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Improved return values of pcr_read. #281

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1 change: 1 addition & 0 deletions tss-esapi/src/abstraction/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ pub mod ak;
pub mod cipher;
pub mod ek;
pub mod nv;
pub mod pcr;
pub mod transient;

use crate::{attributes::ObjectAttributesBuilder, structures::PublicBuilder};
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71 changes: 71 additions & 0 deletions tss-esapi/src/abstraction/pcr.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,71 @@
// Copyright 2021 Contributors to the Parsec project.
// SPDX-License-Identifier: Apache-2.0
mod bank;
mod data;

use crate::{structures::PcrSelectionList, Context, Result};

pub use bank::PcrBank;
pub use data::PcrData;

/// Function that reads all the PCRs in a selection list and returns
/// the result as PCR data.
///
/// # Example
///
/// ```rust
/// # use tss_esapi::{Context, TctiNameConf};
/// # // Create context
/// # let mut context =
/// # Context::new(
/// # TctiNameConf::from_environment_variable().expect("Failed to get TCTI"),
/// # ).expect("Failed to create Context");
/// #
/// use tss_esapi::{
/// interface_types::algorithm::HashingAlgorithm,
/// structures::{PcrSelectionListBuilder, PcrSlot},
/// };
/// // Create PCR selection list with slots in a bank
/// // that is going to be read.
/// let pcr_selection_list = PcrSelectionListBuilder::new()
/// .with_selection(HashingAlgorithm::Sha256,
/// &[
/// PcrSlot::Slot0,
/// PcrSlot::Slot1,
/// PcrSlot::Slot2,
/// PcrSlot::Slot3,
/// PcrSlot::Slot4,
/// PcrSlot::Slot5,
/// PcrSlot::Slot6,
/// PcrSlot::Slot7,
/// PcrSlot::Slot8,
/// PcrSlot::Slot9,
/// PcrSlot::Slot10,
/// PcrSlot::Slot11,
/// PcrSlot::Slot12,
/// PcrSlot::Slot13,
/// PcrSlot::Slot14,
/// PcrSlot::Slot15,
/// PcrSlot::Slot16,
/// PcrSlot::Slot17,
/// PcrSlot::Slot18,
/// PcrSlot::Slot19,
/// PcrSlot::Slot20,
/// PcrSlot::Slot21,
/// ])
/// .build();
/// let _pcr_data = tss_esapi::abstraction::pcr::read_all(&mut context, pcr_selection_list)
/// .expect("pcr::read_all failed");
/// ```
pub fn read_all(
context: &mut Context,
mut pcr_selection_list: PcrSelectionList,
) -> Result<PcrData> {
let mut pcr_data = PcrData::new();
while !pcr_selection_list.is_empty() {
let (_, pcrs_read, pcr_digests) = context.pcr_read(&pcr_selection_list)?;
pcr_data.add(&pcrs_read, &pcr_digests)?;
pcr_selection_list.subtract(&pcrs_read)?;
}
Ok(pcr_data)
}
134 changes: 134 additions & 0 deletions tss-esapi/src/abstraction/pcr/bank.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,134 @@
// Copyright 2021 Contributors to the Parsec project.
// SPDX-License-Identifier: Apache-2.0

use crate::{
structures::{Digest, PcrSlot},
Error, Result, WrapperErrorKind,
};
use log::error;
use std::collections::BTreeMap;

/// Struct for holding PcrSlots and their
/// corresponding values.
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct PcrBank {
bank: BTreeMap<PcrSlot, Digest>,
}

impl PcrBank {
/// Function that creates PcrBank from a vector of pcr slots and
/// a vector of pcr digests.
///
/// # Details
/// The order of pcr slots are assumed to match the order of the Digests.
///
/// # Error
/// - If number of pcr slots does not match the number of pcr digests
/// InconsistentParams error is returned.
///
/// - If the vector of pcr slots contains duplicates then
/// InconsistentParams error is returned.
pub fn create(mut pcr_slots: Vec<PcrSlot>, mut digests: Vec<Digest>) -> Result<PcrBank> {
if pcr_slots.len() != digests.len() {
error!(
"Number of PcrSlots does not match the number of PCR digests. ({} != {})",
pcr_slots.len(),
digests.len()
);
return Err(Error::local_error(WrapperErrorKind::InconsistentParams));
}
pcr_slots
.drain(..)
.zip(digests.drain(..))
.try_fold(BTreeMap::<PcrSlot, Digest>::new(), |mut data, (pcr_slot, digest)| {
if data.insert(pcr_slot, digest).is_none() {
Ok(data)
} else {
error!("Error trying to insert data into PcrSlot {:?} where data have already been inserted", pcr_slot);
Err(Error::local_error(WrapperErrorKind::InconsistentParams))
}
})
.map(|bank| PcrBank { bank })
}

