Fix attestation secret release, key naming, and tests (#144)

Signed-off-by: Wojciech Ozga <woz@zurich.ibm.com>

Author: wojciechozga

confidential-vms/linux_vm/Makefile

@@ -80,13 +80,13 @@ overlay: setup
 	rm -rf $(HYPERVISOR_OVERLAY_LINUX_VM_DIR) && mkdir -p $(HYPERVISOR_OVERLAY_LINUX_VM_DIR) ;\
 	rm -f $(LINUX_VM_COVE_TAP_QEMU) ;\
 	$(eval $@_TMP = $(shell $(TOOLS_WORK_DIR)/cove-tap-tool measure --base-address=0x80000000 --kernel-file=$(LINUX_VM_IMAGE) | cut -d' ' -f2-;) )
-	$(TOOLS_WORK_DIR)/cove-tap-tool generate --pcrs 4=$($@_TMP) --secrets 0=0xc0ffee --output-file=$(LINUX_VM_COVE_TAP_QEMU)
+	$(TOOLS_WORK_DIR)/cove-tap-tool generate --pcrs 4=$($@_TMP) --secrets 0=0xc0ffeec0ffeec0ffeec0ffee --output-file=$(LINUX_VM_COVE_TAP_QEMU)
 	cp $(LINUX_VM_COVE_TAP_QEMU) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)/
 	cp $(LINUX_VM_IMAGE) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)/
 	cp $(LINUX_VM_BUILDROOT_ROOTFS) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)
 	rm -f $(LINUX_VM_COVE_TAP_KVMTOOL)
 	$(eval $@_TMP = $(shell $(TOOLS_WORK_DIR)/cove-tap-tool measure --base-address=0x80200000 --kernel-file=$(LINUX_VM_IMAGE) | cut -d' ' -f2-;) )
-	$(TOOLS_WORK_DIR)/cove-tap-tool generate --pcrs 4=$($@_TMP) --secrets 0=0xc0ffee --output-file=$(LINUX_VM_COVE_TAP_KVMTOOL)
+	$(TOOLS_WORK_DIR)/cove-tap-tool generate --pcrs 4=$($@_TMP) --secrets 0=0xc0ffeec0ffeec0ffeec0ffee --output-file=$(LINUX_VM_COVE_TAP_KVMTOOL)
 	cp $(LINUX_VM_COVE_TAP_KVMTOOL) $(HYPERVISOR_OVERLAY_LINUX_VM_DIR)/
 
 

hypervisor/rootfs/test_attestation.sh

@@ -17,7 +17,7 @@ wait_for_ssh $TVM_USER $TVM_HOST $TVM_PORT
 $SSH_CMD -p${TVM_PORT} ${TVM_USER}@${TVM_HOST} 'insmod /root/ace_module/ace.ko'
 $SSH_CMD -p${TVM_PORT} ${TVM_USER}@${TVM_HOST} 'dmesg | grep Secret' > tmp_dmesg.log
 
-ATTESTATION_RESULT="$(grep 'Secret=0xc0ffee' tmp_dmesg.log | wc -l)"
+ATTESTATION_RESULT="$(grep 'Secret=0xc0ffeec0ffeec0ffeec0ffee' tmp_dmesg.log | wc -l)"
 
 kill_confidential_vm
 sleep 5

security-monitor/rust-crates/riscv_cove_tap/src/spec.rs

@@ -141,22 +141,22 @@ impl Digest {
 #[derive(Debug, PartialEq, Eq)]
 pub enum DigestAlgorithm {
     Debug = 0,
-    Sha512 = 1,
+    Sha3_256 = 1,
 }
 
 impl DigestAlgorithm {
     pub fn from_u16(value: u16) -> Result<Self, TapError> {
         match value {
             0 => Ok(Self::Debug),
-            1 => Ok(Self::Sha512),
+            1 => Ok(Self::Sha3_256),
             v => Err(TapError::UnsupportedDigestAlgorithm(v)),
         }
     }
 
     pub fn digest_size(&self) -> u16 {
         match self {
             &Self::Debug => 0,
-            &Self::Sha512 => 512 / 8,
+            &Self::Sha3_256 => 512 / 8,
         }
     }
 }

