| // Copyright 2022, 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. |
| |
| //! This module implements test utils to generate various types of keys. |
| |
| use anyhow::Result; |
| |
| use android_hardware_security_keymint::aidl::android::hardware::security::keymint::{ |
| Algorithm::Algorithm, BlockMode::BlockMode, Digest::Digest, EcCurve::EcCurve, |
| ErrorCode::ErrorCode, KeyPurpose::KeyPurpose, PaddingMode::PaddingMode, |
| }; |
| use android_system_keystore2::aidl::android::system::keystore2::{ |
| Domain::Domain, IKeystoreSecurityLevel::IKeystoreSecurityLevel, KeyDescriptor::KeyDescriptor, |
| KeyMetadata::KeyMetadata, ResponseCode::ResponseCode, |
| }; |
| |
| use crate::authorizations::AuthSetBuilder; |
| use android_system_keystore2::binder::{ExceptionCode, Result as BinderResult}; |
| |
| /// Shell namespace. |
| pub const SELINUX_SHELL_NAMESPACE: i64 = 1; |
| /// Vold namespace. |
| pub const SELINUX_VOLD_NAMESPACE: i64 = 100; |
| |
| /// SU context. |
| pub const TARGET_SU_CTX: &str = "u:r:su:s0"; |
| |
| /// Vold context |
| pub const TARGET_VOLD_CTX: &str = "u:r:vold:s0"; |
| |
| /// Key parameters to generate a key. |
| pub struct KeyParams { |
| /// Key Size. |
| pub key_size: i32, |
| /// Key Purposes. |
| pub purpose: Vec<KeyPurpose>, |
| /// Padding Mode. |
| pub padding: Option<PaddingMode>, |
| /// Digest. |
| pub digest: Option<Digest>, |
| /// MFG Digest. |
| pub mgf_digest: Option<Digest>, |
| /// Block Mode. |
| pub block_mode: Option<BlockMode>, |
| /// Attestation challenge. |
| pub att_challenge: Option<Vec<u8>>, |
| /// Attestation app id. |
| pub att_app_id: Option<Vec<u8>>, |
| } |
| |
| /// To map Keystore errors. |
| #[derive(thiserror::Error, Debug, Eq, PartialEq)] |
| pub enum Error { |
| /// Keystore2 error code |
| #[error("ResponseCode {0:?}")] |
| Rc(ResponseCode), |
| /// Keymint error code |
| #[error("ErrorCode {0:?}")] |
| Km(ErrorCode), |
| /// Exception |
| #[error("Binder exception {0:?}")] |
| Binder(ExceptionCode), |
| /// This is returned if the C implementation of extractSubjectFromCertificate failed. |
| #[error("Failed to validate certificate chain.")] |
| ValidateCertChainFailed, |
| } |
| |
| /// Keystore2 error mapping. |
| pub fn map_ks_error<T>(r: BinderResult<T>) -> Result<T, Error> { |
| r.map_err(|s| { |
| match s.exception_code() { |
| ExceptionCode::SERVICE_SPECIFIC => { |
| match s.service_specific_error() { |
| se if se < 0 => { |
| // Negative service specific errors are KM error codes. |
| Error::Km(ErrorCode(se)) |
| } |
| se => { |
| // Positive service specific errors are KS response codes. |
| Error::Rc(ResponseCode(se)) |
| } |
| } |
| } |
| // We create `Error::Binder` to preserve the exception code |
| // for logging. |
| e_code => Error::Binder(e_code), |
| } |
| }) |
| } |
| |
| /// Generate EC Key using given security level and domain with below key parameters and |
| /// optionally allow the generated key to be attested with factory provisioned attest key using |
| /// given challenge and application id - |
| /// Purposes: SIGN and VERIFY |
| /// Digest: SHA_2_256 |
| /// Curve: P_256 |
| pub fn generate_ec_p256_signing_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| domain: Domain, |
| nspace: i64, |
| alias: Option<String>, |
| att_challenge: Option<&[u8]>, |
| att_app_id: Option<&[u8]>, |
| ) -> binder::Result<KeyMetadata> { |
| let mut key_attest = false; |
| let mut gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::EC) |
| .purpose(KeyPurpose::SIGN) |
| .purpose(KeyPurpose::VERIFY) |
| .digest(Digest::SHA_2_256) |
| .ec_curve(EcCurve::P_256); |
| |
| if let Some(challenge) = att_challenge { |
| key_attest = true; |
| gen_params = gen_params.clone().attestation_challenge(challenge.to_vec()); |
| } |
| |
| if let Some(app_id) = att_app_id { |
| key_attest = true; |
| gen_params = gen_params.clone().attestation_app_id(app_id.to_vec()); |
| } |
| |
| match sec_level.generateKey( |
| &KeyDescriptor { domain, nspace, alias, blob: None }, |
| None, |
| &gen_params, |
| 0, |
| b"entropy", |
| ) { |
| Ok(key_metadata) => { |
| assert!(key_metadata.certificate.is_some()); |
| if key_attest { |
| assert!(key_metadata.certificateChain.is_some()); |
| } |
| if domain == Domain::BLOB { |
