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Merge pull request #219 from rolandshoemaker/caa 

Fix CAA parsing
This commit is contained in:
Miek Gieben 2015-06-19 08:20:59 +01:00
parent db86274360 52647ae7a7
commit 65752c4214
6 changed files with 148 additions and 28 deletions
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2
README.md
View File

@ -118,6 +118,7 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
* 6605 - ECDSA
* 6725 - IANA Registry Update
* 6742 - ILNP DNS
* 6844 - CAA record
* 6891 - EDNS0 update
* 6895 - DNS IANA considerations
* 6975 - Algorithm Understanding in DNSSEC
@ -138,6 +139,5 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
* privatekey.Precompute() when signing?
* Last remaining RRs: APL, ATMA, A6 and NXT and IPSECKEY;
* Missing in parsing: ISDN, UNSPEC, ATMA;
* CAA parsing is broken;
* NSEC(3) cover/match/closest enclose;
* Replies with TC bit are not parsed to the end;

3
dns_test.go
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@ -429,9 +429,6 @@ func TestToRFC3597(t *testing.T) {
func TestNoRdataPack(t *testing.T) {
data := make([]byte, 1024)
for typ, fn := range typeToRR {
if typ == TypeCAA {
continue // TODO(miek): known omission
}
r := fn()
*r.Header() = RR_Header{Name: "miek.nl.", Rrtype: typ, Class: ClassINET, Ttl: 3600}
_, err := PackRR(r, data, 0, nil, false)

43
msg.go
View File

@ -543,6 +543,36 @@ func packTxtString(s string, msg []byte, offset int, tmp []byte) (int, error) {
return offset, nil
}
func packOctetString(s string, msg []byte, offset int, tmp []byte) (int, error) {
if offset >= len(msg) {
return offset, ErrBuf
}
bs := tmp[:len(s)]
copy(bs, s)
for i := 0; i < len(bs); i++ {
if len(msg) <= offset {
return offset, ErrBuf
}
if bs[i] == '\\' {
i++
if i == len(bs) {
break
}
// check for \DDD
if i+2 < len(bs) && isDigit(bs[i]) && isDigit(bs[i+1]) && isDigit(bs[i+2]) {
msg[offset] = dddToByte(bs[i:])
i += 2
} else {
msg[offset] = bs[i]
}
} else {
msg[offset] = bs[i]
}
offset++
}
return offset, nil
}
func unpackTxt(msg []byte, offset, rdend int) ([]string, int, error) {
var err error
var ss []string
@ -890,6 +920,12 @@ func packStructValue(val reflect.Value, msg []byte, off int, compression map[str
// length of string. String is RAW (not encoded in hex, nor base64)
copy(msg[off:off+len(s)], s)
off += len(s)
case `dns:"octet"`:
bytesTmp := make([]byte, 0)
off, err = packOctetString(fv.String(), msg, off, bytesTmp)
if err != nil {
return lenmsg, err
}
case `dns:"txt"`:
fallthrough
case "":
@ -1254,6 +1290,13 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, err er
switch val.Type().Field(i).Tag {
default:
return lenmsg, &Error{"bad tag unpacking string: " + val.Type().Field(i).Tag.Get("dns")}
case `dns:"octet"`:
strend := lenrd
if strend > lenmsg {
return lenmsg, &Error{err: "overflow unpacking octet"}
}
s = string(msg[off:strend])
off = strend
case `dns:"hex"`:
hexend := lenrd
if val.FieldByName("Hdr").FieldByName("Rrtype").Uint() == uint64(TypeHIP) {

22
parse_test.go
View File

@ -1455,3 +1455,25 @@ func TestParseHINFO(t *testing.T) {
}
}
}
func TestParseCAA(t *testing.T) {
lt := map[string]string{
"example.net. CAA 0 issue \"symantec.com\"": "example.net.\t3600\tIN\tCAA\t0 issue \"symantec.com\"",
"example.net. CAA 0 issuewild \"symantec.com; stuff\"": "example.net.\t3600\tIN\tCAA\t0 issuewild \"symantec.com; stuff\"",
"example.net. CAA 128 tbs \"critical\"": "example.net.\t3600\tIN\tCAA\t128 tbs \"critical\"",
"example.net. CAA 2 auth \"0>09\\006\\010+\\006\\001\\004\\001\\214y\\002\\003\\001\\006\\009`\\134H\\001e\\003\\004\\002\\001\\004 y\\209\\012\\221r\\220\\156Q\\218\\150\\150{\\166\\245:\\231\\182%\\157:\\133\\179}\\1923r\\238\\151\\255\\128q\\145\\002\\001\\000\"": "example.net.\t3600\tIN\tCAA\t2 auth \"0>09\\006\\010+\\006\\001\\004\\001\\214y\\002\\003\\001\\006\\009`\\134H\\001e\\003\\004\\002\\001\\004 y\\209\\012\\221r\\220\\156Q\\218\\150\\150{\\166\\245:\\231\\182%\\157:\\133\\179}\\1923r\\238\\151\\255\\128q\\145\\002\\001\\000\"",
"example.net. TYPE257 0 issue \"symantec.com\"": "example.net.\t3600\tIN\tCAA\t0 issue \"symantec.com\"",
}
for i, o := range lt {
rr, err := NewRR(i)
if err != nil {
t.Error("failed to parse RR: ", err)
continue
}
if rr.String() != o {
t.Errorf("`%s' should be equal to\n`%s', but is `%s'", i, o, rr.String())
} else {
t.Logf("RR is OK: `%s'", rr.String())
}
}
}