/// Retrieves reference to a [Digest] associated with the provided [PcrSlot].
///
/// # Details
/// Returns a reference to a [Digest] associated with the provided [PcrSlot]
/// if one exists else returns None.
pub fn get_digest(&self, pcr_slot: PcrSlot) -> Option<&Digest> {
self.bank.get(&pcr_slot)
}

/// Returns true if the [PcrBank] contains a digest
/// for the provided [PcrSlot].
pub fn has_digest(&self, pcr_slot: PcrSlot) -> bool {
self.bank.contains_key(&pcr_slot)
}

/// Number of digests in the [PcrBank]
pub fn len(&self) -> usize {
self.bank.len()
}

/// Returns true if the [PcrBank] is empty
pub fn is_empty(&self) -> bool {
self.bank.is_empty()
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I think it's okay here but too bad that now we've got some types that Deref to their inner types and some that don't. But Vecs are quite a lot simpler than BTreeMaps I guess.

}

/// Removees the [Digest] associated with the [PcrSlot] and
/// returns it.
///
/// # Details
/// Removes the [Digest] associated with the provided [PcrSlot]
/// out of the bank and returns it if it exists else returns None.
pub fn remove_digest(&mut self, pcr_slot: PcrSlot) -> Option<Digest> {
self.bank.remove(&pcr_slot)
}

/// Inserts [Digest] value associated with a [PcrSlot] into the bank.
///
/// # Error
/// Returns an error if a [Digest] is already associated with the
/// provided [PcrSlot].
pub fn insert_digest(&mut self, pcr_slot: PcrSlot, digest: Digest) -> Result<()> {
self.ensure_non_existing(pcr_slot, "Failed to insert")?;
let _ = self.bank.insert(pcr_slot, digest);
Ok(())
}

/// Attempts to extend the [PcrBank] with `other`.
///
/// # Error
/// Returns an error if the a value in `other` already
/// exists.
pub fn try_extend(&mut self, other: PcrBank) -> Result<()> {
other
.bank
.keys()
.try_for_each(|&pcr_slot| self.ensure_non_existing(pcr_slot, "Failed to extend"))?;
self.bank.extend(other.bank);
Ok(())
}

/// Returns an error if a [Digest] for [PcrSlot] already exists in the bank
fn ensure_non_existing(&self, pcr_slot: PcrSlot, error_msg: &str) -> Result<()> {
if self.has_digest(pcr_slot) {
error!(
"{}, a digest already for PcrSlot {:?} exists in the bank",
error_msg, pcr_slot
);
return Err(Error::local_error(WrapperErrorKind::InvalidParam));
}
Ok(())
}
}

impl<'a> IntoIterator for &'a PcrBank {
type Item = (&'a PcrSlot, &'a Digest);
type IntoIter = ::std::collections::btree_map::Iter<'a, PcrSlot, Digest>;

fn into_iter(self) -> Self::IntoIter {
self.bank.iter()
}
}
134 changes: 134 additions & 0 deletions tss-esapi/src/abstraction/pcr/data.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,134 @@
// Copyright 2021 Contributors to the Parsec project.
// SPDX-License-Identifier: Apache-2.0

use crate::{
abstraction::pcr::PcrBank,
interface_types::algorithm::HashingAlgorithm,
structures::{Digest, DigestList, PcrSelectionList},
tss2_esys::TPML_DIGEST,
Error, Result, WrapperErrorKind,
};
use log::error;
/// Struct holding pcr banks and their associated
/// hashing algorithm
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct PcrData {
data: Vec<(HashingAlgorithm, PcrBank)>,
}

impl PcrData {
/// Creates new empty PcrData
pub const fn new() -> Self {
PcrData { data: Vec::new() }
}

/// Function for creating PcrData from a pcr selection list and pcr digests list.
pub fn create(
pcr_selection_list: &PcrSelectionList,
digest_list: &DigestList,
) -> Result<PcrData> {
Ok(PcrData {
data: Self::create_data(pcr_selection_list, digest_list.value().to_vec())?,
})
}