| assert!(key_metadata.key.blob.is_some()); |
| } |
| |
| Ok(key_metadata) |
| } |
| Err(e) => Err(e), |
| } |
| } |
| |
| /// Generate EC signing key. |
| pub fn generate_ec_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| domain: Domain, |
| nspace: i64, |
| alias: Option<String>, |
| ec_curve: EcCurve, |
| digest: Digest, |
| ) -> binder::Result<KeyMetadata> { |
| let gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::EC) |
| .purpose(KeyPurpose::SIGN) |
| .purpose(KeyPurpose::VERIFY) |
| .digest(digest) |
| .ec_curve(ec_curve); |
| |
| let key_metadata = sec_level.generateKey( |
| &KeyDescriptor { domain, nspace, alias, blob: None }, |
| None, |
| &gen_params, |
| 0, |
| b"entropy", |
| )?; |
| |
| // Must have a public key. |
| assert!(key_metadata.certificate.is_some()); |
| |
| // Should not have an attestation record. |
| assert!(key_metadata.certificateChain.is_none()); |
| |
| if domain == Domain::BLOB { |
| assert!(key_metadata.key.blob.is_some()); |
| } else { |
| assert!(key_metadata.key.blob.is_none()); |
| } |
| Ok(key_metadata) |
| } |
| |
| /// Generate a RSA key with the given key parameters, alias, domain and namespace. |
| pub fn generate_rsa_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| domain: Domain, |
| nspace: i64, |
| alias: Option<String>, |
| key_params: &KeyParams, |
| attest_key: Option<&KeyDescriptor>, |
| ) -> binder::Result<KeyMetadata> { |
| let mut gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::RSA) |
| .rsa_public_exponent(65537) |
| .key_size(key_params.key_size); |
| |
| for purpose in &key_params.purpose { |
| gen_params = gen_params.purpose(*purpose); |
| } |
| if let Some(value) = key_params.digest { |
| gen_params = gen_params.digest(value) |
| } |
| if let Some(value) = key_params.padding { |
| gen_params = gen_params.padding_mode(value); |
| } |
| if let Some(value) = key_params.mgf_digest { |
| gen_params = gen_params.mgf_digest(value); |
| } |
| if let Some(value) = key_params.block_mode { |
| gen_params = gen_params.block_mode(value) |
| } |
| if let Some(value) = &key_params.att_challenge { |
| gen_params = gen_params.attestation_challenge(value.to_vec()) |
| } |
| if let Some(value) = &key_params.att_app_id { |
| gen_params = gen_params.attestation_app_id(value.to_vec()) |
| } |
| |
| let key_metadata = sec_level.generateKey( |
| &KeyDescriptor { domain, nspace, alias, blob: None }, |
| attest_key, |
| &gen_params, |
| 0, |
| b"entropy", |
| )?; |
| |
| // Must have a public key. |
| assert!(key_metadata.certificate.is_some()); |
| |
| if attest_key.is_none() && key_params.att_challenge.is_some() && key_params.att_app_id.is_some() |
| { |
| // Should have an attestation record. |
| assert!(key_metadata.certificateChain.is_some()); |
| } else { |
| // Should not have an attestation record. |
| assert!(key_metadata.certificateChain.is_none()); |
| } |
| |
| assert!( |
| (domain == Domain::BLOB && key_metadata.key.blob.is_some()) |
| || key_metadata.key.blob.is_none() |
| ); |
| |
| Ok(key_metadata) |
| } |
| |
| /// Generate AES/3DES key. |
| pub fn generate_sym_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| algorithm: Algorithm, |
| size: i32, |
| alias: &str, |
| padding_mode: &PaddingMode, |
| block_mode: &BlockMode, |
| min_mac_len: Option<i32>, |
| ) -> binder::Result<KeyMetadata> { |
| let mut gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(algorithm) |
| .purpose(KeyPurpose::ENCRYPT) |
| .purpose(KeyPurpose::DECRYPT) |
| .key_size(size) |
| .padding_mode(*padding_mode) |
| .block_mode(*block_mode); |
| |
| if let Some(val) = min_mac_len { |
| gen_params = gen_params.min_mac_length(val); |
| } |
| |
| let key_metadata = sec_level.generateKey( |
| &KeyDescriptor { |
| domain: Domain::APP, |
| nspace: -1, |
| alias: Some(alias.to_string()), |
| blob: None, |
| }, |
| None, |
| &gen_params, |
| 0, |
| b"entropy", |
| )?; |
| |
| // Should not have public certificate. |
| assert!(key_metadata.certificate.is_none()); |
| |
| // Should not have an attestation record. |
| assert!(key_metadata.certificateChain.is_none()); |
| Ok(key_metadata) |
| } |
| |
| /// Generate HMAC key. |
| pub fn generate_hmac_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| alias: &str, |
