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('secp160r1');
 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');
 my $public_raw = $pk->export_key_raw('public');

 ### 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 as implementation of ECDSA and ECDH.

Supports elliptic curves "y^2 = x^3 + a*x + b" over prime fields "Fp = Z/pZ" (binary fields not supported).

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);

Support for password protected PEM keys

 my $pk = Crypt::PK::ECC->new($priv_pem_key_filename, $password);
 #or
 my $pk = Crypt::PK::ECC->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).

 $pk->generate_key($curve_name);
 #or
 $pk->generate_key($hashref_with_curve_params);

The following predefined $curve_name values are supported:

 # curves from http://www.ecc-brainpool.org/download/Domain-parameters.pdf
 'brainpoolp160r1'
 'brainpoolp192r1'
 'brainpoolp224r1'
 'brainpoolp256r1'
 'brainpoolp320r1'
 'brainpoolp384r1'
 'brainpoolp512r1'
 # curves from http://www.secg.org/collateral/sec2_final.pdf
 'secp112r1'
 'secp112r2'
 'secp128r1'
 'secp128r2'
 'secp160k1'
 'secp160r1'
 'secp160r2'
 'secp192k1'
 'secp192r1'   ... same as nistp192, prime192v1
 'secp224k1'
 'secp224r1'   ... same as nistp224
 'secp256k1'   ... used by Bitcoin
 'secp256r1'   ... same as nistp256, prime256v1
 'secp384r1'   ... same as nistp384
 'secp521r1'   ... same as nistp521
 #curves from http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf
 'nistp192'    ... same as secp192r1, prime192v1
 'nistp224'    ... same as secp224r1
 'nistp256'    ... same as secp256r1, prime256v1
 'nistp384'    ... same as secp384r1
 'nistp521'    ... same as secp521r1
 # curves from ANS X9.62
 'prime192v1'   ... same as nistp192, secp192r1
 'prime192v2'
 'prime192v3'
 'prime239v1'
 'prime239v2'
 'prime239v3'
 'prime256v1'   ... same as nistp256, secp256r1

Using custom curve parameters:

 $pk->generate_key({ prime    => 'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF',
                     A        => 'FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFC',
                     B        => '22123DC2395A05CAA7423DAECCC94760A7D462256BD56916',
                     Gx       => '7D29778100C65A1DA1783716588DCE2B8B4AEE8E228F1896',
                     Gy       => '38A90F22637337334B49DCB66A6DC8F9978ACA7648A943B0',
                     order    => 'FFFFFFFFFFFFFFFFFFFFFFFF7A62D031C83F4294F640EC13',
                     cofactor => 1 });

See <http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf>, <http://www.secg.org/collateral/sec2_final.pdf>, <http://www.ecc-brainpool.org/download/Domain-parameters.pdf>

import_key

Loads private or public key in DER or PEM format.

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

Support for password protected PEM keys:

 $pk->import_key($filename, $password);
 #or
 $pk->import_key(\$buffer_containing_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({
      curve_A        => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFC",
      curve_B        => "1C97BEFC54BD7A8B65ACF89F81D4D4ADC565FA45",
      curve_bits     => 160,
      curve_bytes    => 20,
      curve_cofactor => 1,
      curve_Gx       => "4A96B5688EF573284664698968C38BB913CBFC82",
      curve_Gy       => "23A628553168947D59DCC912042351377AC5FB32",
      curve_order    => "0100000000000000000001F4C8F927AED3CA752257",
      curve_prime    => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFF",
      k              => "B0EE84A749FE95DF997E33B8F333E12101E824C3",
      pub_x          => "5AE1ACE3ED0AEA9707CE5C0BCE014F6A2F15023A",
      pub_y          => "895D57E992D0A15F88D6680B27B701F615FCDC0F",
 });

 # or with the curve defined just by name
 $pk->import_key({
      curve_name => "secp160r1",
      k          => "B0EE84A749FE95DF997E33B8F333E12101E824C3",
      pub_x      => "5AE1ACE3ED0AEA9707CE5C0BCE014F6A2F15023A",
      pub_y      => "895D57E992D0A15F88D6680B27B701F615FCDC0F",
 });

 # or a hash with items corresponding to JWK (JSON Web Key)
 $pk->import_key({
       kty => "EC",
       crv => "P-256",
       x   => "MKBCTNIcKUSDii11ySs3526iDZ8AiTo7Tu6KPAqv7D4",
       y   => "4Etl6SRW2YiLUrN5vfvVHuhp7x8PxltmWWlbbM4IFyM",
       d   => "870MB6gfuTJ4HtUnUvYMyJpr5eUZNP4Bk43bVdj3eAE",
 });

Supported key formats:

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

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

EC private keys with with all curve parameters

EC private keys with curve defined by OID (short form)

EC private keys with curve defined by OID + compressed form (supported since: CryptX-0.059)

 -----BEGIN EC PRIVATE KEY-----
 MFcCAQEEIBG1c3z52T8XwMsahGVdOZWgKCQJfv+l7djuJjgetdbDoAoGCCqGSM49
 AwEHoSQDIgADoBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE=
 -----END EC PRIVATE KEY-----

