// sigSerializeUserAttribute calculates the user attribute packet hash
// TODO: clean up & contribute this to go.crypto/openpgp
func (pubkey *Pubkey) sigSerializeUserAttribute(uat *UserAttribute, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
// Get user attribute opaque packet
var uatOpaque *packet.OpaquePacket
if uatOpaque, err = uat.GetOpaquePacket(); err != nil {
return
}
// Get public key opaque packet.
var pkOpaque *packet.OpaquePacket
if pkOpaque, err = pubkey.GetOpaquePacket(); err != nil {
return
}
// RFC 4880, section 5.2.4
// Write the signature prefix and public key contents to hash
pubkey.PublicKey.SerializeSignaturePrefix(h)
h.Write(pkOpaque.Contents)
// V4 certification hash
var buf [5]byte
// User attribute constant
buf[0] = 0xd1
// Big-endian length of user attribute contents
l := len(uatOpaque.Contents)
buf[1] = byte(l >> 24)
buf[2] = byte(l >> 16)
buf[3] = byte(l >> 8)
buf[4] = byte(l)
h.Write(buf[:])
// User attribute contents
h.Write(uatOpaque.Contents)
return
}
func checksumFor(h crypto.Hash, payload []byte) ([]byte, error) {
if !h.Available() {
return nil, errors.New("requested hash function not available")
}
hash := h.New()
hash.Write(payload) // guaranteed not to error
return hash.Sum([]byte{}), nil
}
// userIdSignatureHash returns a Hash of the message that needs to be signed
// to assert that pk is a valid key for id.
func userIdSignatureHash(id string, pk *PublicKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
updateUserIdSignatureHash(id, pk, h)
return
}
func (pkcs1v15 *pkcs1v15Sign) Sign(src []byte, hash crypto.Hash, prk *rsa.PrivateKey) ([]byte, error) {
if !hash.Available() {
return nil, errors.New("unsupport hash type")
}
h := hash.New()
h.Write(src)
hashed := h.Sum(nil)
return rsa.SignPKCS1v15(rand.Reader, prk, hash, hashed)
}
// keySignatureHash returns a Hash of the message that needs to be signed for
// pk to assert a subkey relationship to signed.
func keySignatureHash(pk, signed signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
updateKeySignatureHash(pk, signed, h)
return
}
func checkSignature(c *x509.Certificate, algo x509.SignatureAlgorithm, signed, signature []byte) (err error) {
var hashType crypto.Hash
switch algo {
case x509.SHA1WithRSA, x509.DSAWithSHA1, x509.ECDSAWithSHA1:
hashType = crypto.SHA1
case x509.SHA256WithRSA, x509.DSAWithSHA256, x509.ECDSAWithSHA256:
hashType = crypto.SHA256
case x509.SHA384WithRSA, x509.ECDSAWithSHA384:
hashType = crypto.SHA384
case x509.SHA512WithRSA, x509.ECDSAWithSHA512:
hashType = crypto.SHA512
default:
return x509.ErrUnsupportedAlgorithm
}
if !hashType.Available() {
return x509.ErrUnsupportedAlgorithm
}
h := hashType.New()
h.Write(signed)
digest := h.Sum(nil)
switch pub := c.PublicKey.(type) {
case *rsa.PublicKey:
// the digest is already hashed, so we force a 0 here
return rsa.VerifyPKCS1v15(pub, 0, digest, signature)
case *dsa.PublicKey:
dsaSig := new(dsaSignature)
if _, err := asn1.Unmarshal(signature, dsaSig); err != nil {
return err
}
if dsaSig.R.Sign() <= 0 || dsaSig.S.Sign() <= 0 {
return errors.New("x509: DSA signature contained zero or negative values")
}
if !dsa.Verify(pub, digest, dsaSig.R, dsaSig.S) {
return errors.New("x509: DSA verification failure")
}
return
case *ecdsa.PublicKey:
ecdsaSig := new(ecdsaSignature)
if _, err := asn1.Unmarshal(signature, ecdsaSig); err != nil {
return err
}
if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
return errors.New("x509: ECDSA signature contained zero or negative values")
}
if !ecdsa.Verify(pub, digest, ecdsaSig.R, ecdsaSig.S) {
return errors.New("x509: ECDSA verification failure")
}
return
}
return x509.ErrUnsupportedAlgorithm
}
func (pkcs1v15 *pkcs1v15Sign) Verify(src []byte, sign []byte, hash crypto.Hash, puk *rsa.PublicKey) error {
if !hash.Available() {
return errors.New("unsupport hash type")
}
h := hash.New()
h.Write(src)
hashed := h.Sum(nil)
return rsa.VerifyPKCS1v15(puk, hash, hashed, sign)
}
func NewHashRender(w Responser, hasher crypto.Hash) Render {
if !hasher.Available() {
panic(ErrHash.Error())
}
render := &HashRender{
response: w,
hash: hasher.New(),
}
return render
}
func keyRevocationHash(pk signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
return
}
func (e *Entry) Calculate(h crypto.Hash) (sum []byte, err error) {
if !h.Available() {
return nil, HashUnavailableError{h}
}
hash := h.New()
if file, err := os.Open(e.Filename); err != nil {
return nil, err
} else if _, err = io.Copy(hash, file); err != nil {
return nil, err
}
return hash.Sum(nil), nil
}
// userIdSignatureV3Hash returns a Hash of the message that needs to be signed
// to assert that pk is a valid key for id.