| key_size: i32, |
| min_mac_len: i32, |
| digest: Digest, |
| ) -> binder::Result<KeyMetadata> { |
| let gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::HMAC) |
| .purpose(KeyPurpose::SIGN) |
| .purpose(KeyPurpose::VERIFY) |
| .key_size(key_size) |
| .min_mac_length(min_mac_len) |
| .digest(digest); |
| |
| let key_metadata = sec_level.generateKey( |
| &KeyDescriptor { |
| domain: Domain::APP, |
| nspace: -1, |
| alias: Some(alias.to_string()), |
| blob: None, |
| }, |
| None, |
| &gen_params, |
| 0, |
| b"entropy", |
| )?; |
| |
| // Should not have public certificate. |
| assert!(key_metadata.certificate.is_none()); |
| |
| // Should not have an attestation record. |
| assert!(key_metadata.certificateChain.is_none()); |
| |
| Ok(key_metadata) |
| } |
| |
| /// Generate RSA or EC attestation keys using below parameters - |
| /// Purpose: ATTEST_KEY |
| /// Digest: Digest::SHA_2_256 |
| /// Padding: PaddingMode::RSA_PKCS1_1_5_SIGN |
| /// RSA-Key-Size: 2048 |
| /// EC-Curve: EcCurve::P_256 |
| pub fn generate_attestation_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| algorithm: Algorithm, |
| att_challenge: &[u8], |
| att_app_id: &[u8], |
| ) -> binder::Result<KeyMetadata> { |
| assert!(algorithm == Algorithm::RSA || algorithm == Algorithm::EC); |
| |
| if algorithm == Algorithm::RSA { |
| let alias = "ks_rsa_attest_test_key"; |
| let metadata = generate_rsa_key( |
| sec_level, |
| Domain::APP, |
| -1, |
| Some(alias.to_string()), |
| &KeyParams { |
| key_size: 2048, |
| purpose: vec![KeyPurpose::ATTEST_KEY], |
| padding: Some(PaddingMode::RSA_PKCS1_1_5_SIGN), |
| digest: Some(Digest::SHA_2_256), |
| mgf_digest: None, |
| block_mode: None, |
| att_challenge: Some(att_challenge.to_vec()), |
| att_app_id: Some(att_app_id.to_vec()), |
| }, |
| None, |
| ) |
| .unwrap(); |
| Ok(metadata) |
| } else { |
| let metadata = generate_ec_attestation_key( |
| sec_level, |
| att_challenge, |
| att_app_id, |
| Digest::SHA_2_256, |
| EcCurve::P_256, |
| ) |
| .unwrap(); |
| |
| Ok(metadata) |
| } |
| } |
| |
| /// Generate EC attestation key with the given |
| /// curve, attestation-challenge and attestation-app-id. |
| pub fn generate_ec_attestation_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| att_challenge: &[u8], |
| att_app_id: &[u8], |
| digest: Digest, |
| ec_curve: EcCurve, |
| ) -> binder::Result<KeyMetadata> { |
| let alias = "ks_attest_ec_test_key"; |
| let gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::EC) |
| .purpose(KeyPurpose::ATTEST_KEY) |
| .ec_curve(ec_curve) |
| .digest(digest) |
| .attestation_challenge(att_challenge.to_vec()) |
| .attestation_app_id(att_app_id.to_vec()); |
| |
| let attestation_key_metadata = sec_level.generateKey( |
| &KeyDescriptor { |
| domain: Domain::APP, |
| nspace: -1, |
| alias: Some(alias.to_string()), |
| blob: None, |
| }, |
| None, |
| &gen_params, |
| 0, |
| b"entropy", |
| )?; |
| |
| // Should have public certificate. |
| assert!(attestation_key_metadata.certificate.is_some()); |
| // Should have an attestation record. |
| assert!(attestation_key_metadata.certificateChain.is_some()); |
| |
| Ok(attestation_key_metadata) |
| } |
| |
| /// Generate EC-P-256 key and attest it with given attestation key. |
| pub fn generate_ec_256_attested_key( |
| sec_level: &binder::Strong<dyn IKeystoreSecurityLevel>, |
| alias: Option<String>, |
| att_challenge: &[u8], |
| att_app_id: &[u8], |
| attest_key: &KeyDescriptor, |
| ) -> binder::Result<KeyMetadata> { |
| let ec_gen_params = AuthSetBuilder::new() |
| .no_auth_required() |
| .algorithm(Algorithm::EC) |
| .purpose(KeyPurpose::SIGN) |
| .purpose(KeyPurpose::VERIFY) |
| .digest(Digest::SHA_2_256) |
| .ec_curve(EcCurve::P_256) |
| .attestation_challenge(att_challenge.to_vec()) |
| .attestation_app_id(att_app_id.to_vec()); |
| |
| let ec_key_metadata = sec_level |
| .generateKey( |
| &KeyDescriptor { domain: Domain::APP, nspace: -1, alias, blob: None }, |
| Some(attest_key), |
| &ec_gen_params, |
| 0, |
| b"entropy", |
| ) |
| .unwrap(); |
| |
| // Should have public certificate. |
| assert!(ec_key_metadata.certificate.is_some()); |
| // Shouldn't have an attestation record. |
| assert!(ec_key_metadata.certificateChain.is_none()); |
| |
| Ok(ec_key_metadata) |
| } |