Update crypto_box requirement from 0.7.1 to 0.8.1 (#107)

* Update crypto_box requirement from 0.7.1 to 0.8.1

Updates the requirements on [crypto_box](https://github.com/RustCrypto/nacl-compat) to permit the latest version.
- [Release notes](https://github.com/RustCrypto/nacl-compat/releases)
- [Commits](RustCrypto/nacl-compat@crypto_box-v0.7.1...crypto_box-v0.8.1)

---
updated-dependencies:
- dependency-name: crypto_box
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* update with crypto_box new API

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Alex Xiong <alex.xiong.tech@gmail.com>

primitives/Cargo.toml

@@ -31,7 +31,7 @@ zeroize = { version = "1.3", default-features = false }
 itertools = { version = "0.10.1", default-features = false, features = [ "use_alloc" ] }
 serde = { version = "1.0", features = ["derive"] }
 generic-array = { version = "^0.14", default-features = false }
-crypto_box = { version = "0.7.1", default-features = false, features = [ "u64_backend", "alloc" ] }
+crypto_box = "0.8.1"
 displaydoc = { version = "0.2.3", default-features = false }
 derivative = { version = "2", features = ["use_core"] }
 rand_chacha = { version = "0.3.1", default-features = false }

primitives/src/aead.rs

@@ -15,7 +15,7 @@ use ark_std::{
     vec::Vec,
 };
 use crypto_box::{
-    aead::{Aead, Nonce, Payload},
+    aead::{Aead, AeadCore, Nonce, Payload},
     ChaChaBox,
 };
 use generic_array::{typenum::U24, GenericArray};
@@ -82,19 +82,16 @@ impl EncKey {
     /// during encryption will cause decryption to fail, which is useful if you
     /// would like to "bind" the ciphertext to some identifier, like a
     /// digital signature key.
-    pub fn encrypt<R>(
+    pub fn encrypt(
         &self,
-        rng: &mut R,
+        mut rng: impl RngCore + CryptoRng,
         message: &[u8],
         aad: &[u8],
-    ) -> Result<Ciphertext, PrimitivesError>
-    where
-        R: RngCore + CryptoRng,
-    {
-        let nonce = crypto_box::generate_nonce(rng);
+    ) -> Result<Ciphertext, PrimitivesError> {
+        let nonce = ChaChaBox::generate_nonce(&mut rng);
 
         // generate an ephemeral key pair as the virtual sender to derive the crypto box
-        let ephemeral_sk = crypto_box::SecretKey::generate(rng);
+        let ephemeral_sk = crypto_box::SecretKey::generate(&mut rng);
         let ephemeral_pk = EncKey(crypto_box::PublicKey::from(&ephemeral_sk));
         let my_box = ChaChaBox::new(&self.0, &ephemeral_sk);