CONTENTS

NAME

Crypt::PK::RSA - Public key cryptography based on RSA

SYNOPSIS

### OO interface

#Encryption: Alice
my $pub = Crypt::PK::RSA->new('Bob_pub_rsa1.der');
my $ct = $pub->encrypt("secret message");
#
#Encryption: Bob (received ciphertext $ct)
my $priv = Crypt::PK::RSA->new('Bob_priv_rsa1.der');
my $pt = $priv->decrypt($ct);

#Signature: Alice
my $priv = Crypt::PK::RSA->new('Alice_priv_rsa1.der');
my $sig = $priv->sign_message($message);
#
#Signature: Bob (received $message + $sig)
my $pub = Crypt::PK::RSA->new('Alice_pub_rsa1.der');
$pub->verify_message($sig, $message) or die "ERROR";

#Key generation
my $pk = Crypt::PK::RSA->new();
$pk->generate_key(256, 65537);
my $private_der = $pk->export_key_der('private');
my $public_der = $pk->export_key_der('public');
my $private_pem = $pk->export_key_pem('private');
my $public_pem = $pk->export_key_pem('public');

### Functional interface

#Encryption: Alice
my $ct = rsa_encrypt('Bob_pub_rsa1.der', "secret message");
#Encryption: Bob (received ciphertext $ct)
my $pt = rsa_decrypt('Bob_priv_rsa1.der', $ct);

#Signature: Alice
my $sig = rsa_sign_message('Alice_priv_rsa1.der', $message);
#Signature: Bob (received $message + $sig)
rsa_verify_message('Alice_pub_rsa1.der', $sig, $message) or die "ERROR";

DESCRIPTION

The module provides a full featured RSA implementation.

METHODS

new

my $pk = Crypt::PK::RSA->new();
#or
my $pk = Crypt::PK::RSA->new($priv_or_pub_key_filename);
#or
my $pk = Crypt::PK::RSA->new(\$buffer_containing_priv_or_pub_key);

Support for password protected PEM keys

my $pk = Crypt::PK::RSA->new($priv_pem_key_filename, $password);
#or
my $pk = Crypt::PK::RSA->new(\$buffer_containing_priv_pem_key, $password);

generate_key

Uses Yarrow-based cryptographically strong random number generator seeded with random data taken from /dev/random (UNIX) or CryptGenRandom (Win32).

$pk->generate_key($size, $e);
# $size .. key size: 128-512 bytes (DEFAULT is 256)
# $e ..... exponent: 3, 17, 257 or 65537 (DEFAULT is 65537)

import_key

Loads private or public key in DER or PEM format.

$pk->import_key($priv_or_pub_key_filename);
#or
$pk->import_key(\$buffer_containing_priv_or_pub_key);

Support for password protected PEM keys

$pk->import_key($pem_filename, $password);
#or
$pk->import_key(\$buffer_containing_pem_key, $password);

Loading private or public keys form perl hash:

$pk->import_key($hashref);

# the $hashref is either a key exported via key2hash
$pk->import_key({
  e  => "10001", #public exponent
  d  => "9ED5C3D3F866E06957CA0E9478A273C39BBDA4EEAC5B...", #private exponent
  N  => "D0A5CCCAE03DF9C2F5C4C8C0CE840D62CDE279990DC6...", #modulus
  p  => "D3EF0028FFAB508E2773C659E428A80FB0E9211346B4...", #p factor of N
  q  => "FC07E46B163CAB6A83B8E467D169534B2077DCDEECAE...", #q factor of N
  qP => "88C6D406F833DF73C8B734548E0385261AD51F4187CF...", #1/q mod p CRT param
  dP => "486F142FEF0A1F53269AC43D2EE4D263E2841B60DA36...", #d mod (p - 1) CRT param
  dQ => "4597284B2968B72C4212DB7E8F24360B987B80514DA9...", #d mod (q - 1) CRT param
});

