add FromStr representations of kdf, kem, and aead

src/aead.rs

@@ -1,8 +1,10 @@
+use crate::IdLookupError;
+use num_enum::TryFromPrimitive;
+use std::str::FromStr;
+
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::*;
 
-use num_enum::TryFromPrimitive;
-
 /**
 Aead represents an authenticated encryption with additional data
 encryption function, as per [RFC9180§7.3](https://www.rfc-editor.org/rfc/rfc9180.html#section-7.3)
@@ -29,6 +31,25 @@ pub enum Aead {
     ChaCha20Poly1305 = 3,
 }
 
+impl FromStr for Aead {
+    type Err = IdLookupError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match &*s.to_lowercase() {
+            #[cfg(feature = "aead-aes-gcm-128")]
+            "aesgcm128" | "aes-gcm-128" | "aes-128-gcm" => Ok(Self::AesGcm128),
+            #[cfg(feature = "aead-aes-gcm-256")]
+            "aesgcm256" | "aes-gcm-256" | "aes-256-gcm" => Ok(Self::AesGcm256),
+            #[cfg(feature = "aead-chacha-20-poly-1305")]
+            "chacha20poly1305"
+            | "chacha-20-poly-1305"
+            | "cha-cha-20-poly-1305"
+            | "chacha20-poly1305" => Ok(Self::ChaCha20Poly1305),
+            _ => Err(IdLookupError("aead not recognized")),
+        }
+    }
+}
+
 /// An iterable slice of [`Aead`] variants
 pub const AEAD_ALL: &[Aead] = &[
     #[cfg(feature = "aead-aes-gcm-128")]

src/kdf.rs

@@ -1,8 +1,10 @@
+use crate::IdLookupError;
+use num_enum::TryFromPrimitive;
+use std::str::FromStr;
+
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::*;
 
-use num_enum::TryFromPrimitive;
-
 /**
 Kdf represents an key derivation function, as per
 [RFC9180§7.2](https://www.rfc-editor.org/rfc/rfc9180.html#section-7.2)
@@ -29,6 +31,22 @@ pub enum Kdf {
     Sha512 = 3,
 }
 
+impl FromStr for Kdf {
+    type Err = IdLookupError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match &*s.to_lowercase() {
+            #[cfg(feature = "kdf-sha256")]
+            "sha256" | "sha-256" => Ok(Self::Sha256),
+            #[cfg(feature = "kdf-sha384")]
+            "sha384" | "sha-384" => Ok(Self::Sha384),
+            #[cfg(feature = "kdf-sha512")]
+            "sha512" | "sha-512" => Ok(Self::Sha512),
+            _ => Err(IdLookupError("kdf not recognized")),
+        }
+    }
+}
+
 /// An iterable slice of [`Kdf`] variants
 pub const KDF_ALL: &[Kdf] = &[
     #[cfg(feature = "kdf-sha256")]

src/kem.rs

@@ -1,9 +1,10 @@
+use crate::{IdLookupError, Keypair};
+use num_enum::TryFromPrimitive;
+use std::str::FromStr;
+
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::*;
 
-use crate::Keypair;
-use num_enum::TryFromPrimitive;
-
 /**
 Kem represents an asymmetric key encapsulation mechanism, as per
 [RFC9180§7.1][section-7.1]. Currently only two of options listed in
@@ -31,6 +32,24 @@ pub enum Kem {
     X25519HkdfSha256 = 32,
 }
 
+impl FromStr for Kem {
+    type Err = IdLookupError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match &*s.to_lowercase() {
+            #[cfg(feature = "kem-dh-p256-hkdf-sha256")]
+            "dhp256hkdfsha256" | "dh-p256-hkdf-sha256" | "dhkem(p-256, hkdf-sha256)" => {
+                Ok(Self::DhP256HkdfSha256)
+            }
+            #[cfg(feature = "kem-x25519-hkdf-sha256")]
+            "x25519hkdfsha256" | "x25519-hkdf-sha256" | "dhkem(x25519, hkdf-sha256)" => {
+                Ok(Self::X25519HkdfSha256)
+            }
+            _ => Err(IdLookupError("kem not recognized")),
+        }
+    }
+}
+
 impl Kem {
     /// generate a [`Keypair`] for this [`Config`] or [`Kem`].
     #[must_use]