| 1 |
NAME |
| 2 |
Crypt::Ed25519 - bare-bones Ed25519 public key signing/verification |
| 3 |
system |
| 4 |
|
| 5 |
SYNOPSIS |
| 6 |
use Crypt::Ed25519; # no symbols exported |
| 7 |
|
| 8 |
# generate a public/private key pair once |
| 9 |
($pubkey, $privkey) = Crypt::Ed25519::generate_keypair; |
| 10 |
|
| 11 |
# sign messages |
| 12 |
$signature = Crypt::Ed25519::sign $message, $pubkey, $privkey; |
| 13 |
|
| 14 |
# verify message |
| 15 |
$valid = Crypt::Ed25519::verify $message, $pubkey, $signature; |
| 16 |
|
| 17 |
# verify, but croak on failure |
| 18 |
Crypt::Ed25519::verify_croak $message, $pubkey, $signature; |
| 19 |
|
| 20 |
DESCRIPTION |
| 21 |
This module implements Ed25519 public key generation, message signing |
| 22 |
and verification. It is a pretty bare-bones implementation that |
| 23 |
implements the standard Ed25519 variant with SHA512 hash, as well as a |
| 24 |
slower API compatible with the upcoming EdDSA RFC. |
| 25 |
|
| 26 |
The security target for Ed25519 is to be equivalent to 3000 bit RSA or |
| 27 |
AES-128. |
| 28 |
|
| 29 |
The advantages of Ed25519 over most other signing algorithms are: small |
| 30 |
public/private key and signature sizes (<= 64 octets), good key |
| 31 |
generation, signing and verification performance, no reliance on random |
| 32 |
number generators for signing and by-design immunity against branch or |
| 33 |
memory access pattern side-channel attacks. |
| 34 |
|
| 35 |
More detailed praise and other info can be found at |
| 36 |
<http://ed25519.cr.yp.to/index.html>. |
| 37 |
|
| 38 |
Ed25519 API |
| 39 |
($public_key, $private_key) = Crypt::Ed25519::generate_keypair |
| 40 |
Creates and returns a new random public and private key pair. The |
| 41 |
public key is always 32 octets, the private key is always 64 octets |
| 42 |
long. |
| 43 |
|
| 44 |
$signature = Crypt::Ed25519::sign $message, $public_key, $private_key |
| 45 |
Generates a signature for the given message using the public and |
| 46 |
private keys. |
| 47 |
|
| 48 |
$valid = Crypt::Ed25519::verify $message, $public_key, $signature |
| 49 |
Checks whether the $signature is valid for the $message and |
| 50 |
$public_ke. |
| 51 |
|
| 52 |
Crypt::Ed25519::verify_croak $message, $public_key, $signature |
| 53 |
Same as "Crypt::Ed25519::verify", but instead of returning a |
| 54 |
boolean, simply croaks with an error message when the signature |
| 55 |
isn't valid, so you don't have to think about what the return value |
| 56 |
really means. |
| 57 |
|
| 58 |
EdDSA compatible API |
| 59 |
The upcoming EdDSA draft RFC uses a slightly different (and slower) API |
| 60 |
for Ed25519. This API is provided by the following functions: |
| 61 |
|
| 62 |
$secret_key = Crypt::Ed25519::eddsa_secret_key |
| 63 |
Creates and returns a new secret key, which is always 32 octets |
| 64 |
long. The secret key can be used to generate the public key via |
| 65 |
"Crypt::Ed25519::eddsa_public_key" and is not the same as the |
| 66 |
private key used in the Ed25519 API. |
| 67 |
|
| 68 |
$public_key = Crypt::Ed25519::eddsa_public_key $secret_key |
| 69 |
Takes a secret key generated by "Crypt::Ed25519::eddsa_secret_key" |
| 70 |
and returns the corresponding $public_key. |
| 71 |
|
| 72 |
This public key corresponds to the public key in the Ed25519 API |
| 73 |
above. |
| 74 |
|
| 75 |
$signature = Crypt::Ed25519::eddsa_sign $message, $public_key, |
| 76 |
$secret_key |
| 77 |
Generates a signature for the given message using the public and |
| 78 |
secret keys. |
| 79 |
|
| 80 |
$valid = Crypt::Ed25519::eddsa_verify $message, $public_key, $signature |
| 81 |
Crypt::Ed25519::eddsa_verify_croak $message, $public_key, $signature |
| 82 |
Really the same as "Crypt::Ed25519::verify" and |
| 83 |
"Crypt::Ed25519::verify_croak", i.e. the functions without the |
| 84 |
"eddsa_" prefix. These aliases are provided so it's clear that you |
| 85 |
are using EdDSA and not Ed25519 API. |
| 86 |
|
| 87 |
CONVERTING BETWEEN Ed25519 and EdDSA |
| 88 |
The Ed25519 and EdDSA compatible APIs handle keys slightly differently: |
| 89 |
The Ed25519 API gives you a public/private key pair, while EdDSA takes a |
| 90 |
secret and generates a public key from it. |
| 91 |
|
| 92 |
You can convert an EdDSA secret to an Ed25519 private/public key pair |
| 93 |
using "Crypt::Ed25519::generate_keypair": |
| 94 |
|
| 95 |
($public_key, $private_key) = Crypt::Ed25519::generate_keypair $secret |
| 96 |
|
| 97 |
IMPLEMENTATIOIN |
| 98 |
This module currently uses "Nightcracker's Ed25519" implementation, but |
| 99 |
the interface is kept implementation-agnostic to allow usage of other |
| 100 |
implementations in the future. |
| 101 |
|
| 102 |
AUTHOR |
| 103 |
Marc Lehmann <schmorp@schmorp.de> |
| 104 |
http://sfotware.schmorp.de/pkg/Crypt-Ed25519.html |
| 105 |
|