func userIdSignatureV3Hash(id string, pk signingKey, hfn crypto.Hash) (h hash.Hash, err error) {
if !hfn.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hfn.New()
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
h.Write([]byte(id))
return
}
// hashForSignature returns a pair of hashes that can be used to verify a
// signature. The signature may specify that the contents of the signed message
// should be preprocessed (i.e. to normalize line endings). Thus this function
// returns two hashes. The second should be used to hash the message itself and
// performs any needed preprocessing.
func hashForSignature(hashId crypto.Hash, sigType packet.SignatureType) (hash.Hash, hash.Hash, error) {
if !hashId.Available() {
return nil, nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hashId)))
}
h := hashId.New()
switch sigType {
case packet.SigTypeBinary:
return h, h, nil
case packet.SigTypeText:
return h, NewCanonicalTextHash(h), nil
}
return nil, nil, errors.UnsupportedError("unsupported signature type: " + strconv.Itoa(int(sigType)))
}
// NewHmacAuth returns an HmacAuth object that can be used to sign or
// authenticate HTTP requests based on the supplied parameters.
func NewHmacAuth(hash crypto.Hash, key []byte, header string,
headers []string) HmacAuth {
if hash.Available() == false {
var name string
var supported bool
if name, supported = algorithmName[hash]; !supported {
name = "#" + strconv.Itoa(int(hash))
}
panic("hmacauth: hash algorithm " + name + " is unavailable")
}
canonicalHeaders := make([]string, len(headers))
for i, h := range headers {
canonicalHeaders[i] = http.CanonicalHeaderKey(h)
}
return &hmacAuth{hash, key, header, canonicalHeaders}
}
// CheckSignature verifies a signature made by the key on a CSR, such
// as on the CSR itself.
func CheckSignature(csr *x509.CertificateRequest, algo x509.SignatureAlgorithm, signed, signature []byte) error {
var hashType crypto.Hash
switch algo {
case x509.SHA1WithRSA, x509.ECDSAWithSHA1:
hashType = crypto.SHA1
case x509.SHA256WithRSA, x509.ECDSAWithSHA256:
hashType = crypto.SHA256
case x509.SHA384WithRSA, x509.ECDSAWithSHA384:
hashType = crypto.SHA384
case x509.SHA512WithRSA, x509.ECDSAWithSHA512:
hashType = crypto.SHA512
default:
return x509.ErrUnsupportedAlgorithm
}
if !hashType.Available() {
return x509.ErrUnsupportedAlgorithm
}
h := hashType.New()
h.Write(signed)
digest := h.Sum(nil)
switch pub := csr.PublicKey.(type) {
case *rsa.PublicKey:
return rsa.VerifyPKCS1v15(pub, hashType, digest, signature)
case *ecdsa.PublicKey:
ecdsaSig := new(struct{ R, S *big.Int })
if _, err := asn1.Unmarshal(signature, ecdsaSig); err != nil {
return err
}
if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
return errors.New("x509: ECDSA signature contained zero or negative values")
}
if !ecdsa.Verify(pub, digest, ecdsaSig.R, ecdsaSig.S) {
return errors.New("x509: ECDSA verification failure")
}
return nil
}
return x509.ErrUnsupportedAlgorithm
}
// CheckSignature verifies that signature is a valid signature over signed from
// c's public key.
