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