.StdinPipe() - if err != nil { - t.Fatal(err) - } - defer out.Close() - stdout, err := cmd.StdoutPipe() - if err != nil { - t.Fatal(err) - } - in := bufio.NewReader(stdout) - - if err := cmd.Start(); err != nil { - t.Fatal(err) - } - - out.Write([]byte(QueryMessage)) - out.Write([]byte("\n")) - var expectedText = []byte("test message") - - for { - line, isPrefix, err := in.ReadLine() - if isPrefix { - t.Fatal("line from subprocess too long") - } - if err != nil { - t.Fatal(err) - } - text, encrypted, change, alicesMessage, err := alice.Receive(line) - if err != nil { - t.Fatal(err) - } - for _, msg := range alicesMessage { - out.Write(msg) - out.Write([]byte("\n")) - } - if change == NewKeys { - alicesMessage, err := alice.Send([]byte("Go -> libotr test message")) - if err != nil { - t.Fatalf("error sending message: %s", err.Error()) - } else { - for _, msg := range alicesMessage { - out.Write(msg) - out.Write([]byte("\n")) - } - } - } - if len(text) > 0 { - if !bytes.Equal(text, expectedText) { - t.Fatalf("expected %x, but got %x", expectedText, text) - } - if !encrypted { - t.Fatal("message wasn't encrypted") - } - } - } -} diff --git a/vendor/golang.org/x/crypto/otr/smp.go b/vendor/golang.org/x/crypto/otr/smp.go deleted file mode 100644 index dc6de4e..0000000 --- a/vendor/golang.org/x/crypto/otr/smp.go +++ /dev/null @@ -1,572 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// This file implements the Socialist Millionaires Protocol as described in -// http://www.cypherpunks.ca/otr/Protocol-v2-3.1.0.html. The protocol -// specification is required in order to understand this code and, where -// possible, the variable names in the code match up with the spec. - -package otr - -import ( - "bytes" - "crypto/sha256" - "errors" - "hash" - "math/big" -) - -type smpFailure string - -func (s smpFailure) Error() string { - return string(s) -} - -var smpFailureError = smpFailure("otr: SMP protocol failed") -var smpSecretMissingError = smpFailure("otr: mutual secret needed") - -const smpVersion = 1 - -const ( - smpState1 = iota - smpState2 - smpState3 - smpState4 -) - -type smpState struct { - state int - a2, a3, b2, b3, pb, qb *big.Int - g2a, g3a *big.Int - g2, g3 *big.Int - g3b, papb, qaqb, ra *big.Int - saved *tlv - secret *big.Int - question string -} - -func (c *Conversation) startSMP(question string) (tlvs []tlv) { - if c.smp.state != smpState1 { - tlvs = append(tlvs, c.generateSMPAbort()) - } - tlvs = append(tlvs, c.generateSMP1(question)) - c.smp.question = "" - c.smp.state = smpState2 - return -} - -func (c *Conversation) resetSMP() { - c.smp.state = smpState1 - c.smp.secret = nil - c.smp.question = "" -} - -func (c *Conversation) processSMP(in tlv) (out