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.IX Title "Crypt::PK::X448 3"
.TH Crypt::PK::X448 3 2026-08-10 "perl v5.42.2" "User Contributed Perl Documentation"
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.nh
.SH NAME
Crypt::PK::X448 \- Asymmetric cryptography based on X448
.SH SYNOPSIS
.IX Header "SYNOPSIS"
.Vb 1
\& use Crypt::PK::X448;
\&
\& my $alice = Crypt::PK::X448\->new\->generate_key;
\& my $bob = Crypt::PK::X448\->new\->generate_key;
\& my $alice_secret = $alice\->shared_secret($bob);
\& my $bob_secret = $bob\->shared_secret($alice);
\& die "ERROR" unless $alice_secret eq $bob_secret;
\&
\& my $pk = Crypt::PK::X448\->new;
\& $pk\->import_key_raw(
\&   pack("H*", "cf807ab0fc3efa03108469f29e499db2eefefeb12544d8d4e711f187385aaf31b4f38c8f84a3dd9e43da309fd410c3816a50e644b5500c05"),
\&   "public",
\& );
\&
\& my $sk = Crypt::PK::X448\->new;
\& $sk\->import_key_raw(
\&   pack("H*", "10d418b111401956abc5a92c2fbb8406d1d646ba930fdefa2108efe68f2000973755aa952be018f640947c05135fbf9925ebd4da828d86ec"),
\&   "private",
\& );
\&
\& my $generated = Crypt::PK::X448\->new\->generate_key;
\& my $private_der = $generated\->export_key_der(\*(Aqprivate\*(Aq);
\& my $public_pem  = $generated\->export_key_pem(\*(Aqpublic\*(Aq);
\& my $private_jwk = $generated\->export_key_jwk(\*(Aqprivate\*(Aq);
.Ve
.SH DESCRIPTION
.IX Header "DESCRIPTION"
\&\fISince: CryptX\-0.089\fR
.SH METHODS
.IX Header "METHODS"
.SS new
.IX Subsection "new"
.Vb 2
\& my $source = Crypt::PK::X448\->new();
\& $source\->generate_key;
\&
\& my $public_der = $source\->export_key_der(\*(Aqpublic\*(Aq);
\& my $pub = Crypt::PK::X448\->new(\e$public_der);
\&
\& my $private_pem = $source\->export_key_pem(\*(Aqprivate\*(Aq, \*(Aqsecret\*(Aq, \*(AqAES\-256\-CBC\*(Aq);
\& my $priv = Crypt::PK::X448\->new(\e$private_pem, \*(Aqsecret\*(Aq);
.Ve
.PP
Passing \f(CW$filename\fR or \f(CW\*(C`\e$buffer\*(C'\fR to \f(CW\*(C`new\*(C'\fR is equivalent: both forms
immediately import the key material into the new object.
.SS generate_key
.IX Subsection "generate_key"
Returns the object itself (for chaining).
.PP
.Vb 1
\& $pk\->generate_key;
.Ve
.SS import_key
.IX Subsection "import_key"
Loads X448 private or public keys from DER, PEM, PKCS#8, SubjectPublicKeyInfo, or JWK.
.PP
.Vb 2
\& my $source = Crypt::PK::X448\->new();
\& $source\->generate_key;
\&
\& my $public_der = $source\->export_key_der(\*(Aqpublic\*(Aq);
\& my $pub = Crypt::PK::X448\->new();
\& $pub\->import_key(\e$public_der);
\& my $private_pem = $source\->export_key_pem(\*(Aqprivate\*(Aq, \*(Aqsecret\*(Aq, \*(AqAES\-256\-CBC\*(Aq);
\& my $priv = Crypt::PK::X448\->new();
\& $priv\->import_key(\e$private_pem, \*(Aqsecret\*(Aq);
\& $pk\->import_key({
\&   curve => "x448",
\&   pub   => "CF807AB0FC3EFA03108469F29E499DB2EEFEFEB12544D8D4E711F187385AAF31B4F38C8F84A3DD9E43DA309FD410C3816A50E644B5500C05",
\&   priv  => "10D418B111401956ABC5A92C2FBB8406D1D646BA930FDEFA2108EFE68F2000973755AA952BE018F640947C05135FBF9925EBD4DA828D86EC",
\& });
\& $pk\->import_key({
\&   kty => "OKP",
\&   crv => "X448",
\&   d   => "ENQYsRFAGVarxaksL7uEBtHWRrqTD976IQjv5o8gAJc3VaqVK\-AY9kCUfAUTX7\-ZJevU2oKNhuw",
\&   x   => "z4B6sPw\-\-gMQhGnynkmdsu7\-_rElRNjU5xHxhzharzG084yPhKPdnkPaMJ_UEMOBalDmRLVQDAU",
\& });
.Ve
.PP
The same method also accepts filenames instead of buffers.
