class HrrRbSsh::Algorithm::Publickey::SshDss

Constants

DIGEST
NAME

Public Class Methods

new(arg, logger: nil) click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 15
def initialize arg, logger: nil
  self.logger = logger
  begin
    new_by_key_str arg
  rescue OpenSSL::PKey::DSAError
    new_by_public_key_blob arg
  end
end

Public Instance Methods

new_by_key_str(key_str) click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 24
def new_by_key_str key_str
  @publickey = OpenSSL::PKey::DSA.new(key_str)
end
new_by_public_key_blob(public_key_blob) click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 28
def new_by_public_key_blob public_key_blob
  public_key_blob_h = PublicKeyBlob.new(logger: logger).decode public_key_blob
  @publickey = OpenSSL::PKey::DSA.new
  if @publickey.respond_to?(:set_pqg)
    @publickey.set_pqg public_key_blob_h[:'p'], public_key_blob_h[:'q'], public_key_blob_h[:'g']
  else
    @publickey.p = public_key_blob_h[:'p']
    @publickey.q = public_key_blob_h[:'q']
    @publickey.g = public_key_blob_h[:'g']
  end
  if @publickey.respond_to?(:set_key)
    @publickey.set_key public_key_blob_h[:'y'], nil
  else
    @publickey.pub_key = public_key_blob_h[:'y']
  end
end
sign(signature_blob) click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 60
def sign signature_blob
  hash = OpenSSL::Digest.digest(self.class::DIGEST, signature_blob)
  sign_der = @publickey.syssign(hash)
  sign_asn1 = OpenSSL::ASN1.decode sign_der
  sign_r = sign_asn1.value[0].value.to_s(2).rjust(20, ["00"].pack("H"))
  sign_s = sign_asn1.value[1].value.to_s(2).rjust(20, ["00"].pack("H"))
  signature_h = {
    :'public key algorithm name' => self.class::NAME,
    :'signature blob'            => (sign_r + sign_s),
  }
  Signature.new(logger: logger).encode signature_h
end
to_pem() click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 45
def to_pem
  @publickey.public_key.to_pem
end
to_public_key_blob() click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 49
def to_public_key_blob
  public_key_blob_h = {
    :'public key algorithm name' => self.class::NAME,
    :'p'                         => @publickey.p.to_i,
    :'q'                         => @publickey.q.to_i,
    :'g'                         => @publickey.g.to_i,
    :'y'                         => @publickey.pub_key.to_i,
  }
  PublicKeyBlob.new(logger: logger).encode public_key_blob_h
end
verify(signature, signature_blob) click to toggle source
# File lib/hrr_rb_ssh/algorithm/publickey/ssh_dss.rb, line 73
def verify signature, signature_blob
  signature_h = Signature.new(logger: logger).decode signature
  sign_r = signature_h[:'signature blob'][ 0, 20]
  sign_s = signature_h[:'signature blob'][20, 20]
  sign_asn1 = OpenSSL::ASN1::Sequence.new(
    [
      OpenSSL::ASN1::Integer.new(OpenSSL::BN.new(sign_r, 2)),
      OpenSSL::ASN1::Integer.new(OpenSSL::BN.new(sign_s, 2)),
    ]
  )
  sign_der = sign_asn1.to_der
  hash = OpenSSL::Digest.digest(self.class::DIGEST, signature_blob)
  signature_h[:'public key algorithm name'] == self.class::NAME && @publickey.sysverify(hash, sign_der)
end