# or a hash with items corresponding to JWK (JSON Web Key)
$pk->import_key({
{
  kty => "RSA",
  n   => "0vx7agoebGcQSuuPiLJXZpt...eZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
  e   => "AQAB",
  d   => "X4cTteJY_gn4FYPsXB8rdXi...FLN5EEaG6RoVH-HLKD9Mdx5ooGURknhnrRwUkC7h5fJLMWbFAKLWY2v7B6NqSzUvx0_YSf",
  p   => "83i-7IvMGXoMXCskv73TKr8...Z27zvoj6pbUQyLPBQxtPnwD20-60eTmD2ujMt5PoMrm8RmNhVWtjjMmMjOpSicFHjXOuVI",
  q   => "3dfOR9cuYq-0S-mkFLzgItg...q3hWeMuG0ouqnb3obLyuqjVZQ1dIrdgTnCdYzBcOW5r37AFXjift_NGiovonzhKpoVVS78",
  dp  => "G4sPXkc6Ya9y8oJW9_ILj4...zi_H7TkS8x5SdX3oE0oiYwxIiemTAu0UOa5pgFGyJ4c8t2VF40XRugKTP8akhFo5tA77Qe",
  dq  => "s9lAH9fggBsoFR8Oac2R_E...T2kGOhvIllTE1efA6huUvMfBcpn8lqW6vzzYY5SSF7pMd_agI3G8IbpBUb0JiraRNUfLhc",
  qi  => "GyM_p6JrXySiz1toFgKbWV...4ypu9bMWx3QJBfm0FoYzUIZEVEcOqwmRN81oDAaaBk0KWGDjJHDdDmFW3AN7I-pux_mHZG",
});

Supported key formats:

# all formats can be loaded from a file
my $pk = Crypt::PK::RSA->new($filename);

# or from a buffer containing the key
my $pk = Crypt::PK::RSA->new(\$buffer_with_key);

export_key_der

my $private_der = $pk->export_key_der('private');
#or
my $public_der = $pk->export_key_der('public');

export_key_pem

my $private_pem = $pk->export_key_pem('private');
#or
my $public_pem = $pk->export_key_pem('public');
#or
my $public_pem = $pk->export_key_pem('public_x509');

With parameter 'public' uses header and footer lines:

-----BEGIN RSA PUBLIC KEY------
-----END RSA PUBLIC KEY------

With parameter 'public_x509' uses header and footer lines:

-----BEGIN PUBLIC KEY------
-----END PUBLIC KEY------

Support for password protected PEM keys

my $private_pem = $pk->export_key_pem('private', $password);
#or
my $private_pem = $pk->export_key_pem('private', $password, $cipher);

# supported ciphers: 'DES-CBC'
#                    'DES-EDE3-CBC'
#                    'SEED-CBC'
#                    'CAMELLIA-128-CBC'
#                    'CAMELLIA-192-CBC'
#                    'CAMELLIA-256-CBC'
#                    'AES-128-CBC'
#                    'AES-192-CBC'
#                    'AES-256-CBC' (DEFAULT)

export_key_jwk

Since: CryptX-0.022

Exports public/private keys as a JSON Web Key (JWK).

my $private_json_text = $pk->export_key_jwk('private');
#or
my $public_json_text = $pk->export_key_jwk('public');

Also exports public/private keys as a perl HASH with JWK structure.

my $jwk_hash = $pk->export_key_jwk('private', 1);
#or
my $jwk_hash = $pk->export_key_jwk('public', 1);

BEWARE: For JWK support you need to have JSON module installed.

export_key_jwk_thumbprint

Since: CryptX-0.031

Exports the key's JSON Web Key Thumbprint as a string.

If you don't know what this is, see RFC 7638 https://tools.ietf.org/html/rfc7638.

my $thumbprint = $pk->export_key_jwk_thumbprint('SHA256');

encrypt

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $ct = $pk->encrypt($message);
#or
my $ct = $pk->encrypt($message, $padding);
#or
my $ct = $pk->encrypt($message, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

decrypt

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $pt = $pk->decrypt($ciphertext);
#or
my $pt = $pk->decrypt($ciphertext, $padding);
#or
my $pt = $pk->decrypt($ciphertext, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

sign_message

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $signature = $priv->sign_message($message);
#or
my $signature = $priv->sign_message($message, $hash_name);
#or
my $signature = $priv->sign_message($message, $hash_name, $padding);
#or
my $signature = $priv->sign_message($message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

verify_message

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $valid = $pub->verify_message($signature, $message);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name, $padding);
#or
my $valid = $pub->verify_message($signature, $message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

sign_hash

my $pk = Crypt::PK::RSA->new($priv_key_filename);
my $signature = $priv->sign_hash($message_hash);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name, $padding);
#or
my $signature = $priv->sign_hash($message_hash, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

verify_hash

my $pk = Crypt::PK::RSA->new($pub_key_filename);
my $valid = $pub->verify_hash($signature, $message_hash);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name, $padding);
#or
my $valid = $pub->verify_hash($signature, $message_hash, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

is_private

my $rv = $pk->is_private;
# 1 .. private key loaded
# 0 .. public key loaded
# undef .. no key loaded

size

my $size = $pk->size;
# returns key size in bytes or undef if no key loaded

key2hash

my $hash = $pk->key2hash;

