NAME

crypt: dsagen, eggen, rsagen, rsafill, rsaencrypt, rsadecrypt - specific public key systems

SYNOPSIS

include "ipints.m";
ipints := load IPints IPints->PATH;
IPint: import ipints;

include "crypt.m";
crypt := load Crypt Crypt->PATH;

dsagen:     fn(oldpk: ref PK.DSA): ref SK.DSA;

eggen:      fn(nlen: int, nrep: int): ref SK.Elgamal;

rsagen:     fn(nlen: int, elen: int, nrep: int): ref SK.RSA;
rsafill:    fn(n: ref IPint, ek: ref IPint, dk: ref IPint,
               p: ref IPint, q: ref IPint): ref SK.RSA;
rsaencrypt: fn(k: ref PK.RSA, m: ref IPint): ref IPint;
rsadecrypt: fn(k: ref SK.RSA, m: ref IPint): ref IPint;

DESCRIPTION

Crypt-gensk(2) describes a set of functions that generate public/private key pairs given an algorithm name and a key length. Some key types allow further parameters for key generation or support further operations.

Dsagen generates a DSA public/private key pair, represented by the pick adt SK.DSA, and compatible with the containing type SK. If the parameter oldpk is not nil, dsagen takes the new key's modulus and group order from the existing key; otherwise it generates a new pair of primes.

Eggen generates a new El-Gamal key pair, represented by the pick adt SK.Elgamal. Nlen is the length of the modulus; nrep is the number of repetitions of the Miller-Rabin primality test (0 gives the default, currently 18).

Rsagen generates an RSA public/private key pair, represented by the pick adt SK.RSA, and compatible with the containing type SK. Nlen gives the length of the key modulus in bits; elen gives the exponent length in bits; and nrep is as above.

The RSA private key representation used by Inferno includes some extra values to speed computation. Rsagen provides those values but keys imported from other systems might not. Given the essential set of RSA private key parameters for a given key, represented as IPints, rsafill returns a suitable SK.RSA for that key, including the extra values.

The public key of type PK.RSA can be extracted from a given private key value sk by referencing the field sk.pk.

Rsaencrypt encrypts a message m, represented by an IPint, using the public key pk.

Rsadecrypt decrypts m using private key sk. The result is again returned as an IPint.

SEE ALSO

crypt-gensk(2), crypt-sha1(2), security-auth(2), security-oldauth(2)

CRYPT-DSAGEN(2 )

Rev:  Tue Mar 31 02:42:39 GMT 2015