Go GOST TLS 1.3 ¶

This is a fork of Go 1.21.4 with:

• crypto/x509 supporting GOST 34.10-2012 X.509 certificates and PKCS#8 private keys
• crypto/tls supporting GOST TLS 1.3

You can build it with the following steps:

• either clone full forked Go repository:

  $ git clone git://git.cypherpunks.ru/gostls13.git
  

  or add it like an additional Git remote:

  $ git remote add gostls13 git://git.cypherpunks.ru/gostls13.git
  $ git fetch gostls13
  

• verify tag’s OpenSSH signature with the following key:

  pub   rsa2048/0x6D3CFF7C76DADF42 2020-09-03
        ADC9 BE5B 198E 8B56 90A8  EC50 6D3C FF7C 76DA DF42
  uid   Go GOST TLS 1.3 <gostls13 at cypherpunks dot ru>
  

  $ gpg --auto-key-locate dane --locate-keys gostls13 at cypherpunks dot ru
  $ gpg --auto-key-locate  wkd --locate-keys gostls13 at cypherpunks dot ru
  

  -----BEGIN PGP PUBLIC KEY BLOCK-----
  
  mQENBF9Qn0cBCADORW5ccCbaFTTSsBqeGoPo66RJd+rM0EOmJWPrG10ZX/3FAZlG
  +5iBqmoUQexuK1+/qnD98ghTH2TCxle0BXPzirjuX/pGHJLaR62ps/2kXl8xypAt
  5/78npdo7TlWMN7Y7gDgz25QzuBVPIQW8esJC+/4r/CSuj6NTPJOyhJs/osToQUQ
  LAvJ0thSA61L8oVMToKQgkpatOV2X5em4naoUgMvsh2RpAcWJbp/C7tWL/q+oneN
  OBoapJmv+Sy2QFNAzx1AEclhb5W3AhCJCqaF3QxAo3tWyUSrQXYwGLHDc4dAoY0U
  cJcQ0QZwoyt0xTLuUfB8FXEgjsKtHLt6TqIHABEBAAG0KUdvIEdPU1QgVExTIDEu
  MyA8Z29zdGxzMTNAY3lwaGVycHVua3MucnU+iQFXBBMBCgBBAhsDDAsKCQ0IDAcL
  AwQBAgcVCgkICwMCBRYCAQMAAh4BAheAFiEErcm+WxmOi1aQqOxQbTz/fHba30IF
  Al9QoLIACgkQbTz/fHba30JJmwgArWo/vmmy95vm48He36mv74n6dqCvPCyZkfL+
  aVNcSRX/08yiwgMznoxSBRzYnXmXyEEaE/nNE7ZJvzl8t2GibMP0nnHwhULayowR
  blSPF+OVIK7OcOUdrnpyYTJqXf2JZH9hoEkur3U48JldBdAJ+qYteF9Jc181UH9i
  Wv+ggHlgIt9R363ail7qUnEDNhuyqt11Kb2m7HvH1jYTXtwSbgsLvH+SCNqzWihH
  9/cw1kIYgOp9Tr1SGZltpiM7o8D0p//2WIAM9F4NCi/YuqVZK/6LNEQxHIZU6jE+
  w3ee/f4dWiEO2N/n5Bbec8MfXb/3LbiX0PVx6PT+pAoWEVyNuYh1BBARCgAdFiEE
  z2DomlkjHnbiY2QirhqBCeSYV+8FAl9QoMoACgkQrhqBCeSYV+/pcQD8C6VmHI8U
  FRE/Qso1G0oEiry+2J9qE8N7VIbrV+njgwYA/R/kkLSkcgRLcIuQVrJPXyjx5IwX
  HHSRAxR0w9sfiB9riHUEEBYKAB0WIQQSrTJonGYNQmln/XXLggVjIQetigUCYuo5
  WAAKCRDLggVjIQetisQxAQCH2OyxJf8hJwSwZ25k8abhhdlDhkoxr0nP3Tre30gc
  vAD/QfX9gHKejMQRVDdnznpgaKUoyFJ7UTQO+W95hZobawc=
  =85EV
  -----END PGP PUBLIC KEY BLOCK-----
  

  It is signed with author’s one.

  $ gpg --verify PUBKEY-SSH.pub.asc
  $ git config gpg.ssh.allowedSignersFile `realpath PUBKEY-SSH.pub`
  $ git tag --verify go1.21.4-gost
  

• checkout go1.21.4-gost tag

  $ git checkout go1.21.4-gost
  

• run GoGOST installer:

  $ ./gogost-install
  

• build Go by ordinary way, for example:

  # $ ./debash # can help on systems without GNU Bash
  $ cd src ; GOROOT_BOOTSTRAP=$HOME/go17 ./all.bash
  

  One dependencies-related unittest will fail.

GOST-related crypto/tls.SignatureSchemes are not enabled by default, simply because it will fail native unittests. crypto/tls also does not provide ability to control TLS 1.3 CipherSuite choice and GOST-related suites are not enabled by default too. You can use tls.GOSTInstall*() functions for enabling all of that.

Pay attention that:

• GOST X.509 certificates uses reversed digest (relatively to native gogost/gost3410 output) during signing, so you should use gogost/gost3410.PrivateKeyReverseDigest crypto.Signer
• GOST TLS 1.3 uses both reversed digest and signature values, so you should use gogost/gost3410.PrivateKeyReverseDigestAndSignature in that case
• GoGOST is quite slow, do not expect high performance

Look at src/crypto/x509/x509_test.go and src/crypto/tls/gost_test.go for example usage.

If you want to always enable GOST TLS 1.3 support, then you can just simply:

$ cat >> src/crypto/tls/gost.go <<EOF
func init() {
    GOSTInstall()
}
EOF

GOST preferred client connection:

serverCAs := x509.NewCertPool()
serverCAs.AddCert(serverCertGOST)
clientConfig := &tls.Config{
    MinVersion:       tls.VersionTLS13,
    MaxVersion:       tls.VersionTLS13,
    CurvePreferences: []tls.CurveID{tls.GOSTCurve256A},
    RootCAs:          serverCAs,
    ServerName:       "server.com",
}
conn, err := tls.Dial("tcp", "...", clientConfig)