NAME

Crypt::PK::ECC - Public key cryptography based on EC

SYNOPSIS

### OO interface

#Encryption: Alice
my $pub = Crypt::PK::ECC->new('Bob_pub_ecc1.der');
my $ct = $pub->encrypt("secret message");
#
#Encryption: Bob (received ciphertext $ct)
my $priv = Crypt::PK::ECC->new('Bob_priv_ecc1.der');
my $pt = $priv->decrypt($ct);

#Signature: Alice
my $priv = Crypt::PK::ECC->new('Alice_priv_ecc1.der');
my $sig = $priv->sign_message($message);
#
#Signature: Bob (received $message + $sig)
my $pub = Crypt::PK::ECC->new('Alice_pub_ecc1.der');
$pub->verify_message($sig, $message) or die "ERROR";

#Shared secret
my $priv = Crypt::PK::ECC->new('Alice_priv_ecc1.der');
my $pub = Crypt::PK::ECC->new('Bob_pub_ecc1.der');
my $shared_secret = $priv->shared_secret($pub);

#Key generation
my $pk = Crypt::PK::ECC->new();
$pk->generate_key(24);
my $private_der = $pk->export_key_der('private');
my $public_der = $pk->export_key_der('public');
my $public_ansi_x963 = $pk->export_key_x963();

### Functional interface

#Encryption: Alice
my $ct = ecc_encrypt('Bob_pub_ecc1.der', "secret message");
#Encryption: Bob (received ciphertext $ct)
my $pt = ecc_decrypt('Bob_priv_ecc1.der', $ct);

#Signature: Alice
my $sig = ecc_sign_message('Alice_priv_ecc1.der', $message);
#Signature: Bob (received $message + $sig)
ecc_verify_message('Alice_pub_ecc1.der', $sig, $message) or die "ERROR";

#Shared secret
my $shared_secret = ecc_shared_secret('Alice_priv_ecc1.der', 'Bob_pub_ecc1.der');

DESCRIPTION

The module provides a set of core ECC functions as well that are designed to be the Elliptic Curve analogy of all of the Diffie-Hellman routines (ECDH).

FUNCTIONS

ecc_encrypt

Elliptic Curve Diffie-Hellman (ECDH) encryption as implemented by libtomcrypt. See method "encrypt" below.

my $ct = ecc_encrypt($pub_key_filename, $message);
#or
my $ct = ecc_encrypt(\$buffer_containing_pub_key, $message);
#or
my $ct = ecc_encrypt($pub_key_filename, $message, $hash_name);

#NOTE: $hash_name can be 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest

ECCDH Encryption is performed by producing a random key, hashing it, and XOR'ing the digest against the plaintext.

ecc_decrypt

Elliptic Curve Diffie-Hellman (ECDH) decryption as implemented by libtomcrypt. See method "decrypt" below.

my $pt = ecc_decrypt($priv_key_filename, $ciphertext);
#or
my $pt = ecc_decrypt(\$buffer_containing_priv_key, $ciphertext);

ecc_sign_message

Elliptic Curve Digital Signature Algorithm (ECDSA) - signature generation. See method "sign_message" below.

my $sig = ecc_sign_message($priv_key_filename, $message);
#or
my $sig = ecc_sign_message(\$buffer_containing_priv_key, $message);
#or
my $sig = ecc_sign_message($priv_key, $message, $hash_name);

ecc_verify_message

Elliptic Curve Digital Signature Algorithm (ECDSA) - signature verification. See method "verify_message" below.

ecc_verify_message($pub_key_filename, $signature, $message) or die "ERROR";
#or
ecc_verify_message(\$buffer_containing_pub_key, $signature, $message) or die "ERROR";
#or
ecc_verify_message($pub_key, $signature, $message, $hash_name) or die "ERROR";

ecc_sign_hash

Elliptic Curve Digital Signature Algorithm (ECDSA) - signature generation. See method "sign_hash" below.

my $sig = ecc_sign_hash($priv_key_filename, $message_hash);
#or
my $sig = ecc_sign_hash(\$buffer_containing_priv_key, $message_hash);

ecc_verify_hash

Elliptic Curve Digital Signature Algorithm (ECDSA) - signature verification. See method "verify_hash" below.

ecc_verify_hash($pub_key_filename, $signature, $message_hash) or die "ERROR";
#or
ecc_verify_hash(\$buffer_containing_pub_key, $signature, $message_hash) or die "ERROR";

ecc_shared_secret

Elliptic curve Diffie-Hellman (ECDH) - construct a Diffie-Hellman shared secret with a private and public ECC key. See method "shared_secret" below.

