Class: Himari::SigningKey

Inherits:
Object
  • Object
show all
Defined in:
lib/himari/signing_key.rb

Defined Under Namespace

Classes: AlgUnknown, OperationInvalid

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id:, pkey:, alg: nil, inactive: false, group: nil) ⇒ SigningKey

Returns a new instance of SigningKey.



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# File 'lib/himari/signing_key.rb', line 8

def initialize(id:, pkey:, alg: nil, inactive: false, group: nil)
  @id = id
  @pkey = pkey
  @alg = alg
  @inactive = inactive
  @group = group
end

Instance Attribute Details

#groupObject (readonly)

Returns the value of attribute group.



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# File 'lib/himari/signing_key.rb', line 16

def group
  @group
end

#idObject (readonly)

Returns the value of attribute id.



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# File 'lib/himari/signing_key.rb', line 16

def id
  @id
end

#pkeyObject (readonly)

Returns the value of attribute pkey.



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# File 'lib/himari/signing_key.rb', line 16

def pkey
  @pkey
end

Instance Method Details

#active?Boolean

Returns:

  • (Boolean)


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# File 'lib/himari/signing_key.rb', line 19

def active?
  !@inactive
end

#algObject



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# File 'lib/himari/signing_key.rb', line 47

def alg
  @alg ||= inferred_alg
end

#as_jwkObject



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# File 'lib/himari/signing_key.rb', line 94

def as_jwk
  # https://www.rfc-editor.org/rfc/rfc7517#section-4
  case pkey
  when OpenSSL::PKey::EC # https://www.rfc-editor.org/rfc/rfc7518#section-6.2
    # https://www.secg.org/sec1-v2.pdf - 2.3.3. Elliptic-Curve-Point-to-Octet-String Conversion
    xy = pkey.public_key.to_octet_string(:uncompressed) # 0x04 || X || Y
    len = pkey.group.degree/8
    raise unless xy[0] == "\x04".b && xy.size == ((len*2)+1)
    x = xy[1,len]
    y = xy[1+len,len]

    {
      kid: id,
      kty: 'EC',
      crv: ec_crv,
      use: "sig",
      alg: alg,
      x: Base64.urlsafe_encode64(OpenSSL::BN.new(x, 2).to_s(2)).gsub(/\n|=/, ''),
      y: Base64.urlsafe_encode64(OpenSSL::BN.new(y, 2).to_s(2)).gsub(/\n|=/, ''),
    }
  when OpenSSL::PKey::RSA # https://www.rfc-editor.org/rfc/rfc7518#section-6.3
    {
      kid: id,
      kty: 'RSA',
      use: "sig",
      alg: alg,
      n: Base64.urlsafe_encode64(pkey.n.to_s(2)).gsub(/=+/,''),
      e: Base64.urlsafe_encode64(pkey.e.to_s(2)).gsub(/=+/,''),
    }
  else
    raise AlgUnknown
  end
end

#ec_crvObject

Raises:



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# File 'lib/himari/signing_key.rb', line 79

def ec_crv
  raise OperationInvalid, "this key is not EC" unless pkey.is_a?(OpenSSL::PKey::EC)
  # https://www.rfc-editor.org/rfc/rfc8422.html#appendix-A
  case pkey.group.curve_name
  when 'prime256v1', 'secp256r1'
    'P-256'
  when 'secp384r1'
    'P-384'
  when 'secp521r1'
    'P-521'
  else
    raise AlgUnknown
  end
end

#hash_functionObject



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# File 'lib/himari/signing_key.rb', line 69

def hash_function
  case alg
  when 'ES256', 'RS256'; Digest::SHA256
  when 'ES384'; Digest::SHA384
  when 'ES512'; Digest::SHA512
  else
    raise AlgUnknown
  end
end

#inferred_algObject



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# File 'lib/himari/signing_key.rb', line 51

def inferred_alg
  # https://datatracker.ietf.org/doc/html/rfc7518#section-3.1
  case pkey
  when OpenSSL::PKey::RSA
    'RS256'
  when OpenSSL::PKey::EC
    case ec_crv
    when 'P-256'; 'ES256'
    when 'P-384'; 'ES384'
    when 'P-521'; 'ES512'
    else
      raise AlgUnknown
    end
  else
    raise AlgUnknown
  end
end

#match_hint?(id: nil, active: nil, group: nil) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/himari/signing_key.rb', line 23

def match_hint?(id: nil, active: nil, group: nil)
  result = true

  result &&= if id
    id == self.id
  else
    true
  end

  result &&= if !active.nil?
    active == self.active?
  else
    true
  end

  result &&= if group
    group == self.group
  else
    true
  end

  result
end