Added signing and verify

kernel/src/crypto.rs

@@ -1,4 +1,5 @@
 use crate::crypto::errors::CryptoError;
+use rsa::signature::{Error, SignatureEncoding};
 use rsa::{
     pkcs1::DecodeRsaPrivateKey,
     pkcs1::DecodeRsaPublicKey,
@@ -18,8 +19,8 @@ pub trait Decrypt {
 }
 
 pub trait Signature {
-    fn sign(&self, data: Vec<u8>) -> Result<Vec<u8>, CryptoError>;
-    fn verify(&self, data: &[u8]) -> Result<Vec<u8>, CryptoError>;
+    fn sign(&self, data: &[u8]) -> Vec<u8>;
+    fn verify(&self, data: &[u8], signature: &[u8]) -> Result<bool, CryptoError>;
 }
 
 // TODO: This is an UGLY name. Rename it something other than Handler. Almost everything is a handler
@@ -91,6 +92,34 @@ impl Decrypt for RSACryptoHandler {
     }
 }
 
+impl Signature for RSACryptoHandler {
+    fn sign(&self, data: &[u8]) -> Vec<u8> {
+        // TODO: should this be called every time?
+        let mut rng = rand::thread_rng();
+
+        // TODO: is it stupid to use clone here?
+        let signing_key = SigningKey::<Sha256>::new(self.private_key.clone());
+        let signature = signing_key.sign_with_rng(&mut rng, data);
+
+        signature.to_vec()
+    }
+
+    fn verify(&self, data: &[u8], signature: &[u8]) -> Result<bool, CryptoError> {
+        let signature = match rsa::pkcs1v15::Signature::try_from(signature) {
+            Ok(s) => s,
+            Err(_) => return Err(CryptoError::InvalidSignature),
+        };
+
+        // TODO: is it stupid to use clone here?
+        let verifying_key = VerifyingKey::<Sha256>::new(self.public_key.clone());
+
+        match verifying_key.verify(data, &signature) {
+            Ok(_) => Ok(true),
+            Err(_) => Err(CryptoError::SignatureVerification),
+        }
+    }
+}
+
 mod errors {
     #[derive(Debug)]
     pub enum CryptoError {
@@ -102,6 +131,8 @@ mod errors {
         PublicKeyNotFound,
         PrivateKeyInvalid,
         PublicKeyInvalid,
+        InvalidSignature,
+        SignatureVerification,
     }
 }
 
@@ -164,7 +195,7 @@ m/A1vde9ULfntRXDT+44rL5BfsLB9oNfknDtLSk/TsE9zQ6f/zghzw==
         let encrypted_data = crypto_handler.encrypt(data).unwrap();
         let encrypted_data = &encrypted_data[..];
 
-        assert!(data.into_iter().ne(encrypted_data.into_iter()))
+        assert!(data.iter().ne(encrypted_data.iter()))
     }
 
     #[test]
@@ -180,6 +211,6 @@ m/A1vde9ULfntRXDT+44rL5BfsLB9oNfknDtLSk/TsE9zQ6f/zghzw==
         let decrypted_data = crypto_handler.decrypt(encrypted_data).unwrap();
         let decrypted_data = &decrypted_data[..];
 
-        assert!(data.into_iter().eq(decrypted_data.into_iter()))
+        assert!(data.iter().eq(decrypted_data.iter()))
     }
 }