tlv, complete bool, err error) { - data := in.data - - switch in.typ { - case tlvTypeSMPAbort: - if c.smp.state != smpState1 { - err = smpFailureError - } - c.resetSMP() - return - case tlvTypeSMP1WithQuestion: - // We preprocess this into a SMP1 message. - nulPos := bytes.IndexByte(data, 0) - if nulPos == -1 { - err = errors.New("otr: SMP message with question didn't contain a NUL byte") - return - } - c.smp.question = string(data[:nulPos]) - data = data[nulPos+1:] - } - - numMPIs, data, ok := getU32(data) - if !ok || numMPIs > 20 { - err = errors.New("otr: corrupt SMP message") - return - } - - mpis := make([]*big.Int, numMPIs) - for i := range mpis { - var ok bool - mpis[i], data, ok = getMPI(data) - if !ok { - err = errors.New("otr: corrupt SMP message") - return - } - } - - switch in.typ { - case tlvTypeSMP1, tlvTypeSMP1WithQuestion: - if c.smp.state != smpState1 { - c.resetSMP() - out = c.generateSMPAbort() - return - } - if c.smp.secret == nil { - err = smpSecretMissingError - return - } - if err = c.processSMP1(mpis); err != nil { - return - } - c.smp.state = smpState3 - out = c.generateSMP2() - case tlvTypeSMP2: - if c.smp.state != smpState2 { - c.resetSMP() - out = c.generateSMPAbort() - return - } - if out, err = c.processSMP2(mpis); err != nil { - out = c.generateSMPAbort() - return - } - c.smp.state = smpState4 - case tlvTypeSMP3: - if c.smp.state != smpState3 { - c.resetSMP() - out = c.generateSMPAbort() - return - } - if out, err = c.processSMP3(mpis); err != nil { - return - } - c.smp.state = smpState1 - c.smp.secret = nil - complete = true - case tlvTypeSMP4: - if c.smp.state != smpState4 { - c.resetSMP() - out = c.generateSMPAbort() - return - } - if err = c.processSMP4(mpis); err != nil { - out = c.generateSMPAbort() - return - } - c.smp.state = smpState1 - c.smp.secret = nil - complete = true - default: - panic("unknown SMP message") - } - - return -} - -func (c *Conversation) calcSMPSecret(mutualSecret []byte, weStarted bool) { - h := sha256.New() - h.Write([]byte{smpVersion}) - if weStarted { - h.Write(c.PrivateKey.PublicKey.Fingerprint()) - h.Write(c.TheirPublicKey.Fingerprint()) - } else { - h.Write(c.TheirPublicKey.Fingerprint()) - h.Write(c.PrivateKey.PublicKey.Fingerprint()) - } - h.Write(c.SSID[:]) - h.Write(mutualSecret) - c.smp.secret = new(big.Int).SetBytes(h.Sum(nil)) -} - -func (c *Conversation) generateSMP1(question string) tlv { - var randBuf [16]byte - c.smp.a2 = c.randMPI(randBuf[:]) - c.smp.a3 = c.randMPI(randBuf[:]) - g2a := new(big.Int).Exp(g, c.smp.a2, p) - g3a := new(big.Int).Exp(g, c.smp.a3, p) - h := sha256.New() - - r2 := c.randMPI(randBuf[:]) - r := new(big.Int).Exp(g, r2, p) - c2 := new(big.Int).SetBytes(hashMPIs(h, 