298 lines
13 KiB
Markdown
298 lines
13 KiB
Markdown
# sodium.cr
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[](https://travis-ci.org/didactic-drunk/sodium.cr)
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[](https://github.com/didactic-drunk/sodium.cr/releases)
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[](https://didactic-drunk.github.io/sodium.cr/)
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Crystal bindings for the [libsodium API](https://libsodium.gitbook.io/doc/)
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## Goals
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* Provide the most commonly used libsodium API's.
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* Provide an easy to use API based on reviewing most other [libsodium bindings](https://libsodium.gitbook.io/doc/bindings_for_other_languages).
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* Test for compatibility against other libsodium bindings to ensure interoperability.
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* Always provide a stream interface to handle arbitrarily sized data when one is available.
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* Drop in replacement classes compatible with OpenSSL::{Digest,Cipher} when possible.
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* Use the newest system packaged libsodium or download the most recent stable version without manual configuration.
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## Features
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- [Public-Key Cryptography](https://libsodium.gitbook.io/doc/public-key_cryptography)
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- [x] ☑ [Crypto Box Easy](https://libsodium.gitbook.io/doc/public-key_cryptography/authenticated_encryption)
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- [x] [Sealed Box](https://libsodium.gitbook.io/doc/public-key_cryptography/sealed_boxes)
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- [ ] [Combined Signatures](https://libsodium.gitbook.io/doc/public-key_cryptography/public-key_signatures)
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- [x] ☑ [Detached Signatures](https://libsodium.gitbook.io/doc/public-key_cryptography/public-key_signatures)
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- [ ] [Pre-hashed Signatures](https://libsodium.gitbook.io/doc/public-key_cryptography/public-key_signatures)
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- [Secret-Key Cryptography](https://libsodium.gitbook.io/doc/secret-key_cryptography)
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- Secret Box
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- [x] ☑ [Combined mode](https://libsodium.gitbook.io/doc/secret-key_cryptography/authenticated_encryption)
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- [ ] [Detached mode](https://libsodium.gitbook.io/doc/secret-key_cryptography/authenticated_encryption)
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- [x] [Secret Stream](https://libsodium.gitbook.io/doc/secret-key_cryptography/secretstream)
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- [AEAD](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead)
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- [ ] AES256-GCM (Requires hardware acceleration)
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- [x] ☑ [XChaCha20-Poly1305-IETF](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/xchacha20-poly1305_construction)
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- [ ] [ChaCha20-Poly1305-IETF](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/ietf_chacha20-poly1305_construction)
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- [ ] [ChaCha20-Poly1305](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305)
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- [x] Combined and detached mode
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- [Hashing](https://libsodium.gitbook.io/doc/hashing)
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- [x] ☑ [Blake2b](https://libsodium.gitbook.io/doc/hashing/generic_hashing)
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- [x] Complete libsodium implementation including `key`, `salt`, `personal` and fully selectable output sizes.
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- [ ] [SipHash](https://libsodium.gitbook.io/doc/hashing/short-input_hashing)
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- [Password Hashing](https://libsodium.gitbook.io/doc/password_hashing)
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- [x] ☑ [Argon2](https://libsodium.gitbook.io/doc/password_hashing/the_argon2i_function) (Use for new applications)
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- [ ] [Scrypt](https://libsodium.gitbook.io/doc/advanced/scrypt) (For compatibility with older applications)
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- Other
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- [x] [Key Derivation](https://libsodium.gitbook.io/doc/key_derivation)
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- [ ] [Key Exchange](https://libsodium.gitbook.io/doc/key_exchange)
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- [Advanced](https://libsodium.gitbook.io/doc/advanced)
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- [Stream Ciphers](https://libsodium.gitbook.io/doc/advanced/stream_ciphers)
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- [x] XSalsa20
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- [x] Salsa20
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- [x] XChaCha20
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- [x] ChaCha20 Ietf
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- [x] ChaCha20
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- [x] Easy to use methods available for use as a CSPRNG that are faster and safer than Crystal's. See `benchmarks/rand.out`.
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- [ ] [One time auth](https://libsodium.gitbook.io/doc/advanced/poly1305)
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- [ ] Padding
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- Library features
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- [x] Faster builds by requiring what you need (`require "sodium/secret_box"`)
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- [x] Nonce reuse detection.
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- [x] All SecretKey's held in libsodium guarded memory.
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- [x] No heap allocations after #initialize when possible.
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- [x] Fast. Benchmarks available in `benchmarks`.
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- [x] [Most classes are safe to share between threads.](THREAD_SAFETY.md)
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- [x] Tested with real crystal threads and will continue to work when crystal officially supports threading.
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- [x] Most classes are safe to share between threads. Even
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- [ ] Controlled memory wiping (by calling `.close`)
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☑ Indicate specs are compared against test vectors from another source.
