Add definition for NV_Extend

Add a implementation for NV_Extend, which is used with a NV Index
defined with the NvIndexType::Extend to provide a PCR equivalent that
uses NV memory. The hashing algorithm used is defined by the index name
algorithm.

An example and test are included for this function, setting up the NV
index with the required type and typical attributes and performing an
extend of the index and confirming the resulting hash value.

Signed-off-by: Nathan Rossi <[email protected]>

Author: Nathan Rossi

tss-esapi/src/context/tpm_commands/non_volatile_storage.rs

@@ -6,8 +6,9 @@ use crate::{
     interface_types::reserved_handles::{NvAuth, Provision},
     structures::{Auth, MaxNvBuffer, Name, NvPublic},
     tss2_esys::{
-        Esys_NV_DefineSpace, Esys_NV_Increment, Esys_NV_Read, Esys_NV_ReadPublic,
-        Esys_NV_UndefineSpace, Esys_NV_UndefineSpaceSpecial, Esys_NV_Write,
+        Esys_NV_DefineSpace, Esys_NV_Extend, Esys_NV_Increment, Esys_NV_Read,
+        Esys_NV_ReadPublic, Esys_NV_UndefineSpace, Esys_NV_UndefineSpaceSpecial,
+        Esys_NV_Write,
     },
     Context, Result, ReturnCode,
 };
@@ -698,7 +699,123 @@ impl Context {
         )
     }
 
-    // Missing function: NV_Extend
+    /// Extends data to the NV memory associated with a nv index.
+    ///
+    /// # Details
+    /// This method is used to extend a value to
+    /// the nv memory in the TPM.
+    ///
+    /// Please beware that this method requires an authorization
+    /// session handle to be present.
+    ///
+    /// # Arguments
+    /// * `auth_handle` - Handle indicating the source of authorization value.
+    /// * `nv_index_handle` - The [NvIndexHandle] associated with NV memory
+    ///   which will be extended by data hashed with the previous data.
+    /// * `data` - The data, in the form of a [MaxNvBuffer], that is to be written.
+    ///
+    /// # Example
+    /// ```rust
+    /// # use tss_esapi::{
+    /// #     Context, TctiNameConf, attributes::{SessionAttributes, NvIndexAttributes},
+    /// #     handles::NvIndexTpmHandle, interface_types::algorithm::HashingAlgorithm,
+    /// #     structures::{SymmetricDefinition, NvPublic},
+    /// #     constants::SessionType, constants::nv_index_type::NvIndexType,
+    /// # };
+    /// use tss_esapi::{
+    ///       interface_types::reserved_handles::{Provision, NvAuth}, structures::MaxNvBuffer,
+    /// };
+    ///
+    /// # // Create context
+    /// # let mut context =
+    /// #     Context::new(
+    /// #         TctiNameConf::from_environment_variable().expect("Failed to get TCTI"),
+    /// #     ).expect("Failed to create Context");
+    /// #
+    /// # let session = context
+    /// #     .start_auth_session(
+    /// #         None,
+    /// #         None,
+    /// #         None,
+    /// #         SessionType::Hmac,
+    /// #         SymmetricDefinition::AES_256_CFB,
+    /// #         tss_esapi::interface_types::algorithm::HashingAlgorithm::Sha256,
+    /// #     )
+    /// #     .expect("Failed to create session")
+    /// #     .expect("Received invalid handle");
+    /// # let (session_attributes, session_attributes_mask) = SessionAttributes::builder()
+    /// #     .with_decrypt(true)
+    /// #     .with_encrypt(true)
+    /// #     .build();
+    /// # context.tr_sess_set_attributes(session, session_attributes, session_attributes_mask)
+    /// #     .expect("Failed to set attributes on session");
+    /// # context.set_sessions((Some(session), None, None));
+    /// #
+    /// # let nv_index = NvIndexTpmHandle::new(0x01500028)
+    /// #     .expect("Failed to create NV index tpm handle");
+    /// #
+    /// // Create NV index attributes
+    /// let owner_nv_index_attributes = NvIndexAttributes::builder()
+    ///     .with_owner_write(true)
+    ///     .with_owner_read(true)
+    ///     .with_orderly(true)
+    ///     .with_nv_index_type(NvIndexType::Extend)
+    ///     .build()
+    ///     .expect("Failed to create owner nv index attributes");
+    ///
+    /// // Create owner nv public.
+    /// let owner_nv_public = NvPublic::builder()
+    ///     .with_nv_index(nv_index)
+    ///     .with_index_name_algorithm(HashingAlgorithm::Sha256)
+    ///     .with_index_attributes(owner_nv_index_attributes)
+    ///     .with_data_area_size(32)
+    ///     .build()
+    ///     .expect("Failed to build NvPublic for owner");
+    ///
+    /// let nv_index_handle = context
+    ///     .nv_define_space(Provision::Owner, None, owner_nv_public.clone())
+    ///     .expect("Call to nv_define_space failed");
+    ///
+    /// let data = MaxNvBuffer::try_from(vec![0x0]).unwrap();
+    /// let result = context.nv_extend(NvAuth::Owner, nv_index_handle, data);
+    ///
+    /// # let nv_read_result = context
+    /// #     .nv_read(NvAuth::Owner, nv_index_handle, 32, 0);
+    /// # let read_data = nv_read_result.expect("Call to nv_read failed");
+    /// # // expected value is sha256([0; 32] + [0; 1])
+    /// # assert_eq!([
+    /// #         0x7f, 0x9c, 0x9e, 0x31, 0xac, 0x82, 0x56, 0xca,
+    /// #         0x2f, 0x25, 0x85, 0x83, 0xdf, 0x26, 0x2d, 0xbc,
+    /// #         0x7d, 0x6f, 0x68, 0xf2, 0xa0, 0x30, 0x43, 0xd5,
+    /// #         0xc9, 0x9a, 0x4a, 0xe5, 0xa7, 0x39, 0x6c, 0xe9],
+    /// #     read_data.as_ref());
+    /// #
+    /// # context
+    /// #    .nv_undefine_space(Provision::Owner, nv_index_handle)
+    /// #    .expect("Call to nv_undefine_space failed");
+    /// ```
+    pub fn nv_extend(
+        &mut self,
+        auth_handle: NvAuth,
+        nv_index_handle: NvIndexHandle,
+        data: MaxNvBuffer,
+    ) -> Result<()> {
+        ReturnCode::ensure_success(
+            unsafe {
+                Esys_NV_Extend(
+                    self.mut_context(),
+                    AuthHandle::from(auth_handle).into(),
+                    nv_index_handle.into(),
+                    self.required_session_1()?,
+                    self.optional_session_2(),
+                    self.optional_session_3(),
+                    &data.into(),
+                )
+            },
+            |ret| error!("Error when extending NV: {:#010X}", ret),
+        )
+    }
+
     // Missing function: NV_SetBits
     // Missing function: NV_WriteLock
     // Missing function: NV_GlobalWriteLock