1, r)) - d2 := new(big.Int).Mul(c.smp.a2, c2) - d2.Sub(r2, d2) - d2.Mod(d2, q) - if d2.Sign() < 0 { - d2.Add(d2, q) - } - - r3 := c.randMPI(randBuf[:]) - r.Exp(g, r3, p) - c3 := new(big.Int).SetBytes(hashMPIs(h, 2, r)) - d3 := new(big.Int).Mul(c.smp.a3, c3) - d3.Sub(r3, d3) - d3.Mod(d3, q) - if d3.Sign() < 0 { - d3.Add(d3, q) - } - - var ret tlv - if len(question) > 0 { - ret.typ = tlvTypeSMP1WithQuestion - ret.data = append(ret.data, question...) - ret.data = append(ret.data, 0) - } else { - ret.typ = tlvTypeSMP1 - } - ret.data = appendU32(ret.data, 6) - ret.data = appendMPIs(ret.data, g2a, c2, d2, g3a, c3, d3) - return ret -} - -func (c *Conversation) processSMP1(mpis []*big.Int) error { - if len(mpis) != 6 { - return errors.New("otr: incorrect number of arguments in SMP1 message") - } - g2a := mpis[0] - c2 := mpis[1] - d2 := mpis[2] - g3a := mpis[3] - c3 := mpis[4] - d3 := mpis[5] - h := sha256.New() - - r := new(big.Int).Exp(g, d2, p) - s := new(big.Int).Exp(g2a, c2, p) - r.Mul(r, s) - r.Mod(r, p) - t := new(big.Int).SetBytes(hashMPIs(h, 1, r)) - if c2.Cmp(t) != 0 { - return errors.New("otr: ZKP c2 incorrect in SMP1 message") - } - r.Exp(g, d3, p) - s.Exp(g3a, c3, p) - r.Mul(r, s) - r.Mod(r, p) - t.SetBytes(hashMPIs(h, 2, r)) - if c3.Cmp(t) != 0 { - return errors.New("otr: ZKP c3 incorrect in SMP1 message") - } - - c.smp.g2a = g2a - c.smp.g3a = g3a - return nil -} - -func (c *Conversation) generateSMP2() tlv { - var randBuf [16]byte - b2 := c.randMPI(randBuf[:]) - c.smp.b3 = c.randMPI(randBuf[:]) - r2 := c.randMPI(randBuf[:]) - r3 := c.randMPI(randBuf[:]) - r4 := c.randMPI(randBuf[:]) - r5 := c.randMPI(randBuf[:]) - r6 := c.randMPI(randBuf[:]) - - g2b := new(big.Int).Exp(g, b2, p) - g3b := new(big.Int).Exp(g, c.smp.b3, p) - - r := new(big.Int).Exp(g, r2, p) - h := sha256.New() - c2 := new(big.Int).SetBytes(hashMPIs(h, 3, r)) - d2 := new(big.Int).Mul(b2, c2) - d2.Sub(r2, d2) - d2.Mod(d2, q) - if d2.Sign() < 0 { - d2.Add(d2, q) - } - - r.Exp(g, r3, p) - c3 := new(big.Int).SetBytes(hashMPIs(h, 4, r)) - d3 := new(big.Int).Mul(c.smp.b3, c3) - d3.Sub(r3, d3) - d3.Mod(d3, q) - if d3.Sign() < 0 { - d3.Add(d3, q) - } - - c.smp.g2 = new(big.Int).Exp(c.smp.g2a, b2, p) - c.smp.g3 = new(big.Int).Exp(c.smp.g3a, c.smp.b3, p) - c.smp.pb = new(big.Int).Exp(c.smp.g3, r4, p) - c.smp.qb = new(big.Int).Exp(g, r4, p) - r.Exp(c.smp.g2, c.smp.secret, p) - c.smp.qb.Mul(c.smp.qb, r) - c.smp.qb.Mod(c.smp.qb, p) - - s := new(big.Int) - s.Exp(c.smp.g2, r6, p) - r.Exp(g, r5, p) - s.Mul(r, s) - s.Mod(s, p) - r.Exp(c.smp.g3, r5, p) - cp := new(big.Int).SetBytes(hashMPIs(h, 5, r, s)) - - // D5 = r5 - r4 cP mod q and D6 = r6 - y cP mod q - - s.Mul(r4, cp) - r.Sub(r5, s) - d5 := new(big.Int).Mod(r, q) - if