Class: Saro::Dat::DatSignatureKey

Inherits:
Object
  • Object
show all
Defined in:
lib/saro/dat/signature.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(algorithm, signing_key, verifying_key, config = nil) ⇒ DatSignatureKey

Returns a new instance of DatSignatureKey.



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# File 'lib/saro/dat/signature.rb', line 45

def initialize(algorithm, signing_key, verifying_key, config = nil)
  @algorithm = algorithm
  @signing_key = signing_key
  @verifying_key = verifying_key
  @config = config || Saro::Dat.get_signature_config(algorithm)
end

Instance Attribute Details

#algorithm ⇒ Object (readonly)

Returns the value of attribute algorithm.



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# File 'lib/saro/dat/signature.rb', line 43

def algorithm
  @algorithm
end

#signing_key ⇒ Object (readonly)

Returns the value of attribute signing_key.



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# File 'lib/saro/dat/signature.rb', line 43

def signing_key
  @signing_key
end

#verifying_key ⇒ Object (readonly)

Returns the value of attribute verifying_key.



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# File 'lib/saro/dat/signature.rb', line 43

def verifying_key
  @verifying_key
end

Class Method Details

.generate(algorithm) ⇒ Object 



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# File 'lib/saro/dat/signature.rb', line 93

def self.generate(algorithm)
  config = Saro::Dat.get_signature_config(algorithm)
  key = OpenSSL::PKey::EC.generate(config[:curve])
  new(algorithm, key, key, config)
end

.imports(algorithm, format_str) ⇒ Object 



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# File 'lib/saro/dat/signature.rb', line 99

def self.imports(algorithm, format_str)
  config = Saro::Dat.get_signature_config(algorithm)
  parts = format_str.split("~", -1)
  
  unless (1..2).cover?(parts.length)
    raise ArgumentError, "Invalid DAT Signature Key Format: No keys found"
  end

  signing_key = nil
  verifying_key = nil

  if parts[0] && !parts[0].empty?
    d_bytes = Saro::Dat::Util.decode_base64_url(parts[0])
    d_value = OpenSSL::BN.new(d_bytes, 2)
    
    # Handle public key if provided in parts[1] for signing key as well
    v_octet = if parts.length == 2 && parts[1] && !parts[1].empty?
                Saro::Dat::Util.decode_base64_url(parts[1])
              end

    signing_key = create_ec_key(config[:curve], d_value, v_octet)
    verifying_key = signing_key
  end

  if parts.length == 2 && parts[1] && !parts[1].empty?
    unless signing_key
      public_bytes = Saro::Dat::Util.decode_base64_url(parts[1])
      verifying_key = create_ec_key(config[:curve], nil, public_bytes)
    end
  elsif !signing_key
    raise ArgumentError, "Invalid DAT Signature Key Format: No keys found"
  end

  new(algorithm, signing_key, verifying_key, config)
end

Instance Method Details

#exports(option) ⇒ Object 



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# File 'lib/saro/dat/signature.rb', line 135

def exports(option)
  rv_parts = ["", ""]

  if [DatSignatureKeyExportOption::PAIR, DatSignatureKeyExportOption::SIGNING].include?(option)
    if @signing_key&.private_key
      d_value = @signing_key.private_key
      # Ensure fixed length padding
      curve_size = (@signing_key.group.degree + 7) / 8
      d_bytes = d_value.to_s(2).rjust(curve_size, "\x00".b)
      rv_parts[0] = Saro::Dat::Util.encode_base64_url_str(d_bytes)
    elsif option == DatSignatureKeyExportOption::SIGNING
      raise ArgumentError, "Signature key is not supported - verifying only key"
    end
  end

  if [DatSignatureKeyExportOption::PAIR, DatSignatureKeyExportOption::VERIFYING].include?(option)
    # Uncompressed point: 0x04 + R + S
    public_bytes = @verifying_key.public_key.to_octet_string(:uncompressed)
    rv_parts[1] = Saro::Dat::Util.encode_base64_url_str(public_bytes)
  end

  case option
  when DatSignatureKeyExportOption::SIGNING
    rv_parts[0]
  when DatSignatureKeyExportOption::VERIFYING
    "~#{rv_parts[1]}"
  else
    "#{rv_parts[0]}~#{rv_parts[1]}"
  end
end

#has_signing_key? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/saro/dat/signature.rb', line 196

def has_signing_key?
  !@signing_key.nil?
end

#sign(body) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/saro/dat/signature.rb', line 166

def sign(body)
  raise ArgumentError, "Signature key is not supported - verifying only key" unless @signing_key
  body = body.encode('utf-8') if body.is_a?(String) && body.encoding != Encoding::BINARY
  raise ArgumentError, "Sign Error - body is empty" if body.nil? || body.empty?

  digest = OpenSSL::Digest.new(@config[:hash])
  signature_der = @signing_key.dsa_sign_asn1(digest.digest(body))
  
  der_to_raw_signature(signature_der)
end

#verify(body, signature) ⇒ Object 



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# File 'lib/saro/dat/signature.rb', line 177

def verify(body, signature)
  body = body.encode('utf-8') if body.is_a?(String) && body.encoding != Encoding::BINARY
  return false if body.nil? || body.empty?

  sig_bytes = if signature.is_a?(String) && signature.encoding != Encoding::BINARY
                Saro::Dat::Util.decode_base64_url(signature)
              else
                signature
              end

  begin
    der_sig = raw_to_der_signature(sig_bytes)
    digest = OpenSSL::Digest.new(@config[:hash])
    @verifying_key.dsa_verify_asn1(digest.digest(body), der_sig)
  rescue StandardError
    false
  end
end