# returns hash like this (or undef if no key loaded):
{
  type => 1,   # integer: 1 .. private, 0 .. public
  size => 256, # integer: key size in bytes
  # all the rest are hex strings
  e  => "10001", #public exponent
  d  => "9ED5C3D3F866E06957CA0E9478A273C39BBDA4EEAC5B...", #private exponent
  N  => "D0A5CCCAE03DF9C2F5C4C8C0CE840D62CDE279990DC6...", #modulus
  p  => "D3EF0028FFAB508E2773C659E428A80FB0E9211346B4...", #p factor of N
  q  => "FC07E46B163CAB6A83B8E467D169534B2077DCDEECAE...", #q factor of N
  qP => "88C6D406F833DF73C8B734548E0385261AD51F4187CF...", #1/q mod p CRT param
  dP => "486F142FEF0A1F53269AC43D2EE4D263E2841B60DA36...", #d mod (p - 1) CRT param
  dQ => "4597284B2968B72C4212DB7E8F24360B987B80514DA9...", #d mod (q - 1) CRT param
}

FUNCTIONS

rsa_encrypt

RSA based encryption. See method "encrypt" below.

my $ct = rsa_encrypt($pub_key_filename, $message);
#or
my $ct = rsa_encrypt(\$buffer_containing_pub_key, $message);
#or
my $ct = rsa_encrypt($pub_key, $message, $padding);
#or
my $ct = rsa_encrypt($pub_key, $message, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

rsa_decrypt

RSA based decryption. See method "decrypt" below.

my $pt = rsa_decrypt($priv_key_filename, $ciphertext);
#or
my $pt = rsa_decrypt(\$buffer_containing_priv_key, $ciphertext);
#or
my $pt = rsa_decrypt($priv_key, $ciphertext, $padding);
#or
my $pt = rsa_decrypt($priv_key, $ciphertext, 'oaep', $hash_name, $lparam);

# $padding .................... 'oaep' (DEFAULT), 'v1.5' or 'none' (INSECURE)
# $hash_name (only for oaep) .. 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $lparam (only for oaep) ..... DEFAULT is empty string

rsa_sign_message

Generate RSA signature. See method "sign_message" below.

my $sig = rsa_sign_message($priv_key_filename, $message);
#or
my $sig = rsa_sign_message(\$buffer_containing_priv_key, $message);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name, $padding);
#or
my $sig = rsa_sign_message($priv_key, $message, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_verify_message

Verify RSA signature. See method "verify_message" below.

rsa_verify_message($pub_key_filename, $signature, $message) or die "ERROR";
#or
rsa_verify_message(\$buffer_containing_pub_key, $signature, $message) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name, $padding) or die "ERROR";
#or
rsa_verify_message($pub_key, $signature, $message, $hash_name, 'pss', $saltlen) or die "ERROR";

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_sign_hash

Generate RSA signature. See method "sign_hash" below.

my $sig = rsa_sign_hash($priv_key_filename, $message_hash);
#or
my $sig = rsa_sign_hash(\$buffer_containing_priv_key, $message_hash);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name, $padding);
#or
my $sig = rsa_sign_hash($priv_key, $message_hash, $hash_name, 'pss', $saltlen);

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

rsa_verify_hash

Verify RSA signature. See method "verify_hash" below.

rsa_verify_hash($pub_key_filename, $signature, $message_hash) or die "ERROR";
#or
rsa_verify_hash(\$buffer_containing_pub_key, $signature, $message_hash) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name, $padding) or die "ERROR";
#or
rsa_verify_hash($pub_key, $signature, $message_hash, $hash_name, 'pss', $saltlen) or die "ERROR";

# $hash_name ............... 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest
# $padding ................. 'pss' (DEFAULT) or 'v1.5' or 'none' (INSECURE)
# $saltlen (only for pss) .. DEFAULT is 12

