Class: OpenSSL::PKey::EC

Inherits:
Object
  • Object
show all
Defined in:
lib/net/ssh/transport/openssl.rb

Overview

This class is originally defined in the OpenSSL module. As needed, methods have been added to it by the Net::SSH module for convenience in dealing with SSH functionality.

Defined Under Namespace

Classes: Point

Constant Summary collapse

CurveNameAlias =
{
  'nistp256' => 'prime256v1',
  'nistp384' => 'secp384r1',
  'nistp521' => 'secp521r1'
}.freeze
CurveNameAliasInv =
{
  'prime256v1' => 'nistp256',
  'secp384r1' => 'nistp384',
  'secp521r1' => 'nistp521'
}.freeze

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.read_keyblob(curve_name_in_type, buffer) ⇒ Object


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# File 'lib/net/ssh/transport/openssl.rb', line 153

def self.read_keyblob(curve_name_in_type, buffer)
  curve_name_in_key = buffer.read_string

  unless curve_name_in_type == curve_name_in_key
    raise Net::SSH::Exception, "curve name mismatched (`#{curve_name_in_key}' with `#{curve_name_in_type}')"
  end

  public_key_oct = buffer.read_string
  begin
    curvename = OpenSSL::PKey::EC::CurveNameAlias[curve_name_in_key]
    group = OpenSSL::PKey::EC::Group.new(curvename)
    point = OpenSSL::PKey::EC::Point.new(group, OpenSSL::BN.new(public_key_oct, 2))
    asn1 = OpenSSL::ASN1::Sequence(
      [
        OpenSSL::ASN1::Sequence(
          [
            OpenSSL::ASN1::ObjectId("id-ecPublicKey"),
            OpenSSL::ASN1::ObjectId(curvename)
          ]
        ),
        OpenSSL::ASN1::BitString(point.to_octet_string(:uncompressed))
      ]
    )

    key = OpenSSL::PKey::EC.new(asn1.to_der)

    return key
  rescue OpenSSL::PKey::ECError
    raise NotImplementedError, "unsupported key type `#{type}'"
  end
end

Instance Method Details

#ssh_do_sign(data, sig_alg = nil) ⇒ Object

Returns the signature for the given data.


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# File 'lib/net/ssh/transport/openssl.rb', line 244

def ssh_do_sign(data, sig_alg = nil)
  digest = digester.digest(data)
  sig = dsa_sign_asn1(digest)
  a1sig = OpenSSL::ASN1.decode(sig)

  sig_r = a1sig.value[0].value
  sig_s = a1sig.value[1].value

  Net::SSH::Buffer.from(:bignum, sig_r, :bignum, sig_s).to_s
end

#ssh_do_verify(sig, data, options = {}) ⇒ Object

Verifies the given signature matches the given data.


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# File 'lib/net/ssh/transport/openssl.rb', line 218

def ssh_do_verify(sig, data, options = {})
  digest = digester.digest(data)
  a1sig = nil

  begin
    sig_r_len = sig[0, 4].unpack('H*')[0].to_i(16)
    sig_l_len = sig[4 + sig_r_len, 4].unpack('H*')[0].to_i(16)

    sig_r = sig[4, sig_r_len].unpack('H*')[0]
    sig_s = sig[4 + sig_r_len + 4, sig_l_len].unpack('H*')[0]

    a1sig = OpenSSL::ASN1::Sequence([
                                      OpenSSL::ASN1::Integer(sig_r.to_i(16)),
                                      OpenSSL::ASN1::Integer(sig_s.to_i(16))
                                    ])
  rescue StandardError
  end

  if a1sig.nil?
    return false
  else
    dsa_verify_asn1(digest, a1sig.to_der)
  end
end

#ssh_typeObject Also known as: ssh_signature_type

Returns the description of this key type used by the SSH2 protocol, like “ecdsa-sha2-nistp256”


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# File 'lib/net/ssh/transport/openssl.rb', line 187

def ssh_type
  "ecdsa-sha2-#{CurveNameAliasInv[group.curve_name]}"
end

#to_blobObject

Converts the key to a blob, according to the SSH2 protocol.


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# File 'lib/net/ssh/transport/openssl.rb', line 210

def to_blob
  @blob ||= Net::SSH::Buffer.from(:string, ssh_type,
                                  :string, CurveNameAliasInv[group.curve_name],
                                  :mstring, public_key.to_bn.to_s(2)).to_s
  @blob
end