func (c *Certificate) CheckSignature(algo SignatureAlgorithm, signed, signature []byte) (err error) {
var hashType crypto.Hash
switch algo {
case SHA1WithRSA, DSAWithSHA1:
hashType = crypto.SHA1
case SHA256WithRSA, DSAWithSHA256:
hashType = crypto.SHA256
case SHA384WithRSA:
hashType = crypto.SHA384
case SHA512WithRSA:
hashType = crypto.SHA512
default:
return ErrUnsupportedAlgorithm
}
if !hashType.Available() {
return ErrUnsupportedAlgorithm
}
h := hashType.New()
h.Write(signed)
digest := h.Sum(nil)
switch pub := c.PublicKey.(type) {
case *rsa.PublicKey:
return rsa.VerifyPKCS1v15(pub, hashType, digest, signature)
case *dsa.PublicKey:
dsaSig := new(dsaSignature)
if _, err := asn1.Unmarshal(signature, dsaSig); err != nil {
return err
}
if dsaSig.R.Sign() <= 0 || dsaSig.S.Sign() <= 0 {
return errors.New("DSA signature contained zero or negative values")
}
if !dsa.Verify(pub, digest, dsaSig.R, dsaSig.S) {
return errors.New("DSA verification failure")
}
return
}
return ErrUnsupportedAlgorithm
}
// sigSerializeUserAttribute calculates the user attribute packet hash
// TODO: clean up & contribute this to golang.org/x/crypto/openpgp.
func (pubkey *PrimaryKey) sigSerializeUserAttribute(uat *UserAttribute, hashFunc crypto.Hash) (hash.Hash, error) {
if !hashFunc.Available() {
return nil, errgo.Newf("unsupported hash function: %v", hashFunc)
}
h := hashFunc.New()
// Get user attribute opaque packet
uatOpaque, err := uat.opaquePacket()
if err != nil {
return nil, errgo.Mask(err)
}
// Get public key opaque packet.
pkOpaque, err := pubkey.opaquePacket()
if err != nil {
return nil, errgo.Mask(err)
}
// Get public key v4 packet. User attributes not supported pre-v4.
pk, err := pubkey.PublicKey.publicKeyPacket()
if err != nil {
return nil, errgo.Mask(err)
}
// RFC 4880, section 5.2.4
// Write the signature prefix and public key contents to hash
pk.SerializeSignaturePrefix(h)
h.Write(pkOpaque.Contents)
// V4 certification hash
var buf [5]byte
// User attribute constant
buf[0] = 0xd1
// Big-endian length of user attribute contents
l := len(uatOpaque.Contents)
buf[1] = byte(l >> 24)
buf[2] = byte(l >> 16)
buf[3] = byte(l >> 8)
buf[4] = byte(l)
h.Write(buf[:])
// User attribute contents
h.Write(uatOpaque.Contents)
return h, nil
}
// CheckSignature verifies that the signature on c is a valid signature using
// the public key in c.
func (c *CertificateSigningRequest) CheckSignature() (err error) {
var hashType crypto.Hash
switch c.SignatureAlgorithm {
case x509.SHA1WithRSA, x509.ECDSAWithSHA1:
hashType = crypto.SHA1
case x509.SHA256WithRSA, x509.ECDSAWithSHA256:
hashType = crypto.SHA256
case x509.SHA384WithRSA, x509.ECDSAWithSHA384:
hashType = crypto.SHA384
case x509.SHA512WithRSA, x509.ECDSAWithSHA512:
hashType = crypto.SHA512
default:
return x509.ErrUnsupportedAlgorithm
}
if !hashType.Available() {
return x509.ErrUnsupportedAlgorithm
}
h := hashType.New()
h.Write(c.RawCertificationRequestInfo)
digest := h.Sum(nil)
switch pub := c.PublicKey.(type) {
case *rsa.PublicKey:
return rsa.VerifyPKCS1v15(pub, hashType, digest, c.Signature)
case *ecdsa.PublicKey:
ecdsaSig := new(ecdsaSignature)
if _, err := asn1.Unmarshal(c.Signature, ecdsaSig); err != nil {
return err
}
if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
return errors.New("crypto/x509: ECDSA signature contained zero or negative values")
}
if !ecdsa.Verify(pub, digest, ecdsaSig.R, ecdsaSig.S) {
return errors.New("crypto/x509: ECDSA verification failure")
}
return
}
return x509.ErrUnsupportedAlgorithm
}
// userIdSignatureHash returns a Hash of the message that needs to be signed
// to assert that pk is a valid key for id.
func userIdSignatureHash(id string, pk *PublicKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
var buf [5]byte
buf[0] = 0xb4
buf[1] = byte(len(id) >> 24)
buf[2] = byte(len(id) >> 16)
buf[3] = byte(len(id) >> 8)
buf[4] = byte(len(id))
h.Write(buf[:])
h.Write([]byte(id))
return
}
// CreateCertificateSigningRequest creates a new certificate signing request
// based on a template. The following members of template are used: Subject.
