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/*
* Copyright (C) 2024 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#[cfg(test)]
mod tests {
use android_hardware_security_see::aidl::android::hardware::security::see::hwcrypto::{
IHwCryptoKey::{
DerivedKey::DerivedKey, DerivedKeyParameters::DerivedKeyParameters,
DerivedKeyPolicy::DerivedKeyPolicy, DeviceKeyId::DeviceKeyId,
DiceBoundDerivationKey::DiceBoundDerivationKey, DiceBoundKeyResult::DiceBoundKeyResult,
DiceCurrentBoundKeyResult::DiceCurrentBoundKeyResult, IHwCryptoKey,
ClearKeyPolicy::ClearKeyPolicy,
},
};
use binder::{StatusCode, Strong};
use rpcbinder::RpcSession;
use test::{expect, assert_ok};
use trusty_std::ffi::{CString, FallibleCString};
pub(crate) const RUST_DEVICE_KEY_SERVICE_PORT: &str = "com.android.trusty.rust.hwcryptohal.V1";
pub(crate) const VERSION_0_DICE_POLICY: [u8; 120] = [
0x83, 0x58, 0x30, 0xa3, 0x01, 0x03, 0x3a, 0x00, 0x01, 0x00, 0x02, 0x58, 0x20, 0x7a, 0x87,
0x07, 0x18, 0x72, 0x14, 0xb4, 0x1e, 0x69, 0x60, 0xc8, 0x6e, 0xfd, 0x8d, 0xdf, 0x6e, 0x48,
0xbd, 0x33, 0xa2, 0xdf, 0x6c, 0x76, 0x59, 0xdf, 0x82, 0x93, 0x3e, 0xf3, 0xa9, 0x6a, 0x23,
0x3a, 0x00, 0x01, 0x00, 0x03, 0x01, 0xa0, 0x58, 0x42, 0xea, 0xf7, 0x26, 0xfd, 0x2a, 0x06,
0x0a, 0x4b, 0x9e, 0x8c, 0xba, 0xf3, 0x41, 0x91, 0xac, 0x88, 0xfd, 0xc6, 0x23, 0xc3, 0x3f,
0x33, 0x64, 0x6d, 0x20, 0xb4, 0x18, 0x7a, 0x55, 0x7c, 0x4c, 0xdd, 0x64, 0x84, 0x54, 0x22,
0xec, 0xd9, 0x1d, 0x89, 0x49, 0xf3, 0xcb, 0x37, 0xfb, 0x1c, 0x49, 0x5a, 0xd5, 0xbc, 0xf6,
0x82, 0xd7, 0x82, 0xcc, 0x51, 0x00, 0x3b, 0x71, 0x0f, 0xde, 0xdb, 0x8a, 0xcf, 0x23, 0xf9,
];
pub(crate) const VERSION_0_CLEAR_KEY: [u8; 256] = [
0xf7, 0xf3, 0x3f, 0x34, 0xfd, 0x4c, 0x09, 0xcf, 0xb2, 0x20, 0x8a, 0xcc, 0x08, 0xd8, 0x33,
0x97, 0x66, 0xeb, 0x65, 0xd2, 0xba, 0xd9, 0x48, 0x83, 0x79, 0x6d, 0x43, 0x09, 0x69, 0xe5,
0x2d, 0x54, 0x9b, 0xd8, 0xbb, 0xc0, 0xb9, 0xec, 0xe4, 0x90, 0x8b, 0x43, 0x57, 0x9b, 0x84,
0xad, 0x55, 0xd5, 0x68, 0x43, 0xc6, 0x1b, 0x01, 0x36, 0xca, 0x82, 0x6c, 0x96, 0xae, 0x5f,
0xca, 0xec, 0xc2, 0x48, 0x13, 0x5a, 0x72, 0x17, 0x20, 0x56, 0x9e, 0x3b, 0xe3, 0xe5, 0xbd,
0x20, 0x38, 0x56, 0x01, 0x8a, 0x32, 0x92, 0x47, 0xb1, 0x0f, 0x0e, 0x8f, 0x69, 0x1d, 0x7f,
0x33, 0x84, 0xb8, 0x46, 0x58, 0x0d, 0xf6, 0xa2, 0xb1, 0xc7, 0xe9, 0x7a, 0xbc, 0x18, 0xa9,
0x78, 0x70, 0x61, 0xff, 0x4b, 0x70, 0x41, 0x58, 0xdd, 0xbb, 0xcb, 0x71, 0x46, 0x92, 0x4d,
0xf2, 0x26, 0xe0, 0x20, 0x6d, 0x81, 0x4c, 0x82, 0x5a, 0x29, 0xee, 0x1e, 0x01, 0xb7, 0xd1,
0x8b, 0x32, 0xef, 0x00, 0x5e, 0x83, 0x1e, 0x30, 0x1d, 0xc4, 0xb2, 0x95, 0x5a, 0xa5, 0x75,
0x02, 0x9c, 0xae, 0xf5, 0x8e, 0x88, 0xd8, 0x94, 0xac, 0x9a, 0x04, 0x88, 0x6f, 0x38, 0x8b,
0x1b, 0x22, 0x5a, 0x33, 0x3e, 0xfb, 0x2e, 0xfd, 0x6f, 0xaa, 0x7d, 0xcd, 0xf1, 0xab, 0x61,
0x69, 0xc0, 0x54, 0x09, 0xf9, 0xe9, 0x43, 0xa1, 0x7f, 0x48, 0xf5, 0xe9, 0xfe, 0xf3, 0xd5,
0xd1, 0xdf, 0x0c, 0xe7, 0xc9, 0xd4, 0xfd, 0xe2, 0x31, 0x33, 0x6c, 0x71, 0xe1, 0xe0, 0x9b,
0x35, 0x1f, 0xea, 0x7a, 0x3e, 0xaa, 0x36, 0x70, 0xda, 0xb7, 0xcc, 0x5e, 0x1f, 0xe5, 0x70,
0xf6, 0x60, 0xe8, 0xa4, 0x8a, 0xa3, 0x1d, 0x08, 0x6a, 0xa6, 0xf9, 0x6c, 0xac, 0x5b, 0xa2,
0xa9, 0x45, 0x67, 0xae, 0x34, 0x55, 0xc0, 0xd0, 0xf5, 0x37, 0xde, 0xc6, 0x13, 0x06, 0x16,
0x82,
];
fn connect() -> Result<Strong<dyn IHwCryptoKey>, StatusCode> {
let port =
CString::try_new(RUST_DEVICE_KEY_SERVICE_PORT).expect("Failed to allocate port name");
RpcSession::new().setup_trusty_client(port.as_c_str())
}
fn keys_are_sufficiently_distinct(key1: Vec<u8>, key2: Vec<u8>) -> bool {
