Make CoseKeyBuilder more useful (#54)

Author: daviddrysdale

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change Log
 
+## 0.3.3 - TBD
+
+- Add `CoseKeyBuilder` methods `kty`, `key_type` and `new_okp_key`.
+
 ## 0.3.2 - 2022-04-02
 
 - Add basic [CWT](https://datatracker.ietf.org/doc/html/rfc8392) support in `cwt` module, via the `ClaimsSet` type.

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "coset"
-version = "0.3.2"
+version = "0.3.3-alpha.1"
 authors = ["David Drysdale <[email protected]>", "Paul Crowley <[email protected]>"]
 edition = "2018"
 license = "Apache-2.0"

Cargo.toml

@@ -183,6 +183,7 @@ pub struct CoseKeyBuilder(CoseKey);
 
 impl CoseKeyBuilder {
     builder! {CoseKey}
+    builder_set! {kty: KeyType}
     builder_set! {key_id: Vec<u8>}
     builder_set! {base_iv: Vec<u8>}
 
@@ -250,6 +251,21 @@ impl CoseKeyBuilder {
         })
     }
 
+    /// Constructor for a octet keypair key.
+    pub fn new_okp_key() -> Self {
+        Self(CoseKey {
+            kty: KeyType::Assigned(iana::KeyType::OKP),
+            ..Default::default()
+        })
+    }
+
+    /// Set the key type.
+    #[must_use]
+    pub fn key_type(mut self, key_type: iana::KeyType) -> Self {
+        self.0.kty = KeyType::Assigned(key_type);
+        self
+    }
+
     /// Set the algorithm.
     #[must_use]
     pub fn algorithm(mut self, alg: iana::Algorithm) -> Self {

src/key/mod.rs

@@ -16,7 +16,7 @@
 
 use super::*;
 use crate::{cbor::value::Value, iana, util::expect_err, CborSerializable};
-use alloc::{borrow::ToOwned, vec};
+use alloc::{borrow::ToOwned, string::ToString, vec};
 
 #[test]
 fn test_cose_key_encode() {
@@ -702,6 +702,31 @@ fn test_key_builder() {
                 ..Default::default()
             },
         ),
+        (
+            CoseKeyBuilder::new_okp_key().build(),
+            CoseKey {
+                kty: KeyType::Assigned(iana::KeyType::OKP),
+                ..Default::default()
+            },
+        ),
+        (
+            CoseKeyBuilder::new()
+                .key_type(iana::KeyType::WalnutDSA)
+                .build(),
+            CoseKey {
+                kty: KeyType::Assigned(iana::KeyType::WalnutDSA),
+                ..Default::default()
+            },
+        ),
+        (
+            CoseKeyBuilder::new()
+                .kty(KeyType::Text("test".to_string()))
+                .build(),
+            CoseKey {
+                kty: KeyType::Text("test".to_string()),
+                ..Default::default()
+            },
+        ),
     ];
     for (got, want) in tests {
         assert_eq!(got, want);