Add binding for single-part digest function.

Signed-off-by: Helmut Eller <[email protected]>

cryptoki/src/session/digesting.rs

@@ -0,0 +1,54 @@
+// Copyright 2021 Contributors to the Parsec project.
+// SPDX-License-Identifier: Apache-2.0
+//! Digesting functions
+
+use crate::error::{Result, Rv};
+use crate::mechanism::Mechanism;
+use crate::session::Session;
+use cryptoki_sys::*;
+use std::convert::TryInto;
+
+impl Session {
+    /// Single-part digesting operation
+    pub fn digest(&self, m: &Mechanism, data: &[u8]) -> Result<Vec<u8>> {
+        let mut mechanism: CK_MECHANISM = m.into();
+        let mut digest_len = 0;
+
+        unsafe {
+            Rv::from(get_pkcs11!(self.client(), C_DigestInit)(
+                self.handle(),
+                &mut mechanism as CK_MECHANISM_PTR,
+            ))
+            .into_result()?;
+        }
+
+        // Get the output buffer length
+        unsafe {
+            Rv::from(get_pkcs11!(self.client(), C_Digest)(
+                self.handle(),
+                data.as_ptr() as *mut u8,
+                data.len().try_into()?,
+                std::ptr::null_mut(),
+                &mut digest_len,
+            ))
+            .into_result()?;
+        }
+
+        let mut digest = vec![0; digest_len.try_into()?];
+
+        unsafe {
+            Rv::from(get_pkcs11!(self.client(), C_Digest)(
+                self.handle(),
+                data.as_ptr() as *mut u8,
+                data.len().try_into()?,
+                digest.as_mut_ptr(),
+                &mut digest_len,
+            ))
+            .into_result()?;
+        }
+
+        digest.resize(digest_len.try_into()?, 0);
+
+        Ok(digest)
+    }
+}

cryptoki/src/session/mod.rs

@@ -9,6 +9,7 @@ use std::fmt::Formatter;
 use std::marker::PhantomData;
 
 mod decryption;
+mod digesting;
 mod encryption;
 mod key_management;
 mod object_management;

cryptoki/tests/basic.rs

@@ -874,3 +874,28 @@ fn update_attributes_key() -> TestResult {
 
     Ok(())
 }
+
+#[test]
+#[serial]
+fn sha256_digest() -> TestResult {
+    let (pkcs11, slot) = init_pins();
+
+    // open a session
+    let session = pkcs11.open_rw_session(slot)?;
+
+    // log in the session
+    session.login(UserType::User, Some(&AuthPin::new(USER_PIN.into())))?;
+
+    // data to digest
+    let data = vec![0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF];
+
+    let want = vec![
+        0x17, 0x22, 0x6b, 0x1f, 0x68, 0xae, 0xba, 0xcd, 0xef, 0x07, 0x46, 0x45, 0x0f, 0x64, 0x28,
+        0x74, 0x63, 0x8b, 0x29, 0x57, 0x07, 0xef, 0x73, 0xfb, 0x2c, 0x6b, 0xb7, 0xf8, 0x8e, 0x89,
+        0x92, 0x9f,
+    ];
+    let have = session.digest(&Mechanism::Sha256, &data)?;
+    assert_eq!(want[..], have[..]);
+
+    Ok(())
+}