Class: OpenSSL::PKey::RSA

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

Constant Summary collapse

RSA1 = 
0x31415352
RSA2 = 
0x32415352
PUBLICKEYBLOB = 
0x6
PRIVATEKEYBLOB = 
0x7
CALG_RSA_KEYX = 
0x0000a400

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.from_mskeyblob(key) ⇒ Object

Raises:

  • (OpenSSL::PKey::RSAError) 


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# File 'lib/mskeyblob.rb', line 14

def self.from_mskeyblob(key)
  b_type, b_version, reserved, alg_id,  # PUBLICKEYSTRUC
      magic, bit_len, public_exponent,  # RSAPUBKEY
      rest =
      key.unpack('CCSL LLL a*')

  # PUBLICKEYBLOB || PRIVATEKEYBLOB
  raise OpenSSL::PKey::RSAError, "Neither PUB key nor PRIV key: invalid bType #{b_type}" unless [PUBLICKEYBLOB, 0x7].include? b_type
  raise OpenSSL::PKey::RSAError, "Neither PUB key nor PRIV key: invalid bVersion #{b_version}" unless b_version == 2
  raise OpenSSL::PKey::RSAError, "Neither PUB key nor PRIV key: invalid magic #{magic}" unless [RSA1, RSA2].include? magic

  b8 = "a#{bit_len / 8}"
  b16 = "a#{bit_len / 16}"

  unpack_pattern = [b8, b16, b16, b16, b16, b16, b8].join('')

  modulus, p1, p2, e1, e2, c, private_exponent = rest.unpack(unpack_pattern)

  modulus, p1, p2, e1, e2, c, private_exponent = [modulus, p1, p2, e1, e2, c, private_exponent].map  do |byte_array|
    if byte_array.empty?
      nil
    else
      OpenSSL::BN.new byte_array.reverse, 2
    end
  end

  key = OpenSSL::PKey::RSA.new
  key.n = modulus
  key.e = public_exponent

  if private_exponent
    key.d = private_exponent
    key.p = p1
    key.q = p2
    key.dmp1 = e1
    key.dmq1 = e2
    key.iqmp = c
  end

  key
end

Instance Method Details

#to_mskeyblob(include_private: :not_set) ⇒ Object 



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# File 'lib/mskeyblob.rb', line 56

def to_mskeyblob(include_private: :not_set)
  if include_private == :not_set
    include_private = private?
  else
    if include_private && !private?
      raise OpenSSL::PKey::RSAError, 'Public key can not export private part'
    end
  end

  b_type = include_private ? PRIVATEKEYBLOB : PUBLICKEYBLOB
  b_version = 2
  reserved = 0
  alg_id = CALG_RSA_KEYX
  magic = include_private ? RSA2 : RSA1


  bit_len = n.num_bits # https://github.com/ruby/openssl/issues/5
  public_exponent = e

  b8 = "a#{bit_len / 8}"
  b16 = "a#{bit_len / 16}"

  header = [
      b_type, b_version, reserved, alg_id,  # PUBLICKEYSTRUC
      magic, bit_len, public_exponent,      # RSAPUBKEY
  ].pack('CCSL LLL')

  modulus, p1, p2, e1, e2, c, private_exponent = [n, p, q, dmp1, dmq1, iqmp, d].map  do |bn|
    if bn
      bn.to_s(2).reverse
    else
      nil
    end
  end

  if include_private
    pack_pattern = [b8, b16, b16, b16, b16, b16, b8].join('')

    header + [modulus, p1, p2, e1, e2, c, private_exponent].pack(pack_pattern)
  else
    header + [modulus].pack(b8)
  end
end