/// Adds data to the PcrData
pub fn add(
&mut self,
pcr_selection_list: &PcrSelectionList,
digest_list: &DigestList,
) -> Result<()> {
Self::create_data(pcr_selection_list, digest_list.value().to_vec())?
.drain(..)
.try_for_each(|(hashing_algorithm, pcr_bank)| {
if let Some(existing_pcr_bank) = self.pcr_bank_mut(hashing_algorithm) {
existing_pcr_bank.try_extend(pcr_bank)?;
} else {
self.data.push((hashing_algorithm, pcr_bank));
}
Ok(())
})
}

/// Function for turning a pcr selection list and pcr digests values
/// into the format in which data is stored in PcrData.
fn create_data(
pcr_selection_list: &PcrSelectionList,
mut digests: Vec<Digest>,
) -> Result<Vec<(HashingAlgorithm, PcrBank)>> {
pcr_selection_list
.get_selections()
.iter()
.map(|pcr_selection| {
let pcr_slots = pcr_selection.selected();
if pcr_slots.len() > digests.len() {
error!("More pcr slots in selection then available digests");
return Err(Error::local_error(WrapperErrorKind::InconsistentParams));
}
let digests_in_bank = digests.drain(..pcr_slots.len()).collect();
Ok((
pcr_selection.hashing_algorithm(),
PcrBank::create(pcr_slots, digests_in_bank)?,
))
})
.collect()
}

/// Function for retrieving the first PCR values associated with hashing_algorithm.
pub fn pcr_bank(&self, hashing_algorithm: HashingAlgorithm) -> Option<&PcrBank> {
self.data
.iter()
.find(|(alg, _)| *alg == hashing_algorithm)
.map(|(_, bank)| bank)
}

/// Function for retrieving the number of banks in the data.
pub fn len(&self) -> usize {
self.data.len()
}

/// Returns true if there are no banks in the data.
pub fn is_empty(&self) -> bool {
self.data.is_empty()
}

/// Private method for finding a PCR bank.
fn pcr_bank_mut(&mut self, hashing_algorithm: HashingAlgorithm) -> Option<&mut PcrBank> {
self.data
.iter_mut()
.find(|(alg, _)| *alg == hashing_algorithm)
.map(|(_, bank)| bank)
}
}

impl<'a> IntoIterator for PcrData {
type Item = (HashingAlgorithm, PcrBank);
type IntoIter = ::std::vec::IntoIter<(HashingAlgorithm, PcrBank)>;

fn into_iter(self) -> Self::IntoIter {
self.data.into_iter()
}
}

impl From<PcrData> for Vec<TPML_DIGEST> {
fn from(pcr_data: PcrData) -> Self {
pcr_data
.data
.iter()
.flat_map(|(_, pcr_bank)| pcr_bank.into_iter())
.map(|(_, digest)| digest)
.collect::<Vec<&Digest>>()
.chunks(DigestList::MAX_SIZE)
.map(|digests| {
let mut tpml_digest: TPML_DIGEST = Default::default();
for (index, digest) in digests.iter().enumerate() {
tpml_digest.count += 1;
tpml_digest.digests[index].size = digest.len() as u16;
tpml_digest.digests[index].buffer[..digest.len()]
.copy_from_slice(digest.value());
}
tpml_digest
})
.collect()
}
}
Original file line number Diff line number Diff line change
Expand Up @@ -132,7 +132,7 @@ impl Context {
/// by the value of the different hashes.
///
/// # Constraints
/// * `hash_list` must be at least 2 and at most 8 elements long
/// * `digest_list` must be at least 2 and at most 8 elements long
///
/// # Errors
/// * if the hash list provided is too short or too long, a `WrongParamSize` wrapper error will be returned
Expand All @@ -141,7 +141,13 @@ impl Context {
policy_session: PolicySession,
digest_list: DigestList,
) -> Result<()> {
let digest_list = TPML_DIGEST::try_from(digest_list)?;
if digest_list.len() < 2 {
error!(
"The digest list only contains {} digests, it must contain at least 2",
digest_list.len()
);
return Err(Error::local_error(ErrorKind::WrongParamSize));
}

let ret = unsafe {
Esys_PolicyOR(
Expand All @@ -150,7 +156,7 @@ impl Context {
self.optional_session_1(),
self.optional_session_2(),
self.optional_session_3(),
&digest_list,
&TPML_DIGEST::try_from(digest_list)?,
)
};
let ret = Error::from_tss_rc(ret);
Expand Down
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