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Several features in libsodium are already provided by Crystal:
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* Random (Use [Random::Secure](https://crystal-lang.org/api/latest/Random/Secure.html))
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* SHA-2 (Use [OpenSSL::Digest](https://crystal-lang.org/api/latest/OpenSSL/Digest.html))
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* HMAC SHA-2 (Use [OpenSSL::HMAC](https://crystal-lang.org/api/latest/OpenSSL/HMAC.html))
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* Hex conversion (Use [String#hexbytes](https://crystal-lang.org/api/latest/String.html#hexbytes%3ABytes-instance-method))
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## What should I use for my application?
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| Class | |
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| --- | --- |
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| Only use `CryptoBox::SecretKey` `Sign::SecretKey` `Aead::XChaCha20Poly1305Ietf` `SecretBox` | I don't know much about crypto. |
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| [`Sodium::CryptoBox::SecretKey`](https://didactic-drunk.github.io/sodium.cr/Sodium/CryptoBox/SecretKey.html) .box | I want to encrypt + authenticate data using public key encryption. |
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| [`Sodium::CryptoBox::SecretKey`](https://didactic-drunk.github.io/sodium.cr/Sodium/CryptoBox/PublicKey.html) .encrypt | I want anonymously send encrypted data. (No signatures) |
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| [`Sodium::Sign::SecretKey`](https://didactic-drunk.github.io/sodium.cr/Sodium/Sign/SecretKey.html) | I want to sign or verify messages. (No encryption) |
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| [`Sodium::Cipher::Aead::XChaCha20Poly1305Ietf` (new applications) `Sodium::SecretBox` (compatibility with older applications)](https://didactic-drunk.github.io/sodium.cr/Sodium/Cipher/Aead/XChaCha20Poly1305Ietf.html) | I have a shared key and want to encrypt + authenticate data. |
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| [`Sodium::Cipher::Aead::XChaCha20Poly1305Ietf`](https://didactic-drunk.github.io/sodium.cr/Sodium/Cipher/Aead/XChaCha20Poly1305Ietf.html) | I have a shared key and want to encrypt + authenticate data and authenticate additional plaintext data. |
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| [`Sodium::Cipher::SecretStream`](https://didactic-drunk.github.io/sodium.cr/Sodium/Cipher/SecretStream/XChaCha20Poly1305.html) | I have a shared key and want encrypt + authenticate streamed data. |
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| [`Sodium::Digest::Blake2b`](https://didactic-drunk.github.io/sodium.cr/Sodium/Digest/Blake2b.html) | I want to hash data fast and securely. |
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| `Sodium::Digest::SipHash` | I want to hash data really fast and less securely. (Not implemented yet) |
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| [`Sodium::Password::Hash`](https://didactic-drunk.github.io/sodium.cr/Sodium/Password/Hash.html) | I want to hash a password and store it. |
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| [`Sodium::Password::Key`](https://didactic-drunk.github.io/sodium.cr/Sodium/Password/Key.html) | I want to derive a key from a password. |
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| [`Sodium::Kdf`](https://didactic-drunk.github.io/sodium.cr/Sodium/Kdf.html) | I have a high quality master key and want to make subkeys. |
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| [`Sodium::Cipher::Chalsa`](https://didactic-drunk.github.io/sodium.cr/Sodium/Cipher/Chalsa.html) | What goes with guacamole? |
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| Everything else | I want to design my own crypto protocol and probably do it wrong. |
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## Installation
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**[Optionally Install libsodium.](https://download.libsodium.org/doc/installation/)**
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A recent version of libsodium is automatically downloaded and compiled if you don't install your own version.
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Add this to your application's `shard.yml`:
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```yaml
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dependencies:
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sodium:
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github: didactic-drunk/sodium.cr
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```
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## Usage
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See `examples` for help on using these classes in a complete application.
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The `specs` provide the best examples of how to use or misuse individual classes.
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```
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### CryptoBox authenticated easy encryption
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```crystal
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require "sodium"
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data = "Hello World!"
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# Alice is the sender
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alice = Sodium::CryptoBox::SecretKey.new
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# Bob is the recipient
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bob = Sodium::CryptoBox::SecretKey.new
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# Precompute a shared secret between alice and bob.
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box = alice.box bob.public_key
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# Encrypt a message for Bob using his public key, signing it with Alice's
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# secret key
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encrypted, nonce = box.encrypt data
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# Precompute within a block. The shared secret is wiped when the block exits.
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bob.box alice.public_key do |box|
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# Decrypt the message using Bob's secret key, and verify its signature against
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# Alice's public key
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decrypted = box.decrypt encrypted, nonce: nonce
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String.new(decrypted) # => "Hello World!"
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end
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```
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### Unauthenticated public key encryption
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```crystal
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data = "Hello World!"
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# Bob is the recipient
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bob = Sodium::CryptoBox::SecretKey.new
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# Encrypt a message for Bob using his public key
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encrypted = bob.public_key.encrypt data
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# Decrypt the message using Bob's secret key
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decrypted = bob.decrypt encrypted
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String.new(decrypted) # => "Hello World!"
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```
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### Public key signing
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```crystal
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message = "Hello World!"
