rust/pv_core: Attestation support

Add functionality for:

* sending attestation requests to the uvdevice and retrieve the
  response
* create/read the attestation exchange format file format

Acked-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

rust/pv_core/src/error.rs

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 //
-// Copyright IBM Corp. 2023
+// Copyright IBM Corp. 2023, 2024
 
 /// Result type for this crate
 pub type Result<T, E = Error> = std::result::Result<T, E>;
@@ -49,6 +49,18 @@ pub enum Error {
     #[error("Input contains unsupported user-data type: {0:#06x}")]
     UnsupportedUserData(u16),
 
+    #[error("The input has not the correct format: {field} is too large. Maximal size {max_size}")]
+    AttDataSizeLarge { field: &'static str, max_size: u32 },
+
+    #[error("The input has not the correct format: {field} is too small. Minimal size {min_size}")]
+    AttDataSizeSmall { field: &'static str, min_size: u32 },
+
+    #[error("The attestation request has an unknown algorithm type (.0)")]
+    BinArcbInvAlgorithm(u32),
+
+    #[error("The attestation request does not specify a measurement size or measurement data.")]
+    BinArcbNoMeasurement,
+
     // errors from other crates
     #[error(transparent)]
     Io(#[from] std::io::Error),