Sodium::Cipher::Aead::Xchacha20Poly1305Ietf Add combined mode.

master
Didactic Drunk 2019-09-13 03:15:00 -07:00
parent 192044b27a
commit 964fe714e9
3 changed files with 79 additions and 18 deletions

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@ -32,6 +32,7 @@ Crystal bindings for the [libsodium API](https://libsodium.gitbook.io/doc/)
- [x] [XChaCha20-Poly1305-IETF](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/xchacha20-poly1305_construction)
- [ ] [ChaCha20-Poly1305-IETF](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305/ietf_chacha20-poly1305_construction)
- [ ] [ChaCha20-Poly1305](https://libsodium.gitbook.io/doc/secret-key_cryptography/aead/chacha20-poly1305)
- [x] Combined and detached mode
- [Hashing](https://libsodium.gitbook.io/doc/hashing)
- [x] ☑ [Blake2b](https://libsodium.gitbook.io/doc/hashing/generic_hashing)
- [x] Complete libsodium implementation including `key`, `salt`, `personal` and fully selectable output sizes.

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@ -29,18 +29,43 @@ end
{% for name in %w(Xchacha20Poly1305Ietf) %}
# TODO: verify against test vectors.
describe Sodium::Cipher::Aead::{{ name.id }} do
it "encrypts/decrypts" do
it "encrypts/decrypts in combined mode" do
box = Sodium::Cipher::Aead::{{ name.id }}.new
message = "foobar"
additional = "foo"
mac, encrypted, nonce = box.encrypt_detached message, additional: additional
decrypted = box.decrypt_detached encrypted, nonce: nonce, mac: mac, additional: additional
message.should eq String.new(decrypted)
message = "foo"
additional = "bar"
encrypted, nonce = box.encrypt message, additional: additional
decrypted = box.decrypt_string encrypted, nonce: nonce, additional: additional
decrypted.should eq message
# Wrong additional.
expect_raises(Sodium::Error::DecryptionFailed) do
box.decrypt_detached encrypted, nonce: nonce, mac: mac, additional: "bar".to_slice
box.decrypt encrypted, nonce: nonce, additional: "baz".to_slice
end
# Missing additional.
expect_raises(Sodium::Error::DecryptionFailed) do
box.decrypt encrypted, nonce: nonce
end
# Wrong data.
expect_raises(Sodium::Error::DecryptionFailed) do
box.decrypt "badmsgbadmsgbadmsgbadmsgbadmsg".to_slice, nonce: nonce
end
end
it "encrypts/decrypts in detached mode" do
box = Sodium::Cipher::Aead::{{ name.id }}.new
message = "foo"
additional = "bar"
mac, encrypted, nonce = box.encrypt_detached message, additional: additional
decrypted = box.decrypt_detached_string encrypted, nonce: nonce, mac: mac, additional: additional
decrypted.should eq message
# Wrong additional.
expect_raises(Sodium::Error::DecryptionFailed) do
box.decrypt_detached encrypted, nonce: nonce, mac: mac, additional: "baz".to_slice
end
# Missing additional.
@ -57,7 +82,7 @@ end
it "can't encrypt twice using the same nonce" do
box = Sodium::Cipher::Aead::{{ name.id }}.new
message = "foobar"
message = "foo"
mac, encrypted, nonce = box.encrypt_detached message
expect_raises(Sodium::Nonce::Error::Reused) do

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@ -15,25 +15,56 @@ module Sodium::Cipher::Aead
end
# Encrypts data and returns {ciphertext, nonce}
def encrypt(data)
encrypt data.to_slice
end
# Encrypts data and returns {mac, ciphertext, nonce}
def encrypt_detached(data, dst : Bytes? = nil, *, mac : Bytes? = nil, additional = nil)
encrypt_detached data.to_slice, mac: mac, additional: additional
def encrypt(src, dst : Bytes? = nil, *, nonce = nil, additional = nil)
{Bytes, Nonce}
offset = src.bytesize
dst ||= Bytes.new (offset + mac_size)
mac = dst[offset, mac_size]
_, _, nonce = encrypt_detached src.to_slice, dst[0, offset], mac: mac, nonce: nonce, additional: additional
{dst, nonce}
end
# Decrypts data and returns plaintext
def decrypt(src, dst : Bytes? = nil, *, nonce : Nonce, additional = nil) : Bytes
src = src.to_slice
offset = src.bytesize - mac_size
mac = src[offset, mac_size]
decrypt_detached src[0, offset], dst, nonce: nonce, mac: mac, additional: additional
end
# Decrypts data and returns plaintext
def decrypt_string(src, dst : Bytes? = nil, *, nonce : Nonce, additional = nil) : String
buf = decrypt src, dst, nonce: nonce, additional: additional
# TODO: optimize
String.new buf
end
# Encrypts `src` and returns {mac, ciphertext, nonce}
def encrypt_detached(src, dst : Bytes? = nil, *, nonce = nil, mac : Bytes? = nil, additional = nil) : {Bytes, Bytes, Nonce}
encrypt_detached src.to_slice, mac: mac, nonce: nonce, additional: additional
end
# Decrypts `src` and returns plaintext
# Must supply `mac` and `nonce`
# Must supply `additional` if supplied to #encrypt
def decrypt_detached(data, dst : Bytes? = nil, *, mac : Bytes? = nil, additional = nil)
encrypt_detached data.to_slice, mac: mac, additional: additional
def decrypt_detached(src, dst : Bytes? = nil, *, nonce = nil, mac : Bytes? = nil, additional = nil) : Bytes
decrypt_detached src.to_slice, mac: mac, nonce: nonce, additional: additional
end
# Decrypts `src` and returns plaintext
# Must supply `mac` and `nonce`
# Must supply `additional` if supplied to #encrypt
def decrypt_detached_string(src, dst : Bytes? = nil, *, nonce = nil, mac : Bytes? = nil, additional = nil) : String
buf = decrypt_detached src.to_slice, dst, mac: mac, nonce: nonce, additional: additional
# TODO: optimize
String.new buf
end
abstract def encrypt_detached(src : Bytes, dst : Bytes? = nil, *, nonce : Sodium::Nonce? = nil, mac : Bytes? = nil, additional : String | Bytes | Nil = nil) : {Bytes, Bytes, Sodium::Nonce}
abstract def decrypt_detached(src : Bytes, dst : Bytes? = nil, *, nonce : Sodium::Nonce, mac : Bytes, additional : String | Bytes | Nil = nil) : Bytes
protected abstract def key_size : Int32
protected abstract def mac_size : Int32
end
{% for key, val in {"Xchacha20Poly1305Ietf" => "_xchacha20poly1305_ietf"} %}
@ -53,7 +84,7 @@ module Sodium::Cipher::Aead
# May supply `mac`, otherwise a new one is returned.
# May supply `additional`
def encrypt_detached(src : Bytes, dst : Bytes? = nil, nonce : Sodium::Nonce? = nil, *, mac : Bytes? = nil, additional : String | Bytes | Nil = nil) : {Bytes, Bytes, Sodium::Nonce}
dst ||= Bytes.new(src.bytesize)
dst ||= Bytes.new src.bytesize
nonce ||= Sodium::Nonce.random
mac ||= Bytes.new MAC_SIZE
@ -93,6 +124,10 @@ module Sodium::Cipher::Aead
protected def key_size
KEY_SIZE
end
protected def mac_size
MAC_SIZE
end
end
{% end %}
end