CRYPT-DSAGEN(2)CRYPT-DSAGEN(2)NAME
crypt: dsagen, eggen, rsagen, rsafill, rsaencrypt, rsadecrypt - spe‐
cific 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;
DESCRIPTIONCrypt-gensk(2) describes a set of functions that generate public/pri‐
vate 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 parame‐
ter 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 ALSOcrypt-gensk(2), crypt-sha1(2), security-auth(2), security-oldauth(2)CRYPT-DSAGEN(2)