72
types.go
View File

@ -501,6 +501,34 @@ func sprintName(s string) string {
return string(dst)
}
func sprintCAAValue(s string) string {
src := []byte(s)
dst := make([]byte, 0, len(src))
dst = append(dst, '"')
for i := 0; i < len(src); {
if i+1 < len(src) && src[i] == '\\' && src[i+1] == '.' {
dst = append(dst, src[i:i+2]...)
i += 2
} else {
b, n := nextByte(src, i)
if n == 0 {
i++ // dangling back slash
} else if b == '.' {
dst = append(dst, b)
} else {
if b < ' ' || b > '~' {
dst = appendByte(dst, b)
} else {
dst = append(dst, b)
}
}
i += n
}
}
dst = append(dst, '"')
return string(dst)
}
func sprintTxt(txt []string) string {
var out []byte
for i, s := range txt {
@ -543,21 +571,24 @@ func appendTXTStringByte(s []byte, b byte) []byte {
return append(s, '\\', b)
}
if b < ' ' || b > '~' {
var buf [3]byte
bufs := strconv.AppendInt(buf[:0], int64(b), 10)
s = append(s, '\\')
for i := 0; i < 3-len(bufs); i++ {
s = append(s, '0')
}
for _, r := range bufs {
s = append(s, r)
}
return s
return appendByte(s, b)
}
return append(s, b)
}
func appendByte(s []byte, b byte) []byte {
var buf [3]byte
bufs := strconv.AppendInt(buf[:0], int64(b), 10)
s = append(s, '\\')
for i := 0; i < 3-len(bufs); i++ {
s = append(s, '0')
}
for _, r := range bufs {
s = append(s, r)
}
return s
}
func nextByte(b []byte, offset int) (byte, int) {
if offset >= len(b) {
return 0, 0
@ -1527,8 +1558,6 @@ func (rr *EUI64) copy() RR { return &EUI64{*rr.Hdr.copyHeader(), rr.Ad
func (rr *EUI64) String() string { return rr.Hdr.String() + euiToString(rr.Address, 64) }
func (rr *EUI64) len() int { return rr.Hdr.len() + 8 }
// Support in incomplete - just handle it as unknown record
/*
type CAA struct {
Hdr RR_Header
Flag uint8
@ -1538,14 +1567,9 @@ type CAA struct {
func (rr *CAA) Header() *RR_Header { return &rr.Hdr }
func (rr *CAA) copy() RR { return &CAA{*rr.Hdr.copyHeader(), rr.Flag, rr.Tag, rr.Value} }
func (rr *CAA) len() int { return rr.Hdr.len() + 1 + len(rr.Tag) + 1 + len(rr.Value) }
func (rr *CAA) len() int { return rr.Hdr.len() + 1 + len(rr.Tag) + len(rr.Value)/2 }
func (rr *CAA) String() string { return rr.Hdr.String() + strconv.Itoa(int(rr.Flag)) + " " + rr.Tag + " " + sprintCAAValue(rr.Value) }
func (rr *CAA) String() string {
s := rr.Hdr.String() + strconv.FormatInt(int64(rr.Flag), 10) + " " + rr.Tag
s += strconv.QuoteToASCII(rr.Value)
return s
}
*/
type UID struct {
Hdr RR_Header
@ -1668,10 +1692,10 @@ func copyIP(ip net.IP) net.IP {
// Map of constructors for each RR type.
var typeToRR = map[uint16]func() RR{
TypeA: func() RR { return new(A) },
TypeAAAA: func() RR { return new(AAAA) },
TypeAFSDB: func() RR { return new(AFSDB) },
// TypeCAA: func() RR { return new(CAA) },
TypeA: func() RR { return new(A) },
TypeAAAA: func() RR { return new(AAAA) },
TypeAFSDB: func() RR { return new(AFSDB) },
TypeCAA: func() RR { return new(CAA) },
TypeCDS: func() RR { return new(CDS) },
TypeCERT: func() RR { return new(CERT) },
TypeCNAME: func() RR { return new(CNAME) },

34
zscan_rr.go
View File

@ -2170,10 +2170,44 @@ func setIPSECKEY(h RR_Header, c chan lex, o, f string) (RR, *ParseError, string)
return rr, nil, c1
}
func setCAA(h RR_Header, c chan lex, o, f string) (RR, *ParseError, string) {
rr := new(CAA)
rr.Hdr = h
l := <-c
if l.length == 0 {
return rr, nil, l.comment
}
i, err := strconv.Atoi(l.token)
if err != nil {
return nil, &ParseError{f, "bad CAA Flag", l}, ""
}
rr.Flag = uint8(i)
<-c // zBlank
l = <-c // zString
if l.value != zString {
return nil, &ParseError{f, "bad CAA Tag", l}, ""
}
rr.Tag = l.token
<-c // zBlank
s, e, c1 := endingToTxtSlice(c, "bad CAA Value", f)
if e != nil {
return nil, e, ""
}
if len(s) > 1 {
return nil, &ParseError{f, "bad CAA Value", l}, ""
} else {
rr.Value = s[0]
}
return rr, nil, c1
}
var typeToparserFunc = map[uint16]parserFunc{
TypeAAAA: parserFunc{setAAAA, false},
TypeAFSDB: parserFunc{setAFSDB, false},
TypeA: parserFunc{setA, false},
TypeCAA: parserFunc{setCAA, true},
TypeCDS: parserFunc{setCDS, true},
TypeCDNSKEY: parserFunc{setCDNSKEY, true},
TypeCERT: parserFunc{setCERT, true},