diff options
Diffstat (limited to 'vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/tsig.go')
| -rw-r--r-- | vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/tsig.go | 383 |
1 files changed, 0 insertions, 383 deletions
diff --git a/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/tsig.go b/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/tsig.go deleted file mode 100644 index 24013096b..000000000 --- a/vendor/github.com/rsc/letsencrypt/vendor/github.com/miekg/dns/tsig.go +++ /dev/null @@ -1,383 +0,0 @@ -package dns - -import ( - "crypto/hmac" - "crypto/md5" - "crypto/sha1" - "crypto/sha256" - "crypto/sha512" - "encoding/binary" - "encoding/hex" - "hash" - "strconv" - "strings" - "time" -) - -// HMAC hashing codes. These are transmitted as domain names. -const ( - HmacMD5 = "hmac-md5.sig-alg.reg.int." - HmacSHA1 = "hmac-sha1." - HmacSHA256 = "hmac-sha256." - HmacSHA512 = "hmac-sha512." -) - -// TSIG is the RR the holds the transaction signature of a message. -// See RFC 2845 and RFC 4635. -type TSIG struct { - Hdr RR_Header - Algorithm string `dns:"domain-name"` - TimeSigned uint64 `dns:"uint48"` - Fudge uint16 - MACSize uint16 - MAC string `dns:"size-hex:MACSize"` - OrigId uint16 - Error uint16 - OtherLen uint16 - OtherData string `dns:"size-hex:OtherLen"` -} - -// TSIG has no official presentation format, but this will suffice. - -func (rr *TSIG) String() string { - s := "\n;; TSIG PSEUDOSECTION:\n" - s += rr.Hdr.String() + - " " + rr.Algorithm + - " " + tsigTimeToString(rr.TimeSigned) + - " " + strconv.Itoa(int(rr.Fudge)) + - " " + strconv.Itoa(int(rr.MACSize)) + - " " + strings.ToUpper(rr.MAC) + - " " + strconv.Itoa(int(rr.OrigId)) + - " " + strconv.Itoa(int(rr.Error)) + // BIND prints NOERROR - " " + strconv.Itoa(int(rr.OtherLen)) + - " " + rr.OtherData - return s -} - -// The following values must be put in wireformat, so that the MAC can be calculated. -// RFC 2845, section 3.4.2. TSIG Variables. -type tsigWireFmt struct { - // From RR_Header - Name string `dns:"domain-name"` - Class uint16 - Ttl uint32 - // Rdata of the TSIG - Algorithm string `dns:"domain-name"` - TimeSigned uint64 `dns:"uint48"` - Fudge uint16 - // MACSize, MAC and OrigId excluded - Error uint16 - OtherLen uint16 - OtherData string `dns:"size-hex:OtherLen"` -} - -// If we have the MAC use this type to convert it to wiredata. Section 3.4.3. Request MAC -type macWireFmt struct { - MACSize uint16 - MAC string `dns:"size-hex:MACSize"` -} - -// 3.3. Time values used in TSIG calculations -type timerWireFmt struct { - TimeSigned uint64 `dns:"uint48"` - Fudge uint16 -} - -// TsigGenerate fills out the TSIG record attached to the message. -// The message should contain -// a "stub" TSIG RR with the algorithm, key name (owner name of the RR), -// time fudge (defaults to 300 seconds) and the current time -// The TSIG MAC is saved in that Tsig RR. -// When TsigGenerate is called for the first time requestMAC is set to the empty string and -// timersOnly is false. -// If something goes wrong an error is returned, otherwise it is nil. -func TsigGenerate(m *Msg, secret, requestMAC string, timersOnly bool) ([]byte, string, error) { - if m.IsTsig() == nil { - panic("dns: TSIG not last RR in additional") - } - // If we barf here, the caller is to blame - rawsecret, err := fromBase64([]byte(secret)) - if err != nil { - return nil, "", err - } - - rr := m.Extra[len(m.Extra)-1].