d5.Sign() < 0 { - d5.Add(d5, q) - } - - s.Mul(c.smp.secret, cp) - r.Sub(r6, s) - d6 := new(big.Int).Mod(r, q) - if d6.Sign() < 0 { - d6.Add(d6, q) - } - - var ret tlv - ret.typ = tlvTypeSMP2 - ret.data = appendU32(ret.data, 11) - ret.data = appendMPIs(ret.data, g2b, c2, d2, g3b, c3, d3, c.smp.pb, c.smp.qb, cp, d5, d6) - return ret -} - -func (c *Conversation) processSMP2(mpis []*big.Int) (out tlv, err error) { - if len(mpis) != 11 { - err = errors.New("otr: incorrect number of arguments in SMP2 message") - return - } - g2b := mpis[0] - c2 := mpis[1] - d2 := mpis[2] - g3b := mpis[3] - c3 := mpis[4] - d3 := mpis[5] - pb := mpis[6] - qb := mpis[7] - cp := mpis[8] - d5 := mpis[9] - d6 := mpis[10] - h := sha256.New() - - r := new(big.Int).Exp(g, d2, p) - s := new(big.Int).Exp(g2b, c2, p) - r.Mul(r, s) - r.Mod(r, p) - s.SetBytes(hashMPIs(h, 3, r)) - if c2.Cmp(s) != 0 { - err = errors.New("otr: ZKP c2 failed in SMP2 message") - return - } - - r.Exp(g, d3, p) - s.Exp(g3b, c3, p) - r.Mul(r, s) - r.Mod(r, p) - s.SetBytes(hashMPIs(h, 4, r)) - if c3.Cmp(s) != 0 { - err = errors.New("otr: ZKP c3 failed in SMP2 message") - return - } - - c.smp.g2 = new(big.Int).Exp(g2b, c.smp.a2, p) - c.smp.g3 = new(big.Int).Exp(g3b, c.smp.a3, p) - - r.Exp(g, d5, p) - s.Exp(c.smp.g2, d6, p) - r.Mul(r, s) - s.Exp(qb, cp, p) - r.Mul(r, s) - r.Mod(r, p) - - s.Exp(c.smp.g3, d5, p) - t := new(big.Int).Exp(pb, cp, p) - s.Mul(s, t) - s.Mod(s, p) - t.SetBytes(hashMPIs(h, 5, s, r)) - if cp.Cmp(t) != 0 { - err = errors.New("otr: ZKP cP failed in SMP2 message") - return - } - - var randBuf [16]byte - r4 := c.randMPI(randBuf[:]) - r5 := c.randMPI(randBuf[:]) - r6 := c.randMPI(randBuf[:]) - r7 := c.randMPI(randBuf[:]) - - pa := new(big.Int).Exp(c.smp.g3, r4, p) - r.Exp(c.smp.g2, c.smp.secret, p) - qa := new(big.Int).Exp(g, r4, p) - qa.Mul(qa, r) - qa.Mod(qa, p) - - r.Exp(g, r5, p) - s.Exp(c.smp.g2, r6, p) - r.Mul(r, s) - r.Mod(r, p) - - s.Exp(c.smp.g3, r5, p) - cp.SetBytes(hashMPIs(h, 6, s, r)) - - r.Mul(r4, cp) - d5 = new(big.Int).Sub(r5, r) - d5.Mod(d5, q) - if d5.Sign() < 0 { - d5.Add(d5, q) - } - - r.Mul(c.smp.secret, cp) - d6 = new(big.Int).Sub(r6, r) - d6.Mod(d6, q) - if d6.Sign() < 0 { - d6.Add(d6, q) - } - - r.ModInverse(qb, p) - qaqb := new(big.Int).Mul(qa, r) - qaqb.Mod(qaqb, p) - - ra := new(big.Int).Exp(qaqb, c.smp.a3, p) - r.Exp(qaqb, r7, p) - s.Exp(g, r7, p) - cr := new(big.Int).SetBytes(hashMPIs(h, 7, s, r)) - - r.Mul(c.smp.a3, cr) - d7 := new(big.Int).Sub(r7, r) - d7.Mod(d7, q) - if d7.Sign() < 0 { - d7.Add(d7, q) - } - - c.smp.g3b = g3b - c.smp.qaqb = qaqb - - r.ModInverse(pb, p) - c.smp.papb = new(big.Int).Mul(pa, r) - c.smp.papb.Mod(c.smp.papb, p) - c.smp.ra = ra - - out.typ = tlvTypeSMP3 - out.data = appendU32(out.data, 8) - out.data = appendMPIs(out.data, pa, qa, cp, d5, d6, ra, cr, d7) - return -} - -func (c *Conversation) processSMP3(mpis []*big.Int) (out tlv, err error) { - if len(mpis) != 8 { - err = errors.New("otr: incorrect number of arguments in SMP3 message") - return - } - pa := mpis[0] - qa := mpis[1] - cp := mpis[2] - d5 := mpis[3] - d6 := mpis[4] - ra := mpis[5] - cr := mpis[6] - d7 := mpis[7] - h := sha256.New() - - r := new(big.Int).Exp(g, d5, p) - s := new(big.Int).Exp(c.smp.g2, d6, p) - r.Mul(r, s) - s.Exp(qa, cp, p) - r.Mul(r, s) - r.Mod(r, p) - - s.Exp(c.smp.g3, d5, p) - t := new(big.Int).Exp(pa, cp, p) - s.Mul(s, t) - s.Mod(s, p) - t.SetBytes(hashMPIs(h, 6, s, r)) - if t.Cmp(cp) != 0 { - err = errors.New("otr: ZKP cP failed in SMP3 message") - return - } - - r.ModInverse(c.smp.qb, p) - qaqb := new(big.Int).Mul(qa, r) - qaqb.Mod(qaqb, p) - - r.Exp(qaqb, d7, p) - s.Exp(ra, cr, p) - r.Mul(r, s) - r.Mod(r, p) - - s.Exp(g, d7, p) - t.Exp(c.smp.g3a, cr, p) - s.Mul(s, t) - s.Mod(s, p) - t.SetBytes(hashMPIs(h, 7, s, r)) - if t.Cmp(cr) != 0 { - err = errors.New("otr: ZKP cR failed in SMP3 message") - return - } - - var randBuf [16]byte - r7 := c.randMPI(randBuf[:]) - rb := new(big.Int).Exp(qaqb, c.smp.b3, p) - - r.Exp(qaqb, r7, p) - s.Exp(g, r7, p) - cr = new(big.Int).SetBytes(hashMPIs(h, 8, s, r)) - - r.Mul(c.smp.b3, cr) - d7 = new(big.Int).Sub(r7, r) - d7.Mod(d7, q) - if d7.Sign() < 0 { - d7.Add(d7, q) - } - - out.typ = tlvTypeSMP4 - out.data = appendU32(out.data, 3) - out.data = appendMPIs(out.data, rb, cr, d7) - - r.ModInverse(c.smp.pb, p) - r.Mul(pa, r) - r.Mod(r, p) - s.Exp(ra, c.smp.b3, p) - if r.Cmp(s) != 0 { - err = smpFailureError - } - - return -} - -func (c *Conversation) processSMP4(mpis []*big.Int) error { - if len(mpis) != 3 { - return errors.New("otr: incorrect number of arguments in SMP4 message") - } - rb := mpis[0] - cr := mpis[1] - d7 := mpis[2] - h := sha256.New() - - r := new(big.Int).Exp(c.smp.qaqb, d7, p) - s := new(big.Int).Exp(rb, cr, p) - r.Mul(r, s) - r.Mod(r, p) - - s.Exp(g, d7, p) - t := new(big.Int).Exp(c.smp.g3b, cr, p) - s.Mul(s, t) - s.Mod(s, p) - t.SetBytes(hashMPIs(h, 8, s, r)) - if t.Cmp(cr) != 0 { - return errors.New("otr: ZKP cR failed in SMP4 message") - } - - r.Exp(rb, c.smp.a3, p) - if r.Cmp(c.smp.papb) != 0 { - return smpFailureError - } - - return nil -} - -func (c *Conversation) generateSMPAbort() tlv { - return tlv{typ: tlvTypeSMPAbort} -} - -func hashMPIs(h hash.Hash, magic byte, mpis ...*big.Int) []byte { - if h != nil { - h.Reset() - } else { - h = sha256.New() - } - - h.Write([]byte{magic}) - for _, mpi := range mpis { - h.Write(appendMPI(nil, mpi)) - } - return h.Sum(nil) -} |