EC private keys in password protected PEM format

EC public keys with all curve parameters

EC public keys with curve defined by OID (short form)

 -----BEGIN PUBLIC KEY-----
 MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEoBUyo8CQAFPeYPvv78ylh5MwFZjT
 CLQeb042TjiMJxG+9DLFmRSMlBQ9T/RsLLc+PmpB1+7yPAR+oR5gZn3kJQ==
 -----END PUBLIC KEY-----

EC public keys with curve defined by OID + public point in compressed form (supported since: CryptX-0.059)

 -----BEGIN PUBLIC KEY-----
 MDkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDIgADoBUyo8CQAFPeYPvv78ylh5MwFZjT
 CLQeb042TjiMJxE=
 -----END PUBLIC KEY-----

PKCS#8 private keys with all curve parameters

PKCS#8 private keys with curve defined by OID (short form)

PKCS#8 encrypted private keys - password protected keys (supported since: CryptX-0.059)

EC public key from X509 certificate

SSH public EC keys

 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNT...T3xYfJIs=

SSH public EC keys (RFC-4716 format)

 ---- BEGIN SSH2 PUBLIC KEY ----
 Comment: "521-bit ECDSA, converted from OpenSSH"
 AAAAE2VjZHNhLXNoYTItbmlzdHA1MjEAAAAIbmlzdHA1MjEAAACFBAFk35srteP9twCwYK
 vU9ovMBi77Dd6lEBPrFaMEb0CZdZ5MC3nSqflGHRWkSbUpjdPdO7cYQNpK9YXHbNSO5hbU
 1gFZgyiGFxwJYYz8NAjedBXMgyH4JWplK5FQm5P5cvaglItC9qkKioUXhCc67YMYBtivXl
 Ue0PgIq6kbHTqbX6+5Nw==
 ---- END SSH2 PUBLIC KEY ----

EC private keys in JSON Web Key (JWK) format

See <http://tools.ietf.org/html/draft-ietf-jose-json-web-key>

 {
  "kty":"EC",
  "crv":"P-256",
  "x":"MKBCTNIcKUSDii11ySs3526iDZ8AiTo7Tu6KPAqv7D4",
  "y":"4Etl6SRW2YiLUrN5vfvVHuhp7x8PxltmWWlbbM4IFyM",
  "d":"870MB6gfuTJ4HtUnUvYMyJpr5eUZNP4Bk43bVdj3eAE",
 }

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

EC public keys in JSON Web Key (JWK) format

 {
  "kty":"EC",
  "crv":"P-256",
  "x":"MKBCTNIcKUSDii11ySs3526iDZ8AiTo7Tu6KPAqv7D4",
  "y":"4Etl6SRW2YiLUrN5vfvVHuhp7x8PxltmWWlbbM4IFyM",
 }

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

import_key_raw

Import raw public/private key - can load data exported by "export_key_raw".

 $pk->import_key_raw($key, $curve);
 # $key .... data exported by export_key_raw()
 # $curve .. curve name or hashref with curve parameters - same as by generate_key()

export_key_der

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

Since CryptX-0.36 "export_key_der" can also export keys in a format that does not explicitly contain curve parameters but only curve OID.

 my $private_der = $pk->export_key_der('private_short');
 #or
 my $public_der = $pk->export_key_der('public_short');

Since CryptX-0.59 "export_key_der" can also export keys in "compressed" format that defines curve by OID + stores public point in compressed form.

 my $private_pem = $pk->export_key_der('private_compressed');
 #or
 my $public_pem = $pk->export_key_der('public_compressed');

export_key_pem

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

Since CryptX-0.36 "export_key_pem" can also export keys in a format that does not explicitly contain curve parameters but only curve OID.

 my $private_pem = $pk->export_key_pem('private_short');
 #or
 my $public_pem = $pk->export_key_pem('public_short');

Since CryptX-0.59 "export_key_pem" can also export keys in "compressed" format that defines curve by OID + stores public point in compressed form.

 my $private_pem = $pk->export_key_pem('private_compressed');
 #or
 my $public_pem = $pk->export_key_pem('public_compressed');

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');

Export raw public/private key. Public key is exported in ASN X9.62 format (compressed or uncompressed), private key is exported as raw bytes (padded with leading zeros to have the same size as the ECC curve).

 my $pubkey_octets  = $pk->export_key_raw('public');
 #or
 my $pubckey_octets = $pk->export_key_raw('public_compressed');
 #or
 my $privkey_octets = $pk->export_key_raw('private');

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

sign_message_rfc7518

Since: CryptX-0.024

Same as sign_message only the signature format is as defined by <https://tools.ietf.org/html/rfc7518> (JWA - JSON Web Algorithms).

BEWARE: This creates signatures according to the structure that RFC 7518 describes but does not apply the RFC logic for the hashing algorithm selection. You'll still need to specify, e.g., SHA256 for a P-256 key to get a fully RFC-7518-compliant signature.

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

verify_message_rfc7518

Since: CryptX-0.024

Same as verify_message only the signature format is as defined by <https://tools.ietf.org/html/rfc7518> (JWA - JSON Web Algorithms).

