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

strtocert: fn(s: string)         : ref Certificate;
certtostr: fn(c: ref Certificate): string;
strtopk:   fn(s: string)         : ref PK;
pktostr:   fn(pk: ref PK)        : string;
strtosk:   fn(s: string)         : ref SK;
sktostr:   fn(sk: ref SK)        : string;

Strtocert takes a string argument containing a user name, a hash algorithm, a certifying authority and an expiration time. Fields are separated by a newline. The return value is a Certificate. If the string is of improper format, the result is nil.

Certtostr performs the inverse operation: takes the Certificate c and produces a text string suitable for communication over a network.

Strtopk and strtosk take as their arguments a string s representing the public and private keys respectively. S must contain an algorithm name, a user name and the key. Fields are separated by a newline. Strtopk returns a reference to the resulting PK; strtosk returns a reference to the resulting SK. If the format of s is invalid, the result is nil.

Pktostr and sktostr perform the inverse operations: they take a public key (secret key) and produce a printable representation as a string.