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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);

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)

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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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'
 # $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 File::Slurp 'read_file';

  my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
  my $encfile = read_file("input.encrypted.rsa", binmode=>':raw');
  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 File::Slurp 'write_file';

  my $plaintext = 'secret message';
  my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
  my $encrypted = $pkrsa->encrypt($plaintext, 'v1.5');
  write_file("input.encrypted.rsa", {binmode=>':raw'}, $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 File::Slurp 'read_file';

 my $pkrsa = Crypt::PK::RSA->new("rsakey.pub.pem");
 my $signature = read_file("input.sha1-rsa.sig", binmode=>':raw');
 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 File::Slurp 'write_file';

 my $pkrsa = Crypt::PK::RSA->new("rsakey.priv.pem");
 my $signature = $pkrsa->sign_hash(digest_file("SHA1", "input.data"), "SHA1", "v1.5");
 write_file("input.sha1-rsa.sig", {binmode=>':raw'}, $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 File::Slurp 'write_file';

 my $pkrsa = Crypt::PK::RSA->new;
 $pkrsa->generate_key(256, 65537);
 write_file("rsakey.pub.der",  {binmode=>':raw'}, $pkrsa->export_key_der('public'));
 write_file("rsakey.priv.der", {binmode=>':raw'}, $pkrsa->export_key_der('private'));
 write_file("rsakey.pub.pem",  $pkrsa->export_key_pem('public_x509'));
 write_file("rsakey.priv.pem", $pkrsa->export_key_pem('private'));
 write_file("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;
 use File::Slurp 'write_file';

 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