NAME
Crypt::JWS::OpenSSL - Encode, decode and verify signed compact JWTs using OpenSSL modules
VERSION
version 0.001
SYNOPSYS
use Crypt::JWS::OpenSSL;
my $cjos = Crypt::JWS::OpenSSL->new;
my $token = $cjos->encode(
header => $header_ref,
claims => $claims_ref,
secret => $key,
);
if(!$token) {
$logger->log_error( $cjos->last_error)
}
###################
## in some module
###################
use Crypt::JWS::OpenSSL;
has verifier => ( is => 'ro', default => sub { Crypt::JWS::OpenSSL->new } );
sub permissions_from_token {
my($self, $token) = @_;
my $unverified = $self->verifier->decode_unverified(token => $token);
unless($unverified) {
my $reason = $self->verifier->last_error;
## inspect and log reason
return undef;
}
my ($secret, $permissions) = $self->examine_token(
$unverified->{header}, $unverified->{claims}
);
unless($secret && $permissions) {
## no secret and permissions
return undef;
}
my $ok = $self->verifier->verify(
secret => $secret,
verifytoken => $unverified->{verifytoken}
);
unless( $ok && $ok eq '1' ) {
my $reason = $self->verifier->last_error;
## inspect and log reason
return undef;
}
## log access
## grant permissions
return $permissions;
}DESCRIPTION
Encode, decode and verify signed compact JWTs using Crypt::OpenSSL modules.
SUPPORTED ALGORITHMS
Shared HMAC secret
HS256 HS384 HS512
These algorithms do not require any Crypt::OpenSSL modules. They are included for completeness.
RSA
RS256 RS384 RS512 PS256 PS384 PS512
ECDSA
ES256 ES384 ES512
METHODS
encode
$cjo->encode( header => $header, claims => $claims, secret => $secret )
Accepts a hash reference or an even numbered list.
Returns a signed compact JWT on success or undefined on error.
parameters
- header
-
A reference to a hash containing the header elements for the JWS.
At a minumim this must contain a alg key/value with a value of one of the supported algorithms.
If no typ key/value is present, a default of typ => 'JWT' will be added.
- claims
-
A reference to a hash containing the claim elements for the JWS.
This must contain at least 1 key/value pair.
- secret
-
The secret used to sign the JWS.
For shared HMAC algorithms, this is a scalar containing the raw shared secret.
For RSA and ECDSA algorithms this can be a scalar containing the full text of a pem encoded private key.
A reference to a hash containing the elements of a JWK can also be used.
For a regularly used private key it is more efficient to store the key as pem encoded text. You can convert a JWK using Crypt::JWS::OpenSSL::Util::JWK.
Where a kid is required by a verifying recipient, it must always be added to the header hash. It will not be taken from the value within a JWK.
For errors and exceptions see error handling
decode_unverified
$cjo->decode_unverified( token => $tokenreceived )
Accepts a hash reference or an even numbered list.
On success, returns the decocoded header and claims hash references together with a 'verifytoken' that can be passed to "verify".
Returns undefined on error.
parameters
- token
-
A token to decode.
Returned hash reference structure
{
header => { ... },
claims => { ... },
verifytoken => 'xxxxxxxxxxxx....'
}After inspecting the header and claims, the appropriate secret can be passed to "verify" to verify the signature.
For errors and exceptions see error handling
verify
$cjo->verify( verifytoken => $verifytoken, secret => $secret )
Accepts a hash reference or an even numbered list.
On success returns 1. On failure or error returns 0 or undefined.
parameters
- verifytoken
-
The verifytoken member of the hash reference returned from a prior call to "decode_unverified".
- secret
-
The appropriate public key or shared HMAC secret determined by inspection of the header and claims returned from a prior call to "decode_unverified".
The secret for an RSA or ECDSA algorithm can be a scalar containing the full text of a pem encoded public key.
A reference to a hash containing the elements of a JWK can also be used.
For a regularly used public key it is more efficient to store the key as pem encoded text. You can convert a JWK using Crypt::JWS::OpenSSL::Util::JWK.
For errors and exceptions see error handling
PROPERTIES
last_error
Read only.
When any of the methods "encode", "decode_unverified", "verify" return undefined or false, the reason is available in "last_error".
see error handling
see also "throw_errors"
throw_errors
Read write.
Default value 0 (false)
While "throw_errors" is false, errors or exceptions encountered in "encode", "decode_unverified" and "verify" are caught and stored in "last_error" available to read when the method returns.
If throw_errors is set to 1 ( true ) the module croaks when errors and exceptions are encountered in "encode", "decode_unverified" and "verify".
see error handling
see also "last_error"
can_use_pkcs1_padding
Read only.
Returns true ( 1 ) if Crypt::OpenSSL::RSA can 'use_pkcs1_padding'.
Returns false ( 0 ) if Crypt::OpenSSL::RSA cannot 'use_pkcs1_padding'.
This padding method is necessary for algorithms
RS256, RS384, and RS512
It is likely that your version of Crypt::OpenSSL::RSA supports 'use_pkcs1_padding' as only a couple of short lived versions did not.
can_use_pkcs1_pss_padding
Returns true ( 1 ) if Crypt::OpenSSL::RSA can 'use_pkcs1_pss_padding'.
Returns false ( 0 ) if Crypt::OpenSSL::RSA cannot 'use_pkcs1_pss_padding'.
This padding method is necessary for algorithms
PS256, PS384, and PS512
This padding method requires OpenSSL 3.x and Crypt::OpenSSL::RSA version greater than or equal to 0.38
See also Crypt::JWS::OpenSSL::Local
JSON
Read only. An instance of a JSON encoder / decoder
The default is JSON::MaybeXS->new->utf8(1);
If you have a partcular perference for a JSON module, 'use' that before Crypt::JWS::OpenSSL or provide your own instance.
use JSON::XS;
use Crypt::JWS::OpenSSL;
## OR
use Crypt::JWS::OpenSSL;
use JSON::XS;
my $cjos = Crypt::JWS::OpenSSL->new( JSON => JSON::XS->new->utf8(1) );ERROR HANDLING
When "throw_errors" is 0 ( the default ) if errors or exceptions are encountered in the methods "encode", "decode_unverified" and "verify", the methods return undefined or false and the reason is available in "last_error".
If "throw_errors" is set to 1, the methods croak on errors or exceptions.
SEE ALSO
Crypt OpenSSL modules used
Alternatives for JWT handling.
CryptX ( wraps the LibTomCrypt library )
Crypt::Perl ( pure perl )
AUTHOR
Mark Dootson <mdootson@cpan.org>
COPYRIGHT AND LICENSE
Copyright (C) 2026 by Mark Dootson
This library is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.