Files
Reseed_Tools/su3/su3.go
2014-12-11 11:24:34 -06:00

245 lines
6.2 KiB
Go

package su3
import (
"bytes"
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/x509"
"encoding/binary"
"fmt"
"strconv"
"time"
)
const (
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 = uint8(0)
CONTENT_TYPE_ROUTER = uint8(1)
CONTENT_TYPE_PLUGIN = uint8(2)
CONTENT_TYPE_RESEED = uint8(3)
CONTENT_TYPE_NEWS = uint8(4)
FILE_TYPE_ZIP = uint8(0)
FILE_TYPE_XML = uint8(1)
FILE_TYPE_HTML = uint8(2)
FILE_TYPE_XMLGZ = uint8(3)
)
var (
MAGIC_BYTES = []byte("I2Psu3")
)
type Su3File struct {
Format uint8
SignatureType uint16
FileType uint8
ContentType uint8
Version []byte
SignerId []byte
Content []byte
Signature []byte
SignedBytes []byte
}
func NewSu3File() *Su3File {
s := Su3File{
Version: []byte(strconv.FormatInt(time.Now().Unix(), 10)),
SignatureType: SIGTYPE_RSA_SHA512,
}
return &s
}
func (s *Su3File) Sign(privkey *rsa.PrivateKey) error {
var hashType crypto.Hash
switch s.SignatureType {
case SIGTYPE_DSA:
hashType = crypto.SHA1
case SIGTYPE_ECDSA_SHA256, SIGTYPE_RSA_SHA256:
hashType = crypto.SHA256
case SIGTYPE_ECDSA_SHA384, SIGTYPE_RSA_SHA384:
hashType = crypto.SHA384
case SIGTYPE_ECDSA_SHA512, SIGTYPE_RSA_SHA512:
hashType = crypto.SHA512
default:
return fmt.Errorf("Unknown signature type")
}
h := hashType.New()
h.Write(s.BodyBytes())
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) BodyBytes() []byte {
buf := new(bytes.Buffer)
var (
skip [1]byte
bigSkip [12]byte
versionLength = uint8(len(s.Version))
signatureLength = uint16(512)
signerIdLength = uint8(len(s.SignerId))
contentLength = uint64(len(s.Content))
)
switch s.SignatureType {
case SIGTYPE_DSA:
signatureLength = uint16(40)
case SIGTYPE_ECDSA_SHA256, SIGTYPE_RSA_SHA256:
signatureLength = uint16(256)
case SIGTYPE_ECDSA_SHA384, SIGTYPE_RSA_SHA384:
signatureLength = uint16(384)
case SIGTYPE_ECDSA_SHA512, SIGTYPE_RSA_SHA512:
signatureLength = uint16(512)
}
// pad the version field
if len(s.Version) < MIN_VERSION_LENGTH {
minBytes := make([]byte, MIN_VERSION_LENGTH)
copy(minBytes, s.Version)
s.Version = minBytes
versionLength = uint8(len(s.Version))
}
binary.Write(buf, binary.BigEndian, MAGIC_BYTES)
binary.Write(buf, binary.BigEndian, skip)
binary.Write(buf, binary.BigEndian, s.Format)
binary.Write(buf, binary.BigEndian, s.SignatureType)
binary.Write(buf, binary.BigEndian, signatureLength)
binary.Write(buf, binary.BigEndian, skip)
binary.Write(buf, binary.BigEndian, versionLength)
binary.Write(buf, binary.BigEndian, skip)
binary.Write(buf, binary.BigEndian, signerIdLength)
binary.Write(buf, binary.BigEndian, contentLength)
binary.Write(buf, binary.BigEndian, skip)
binary.Write(buf, binary.BigEndian, s.FileType)
binary.Write(buf, binary.BigEndian, skip)
binary.Write(buf, binary.BigEndian, s.ContentType)
binary.Write(buf, binary.BigEndian, bigSkip)
binary.Write(buf, binary.BigEndian, s.Version)
binary.Write(buf, binary.BigEndian, s.SignerId)
binary.Write(buf, binary.BigEndian, s.Content)
return buf.Bytes()
}
func (s *Su3File) MarshalBinary() ([]byte, error) {
buf := new(bytes.Buffer)
// write the body
buf.Write(s.BodyBytes())
// append the signature
binary.Write(buf, binary.BigEndian, s.Signature)
return buf.Bytes(), nil
}
func (s *Su3File) UnmarshalBinary(data []byte) error {
var (
r = bytes.NewReader(data)
magic = MAGIC_BYTES
skip [1]byte
bigSkip [12]byte
signatureLength uint16
versionLength uint8
signerIdLength uint8
contentLength uint64
)
binary.Read(r, binary.BigEndian, &magic)
binary.Read(r, binary.BigEndian, &skip)
binary.Read(r, binary.BigEndian, &s.Format)
binary.Read(r, binary.BigEndian, &s.SignatureType)
binary.Read(r, binary.BigEndian, &signatureLength)
binary.Read(r, binary.BigEndian, &skip)
binary.Read(r, binary.BigEndian, &versionLength)
binary.Read(r, binary.BigEndian, &skip)
binary.Read(r, binary.BigEndian, &signerIdLength)
binary.Read(r, binary.BigEndian, &contentLength)
binary.Read(r, binary.BigEndian, &skip)
binary.Read(r, binary.BigEndian, &s.FileType)
binary.Read(r, binary.BigEndian, &skip)
binary.Read(r, binary.BigEndian, &s.ContentType)
binary.Read(r, binary.BigEndian, &bigSkip)
s.Version = make([]byte, versionLength)
s.SignerId = make([]byte, signerIdLength)
s.Content = make([]byte, contentLength)
s.Signature = make([]byte, signatureLength)
binary.Read(r, binary.BigEndian, &s.Version)
binary.Read(r, binary.BigEndian, &s.SignerId)
binary.Read(r, binary.BigEndian, &s.Content)
binary.Read(r, binary.BigEndian, &s.Signature)
return nil
}
func (s *Su3File) VerifySignature(cert *x509.Certificate) error {
var sigAlg x509.SignatureAlgorithm
switch s.SignatureType {
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, s.BodyBytes(), s.Signature)
}
func (s *Su3File) String() string {
var b bytes.Buffer
// header
fmt.Fprintln(&b, "---------------------------")
fmt.Fprintf(&b, "Format: %q\n", s.Format)
fmt.Fprintf(&b, "SignatureType: %q\n", s.SignatureType)
fmt.Fprintf(&b, "FileType: %q\n", s.FileType)
fmt.Fprintf(&b, "ContentType: %q\n", s.ContentType)
fmt.Fprintf(&b, "Version: %q\n", bytes.Trim(s.Version, "\x00"))
fmt.Fprintf(&b, "SignerId: %q\n", s.SignerId)
fmt.Fprintf(&b, "---------------------------")
// content & signature
// fmt.Fprintf(&b, "Content: %q\n", s.Content)
// fmt.Fprintf(&b, "Signature: %q\n", s.Signature)
// fmt.Fprintln(&b, "---------------------------")
return b.String()
}