NAME

keyring: IPint - `infinite' precision integer utility functions

SYNOPSIS

include "keyring.m"
keyring:= load Keyring Keyring->PATH;
IPint: adt
{


  iptob64:   fn(i: self ref IPint): string;


  b64toip:   fn(str: string)  : ref IPint;


  iptobytes: fn(i: self ref IPint): array of byte;


  bytestoip: fn(buf: array of byte): ref IPint;


  iptobebytes: fn(i: self ref IPint): array of byte;


  bebytestoip: fn(buf: array of byte): ref IPint;


  inttoip:   fn(i: int): ref IPint;


  iptoint:   fn(i: self ref IPint): int;


  iptostr:   fn(i: self ref IPint, base: int): string;


  strtoip:   fn(str: string, base: int): ref IPint;


  random:    fn(minbits, maxbits: int): ref IPint;


  copy:      fn(i: self ref IPint): ref IPint;


  bits:      fn(i:  self ref IPint): int;


  expmod:    fn(base: self ref IPint, exp, mod: ref IPint):ref IPint;


  add:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;


  sub:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;


  neg:  fn(i: self ref IPint): ref IPint;


  mul:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;


  div:  fn(i1: self ref IPint, i2: ref IPint): (ref IPint, ref IPint);


  eq:   fn(i1:  self ref IPint, i2: ref IPint): int;


  cmp:  fn(i1: self ref IPint, i2: ref IPint): int;


  shl:  fn(i: self ref IPint, n: int): ref IPint;


  shr:  fn(i: self ref IPint, n: int): ref IPint;


  and:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;


  ori:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;


  not:  fn(i: self ref IPint): ref IPint;


  xor:  fn(i1: self ref IPint, i2: ref IPint): ref IPint;
};

DESCRIPTION

IPint provides the following arbitrary-length integer manipulation functions required for cryptographic support in Limbo:

i.iptob64(): Returns a string that represents a large integer textually in base 64 for convenient transmission over a network connection.
b64toip(str): Returns the IPint represented by the base-64 encoded str.
i.iptobytes(): Returns an array of bytes representing a large integer. The representation includes both positive and negative numbers.
bytestoip(buf): The inverse operation of iptobytes.
i.iptobebytes(): Returns an array of bytes in big-endian format representing the magnitude of a large integer; used for instance to pass a value to ssl (3). Only non-negative numbers are represented.
bebytestoip(buf): The inverse operation of iptobebytes.
inttoip(i): Creates a new large integer from integer i.
i.iptoint(): Converts a large integer i to an int; returns 0 on error.
i.iptostr(base): Converts a large integer to a string in base base; returns nil on error. Only the bases 10, 16, 32, and 64 are supported. Anything else defaults to 16.
strtoip(str,base): Converts a string str representing a number in in base base to a large integer; returns nil on error. Only the bases 10, 16, 32, and 64 are supported.
random(minbits,maxbits): Returns a large random number with length from minbits to maxbits. The largest number allowed in the current implementation is 2^8192-1 . The seed for the generator is obtained by duelling clocks.
i.copy(): Returns a reference to the same value as i.
i.bits(): Returns the number of bits of precision of i.
base.expmod(exp , mod): Returns (base**exp) mod mod.
i1.add(i2): Returns (i1+i2).
i1.sub(i2): Returns (i1-i2).
i1.mul(i2): Returns i1*i2.
i1.div(i2): Returns (i1/i2, i1modi2).
i1.eq(i2): Returns 1 if i1 and i2 are equal; 0 otherwise.
i1.cmp(i2): Compares two large integers, returning 1 if i1 is larger, -1 if i2 is larger, and 0 if they are equal.
i.shl(n): Returns i<<n
i.shr(n): Returns i>>n
i1.and(i2): Returns i&n, bitwise AND
i1.ori(i2): Returns i|n, bitwise inclusive-OR (it is ori because plain or is a Limbo keyword)
i.not(): Returns ~i, bitwise ones-complement
i1.xor(i2): Returns i^n, bitwise exclusive-OR