let differing_bytes = key1.iter().zip(key2.iter()).filter(|(&x1, &x2)| x1 != x2).count();
std::cmp::min(key1.len(), key2.len()) - differing_bytes <= 4
}
#[test]
fn generate_new_policy_and_clear_key() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate the current derivation key and policy
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key1,
dicePolicyForKeyVersion: dice_policy,
} = key_and_policy;
expect!(derivation_key1.is_some(), "should have received a key");
expect!(dice_policy.len() > 0, "should have received a DICE policy");
// Derive a clear key from returned current policy and derivation key
let mut params = DerivedKeyParameters {
derivationKey: derivation_key1,
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: "context".as_bytes().to_vec(),
};
let derived_key1 = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key1 = match derived_key1 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key1.len() as i32, 256, "wrong key length");
// Use dice policy to request same key
let key_and_policy =
assert_ok!(hw_device_key.deriveDicePolicyBoundKey(&device_bound_key, &dice_policy));
let DiceBoundKeyResult {
diceBoundKey: derivation_key2,
dicePolicyWasCurrent: dice_policy_current,
} = key_and_policy;
expect!(derivation_key2.is_some(), "should have received a key");
expect!(dice_policy_current, "policy should have been current");
// generate derived key 2 and compare to key 1
params.derivationKey = derivation_key2;
let derived_key2 = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key2 = match derived_key2 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key2.len() as i32, 256, "wrong key length");
// Make sure both derived keys match
assert_eq!(derived_key2, derived_key1, "key mismatch");
// If we request current dice policy again, we expect the same key, but different
// encryption of the returned policy. Note underlying policy is the same (latest),
// but encrypted byte array returned will be different
// Generate the current derivation key and policy again
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key3,
dicePolicyForKeyVersion: dice_policy3,
} = key_and_policy;
// We expect the dice policy to appear different due to encruption
assert_ne!(
dice_policy, dice_policy3,
"expected dice policies to appear different due to encryption"
);
// Ensure derived key from this policy matches previously generated derived key
params.derivationKey = derivation_key3;
let derived_key3 = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key3 = match derived_key3 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key3.len() as i32, 256, "wrong key length");
// Make sure both derived keys match
assert_eq!(derived_key3, derived_key1, "key mismatch");
}
#[test]
fn old_dice_generates_old_clear_key_and_new_policy() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate a derived key from version 0 dice policy
let key_and_policy = assert_ok!(
hw_device_key.deriveDicePolicyBoundKey(&device_bound_key, &VERSION_0_DICE_POLICY)
);
let DiceBoundKeyResult {
diceBoundKey: derivation_key,
dicePolicyWasCurrent: dice_policy_current,
} = key_and_policy;
// We expect version 0 should not be current
expect!(!dice_policy_current, "policy not expected to be current");
// Derive clear key from derivation key
let params = DerivedKeyParameters {
derivationKey: derivation_key,
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: "context".as_bytes().to_vec(),
};
