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=head1 NAME |
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Crypt::Ed25519 - bare-bones Ed25519 public key signing/verification system |
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=head1 SYNOPSIS |
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|
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use Crypt::Ed25519; # no symbols exported |
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|
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# generate a public/private key pair once |
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($pubkey, $privkey) = Crypt::Ed25519::generate_keypair; |
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|
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# sign messages |
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$signature = Crypt::Ed25519::sign $message, $pubkey, $privkey; |
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|
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# verify message |
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$valid = Crypt::Ed25519::verify $message, $pubkey, $signature; |
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|
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# verify, but croak on failure |
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Crypt::Ed25519::verify_croak $message, $pubkey, $signature; |
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=head1 DESCRIPTION |
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|
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This module implements Ed25519 public key generation, message signing and |
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verification. It is a pretty bare-bones implementation that implements |
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the standard Ed25519 variant with SHA512 hash, as well as a slower API |
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compatible with the upcoming EdDSA RFC. |
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The security target for Ed25519 is to be equivalent to 3000 bit RSA or |
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AES-128. |
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The advantages of Ed25519 over most other signing algorithms are: |
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small public/private key and signature sizes (<= 64 octets), good key |
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generation, signing and verification performance, no reliance on random |
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number generators for signing and by-design immunity against branch or |
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memory access pattern side-channel attacks. |
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|
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More detailed praise and other info can be found at |
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L<http://ed25519.cr.yp.to/index.html>. |
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|
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=cut |
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|
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package Crypt::Ed25519; |
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|
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BEGIN { |
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$VERSION = '0.1'; |
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|
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require XSLoader; |
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XSLoader::load Crypt::Ed25519::, $VERSION; |
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} |
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|
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=head1 Ed25519 API |
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|
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=over 4 |
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|
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=item ($public_key, $private_key) = Crypt::Ed25519::generate_keypair |
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|
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Creates and returns a new random public and private key pair. The public |
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key is always 32 octets, the private key is always 64 octets long. |
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|
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=item $signature = Crypt::Ed25519::sign $message, $public_key, $private_key |
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Generates a signature for the given message using the public and private keys. |
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=item $valid = Crypt::Ed25519::verify $message, $public_key, $signature |
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Checks whether the C<$signature> is valid for the C<$message> and C<$public_ke>. |
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|
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=item Crypt::Ed25519::verify_croak $message, $public_key, $signature |
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|
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Same as C<Crypt::Ed25519::verify>, but instead of returning a boolean, |
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simply croaks with an error message when the signature isn't valid, so you |
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don't have to think about what the return value really means. |
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|
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=back |
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|
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=head1 EdDSA compatible API |
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|
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The upcoming EdDSA draft RFC uses a slightly different (and slower) |
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API for Ed25519. This API is provided by the following functions: |
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|
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=over 4 |
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|
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=item $secret_key = Crypt::Ed25519::eddsa_secret_key |
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|
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Creates and returns a new secret key, which is always 32 octets |
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long. The secret key can be used to generate the public key via |
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C<Crypt::Ed25519::eddsa_public_key> and is not the same as the private key |
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used in the Ed25519 API. |
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=item $public_key = Crypt::Ed25519::eddsa_public_key $secret_key |
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Takes a secret key generated by C<Crypt::Ed25519::eddsa_secret_key> and |
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returns the corresponding C<$public_key>. |
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|
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This public key corresponds to the public key in the Ed25519 API above. |
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|
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=item $signature = Crypt::Ed25519::eddsa_sign $message, $public_key, $secret_key |
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|
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Generates a signature for the given message using the public and secret |
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keys. |
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=item $valid = Crypt::Ed25519::eddsa_verify $message, $public_key, $signature |
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|
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=item Crypt::Ed25519::eddsa_verify_croak $message, $public_key, $signature |
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Really the same as C<Crypt::Ed25519::verify> and |
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C<Crypt::Ed25519::verify_croak>, i.e. the functions without the C<eddsa_> |
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prefix. These aliases are provided so it's clear that you are using EdDSA |
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and not Ed25519 API. |
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=back |
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=head1 CONVERTING BETWEEN Ed25519 and EdDSA |
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The Ed25519 and EdDSA compatible APIs handle keys slightly |
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differently: The Ed25519 API gives you a public/private key pair, while |
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EdDSA takes a secret and generates a public key from it. |
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You can convert an EdDSA secret to an Ed25519 private/public key pair |
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using C<Crypt::Ed25519::generate_keypair>: |
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($public_key, $private_key) = Crypt::Ed25519::generate_keypair $secret |
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=head2 IMPLEMENTATIOIN |
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This module currently uses "Nightcracker's Ed25519" implementation, but |
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the interface is kept implementation-agnostic to allow usage of other |
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implementations in the future. |
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|
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=head1 AUTHOR |
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|
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Marc Lehmann <schmorp@schmorp.de> |
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http://sfotware.schmorp.de/pkg/Crypt-Ed25519.html |
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=cut |
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1 |
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