#on Alice side
my $shared_secret = ecc_shared_secret('Alice_priv_ecc1.der', 'Bob_pub_ecc1.der');

#on Bob side
my $shared_secret = ecc_shared_secret('Bob_priv_ecc1.der', 'Alice_pub_ecc1.der');

METHODS

new

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

generate_key

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

$pk->generate_key($keysize);
# $keysize .. key size in bytes: 14, 16, 20, 24, 28, 32, 48 or 65
#   14 => use curve SECP112R1
#   16 => use curve SECP128R1
#   20 => use curve SECP160R1
#   24 => use curve P-192 recommended by FIPS 186-3
#   28 => use curve P-224 recommended by FIPS 186-3
#   32 => use curve P-256 recommended by FIPS 186-3
#   48 => use curve P-384 recommended by FIPS 186-3
#   65 => use curve P-521 recommended by FIPS 186-3

See http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf and http://www.secg.org/collateral/sec2_final.pdf

import_key

Loads private or public key in DER format (exported by "export_key_der").

$pk->import_key($filename);
#or
$pk->import_key(\$buffer_containing_key);

import_key_x963

ANSI X9.63 Import (public key only) - can load data exported by "export_key_x963".

$pk->import_key(\$buffer_containing_pub_key_ansi_x963);

export_key_der

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

export_key_x963

ANSI X9.63 Export (public key only)

my $public_ansi_x963 = $pk->export_key_x963();

encrypt

my $pk = Crypt::PK::ECC->new($pub_key_filename);
my $ct = $pk->encrypt($message);
#or
my $ct = $pk->encrypt($message, $hash_name);

#NOTE: $hash_name can be 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest

decrypt

my $pk = Crypt::PK::ECC->new($priv_key_filename);
my $pt = $pk->decrypt($ciphertext);

sign_message

my $pk = Crypt::PK::ECC->new($priv_key_filename);
my $signature = $priv->sign_message($message);
#or
my $signature = $priv->sign_message($message, $hash_name);

#NOTE: $hash_name can be 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest

verify_message

my $pk = Crypt::PK::ECC->new($pub_key_filename);
my $valid = $pub->verify_message($signature, $message)
#or
my $valid = $pub->verify_message($signature, $message, $hash_name);

#NOTE: $hash_name can be 'SHA1' (DEFAULT), 'SHA256' or any other hash supported by Crypt::Digest

sign_hash

my $pk = Crypt::PK::ECC->new($priv_key_filename);
my $signature = $priv->sign_hash($message_hash);

verify_hash

my $pk = Crypt::PK::ECC->new($pub_key_filename);
my $valid = $pub->verify_hash($signature, $message_hash);

shared_secret

# Alice having her priv key $pk and Bob's public key $pkb
my $pk  = Crypt::PK::ECC->new($priv_key_filename);
my $pkb = Crypt::PK::ECC->new($pub_key_filename);
my $shared_secret = $pk->shared_secret($pkb);

# Bob having his priv key $pk and Alice's public key $pka
my $pk = Crypt::PK::ECC->new($priv_key_filename);
my $pka = Crypt::PK::ECC->new($pub_key_filename);
my $shared_secret = $pk->shared_secret($pka);  # same value as computed by Alice

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 => 32, # integer: key (curve) size in bytes
  #curve parameters
  curve_name  => "ECC-256",
  curve_size  => 32,
  curve_B     => "5AC635D8AA3A93E7B3EBBD55769886BC651D06B0CC53B0F63BCE3C3E27D2604B",
  curve_Gx    => "6B17D1F2E12C4247F8BCE6E563A440F277037D812DEB33A0F4A13945D898C296",
  curve_Gy    => "4FE342E2FE1A7F9B8EE7EB4A7C0F9E162BCE33576B315ECECBB6406837BF51F5",
  curve_order => "FFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551",
  curve_prime => "FFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFFFFFFFFFF",
  #private key
  k => "A7F43ACD4A05D69AE4597E6E723EB5F1E9B9B7EAA51B6DE83CF36F9687B57DEE",
  #public key point coordinates
  pub_x => "AB53ED5D16CE550BAAF16BA4F161332AAD56D63790629C27871ED515D4FC229C",
  pub_y => "78FC34C6A320E22672A96EBB6DA48387A40541A3D7E5CFAE0D58A513E38C8888",
  pub_z => "1",
}