let derived_key = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key = match derived_key {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key.len() as i32, 256, "wrong key length");
// Check we got the old key and a new policy
assert_eq!(derived_key, VERSION_0_CLEAR_KEY.to_vec(), "Retrieved version 0 key mismatch");
}
#[test]
fn dice_updates_are_unique() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate a derived key from version 0 dice policy
let key_and_policy = assert_ok!(
hw_device_key.deriveDicePolicyBoundKey(&device_bound_key, &VERSION_0_DICE_POLICY)
);
let DiceBoundKeyResult {
diceBoundKey: _derivation_key,
dicePolicyWasCurrent: dice_policy_current,
} = key_and_policy;
// We expect version 0 should not be current
expect!(!dice_policy_current, "policy not expected to be current");
// Get current dice policy multiple times
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key1,
dicePolicyForKeyVersion: dice_policy1,
} = key_and_policy;
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key2,
dicePolicyForKeyVersion: dice_policy2,
} = key_and_policy;
// policies should appear different due to encryption and not be zero length
expect!(dice_policy1.len() > 0, "should have received a DICE policy");
expect!(dice_policy2.len() > 0, "should have received a DICE policy");
assert_ne!(dice_policy1, dice_policy2, "expected policies to be different");
expect!(derivation_key1.is_some(), "should have received a key");
expect!(derivation_key2.is_some(), "should have received a key");
// Generate derived clear keys from returned derivation keys
let params = DerivedKeyParameters {
derivationKey: derivation_key1,
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: "context".as_bytes().to_vec(),
};
let derived_key1 = assert_ok!(hw_device_key.deriveKey(&params));
let params = DerivedKeyParameters {
derivationKey: derivation_key2,
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: "context".as_bytes().to_vec(),
};
let derived_key2 = assert_ok!(hw_device_key.deriveKey(&params));
// Check derived keys
let derived_key1 = match derived_key1 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
let derived_key2 = match derived_key2 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
// Check that generated keys match
assert_eq!(derived_key1, derived_key2, "key mismatch");
// Check that both dice policies are considered current
let key_and_policy =
assert_ok!(hw_device_key.deriveDicePolicyBoundKey(&device_bound_key, &dice_policy1));
let DiceBoundKeyResult { diceBoundKey: _, dicePolicyWasCurrent: dice_policy1_current } =
key_and_policy;
expect!(dice_policy1_current, "policy expected to be current");
let key_and_policy =
assert_ok!(hw_device_key.deriveDicePolicyBoundKey(&device_bound_key, &dice_policy2));
let DiceBoundKeyResult { diceBoundKey: _, dicePolicyWasCurrent: dice_policy2_current } =
key_and_policy;
expect!(dice_policy2_current, "policy expected to be current");
}
#[test]
fn explicit_keys_unique_by_context() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate the current derivation key and policy
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key,
dicePolicyForKeyVersion: dice_policy,
} = key_and_policy;
expect!(derivation_key.is_some(), "should have received a key");
expect!(dice_policy.len() > 0, "should have received a DICE policy");
// Define two different contexts and get clear derived keys for each
let context1 = "context1";
let context2 = "context2";
let params1 = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: context1.as_bytes().to_vec(),
};