security-monitor/src/confidential_flow/handlers/attestation/retrieve_secret.rs

@@ -32,13 +32,14 @@ impl RetrieveSecretRequest {
             ensure!(self.output_buffer_size <= PageSize::Size4KiB.in_bytes(), Error::AddressNotAligned())?;
             let secret = confidential_vm.secret(0)?;
             ensure!(secret.len() <= self.output_buffer_size, Error::AddressNotAligned())?;
-            let mut buffer = [0u8; 8];
-            for offset in 0..secret.len().div_ceil(8) {
-                let end_boundary = core::cmp::min(secret.len(), offset + 8);
-                (0..end_boundary).for_each(|i| buffer[i] = secret[offset + i]);
-                (end_boundary..8).for_each(|i| buffer[i] = 0u8);
+            const WORD_SIZE: usize = core::mem::size_of::<usize>();
+            for chunk in 0..secret.len().div_ceil(WORD_SIZE) {
+                let byte_offset = chunk * WORD_SIZE;
+                let chunk_len = core::cmp::min(WORD_SIZE, secret.len() - byte_offset);
+                let mut buffer = [0u8; WORD_SIZE];
+                buffer[..chunk_len].copy_from_slice(&secret[byte_offset..byte_offset + chunk_len]);
                 let confidential_memory_address =
-                    confidential_vm.memory_protector().translate_address(&output_buffer_address.add(offset))?;
+                    confidential_vm.memory_protector().translate_address(&output_buffer_address.add(byte_offset))?;
                 unsafe { confidential_memory_address.write_volatile(usize::from_le_bytes(buffer)) };
             }
             Ok(SbiResponse::success_with_code(secret.len()))

security-monitor/src/core/architecture/riscv/pmp/mod.rs

@@ -47,4 +47,6 @@ fn clear_caches() {
     // See Section 3.7.2 of RISC-V privileged specification v1.12.
     // PMP translations can be cached and address translation can be done speculatively. Thus, it is adviced to flush caching structures.
     super::fence::sfence_vma();
+    // flush G-stage TLBs
+    super::fence::hfence_gvma();
 }

security-monitor/src/core/control_data/confidential_vm_mmio_region.rs

@@ -25,6 +25,6 @@ impl ConfidentialVmMmioRegion {
     }
 
     pub fn contains(&self, other: &Self) -> bool {
-        self.base_address <= other.base_address && other.one_past_the_end_address < self.one_past_the_end_address
+        self.base_address <= other.base_address && other.one_past_the_end_address <= self.one_past_the_end_address
     }
 }

security-monitor/src/core/initialization/mod.rs

@@ -237,7 +237,7 @@ extern "C" fn ace_setup_this_hart() {
     // the `MemoryLayout` has been already initialized by the boot hart.
     if let Err(error) = unsafe { HypervisorMemoryProtector::setup() } {
         debug!("Failed to setup hypervisor memory protector: {:?}", error);
-        // TODO: block access to attestation keys/registers on this hart?
+        // TODO: block access to attestation keys/registers on this hart or freeze
         return;
     }
 

security-monitor/src/non_confidential_flow/handlers/cove_host_extension/promote_to_confidential_vm.rs

@@ -207,7 +207,7 @@ impl PromoteToConfidentialVm {
                 for digest in attestation_payload.digests.iter() {
                     // codeql[rust/cleartext-logging] - digest values intentionally logged in debug builds
                     debug!("Reference PCR{:?}={:?}=0x{}", digest.pcr_id, digest.algorithm, digest.value_in_hex());
-                    ensure!(digest.algorithm == riscv_cove_tap::DigestAlgorithm::Sha512, Error::LocalAttestationNotSupportedDigest())?;
+                    ensure!(digest.algorithm == riscv_cove_tap::DigestAlgorithm::Sha3_256, Error::LocalAttestationNotSupportedDigest())?;
                     let pcr_value = MeasurementDigest::try_from(digest.value.as_slice()).map_err(|_| Error::LocalAttestationFailed())?;
                     ensure!(measurements.compare(digest.pcr_id() as usize, pcr_value)?, Error::LocalAttestationFailed())?;
                 }

tools/cove_tap_tool/src/generate.rs

@@ -54,7 +54,7 @@ pub fn generate_tap(
     for (pcr_id, pcr_value) in pcrs.into_iter() {
         let tap_digest = Digest {
             pcr_id,
-            algorithm: DigestAlgorithm::Sha512,
+            algorithm: DigestAlgorithm::Sha3_256,
             value: pcr_value,
         };
         // codeql[rust/cleartext-logging] - intentional operator output for CLI tool