//
// The certificate signing request is signed with the parameter priv which is
// the private key of the requester. The public part of the priv key is
// included in the certification request information
//
// The returned slice is the certificate signing request in DER encoding.
//
// The only supported key type are RSA and ECDSA (*rsa.PrivateKey or
// *ecdsa.PrivateKey for priv)
func CreateCertificateSigningRequest(rand io.Reader, template *CertificateSigningRequest, priv interface{}) (csr []byte, err error) {
var publicKeyBytes []byte
var publicKeyAlgorithm pkix.AlgorithmIdentifier
var signatureAlgorithm pkix.AlgorithmIdentifier
var hashFunc crypto.Hash
switch priv := priv.(type) {
case *rsa.PrivateKey:
signatureAlgorithm.Algorithm = oidSignatureSHA1WithRSA
hashFunc = crypto.SHA1
publicKeyBytes, err = asn1.Marshal(rsaPublicKey{
N: priv.PublicKey.N,
E: priv.PublicKey.E,
})
publicKeyAlgorithm.Algorithm = oidPublicKeyRSA
case *ecdsa.PrivateKey:
switch priv.Curve {
case elliptic.P224(), elliptic.P256():
hashFunc = crypto.SHA256
signatureAlgorithm.Algorithm = oidSignatureECDSAWithSHA256
case elliptic.P384():
hashFunc = crypto.SHA384
signatureAlgorithm.Algorithm = oidSignatureECDSAWithSHA384
case elliptic.P521():
hashFunc = crypto.SHA512
signatureAlgorithm.Algorithm = oidSignatureECDSAWithSHA512
default:
return nil, errors.New("x509: unknown elliptic curve")
}
oid, ok := oidFromNamedCurve(priv.PublicKey.Curve)
if !ok {
return nil, errors.New("x509: unknown elliptic curve")
}
publicKeyAlgorithm.Algorithm = oidPublicKeyECDSA
var paramBytes []byte
paramBytes, err = asn1.Marshal(oid)
if err != nil {
return
}
publicKeyAlgorithm.Parameters.FullBytes = paramBytes
publicKeyBytes = elliptic.Marshal(priv.PublicKey.Curve, priv.PublicKey.X, priv.PublicKey.Y)
default:
return nil, errors.New("x509: only RSA private keys supported")
}
if err != nil {
return
}
var asn1Subject []byte
if len(template.RawSubject) > 0 {
asn1Subject = template.RawSubject
} else {
asn1Subject, err = asn1.Marshal(template.Subject.ToRDNSequence())
}
if err != nil {
return
}
encodedPublicKey := asn1.BitString{BitLength: len(publicKeyBytes) * 8, Bytes: publicKeyBytes}
c := certificationRequestInfo{
Version: 0,
Subject: asn1.RawValue{FullBytes: asn1Subject},
SubjectPKInfo: publicKeyInfo{nil, publicKeyAlgorithm, encodedPublicKey},
}
csrInfoContents, err := asn1.Marshal(c)
if err != nil {
return
}
c.Raw = csrInfoContents
if !hashFunc.Available() {
return nil, x509.ErrUnsupportedAlgorithm
}
h := hashFunc.New()
h.Write(csrInfoContents)
digest := h.Sum(nil)
var signature []byte
switch priv := priv.(type) {
case *rsa.PrivateKey:
signature, err = rsa.SignPKCS1v15(rand, priv, hashFunc, digest)
case *ecdsa.PrivateKey:
var r, s *big.Int
if r, s, err = ecdsa.Sign(rand, priv, digest); err == nil {
signature, err = asn1.Marshal(ecdsaSignature{r, s})
}
default:
panic("internal error")
}
if err != nil {
return
}
csr, err = asn1.Marshal(certificateSigningRequest{
nil,
c,
signatureAlgorithm,
asn1.BitString{Bytes: signature, BitLength: len(signature) * 8},
})
return
}
func _chash(h crypto.Hash, src interface{}) string {
if !h.Available() {
panic(fmt.Errorf("Hash %v is not available", h))
}
return _hash(h.New(), src)
}