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secret_key = Sodium::Sign::SecretKey.new
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# Sign the message
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signature = secret_key.sign_detached message
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# Send secret_key.public_key to the recipient
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# On the recipient
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public_key = Sodium::Sign::PublicKey.new key_bytes
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# raises Sodium::Error::VerificationFailed on failure.
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public_key.verify_detached message, signature
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```
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### Secret Key Encryption
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```crystal
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box = Sodium::SecretBox.new
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message = "foobar"
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encrypted, nonce = box.encrypt message
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# On the other side.
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box = Sodium::SecretKey.new key
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message = box.decrypt encrypted, nonce: nonce
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```
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### Blake2b
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```crystal
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key = Bytes.new Sodium::Digest::Blake2B::KEY_SIZE
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salt = Bytes.new Sodium::Digest::Blake2B::SALT_SIZE
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personal = Bytes.new Sodium::Digest::Blake2B::PERSONAL_SIZE
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out_size = 64 # bytes between Sodium::Digest::Blake2B::OUT_SIZE_MIN and Sodium::Digest::Blake2B::OUT_SIZE_MAX
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data = "data".to_slice
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# output_size, key, salt, and personal are optional.
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digest = Sodium::Digest::Blake2b.new out_size, key: key, salt: salt, personal: personal
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digest.update data
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output = d.hexfinal
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digest.reset # Reuse existing object to hash again.
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digest.update data
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output = d.hexfinal
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```
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### Key derivation
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```crystal
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kdf = Sodium::Kdf.new
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# kdf.derive(8_byte_context, subkey_id, subkey_size)
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subkey1 = kdf.derive "context1", 0, 16
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subkey2 = kdf.derive "context1", 1, 16
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subkey3 = kdf.derive "context2", 0, 32
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subkey4 = kdf.derive "context2", 1, 64
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```
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### Password based keys
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```crystal
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pwcreate = Sodium::Password::Key::Create.new
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# Take approximately 1 second to derive a key.
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pwcreate.tcost = 1.0
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pass = "1234"
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key, params = pwcreate.create_key pass
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# Store `params` or `params.to_h` for later.
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# Derive the same key from the stored params.
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pwkey = Sodium::Password::Key.from_params params.to_h
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key = pekey.derive_key pass
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```
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### Password Hashing
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```crystal
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pwhash = Sodium::Password::Hash.new
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pwhash.mem = Sodium::Password::MEMLIMIT_MIN
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pwhash.ops = Sodium::Password::OPSLIMIT_MIN
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pass = "1234"
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hash = pwhash.create pass
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pwhash.verify hash, pass
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```
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Use `examples/pwhash_selector.cr` to help choose ops/mem limits.
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Example output:
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Ops limit →
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| | 1 | 4 | 16 | 64 | 256 | 1024 | 4096 | 16384 | 65536 | 262144 | 1048576 |
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| -------- | ------- | ------- | ------- | ------- | ------- | ------- | ------- | ------- | ------- | ------- | ------- |
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| 8K | | | | | | | | | | 0.542s | 2.114s |
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| 32K | | | | | | | | | 0.513s | 2.069s |
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| 128K | | | | | | | | 0.530s | 2.121s |
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| 512K | | | | | | | 0.566s | 2.237s |
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| 2048K | | | | | | 0.567s | 2.290s |
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| 8192K | | | | | 0.670s | 2.542s |
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| 32768K | | | | 0.684s | 2.777s |
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| 131072K | | | 0.805s | 3.106s |
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| 524288K | 0.504s | 1.135s | 3.661s |
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| 2097152K | 2.119s |
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| Memory |
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## Contributing
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1. Fork it ( https://github.com/didactic-drunk/sodium.cr/fork )
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2. **Install a formatting check git hook (ln -sf ../../scripts/git/pre-commit .git/hooks)**
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3. Create your feature branch (git checkout -b my-new-feature)
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4. Commit your changes (git commit -am 'Add some feature')
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5. Push to the branch (git push origin my-new-feature)
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6. Create a new Pull Request
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## Project History
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* Originally created by [Andrew Hamon](https://github.com/andrewhamons/cox)
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* Forked by [Didactic Drunk](https://github.com/didactic-drunk/cox) for lack of updates in the original project.
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* Complaints about the name being too controversial. Project name changed from "cox" to a more libsodium related name of "salty seaman".
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* ~50% complete libsodium API.
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* More complaints about the name. Dead hooker jokes added.
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* None of the original API is left.
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* More complaints threatening a boycott. Told them "Go ahead, I own Coca Cola and Water".
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* Account unsuspended.
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* Unrelated to the boycott the project name changed to "libsodium" because sodium happens to be a tasty byproduct of the two earlier names.
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* Account unsuspended.
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* Dead hooker jokes (mostly) removed.
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## Contributors
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- [andrewhamon](https://github.com/andrewhamon) Andrew Hamon - creator, former maintainer
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- [dorkrawk](https://github.com/dorkrawk) Dave Schwantes - contributor
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- [didactic-drunk](https://github.com/didactic-drunk) - current maintainer
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