feat(tbor): implement KeyReport command (attest a masked key)

ddi/tbor/types/src/key_report.rs

@@ -0,0 +1,87 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+//! Host-side wrapper for the TBOR `KeyReport` command.
+//!
+//! `KeyReport` is an **in-session** command that takes a **masked key**
+//! (e.g. the `masked_key` returned by `SdSealingKeyGen`), unmasks it,
+//! derives the attested key's public component on-device, and returns a
+//! signed COSE_Sign1 key-attestation report over it. The report is signed
+//! by the partition-identity (PID) key.
+//!
+//! The request carries the masked-key envelope to attest plus a
+//! caller-supplied 128-byte `report_data` bound into the report payload.
+
+use alloc::vec::Vec;
+
+use crate::tbor;
+
+/// TBOR opcode for `KeyReport`.
+///
+/// `0x0A..=0x0F` are reserved by the Security-Domain backup schema family
+/// (`SdCreateRemoteBackup` .. `SdRestorePeerBackup`), so `KeyReport`
+/// takes the next free opcode, `0x10`.
+pub const TBOR_OP_KEY_REPORT: u8 = 0x10;
+
+/// Maximum wire length of the `masked_key` request buffer (a masked-key
+/// AEAD envelope; the plaintext size depends on the key kind).
+pub const KEY_REPORT_MASKED_KEY_MAX_LEN: usize = 512;
+
+/// Length of the caller-supplied `report_data` bound into the report.
+pub const KEY_REPORT_DATA_LEN: usize = 128;
+
+/// Maximum wire length of the returned COSE_Sign1 `report`.
+pub const KEY_REPORT_MAX_LEN: usize = 1024;
+
+/// Host-facing TBOR `KeyReport` request.
+#[tbor(opcode = TBOR_OP_KEY_REPORT, session_ctrl = in_session)]
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TborKeyReportReq {
+    /// Session id this request is bound to. Cross-checked against the
+    /// SQE-carried session id by the dispatcher.
+    #[tbor(session_id)]
+    pub session_id: u16,
+
+    /// The masked-key envelope to attest. Variable length up to
+    /// [`KEY_REPORT_MASKED_KEY_MAX_LEN`].
+    #[tbor(max_len = 512)]
+    pub masked_key: Vec<u8>,
+
+    /// Caller-supplied [`KEY_REPORT_DATA_LEN`] (128 B) report data.
+    pub report_data: [u8; KEY_REPORT_DATA_LEN],
+}
+
+/// Host-facing TBOR `KeyReport` response.
+#[tbor(response)]
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TborKeyReportResp {
+    /// The tagged COSE_Sign1 key-attestation report, signed by the PID
+    /// key. Variable length up to [`KEY_REPORT_MAX_LEN`].
+    #[tbor(max_len = 1024)]
+    pub report: Vec<u8>,
+}
+
+#[cfg(test)]
+mod tests {
+    use azihsm_ddi_tbor_types::TborOpReq;
+
+    use super::*;
+
+    #[test]
+    fn request_encodes_session_and_masked_key() {
+        let req = TborKeyReportReq {
+            session_id: 9,
+            masked_key: alloc::vec![0xCD; 180],
+            report_data: [0xAB; KEY_REPORT_DATA_LEN],
+        };
+
+        let mut buf = [0u8; 1024];
+        let frame = req.encode_request(&mut buf).expect("encode");
+
+        // The masked-key bytes must appear in the encoded frame.
+        assert!(
+            frame.windows(4).any(|w| w == [0xCD; 4]),
+            "encoded frame must carry the masked key",
+        );
+    }
+}

ddi/tbor/types/src/lib.rs

@@ -80,6 +80,7 @@ impl From<SessionControlKind> for u8 {
 
 mod api_rev;
 mod evidence;
+mod key_report;
 mod part_final;
 mod part_info;
 mod part_init;
@@ -99,6 +100,7 @@ mod status;
 
 pub use api_rev::*;
 pub use evidence::*;
+pub use key_report::*;
 pub use part_final::*;
 pub use part_info::*;
 pub use part_init::*;

ddi/tbor/types/src/status.rs

@@ -285,6 +285,10 @@ pub enum TborStatus {
     /// `HsmError::UnsupportedKeyScope`).
     UnsupportedKeyScope = 0x08700102,
 
+    /// Returned by `KeyReport` when the masked key's kind cannot be
+    /// attested (mirror of `HsmError::UnsupportedKeyType`).
+    UnsupportedKeyType = 0x08700103,
+
     /// The SQE's out-of-band descriptor-array length (`oob_len`) is
     /// malformed (mirror of `HsmError::IoChannelInvalidOobLen`).
     IoChannelInvalidOobLen = 0x08700104,