Akero (ἄγγελος, messenger) is an easy-to-use library for peer-to-peer public key cryptography. It enables two or more endpoints to exchange encrypted and/or signed messages without requiring a pre-shared secret.
Under the hood Akero uses standard OpenSSL primitives. Each instance wraps a RSA-keypair, a corresponding X.509 certificate and exchanges self-signed messages (PKCS#7) with other instances.
Akero does not try to be a substitute for a fully featured PKI. It is meant to be used as a building block in scenarios where trust-relationships and keyrings can be managed externally, and where the complexity of traditional solutions (X.509 PKI, OpenPGP, custom RSA) yields no tangible benefits.
- Secure 1-to-n messaging (sign-only -or- sign->encrypt->sign)
- Low complexity; easy to use, understand and review (only 192 lines of code)
- Transport agnostic; messages and certificates are self-contained and optionally ascii-armored (base64)
- Built on standard OpenSSL primitives, no homegrown algorithms
- 100% test coverage
gem install akero
require 'akero'
# Alice, Bob and Charlie are Akero instances
alice = Akero.new
bob = Akero.new
charlie = Akero.new
# Inspect Alice's keypair fingerprint
alice.id # => "AK:12:34:56:..."
# Alice signs a message
signed_msg = alice.sign("Hello world!")
# Anyone can receive this message and extract
# Alice's fingerprint and public key from it
msg = bob.receive(signed_msg)
msg.body # => "Hello world!"
msg.type # => :signed
msg.from # => "AK:12:34:56:..."
msg.from_pk # => "(alice-public-key)"
# Bob encrypts a message for Alice
bobs_msg = bob.encrypt(msg.from_pk, "Hello Alice!")
# Alice can receive it...
msg = alice.receive(bobs_msg)
msg.body # => "Hello Alice!"
msg.type # => :encrypted
msg.from # => "AK:ab:cd:ef:..."
msg.from_pk # => "(bob-public-key)"
# ...and Charlie can't
msg = charlie.receive(bobs_msg) # => Exception is raised
# Alice encrypts a message for Bob and Charlie
msg = alice.encrypt([bob.public_key, charlie.public_key], "Hello!")
# Save Alice to a file
File.open('/tmp/alice.akr', 'w') { |f| f.write(alice.private_key) }
# And load her again
new_alice = Akero.load(File.read('/tmp/alice.akr'))
# By default all messages are ascii armored.
# In production Alice disables the armoring
# for better performance.
signed_msg = alice.sign("Hello world!", false)
encrypted_msg = alice.encrypt(alice.public_key, "Hello!", false)
puts alice.receive(encrypted_msg).body # => "Hello!"$ akero id -i /tmp/alice.akr
Private key not found. Generating a new 4096 bits RSA key and saving to /tmp/alice.akr ...
AK:8B:33:5B:AB:4C:78:CA:5E:CC:F5:FE:D7:75:F2:A4:74:16:28:FB:C2
$ akero id -i /tmp/bob.akr
Private key not found. Generating a new 4096 bits RSA key and saving to /tmp/bob.akr ...
AK:CF:B3:4C:BA:7C:9C:2E:31:2D:0D:1D:3F:F9:F4:05:F6:C7:B2:38:3F
$ akero pk -i /tmp/bob.akr >/tmp/bob.pk
$ echo "Hello" | akero encrypt -i /tmp/alice.akr /tmp/bob.pk | akero receive -i /tmp/bob.akr
Hello
The above charts were generated using MRI 1.9.3p362 (x86_64-linux) on an AMD Turion II Neo N40L CPU.
You may run the benchmarks on your own machine with rake benchmark.
Copyright (c) 2012 [email protected]
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