BEWARE: This verifies signatures according to the structure that RFC 7518 describes but does not apply the RFC logic for the hashing algorithm selection. You'll still need to specify, e.g., SHA256 for a P-256 key to get a fully RFC-7518-compliant signature.

sign_hash

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

sign_hash_rfc7518

Since: CryptX-0.059

Same as sign_hash only the signature format is as defined by <https://tools.ietf.org/html/rfc7518> (JWA - JSON Web Algorithms).

verify_hash

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

verify_hash_rfc7518

Since: CryptX-0.059

Same as verify_hash only the signature format is as defined by <https://tools.ietf.org/html/rfc7518> (JWA - JSON Web Algorithms).

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):
 {
   size           => 20, # integer: key (curve) size in bytes
   type           => 1,  # integer: 1 .. private, 0 .. public
   #curve parameters
   curve_A        => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFC",
   curve_B        => "1C97BEFC54BD7A8B65ACF89F81D4D4ADC565FA45",
   curve_bits     => 160,
   curve_bytes    => 20,
   curve_cofactor => 1,
   curve_Gx       => "4A96B5688EF573284664698968C38BB913CBFC82",
   curve_Gy       => "23A628553168947D59DCC912042351377AC5FB32",
   curve_name     => "secp160r1",
   curve_order    => "0100000000000000000001F4C8F927AED3CA752257",
   curve_prime    => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFF",
   #private key
   k              => "B0EE84A749FE95DF997E33B8F333E12101E824C3",
   #public key point coordinates
   pub_x          => "5AE1ACE3ED0AEA9707CE5C0BCE014F6A2F15023A",
   pub_y          => "895D57E992D0A15F88D6680B27B701F615FCDC0F",
 }

curve2hash

Since: CryptX-0.024

 my $crv = $pk->curve2hash;

 # returns a hash that can be passed to: $pk->generate_key($crv)
 {
   A        => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFC",
   B        => "1C97BEFC54BD7A8B65ACF89F81D4D4ADC565FA45",
   cofactor => 1,
   Gx       => "4A96B5688EF573284664698968C38BB913CBFC82",
   Gy       => "23A628553168947D59DCC912042351377AC5FB32",
   order    => "0100000000000000000001F4C8F927AED3CA752257",
   prime    => "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF7FFFFFFF",
 }

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');

OpenSSL interoperability

 ### let's have:
 # ECC private key in PEM format - eckey.priv.pem
 # ECC public key in PEM format  - eckey.pub.pem
 # data file to be signed - input.data

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

Create signature (from commandline):

 openssl dgst -sha1 -sign eckey.priv.pem -out input.sha1-ec.sig input.data

Verify signature (Perl code):

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

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

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

Create signature (Perl code):

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

 my $pkec = Crypt::PK::ECC->new("eckey.priv.pem");
 my $signature = $pkec->sign_hash(digest_file("SHA1", "input.data"), "SHA1", "v1.5");
 write_rawfile("input.sha1-ec.sig", $signature);

Verify signature (from commandline):

 openssl dgst -sha1 -verify eckey.pub.pem -signature input.sha1-ec.sig input.data

Keys generated by Crypt::PK::ECC

Generate keys (Perl code):

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

 my $pkec = Crypt::PK::ECC->new;
 $pkec->generate_key('secp160k1');
 write_rawfile("eckey.pub.der",  $pkec->export_key_der('public'));
 write_rawfile("eckey.priv.der", $pkec->export_key_der('private'));
 write_rawfile("eckey.pub.pem",  $pkec->export_key_pem('public'));
 write_rawfile("eckey.priv.pem", $pkec->export_key_pem('private'));
 write_rawfile("eckey-passwd.priv.pem", $pkec->export_key_pem('private', 'secret'));

Use keys by OpenSSL:

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

Keys generated by OpenSSL

Generate keys:

 openssl ecparam -param_enc explicit -name prime192v3 -genkey -out eckey.priv.pem
 openssl ec -param_enc explicit -in eckey.priv.pem -out eckey.pub.pem -pubout
 openssl ec -param_enc explicit -in eckey.priv.pem -out eckey.priv.der -outform der
 openssl ec -param_enc explicit -in eckey.priv.pem -out eckey.pub.der -outform der -pubout
 openssl ec -param_enc explicit -in eckey.priv.pem -out eckey.privc.der -outform der -conv_form compressed
 openssl ec -param_enc explicit -in eckey.priv.pem -out eckey.pubc.der -outform der -pubout -conv_form compressed
 openssl ec -param_enc explicit -in eckey.priv.pem -passout pass:secret -des3 -out eckey-passwd.priv.pem

Load keys (Perl code):

 use Crypt::PK::ECC;

 my $pkec = Crypt::PK::ECC->new;
 $pkec->import_key("eckey.pub.der");
 $pkec->import_key("eckey.pubc.der");
 $pkec->import_key("eckey.priv.der");
 $pkec->import_key("eckey.privc.der");
 $pkec->import_key("eckey.pub.pem");
 $pkec->import_key("eckey.priv.pem");
 $pkec->import_key("eckey-passwd.priv.pem", "secret");