OpenSSL interoperability

### let's have:
# RSA private key in PEM format - rsakey.priv.pem
# RSA public key in PEM format  - rsakey.pub.pem
# data file to be signed or encrypted - input.data

Encrypt by OpenSSL, decrypt by Crypt::PK::RSA

Create encrypted file (from commandline):

openssl rsautl -encrypt -inkey rsakey.pub.pem -pubin -out input.encrypted.rsa -in input.data

Decrypt file (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'read_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
my $encfile = read_rawfile("input.encrypted.rsa");
my $plaintext = $pkrsa->decrypt($encfile, 'v1.5');
print $plaintext;

Encrypt by Crypt::PK::RSA, decrypt by OpenSSL

Create encrypted file (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'write_rawfile';

my $plaintext = 'secret message';
my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
my $encrypted = $pkrsa->encrypt($plaintext, 'v1.5');
write_rawfile("input.encrypted.rsa", $encrypted);

Decrypt file (from commandline):

openssl rsautl -decrypt -inkey rsakey.priv.pem -in input.encrypted.rsa

Sign by OpenSSL, verify by Crypt::PK::RSA

Create signature (from commandline):

openssl dgst -sha1 -sign rsakey.priv.pem -out input.sha1-rsa.sig input.data

Verify signature (Perl code):

use Crypt::PK::RSA;
use Crypt::Digest 'digest_file';
use Crypt::Misc 'read_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
my $signature = read_rawfile("input.sha1-rsa.sig");
my $valid = $pkrsa->verify_hash($signature, digest_file("SHA1", "input.data"), "SHA1", "v1.5");
print $valid ? "SUCCESS" : "FAILURE";

Sign by Crypt::PK::RSA, verify by OpenSSL

Create signature (Perl code):

use Crypt::PK::RSA;
use Crypt::Digest 'digest_file';
use Crypt::Misc 'write_rawfile';

my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
my $signature = $pkrsa->sign_hash(digest_file("SHA1", "input.data"), "SHA1", "v1.5");
write_rawfile("input.sha1-rsa.sig", $signature);

Verify signature (from commandline):

openssl dgst -sha1 -verify rsakey.pub.pem -signature input.sha1-rsa.sig input.data

Keys generated by Crypt::PK::RSA

Generate keys (Perl code):

use Crypt::PK::RSA;
use Crypt::Misc 'write_rawfile';

my $pkrsa = Crypt::PK::RSA->new;
$pkrsa->generate_key(256, 65537);
write_rawfile("rsakey.pub.der",  $pkrsa->export_key_der('public'));
write_rawfile("rsakey.priv.der", $pkrsa->export_key_der('private'));
write_rawfile("rsakey.pub.pem",  $pkrsa->export_key_pem('public_x509'));
write_rawfile("rsakey.priv.pem", $pkrsa->export_key_pem('private'));
write_rawfile("rsakey-passwd.priv.pem", $pkrsa->export_key_pem('private', 'secret'));

Use keys by OpenSSL:

openssl rsa -in rsakey.priv.der -text -inform der
openssl rsa -in rsakey.priv.pem -text
openssl rsa -in rsakey-passwd.priv.pem -text -inform pem -passin pass:secret
openssl rsa -in rsakey.pub.der -pubin -text -inform der
openssl rsa -in rsakey.pub.pem -pubin -text

Keys generated by OpenSSL

Generate keys:

openssl genrsa -out rsakey.priv.pem 1024
openssl rsa -in rsakey.priv.pem -out rsakey.priv.der -outform der
openssl rsa -in rsakey.priv.pem -out rsakey.pub.pem -pubout
openssl rsa -in rsakey.priv.pem -out rsakey.pub.der -outform der -pubout
openssl rsa -in rsakey.priv.pem -passout pass:secret -des3 -out rsakey-passwd.priv.pem

Load keys (Perl code):

use Crypt::PK::RSA;

my $pkrsa = Crypt::PK::RSA->new;
$pkrsa->import_key("rsakey.pub.der");
$pkrsa->import_key("rsakey.priv.der");
$pkrsa->import_key("rsakey.pub.pem");
$pkrsa->import_key("rsakey.priv.pem");
$pkrsa->import_key("rsakey-passwd.priv.pem", "secret");

SEE ALSO