Files
reseed-tools/su3/su3.go
2014-12-10 01:10:37 -06:00

320 lines
8.2 KiB
Go

package su3
import (
"archive/zip"
"bytes"
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/binary"
"fmt"
"os"
"strconv"
"time"
)
const (
MAGIC_BYTES = "I2Psu3"
MIN_VERSION_LENGTH = 16
SIGTYPE_DSA = uint16(0)
SIGTYPE_ECDSA_SHA256 = uint16(1)
SIGTYPE_ECDSA_SHA384 = uint16(2)
SIGTYPE_ECDSA_SHA512 = uint16(3)
SIGTYPE_RSA_SHA256 = uint16(4)
SIGTYPE_RSA_SHA384 = uint16(5)
SIGTYPE_RSA_SHA512 = uint16(6)
CONTENT_TYPE_UNKNOWN = uint16(0)
CONTENT_TYPE_ROUTER = uint16(1)
CONTENT_TYPE_PLUGIN = uint16(2)
CONTENT_TYPE_RESEED = uint16(3)
CONTENT_TYPE_NEWS = uint16(4)
FILE_TYPE_ZIP = uint8(0)
FILE_TYPE_XML = uint8(1)
FILE_TYPE_HTML = uint8(2)
FILE_TYPE_XMLGZ = uint8(3)
)
type Su3File struct {
Magic [6]byte
Format uint8
SignatureType uint16
SignatureLength uint16
VersionLength uint8
SignerIdLength uint8
ContentLength uint64
FileType uint8
ContentType uint16
Version []byte
SignerId []byte
Content []byte
Signature []byte
SignedBytes []byte
}
func NewSu3File() *Su3File {
var a [6]byte
copy(a[:], MAGIC_BYTES)
s := Su3File{Magic: a}
s.SetVersion(strconv.FormatInt(time.Now().Unix(), 10))
return &s
}
func (s *Su3File) SetSignerId(signer string) {
s.SignerId = []byte(signer)
s.SignerIdLength = uint8(len(s.SignerId))
}
func (s *Su3File) SetContent(content []byte) {
s.Content = content
s.ContentLength = uint64(len(s.Content))
}
func (s *Su3File) SetVersion(version string) {
s.Version = []byte(version)
minBytes := make([]byte, MIN_VERSION_LENGTH)
if len(s.Version) < len(minBytes) {
copy(minBytes, s.Version)
s.Version = minBytes
}
s.VersionLength = uint8(len(s.Version))
}
func (s *Su3File) Sign(privkey *rsa.PrivateKey, sigType uint16) error {
var hashType crypto.Hash
switch sigType {
// case SIGTYPE_DSA:
// case SIGTYPE_ECDSA_SHA256:
// case SIGTYPE_ECDSA_SHA384:
// case SIGTYPE_ECDSA_SHA512:
// case SIGTYPE_RSA_SHA256:
// case SIGTYPE_RSA_SHA384:
case SIGTYPE_RSA_SHA512:
s.SignatureType = SIGTYPE_RSA_SHA512
s.SignatureLength = uint16(512)
hashType = crypto.SHA512
default:
return fmt.Errorf("Unknown signature type")
}
h := hashType.New()
h.Write(s.ContentBytes())
digest := h.Sum(nil)
sig, err := rsa.SignPKCS1v15(rand.Reader, privkey, 0, digest)
if nil != err {
return err
}
s.Signature = sig
return nil
}
func (s *Su3File) ContentBytes() []byte {
buf := new(bytes.Buffer)
var (
skip [1]byte
bigSkip [12]byte
)
// 0-5
binary.Write(buf, binary.BigEndian, s.Magic)
// 6
binary.Write(buf, binary.BigEndian, skip)
// 7
binary.Write(buf, binary.BigEndian, s.Format)
// 8-9
binary.Write(buf, binary.BigEndian, s.SignatureType)
// 10-11
binary.Write(buf, binary.BigEndian, s.SignatureLength)
// 12
binary.Write(buf, binary.BigEndian, skip)
// 13
binary.Write(buf, binary.BigEndian, s.VersionLength)
// 14
binary.Write(buf, binary.BigEndian, skip)
// 15
binary.Write(buf, binary.BigEndian, s.SignerIdLength)
// 16-23
binary.Write(buf, binary.BigEndian, s.ContentLength)
// 24
binary.Write(buf, binary.BigEndian, skip)
// 25
binary.Write(buf, binary.BigEndian, s.FileType)
// 26
binary.Write(buf, binary.BigEndian, skip)
// 27
binary.Write(buf, binary.BigEndian, s.ContentType)
// 28-39
binary.Write(buf, binary.BigEndian, bigSkip)
// 40-55+ Version, UTF-8 padded with trailing 0x00, 16 bytes minimum, length specified at byte 13. Do not append 0x00 bytes if the length is 16 or more.
