--- OpenSSL bindings.
-- \n\n
-- This module is a wrapper for OpenSSL functions that provide encryption and
-- decryption, hashing, and multiprecision integers.
-- \n\n
-- The openssl module may not always be available--it depends on whether
-- OpenSSL support was enabled at compile time. Scripts using the module should
-- be made to fail gracefully using code like the following:
-- \n\n
-- if not pcall(require, "openssl") then\n
--   action = function(host, port)\n
--     stdnse.print_debug(2, "Skipping \"%s\" because OpenSSL is missing.", id)\n
--   end\n
-- end\n
-- action = action or function(host, port)\n
--   ...\n
-- end
-- @author Sven Klemm <sven@c3d2.de>
-- @copyright See nmaps COPYING for licence

module "openssl"

--- Returns the size of bignum in bits.
function openssl.bignum_num_bits(bignum)

--- Returns the size of bignum in bytes.
function openssl.bignum_num_bytes(bignum)

--- Sets the bit at position in bignum.
function openssl.bignum_set_bit(bignum, position)

--- Clears the bit at position in bignum.
function openssl.bignum_clear_bit(bignum, position)

--- Gets the state of the bit at position in bignum.
function openssl.bignum_is_bit_set(bignum, position)

--- Sets the sign of bignum. If negative is true the sign becomes negative,
-- otherwise it becomes positive.
function openssl.bignum_set_negative(bignum, negative)

--- Returns true if bignum is negative, false otherwise.
function openssl.bignum_is_negative(bignum)

--- Converts the binary-encoded string into a bignum.
function openssl.bignum_bin2bn(string)

--- Converts the decimal-encoded string into a bignum.
function openssl.bignum_dec2bn(string)

--- Converts the hex-encoded string into a bignum.
function openssl.bignum_hex2bn(string)

--- Converts bignum into a binary-encoded string.
function openssl.bignum_bn2bin(bignum)

--- Converts bignum into a decimal-encoded string.
function openssl.bignum_bn2dec(bignum)

--- Converts bignum into a hex-encoded string.
function openssl.bignum_bn2hex(bignum)

--- Returns a random bignum with a
function openssl.bignum_rand(bits)

--- Returns a pseudorandom bignum with a the given size in bits.
function openssl.bignum_pseudo_rand(bits)

--- Returns the bignum which is the result of a^p mod m.
function openssl.bignum_mod_exp(a, p, m)

--- Returns a string of length bytes containing random data.
function openssl.rand_bytes(bytes)

--- Returns a string of length bytes containing pseudorandom data.
function openssl.rand_pseudo_bytes(bytes)

--- Returns the MD2 digest of message.
function openssl.md2(message)

--- Returns the MD4 digest of message.
function openssl.md4(message)

--- Returns the MD5 digest of message.
function openssl.md5(message)

--- Returns the SHA-1 digest of message.
function openssl.sha1(message)

--- Returns the RIPEMD-160 digest of message.
function openssl.ripemd160(message)

--- Returns the digest of message using the algorithm given by the string
-- algorithm. The algorithm name may be anything returned by the
-- openssl.supported_digests function.
function openssl.digest(algorithm, message)

--- Returns the message authentication code of message using the given algorithm
-- and key. algorithm may be anything returned by the openssl.supported_digests
-- function.
function openssl.hmac(algorithm, key, message)

--- Encrypt data with the given algorithm, key, and initialization vector.
-- algorithm may be anything returned by the openssl.supported_ciphers function.
-- If padding is true then a partial final block will be padded and encrypted.
function openssl.encrypt(algorithm, key, iv, data, padding = false)

--- Encrypt data with the given algorithm, key, and initialization vector.
-- algorithm may be anything returned by the openssl.supported_ciphers function.
-- If padding is true then the final block must be padded correctly.
function openssl.decrypt(algorithm, key, iv, data, padding = false)

--- Returns a table with the names of the supported cipher algorithms.
function openssl.supported_ciphers()

--- Returns a table with the names of the supported digest algorithms.
function openssl.supported_digests()

--- Converts data, which must be a 7-byte string, into an 8-byte DES key and
-- sets the parity.
function openssl.DES_string_to_key(string data)