(*TSIG) - m.Extra = m.Extra[0 : len(m.Extra)-1] // kill the TSIG from the msg - mbuf, err := m.Pack() - if err != nil { - return nil, "", err - } - buf := tsigBuffer(mbuf, rr, requestMAC, timersOnly) - - t := new(TSIG) - var h hash.Hash - switch strings.ToLower(rr.Algorithm) { - case HmacMD5: - h = hmac.New(md5.New, []byte(rawsecret)) - case HmacSHA1: - h = hmac.New(sha1.New, []byte(rawsecret)) - case HmacSHA256: - h = hmac.New(sha256.New, []byte(rawsecret)) - case HmacSHA512: - h = hmac.New(sha512.New, []byte(rawsecret)) - default: - return nil, "", ErrKeyAlg - } - h.Write(buf) - t.MAC = hex.EncodeToString(h.Sum(nil)) - t.MACSize = uint16(len(t.MAC) / 2) // Size is half! - - t.Hdr = RR_Header{Name: rr.Hdr.Name, Rrtype: TypeTSIG, Class: ClassANY, Ttl: 0} - t.Fudge = rr.Fudge - t.TimeSigned = rr.TimeSigned - t.Algorithm = rr.Algorithm - t.OrigId = m.Id - - tbuf := make([]byte, t.len()) - if off, err := PackRR(t, tbuf, 0, nil, false); err == nil { - tbuf = tbuf[:off] // reset to actual size used - } else { - return nil, "", err - } - mbuf = append(mbuf, tbuf...) - // Update the ArCount directly in the buffer. - binary.BigEndian.PutUint16(mbuf[10:], uint16(len(m.Extra)+1)) - - return mbuf, t.MAC, nil -} - -// TsigVerify verifies the TSIG on a message. -// If the signature does not validate err contains the -// error, otherwise it is nil. -func TsigVerify(msg []byte, secret, requestMAC string, timersOnly bool) error { - rawsecret, err := fromBase64([]byte(secret)) - if err != nil { - return err - } - // Strip the TSIG from the incoming msg - stripped, tsig, err := stripTsig(msg) - if err != nil { - return err - } - - msgMAC, err := hex.DecodeString(tsig.MAC) - if err != nil { - return err - } - - buf := tsigBuffer(stripped, tsig, requestMAC, timersOnly) - - // Fudge factor works both ways. A message can arrive before it was signed because - // of clock skew. - now := uint64(time.Now().Unix()) - ti := now - tsig.TimeSigned - if now < tsig.TimeSigned { - ti = tsig.TimeSigned - now - } - if uint64(tsig.Fudge) < ti { - return ErrTime - } - - var h hash.Hash - switch strings.ToLower(tsig.Algorithm) { - case HmacMD5: - h = hmac.New(md5.New, rawsecret) - case HmacSHA1: - h = hmac.New(sha1.New, rawsecret) - case HmacSHA256: - h = hmac.New(sha256.New, rawsecret) - case HmacSHA512: - h = hmac.New(sha512.New, rawsecret) - default: - return ErrKeyAlg - } - h.Write(buf) - if !hmac.Equal(h.Sum(nil), msgMAC) { - return ErrSig - } - return nil -} - -// Create a wiredata buffer for the MAC calculation. -func tsigBuffer(msgbuf []byte, rr *TSIG, requestMAC string, timersOnly bool) []byte { - var buf []byte - if rr.TimeSigned == 0 { - rr.TimeSigned = uint64(time.Now().Unix()) - } - if rr.Fudge == 0 { - rr.Fudge = 300 // Standard (RFC) default. - } - - if requestMAC != "" { - m := new(macWireFmt) - m.MACSize = uint16(len(requestMAC) / 2) - m.MAC = requestMAC - buf = make([]byte, len(requestMAC)) // long enough - n, _ := packMacWire(m, buf) - buf = buf[:n] - } - - tsigvar := make([]byte, DefaultMsgSize) - if timersOnly { - tsig := new(timerWireFmt) - tsig.TimeSigned = rr.TimeSigned - tsig.Fudge = rr.Fudge - n, _ := packTimerWire(tsig, tsigvar) - tsigvar = tsigvar[:n] - } else { - tsig := new(tsigWireFmt) - tsig.Name = strings.ToLower(rr.Hdr.Name) - tsig.Class = ClassANY - tsig.Ttl = rr.Hdr.Ttl - tsig.Algorithm = strings.ToLower(rr.Algorithm) - tsig.TimeSigned = rr.TimeSigned - tsig.Fudge = rr.Fudge - tsig.Error = rr.Error - tsig.OtherLen = rr.OtherLen - tsig.OtherData = rr.OtherData - n, _ := packTsigWire(tsig, tsigvar) - tsigvar = tsigvar[:n] - } - - if requestMAC != "" { - x := append(buf, msgbuf...) - buf = append(x, tsigvar...) - } else { - buf = append(msgbuf, tsigvar...) - } - return buf -} - -// Strip the TSIG from the raw message. -func stripTsig(msg []byte) ([]byte, *TSIG, error) { - // Copied from msg.go's Unpack() Header, but modified. - var ( - dh Header - err error - ) - off, tsigoff := 0, 0 - - if dh, off, err = unpackMsgHdr(msg, off); err != nil { - return nil, nil, err - } - if dh.Arcount == 0 { - return nil, nil, ErrNoSig - } - - // Rcode, see msg.go Unpack() - if int(dh.Bits&0xF) == RcodeNotAuth { - return nil, nil, ErrAuth - } - - for i := 0; i < int(dh.Qdcount); i++ { - _, off, err = unpackQuestion(msg, off) - if err != nil { - return nil, nil, err - } - } - - _, off, err = unpackRRslice(int(dh.Ancount), msg, off) - if err != nil { - return nil, nil, err - } - _, off, err = unpackRRslice(int(dh.Nscount), msg, off) - if err != nil { - return nil, nil, err - } - - rr := new(TSIG) - var extra RR - for i := 0; i < int(dh.Arcount); i++ { - tsigoff = off - extra, off, err = UnpackRR(msg, off) - if err != nil { - return nil, nil, err - } - if extra.Header().Rrtype == TypeTSIG { - rr = extra.(*TSIG) - // Adjust Arcount. - arcount := binary.BigEndian.Uint16(msg[10:]) - binary.BigEndian.PutUint16(msg[10:], arcount-1) - break - } - } - if rr == nil { - return nil, nil, ErrNoSig - } - return msg[:tsigoff], rr, nil -} - -// Translate the TSIG time signed into a date. There is no -// need for RFC1982 calculations as this date is 48 bits. -func tsigTimeToString(t uint64) string { - ti := time.Unix(int64(t), 0).UTC() - return ti.Format("20060102150405") -} - -func packTsigWire(tw *tsigWireFmt, msg []byte) (int, error) { - // copied from zmsg.go TSIG packing - // RR_Header - off, err := PackDomainName(tw.Name, msg, 0, nil, false) - if err != nil { - return off, err - } - off, err = packUint16(tw.Class, msg, off) - if err != nil { - return off, err - } - off, err = packUint32(tw.Ttl, msg, off) - if err != nil { - return off, err - } - - off, err = PackDomainName(tw.Algorithm, msg, off, nil, false) - if err != nil { - return off, err - } - off, err = packUint48(tw.TimeSigned, msg, off) - if err != nil { - return off, err - } - off, err = packUint16(tw.Fudge, msg, off) - if err != nil { - return off, err - } - - off, err = packUint16(tw.Error, msg, off) - if err != nil { - return off, err - } - off, err = packUint16(tw.OtherLen, msg, off) - if err != nil { - return off, err - } - off, err = packStringHex(tw.OtherData, msg, off) - if err != nil { - return off, err - } - return off, nil -} - -func packMacWire(mw *macWireFmt, msg []byte) (int, error) { - off, err := packUint16(mw.MACSize, msg, 0) - if err != nil { - return off, err - } - off, err = packStringHex(mw.MAC, msg, off) - if err != nil { - return off, err - } - return off, nil -} - -func packTimerWire(tw *timerWireFmt, msg []byte) (int, error) { - off, err := packUint48(tw.TimeSigned, msg, 0) - if err != nil { - return off, err - } - off, err = packUint16(tw.Fudge, msg, off) - if err != nil { - return off, err - } - return off, nil -} |