binary.Write(buf, binary.BigEndian, s.Version)
// xx+ ID of signer, (e.g. "zzz@mail.i2p") UTF-8, not padded, length specified at byte 15
binary.Write(buf, binary.BigEndian, s.SignerId)
// xx+ Content, length and format specified in header
binary.Write(buf, binary.BigEndian, s.Content)
return buf.Bytes()
}
func (s *Su3File) Bytes() []byte {
buf := new(bytes.Buffer)
buf.Write(s.ContentBytes())
// xx+ Signature, length specified in header, covers everything starting at byte 0
binary.Write(buf, binary.BigEndian, s.Signature)
return buf.Bytes()
}
func (s *Su3File) VerifySignature() error {
return verifySig(s.SignatureType, s.SignerId, s.Signature, s.SignedBytes)
}
func (s *Su3File) String() string {
var b bytes.Buffer
// header
fmt.Fprintln(&b, "---------------------------")
fmt.Fprintf(&b, "Magic: %s\n", s.Magic)
fmt.Fprintf(&b, "Format: %q\n", s.Format)
fmt.Fprintf(&b, "SignatureType: %q\n", s.SignatureType)
fmt.Fprintf(&b, "SignatureLength: %s\n", s.SignatureLength)
fmt.Fprintf(&b, "VersionLength: %s\n", s.VersionLength)
fmt.Fprintf(&b, "SignerIdLength: %s\n", s.SignerIdLength)
fmt.Fprintf(&b, "ContentLength: %s\n", s.ContentLength)
fmt.Fprintf(&b, "FileType: %q\n", s.FileType)
fmt.Fprintf(&b, "ContentType: %q\n", s.ContentType)
// content
fmt.Fprintln(&b, "---------------------------")
fmt.Fprintf(&b, "Version: %q\n", bytes.Trim(s.Version, "\x00"))
fmt.Fprintf(&b, "SignerId: %q\n", s.SignerId)
// fmt.Fprintf(&b, "Content: %q\n", s.Content)
fmt.Fprintf(&b, "Signature: %q\n", s.Signature)
fmt.Fprintln(&b, "---------------------------")
return b.String()
}
func uzipData(c []byte) ([]byte, error) {
input := bytes.NewReader(c)
zipReader, err := zip.NewReader(input, int64(len(c)))
if nil != err {
return nil, err
}
var uncompressed []byte
for _, f := range zipReader.File {
rc, err := f.Open()
if err != nil {
panic(err)
}
uncompressed = append(uncompressed, []byte(f.Name+"\n")...)
rc.Close()
}
return uncompressed, nil
}
func verifySig(sigType uint16, signer, signature, signed []byte) (err error) {
var cert *x509.Certificate
if cert, err = certForSigner(string(signer)); nil != err {
return err
}
var sigAlg x509.SignatureAlgorithm
switch sigType {
case SIGTYPE_DSA:
sigAlg = x509.DSAWithSHA1
case SIGTYPE_ECDSA_SHA256:
sigAlg = x509.ECDSAWithSHA256
case SIGTYPE_ECDSA_SHA384:
sigAlg = x509.ECDSAWithSHA384
case SIGTYPE_ECDSA_SHA512:
sigAlg = x509.ECDSAWithSHA512
case SIGTYPE_RSA_SHA256:
sigAlg = x509.SHA256WithRSA
case SIGTYPE_RSA_SHA384:
sigAlg = x509.SHA384WithRSA
case SIGTYPE_RSA_SHA512:
sigAlg = x509.SHA512WithRSA
default:
return fmt.Errorf("Unsupported signature type.")
}
return checkSignature(cert, sigAlg, signed, signature)
}
func ReadSu3(file *os.File, su3File *Su3File) error {
var (
skip [1]byte
bigSkip [12]byte
)
// 0-5
binary.Read(file, binary.BigEndian, &su3File.Magic)
// 6
binary.Read(file, binary.BigEndian, &skip)
// 7
binary.Read(file, binary.BigEndian, &su3File.Format)
// 8-9
binary.Read(file, binary.BigEndian, &su3File.SignatureType)
// 10-11
binary.Read(file, binary.BigEndian, &su3File.SignatureLength)
// 12
binary.Read(file, binary.BigEndian, &skip)
// 13
binary.Read(file, binary.BigEndian, &su3File.VersionLength)
// 14
binary.Read(file, binary.BigEndian, &skip)
// 15
binary.Read(file, binary.BigEndian, &su3File.SignerIdLength)
// 16-23
binary.Read(file, binary.BigEndian, &su3File.ContentLength)
// 24
binary.Read(file, binary.BigEndian, &skip)
// 25
binary.Read(file, binary.BigEndian, &su3File.FileType)
// 26
binary.Read(file, binary.BigEndian, &skip)
// 27
binary.Read(file, binary.BigEndian, &su3File.ContentType)
// 28-39
binary.Read(file, binary.BigEndian, &bigSkip)
su3File.Version = make([]byte, su3File.VersionLength)
su3File.SignerId = make([]byte, su3File.SignerIdLength)
su3File.Content = make([]byte, su3File.ContentLength)
su3File.Signature = make([]byte, su3File.SignatureLength)
// 40-55+ Version, UTF-8 padded with trailing 0x00, 16 bytes minimum, length specified at byte 13. Do not append 0x00 bytes if the length is 16 or more.
binary.Read(file, binary.BigEndian, su3File.Version)
// xx+ ID of signer, (e.g. "zzz@mail.i2p") UTF-8, not padded, length specified at byte 15
binary.Read(file, binary.BigEndian, su3File.SignerId)
// xx+ Content, length and format specified in header
binary.Read(file, binary.BigEndian, su3File.Content)
// re-read from the beginning to get the signed content
signedEnd, _ := file.Seek(0, 1)
file.Seek(0, 0)
su3File.SignedBytes = make([]byte, signedEnd)
binary.Read(file, binary.BigEndian, su3File.SignedBytes)
// xx+ Signature, length specified in header, covers everything starting at byte 0
binary.Read(file, binary.BigEndian, su3File.Signature)
return nil
}