ECDH encryption module
Add a module for encrypting using ECDH, HKDF, and AES-GCM.
Also, add serialization of EC private keys, and remove derivation
from secrets; it turns out this is a better fit for the way
superencryption currently works.
Add a more thorough ECDH test in the crypto module, which simulates an
ephemeral key being used to send a message to a long-term key. The
high-level module has a similar test.
Bug: 163866361
Test: keystore2_crypto_test_rust, keystore2_test
Change-Id: I4c2bb1d8938de078ea37b930619918acc3c28fbe
diff --git a/keystore2/src/crypto/error.rs b/keystore2/src/crypto/error.rs
index 1eec321..a369012 100644
--- a/keystore2/src/crypto/error.rs
+++ b/keystore2/src/crypto/error.rs
@@ -74,9 +74,13 @@
#[error("Failed to generate key.")]
ECKEYGenerateKeyFailed,
- /// This is returned if the C implementation of ECKEYDeriveFromSecret returned null.
- #[error("Failed to derive key.")]
- ECKEYDeriveFailed,
+ /// This is returned if the C implementation of ECKEYMarshalPrivateKey returned 0.
+ #[error("Failed to marshal private key.")]
+ ECKEYMarshalPrivateKeyFailed,
+
+ /// This is returned if the C implementation of ECKEYParsePrivateKey returned null.
+ #[error("Failed to parse private key.")]
+ ECKEYParsePrivateKeyFailed,
/// This is returned if the C implementation of ECPOINTPoint2Oct returned 0.
#[error("Failed to convert point to oct.")]