.SS import_key_raw
.IX Subsection "import_key_raw"
Import raw public/private key bytes.
.PP
.Vb 2
\& $pk\->import_key_raw($key, \*(Aqpublic\*(Aq);
\& $pk\->import_key_raw($key, \*(Aqprivate\*(Aq);
.Ve
.PP
The raw key must be exactly 56 bytes long.
.SS export_key_der
.IX Subsection "export_key_der"
Returns the key as a binary DER\-encoded string.
.PP
.Vb 2
\& my $der = $pk\->export_key_der(\*(Aqprivate\*(Aq);
\& my $der = $pk\->export_key_der(\*(Aqpublic\*(Aq);
.Ve
.SS export_key_pem
.IX Subsection "export_key_pem"
Returns the key as a PEM\-encoded string (ASCII).
.PP
.Vb 3
\& my $pem = $pk\->export_key_pem(\*(Aqprivate\*(Aq);
\& my $pem = $pk\->export_key_pem(\*(Aqpublic\*(Aq);
\& my $pem = $pk\->export_key_pem(\*(Aqprivate\*(Aq, $password, \*(AqAES\-256\-CBC\*(Aq);
.Ve
.SS export_key_jwk
.IX Subsection "export_key_jwk"
Returns a JSON string, or a hashref if the optional second argument is true.
.PP
.Vb 2
\& my $json = $pk\->export_key_jwk(\*(Aqprivate\*(Aq);
\& my $hash = $pk\->export_key_jwk(\*(Aqpublic\*(Aq, 1);
.Ve
.SS export_key_raw
.IX Subsection "export_key_raw"
Returns the raw key as a binary string.
.PP
.Vb 2
\& my $raw = $pk\->export_key_raw(\*(Aqprivate\*(Aq);
\& my $raw = $pk\->export_key_raw(\*(Aqpublic\*(Aq);
.Ve
.SS shared_secret
.IX Subsection "shared_secret"
Returns the shared secret as a binary string (raw bytes).
.PP
.Vb 1
\& my $shared_secret = $private_key\->shared_secret($public_key);
.Ve
.SS is_private
.IX Subsection "is_private"
.Vb 1
\& my $rv = $pk\->is_private;
.Ve
.SS key2hash
.IX Subsection "key2hash"
Returns a hashref with the key components, or \f(CW\*(C`undef\*(C'\fR if no key is loaded.
.PP
.Vb 1
\& my $hash = $pk\->key2hash;
.Ve
.PP
Returns a hash like:
.PP
.Vb 5
\& {
\&   curve => "x448",
\&   pub   => "CF807AB0FC3EFA03108469F29E499DB2EEFEFEB12544D8D4E711F187385AAF31B4F38C8F84A3DD9E43DA309FD410C3816A50E644B5500C05",
\&   priv  => "10D418B111401956ABC5A92C2FBB8406D1D646BA930FDEFA2108EFE68F2000973755AA952BE018F640947C05135FBF9925EBD4DA828D86EC",
\& }
.Ve
.SH "OpenSSL interoperability"
.IX Header "OpenSSL interoperability"
.Vb 3
\& # Generate a key with OpenSSL
\& # openssl genpkey \-algorithm x448 \-out x448_priv.pem
\& # openssl pkey \-in x448_priv.pem \-pubout \-out x448_pub.pem
\&
\& # Load the OpenSSL\-generated key in CryptX
\& use Crypt::PK::X448;
\& my $alice = Crypt::PK::X448\->new("x448_priv.pem");
\& my $bob_pub = Crypt::PK::X448\->new("bob_x448_pub.pem");
\&
\& # Derive shared secret
\& my $shared_secret = $alice\->shared_secret($bob_pub);
\&
\& # Export CryptX key for OpenSSL
\& my $pem = $alice\->export_key_pem(\*(Aqprivate\*(Aq);
\& # then: openssl pkey \-in priv.pem \-text \-noout
.Ve
.SH "SEE ALSO"
.IX Header "SEE ALSO"
.IP \(bu 4
<https://www.rfc\-editor.org/rfc/rfc7748>
.IP \(bu 4
Crypt::PK::X25519