let params2 = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: context2.as_bytes().to_vec(),
};
let derived_key1 = assert_ok!(hw_device_key.deriveKey(&params1));
let derived_key2 = assert_ok!(hw_device_key.deriveKey(&params2));
// Check key2 type and length
let derived_key1 = match derived_key1 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
let derived_key2 = match derived_key2 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key1.len() as i32, 256, "wrong key length");
assert_eq!(derived_key2.len() as i32, 256, "wrong key length");
// Ensure keys are different
assert_ne!(derived_key2, derived_key1, "returned keys are same");
assert!(
keys_are_sufficiently_distinct(derived_key2, derived_key1),
"derived keys share too many bytes"
);
}
#[test]
fn invalid_key_sizes() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate the current derivation key and policy
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key,
dicePolicyForKeyVersion: dice_policy,
} = key_and_policy;
expect!(derivation_key.is_some(), "should have received a key");
expect!(dice_policy.len() > 0, "should have received a DICE policy");
// Request a zero length key
let params = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 0 }),
context: "context".as_bytes().to_vec(),
};
let derived_key = hw_device_key.deriveKey(&params);
expect!(derived_key.is_err(), "expected error on bad key size");
// Request a negative length key
let params = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: -256 }),
context: "context".as_bytes().to_vec(),
};
let derived_key = hw_device_key.deriveKey(&params);
expect!(derived_key.is_err(), "expected error on bad key size");
}
#[test]
fn large_context() {
let hw_device_key = connect().expect("couldn't connect to HW Crypto service");
// Get the device bound key
let device_bound_key = DiceBoundDerivationKey::KeyId(DeviceKeyId::DEVICE_BOUND_KEY);
// Generate the current derivation key and policy
let key_and_policy =
assert_ok!(hw_device_key.deriveCurrentDicePolicyBoundKey(&device_bound_key));
let DiceCurrentBoundKeyResult {
diceBoundKey: derivation_key,
dicePolicyForKeyVersion: dice_policy,
} = key_and_policy;
expect!(derivation_key.is_some(), "should have received a key");
expect!(dice_policy.len() > 0, "should have received a DICE policy");
// Pick a reasonable large context size
const PAYLOAD_LEN: usize = 512;
let mut context = vec![42; PAYLOAD_LEN];
// Get a derived key based on large context
let params = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: context.clone(),
};
let derived_key1 = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key1 = match derived_key1 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key1.len() as i32, 256, "wrong key length");
// Make a minor change to last byte of context and request another key
context[PAYLOAD_LEN - 1] = 43;
let params = DerivedKeyParameters {
derivationKey: derivation_key.clone(),
keyPolicy: DerivedKeyPolicy::ClearKey(ClearKeyPolicy { keySizeBytes: 256 }),
context: context.clone(),
};
let derived_key2 = assert_ok!(hw_device_key.deriveKey(&params));
// Check key type and length
let derived_key2 = match derived_key2 {
DerivedKey::Opaque(_) => panic!("wrong type of key received"),
DerivedKey::ExplicitKey(k) => k,
};
assert_eq!(derived_key2.len() as i32, 256, "wrong key length");
//Ensure keys are different
assert_ne!(derived_key1, derived_key2, "keys expected to differ");
assert!(
keys_are_sufficiently_distinct(derived_key1, derived_key2),
"derived keys share too many bytes"
);
}
}