forked from cerc-io/ipld-eth-server
222 lines
6.9 KiB
Go
222 lines
6.9 KiB
Go
// Copyright 2017 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package qtls
|
|
|
|
import (
|
|
"crypto"
|
|
"crypto/ecdsa"
|
|
"crypto/elliptic"
|
|
"crypto/rsa"
|
|
"encoding/asn1"
|
|
"errors"
|
|
"fmt"
|
|
"hash"
|
|
"io"
|
|
)
|
|
|
|
// pickSignatureAlgorithm selects a signature algorithm that is compatible with
|
|
// the given public key and the list of algorithms from the peer and this side.
|
|
// The lists of signature algorithms (peerSigAlgs and ourSigAlgs) are ignored
|
|
// for tlsVersion < VersionTLS12.
|
|
//
|
|
// The returned SignatureScheme codepoint is only meaningful for TLS 1.2,
|
|
// previous TLS versions have a fixed hash function.
|
|
func pickSignatureAlgorithm(pubkey crypto.PublicKey, peerSigAlgs, ourSigAlgs []SignatureScheme, tlsVersion uint16) (sigAlg SignatureScheme, sigType uint8, hashFunc crypto.Hash, err error) {
|
|
if tlsVersion < VersionTLS12 || len(peerSigAlgs) == 0 {
|
|
// For TLS 1.1 and before, the signature algorithm could not be
|
|
// negotiated and the hash is fixed based on the signature type. For TLS
|
|
// 1.2, if the client didn't send signature_algorithms extension then we
|
|
// can assume that it supports SHA1. See RFC 5246, Section 7.4.1.4.1.
|
|
switch pubkey.(type) {
|
|
case *rsa.PublicKey:
|
|
if tlsVersion < VersionTLS12 {
|
|
return 0, signaturePKCS1v15, crypto.MD5SHA1, nil
|
|
} else {
|
|
return PKCS1WithSHA1, signaturePKCS1v15, crypto.SHA1, nil
|
|
}
|
|
case *ecdsa.PublicKey:
|
|
return ECDSAWithSHA1, signatureECDSA, crypto.SHA1, nil
|
|
default:
|
|
return 0, 0, 0, fmt.Errorf("tls: unsupported public key: %T", pubkey)
|
|
}
|
|
}
|
|
for _, sigAlg := range peerSigAlgs {
|
|
if !isSupportedSignatureAlgorithm(sigAlg, ourSigAlgs) {
|
|
continue
|
|
}
|
|
hashAlg, err := hashFromSignatureScheme(sigAlg)
|
|
if err != nil {
|
|
panic("tls: supported signature algorithm has an unknown hash function")
|
|
}
|
|
sigType := signatureFromSignatureScheme(sigAlg)
|
|
switch pubkey.(type) {
|
|
case *rsa.PublicKey:
|
|
if sigType == signaturePKCS1v15 || sigType == signatureRSAPSS {
|
|
return sigAlg, sigType, hashAlg, nil
|
|
}
|
|
case *ecdsa.PublicKey:
|
|
if sigType == signatureECDSA {
|
|
return sigAlg, sigType, hashAlg, nil
|
|
}
|
|
default:
|
|
return 0, 0, 0, fmt.Errorf("tls: unsupported public key: %T", pubkey)
|
|
}
|
|
}
|
|
return 0, 0, 0, errors.New("tls: peer doesn't support any common signature algorithms")
|
|
}
|
|
|
|
// verifyHandshakeSignature verifies a signature against pre-hashed handshake
|
|
// contents.
|
|
func verifyHandshakeSignature(sigType uint8, pubkey crypto.PublicKey, hashFunc crypto.Hash, digest, sig []byte) error {
|
|
switch sigType {
|
|
case signatureECDSA:
|
|
pubKey, ok := pubkey.(*ecdsa.PublicKey)
|
|
if !ok {
|
|
return errors.New("tls: ECDSA signing requires a ECDSA public key")
|
|
}
|
|
ecdsaSig := new(ecdsaSignature)
|
|
if _, err := asn1.Unmarshal(sig, ecdsaSig); err != nil {
|
|
return err
|
|
}
|
|
if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
|
|
return errors.New("tls: ECDSA signature contained zero or negative values")
|
|
}
|
|
if !ecdsa.Verify(pubKey, digest, ecdsaSig.R, ecdsaSig.S) {
|
|
return errors.New("tls: ECDSA verification failure")
|
|
}
|
|
case signaturePKCS1v15:
|
|
pubKey, ok := pubkey.(*rsa.PublicKey)
|
|
if !ok {
|
|
return errors.New("tls: RSA signing requires a RSA public key")
|
|
}
|
|
if err := rsa.VerifyPKCS1v15(pubKey, hashFunc, digest, sig); err != nil {
|
|
return err
|
|
}
|
|
case signatureRSAPSS:
|
|
pubKey, ok := pubkey.(*rsa.PublicKey)
|
|
if !ok {
|
|
return errors.New("tls: RSA signing requires a RSA public key")
|
|
}
|
|
signOpts := &rsa.PSSOptions{SaltLength: rsa.PSSSaltLengthEqualsHash}
|
|
if err := rsa.VerifyPSS(pubKey, hashFunc, digest, sig, signOpts); err != nil {
|
|
return err
|
|
}
|
|
default:
|
|
return errors.New("tls: unknown signature algorithm")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
const (
|
|
serverSignatureContext = "TLS 1.3, server CertificateVerify\x00"
|
|
clientSignatureContext = "TLS 1.3, client CertificateVerify\x00"
|
|
)
|
|
|
|
var signaturePadding = []byte{
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
|
|
}
|
|
|
|
// writeSignedMessage writes the content to be signed by certificate keys in TLS
|
|
// 1.3 to sigHash. See RFC 8446, Section 4.4.3.
|
|
func writeSignedMessage(sigHash io.Writer, context string, transcript hash.Hash) {
|
|
sigHash.Write(signaturePadding)
|
|
io.WriteString(sigHash, context)
|
|
sigHash.Write(transcript.Sum(nil))
|
|
}
|
|
|
|
// signatureSchemesForCertificate returns the list of supported SignatureSchemes
|
|
// for a given certificate, based on the public key and the protocol version. It
|
|
// does not support the crypto.Decrypter interface, so shouldn't be used on the
|
|
// server side in TLS 1.2 and earlier.
|
|
func signatureSchemesForCertificate(version uint16, cert *Certificate) []SignatureScheme {
|
|
priv, ok := cert.PrivateKey.(crypto.Signer)
|
|
if !ok {
|
|
return nil
|
|
}
|
|
|
|
switch pub := priv.Public().(type) {
|
|
case *ecdsa.PublicKey:
|
|
if version != VersionTLS13 {
|
|
// In TLS 1.2 and earlier, ECDSA algorithms are not
|
|
// constrained to a single curve.
|
|
return []SignatureScheme{
|
|
ECDSAWithP256AndSHA256,
|
|
ECDSAWithP384AndSHA384,
|
|
ECDSAWithP521AndSHA512,
|
|
ECDSAWithSHA1,
|
|
}
|
|
}
|
|
switch pub.Curve {
|
|
case elliptic.P256():
|
|
return []SignatureScheme{ECDSAWithP256AndSHA256}
|
|
case elliptic.P384():
|
|
return []SignatureScheme{ECDSAWithP384AndSHA384}
|
|
case elliptic.P521():
|
|
return []SignatureScheme{ECDSAWithP521AndSHA512}
|
|
default:
|
|
return nil
|
|
}
|
|
case *rsa.PublicKey:
|
|
if version != VersionTLS13 {
|
|
return []SignatureScheme{
|
|
PSSWithSHA256,
|
|
PSSWithSHA384,
|
|
PSSWithSHA512,
|
|
PKCS1WithSHA256,
|
|
PKCS1WithSHA384,
|
|
PKCS1WithSHA512,
|
|
PKCS1WithSHA1,
|
|
}
|
|
}
|
|
// RSA keys with RSA-PSS OID are not supported by crypto/x509.
|
|
return []SignatureScheme{
|
|
PSSWithSHA256,
|
|
PSSWithSHA384,
|
|
PSSWithSHA512,
|
|
}
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// unsupportedCertificateError returns a helpful error for certificates with
|
|
// an unsupported private key.
|
|
func unsupportedCertificateError(cert *Certificate) error {
|
|
switch cert.PrivateKey.(type) {
|
|
case rsa.PrivateKey, ecdsa.PrivateKey:
|
|
return fmt.Errorf("tls: unsupported certificate: private key is %T, expected *%T",
|
|
cert.PrivateKey, cert.PrivateKey)
|
|
}
|
|
|
|
signer, ok := cert.PrivateKey.(crypto.Signer)
|
|
if !ok {
|
|
return fmt.Errorf("tls: certificate private key (%T) does not implement crypto.Signer",
|
|
cert.PrivateKey)
|
|
}
|
|
|
|
switch pub := signer.Public().(type) {
|
|
case *ecdsa.PublicKey:
|
|
switch pub.Curve {
|
|
case elliptic.P256():
|
|
case elliptic.P384():
|
|
case elliptic.P521():
|
|
default:
|
|
return fmt.Errorf("tls: unsupported certificate curve (%s)", pub.Curve.Params().Name)
|
|
}
|
|
case *rsa.PublicKey:
|
|
default:
|
|
return fmt.Errorf("tls: unsupported certificate key (%T)", pub)
|
|
}
|
|
|
|
return fmt.Errorf("tls: internal error: unsupported key (%T)", cert.PrivateKey)
|
|
}
|