Merge pull request #546 from Superhepper/7.x.y-allow-to-specify-exact-key-type

ek, ak abstractions: allow to specficy exact key type

Author: Superhepper

tss-esapi/src/abstraction/ak.rs

@@ -2,31 +2,62 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use crate::{
-    abstraction::{cipher::Cipher, IntoKeyCustomization, KeyCustomization},
+    abstraction::{AsymmetricAlgorithmSelection, IntoKeyCustomization, KeyCustomization},
     attributes::{ObjectAttributesBuilder, SessionAttributesBuilder},
     constants::{AlgorithmIdentifier, SessionType},
     handles::{AuthHandle, KeyHandle, SessionHandle},
     interface_types::{
         algorithm::{
-            AsymmetricAlgorithm, EccSchemeAlgorithm, HashingAlgorithm, PublicAlgorithm,
-            RsaSchemeAlgorithm, SignatureSchemeAlgorithm,
+            EccSchemeAlgorithm, HashingAlgorithm, PublicAlgorithm, RsaSchemeAlgorithm,
+            SignatureSchemeAlgorithm,
         },
-        ecc::EccCurve,
-        key_bits::RsaKeyBits,
         session_handles::PolicySession,
     },
     structures::{
-        Auth, CreateKeyResult, EccScheme, KeyDerivationFunctionScheme, Private, Public,
-        PublicBuilder, PublicEccParametersBuilder, PublicKeyRsa, PublicRsaParametersBuilder,
-        RsaExponent, RsaScheme, SymmetricDefinitionObject,
+        Auth, CreateKeyResult, Digest, DigestList, EccPoint, EccScheme,
+        KeyDerivationFunctionScheme, Private, Public, PublicBuilder, PublicEccParametersBuilder,
+        PublicKeyRsa, PublicRsaParametersBuilder, RsaExponent, RsaScheme,
+        SymmetricDefinitionObject,
     },
     Context, Error, Result, WrapperErrorKind,
 };
-use log::error;
-use std::convert::{TryFrom, TryInto};
+use std::convert::TryFrom;
+
+// Source: TCG EK Credential Profile for TPM Family 2.0; Level 0 Version 2.5 Revision 2
+// Section B.6
+const POLICY_A_SHA384: [u8; 48] = [
+    0x8b, 0xbf, 0x22, 0x66, 0x53, 0x7c, 0x17, 0x1c, 0xb5, 0x6e, 0x40, 0x3c, 0x4d, 0xc1, 0xd4, 0xb6,
+    0x4f, 0x43, 0x26, 0x11, 0xdc, 0x38, 0x6e, 0x6f, 0x53, 0x20, 0x50, 0xc3, 0x27, 0x8c, 0x93, 0x0e,
+    0x14, 0x3e, 0x8b, 0xb1, 0x13, 0x38, 0x24, 0xcc, 0xb4, 0x31, 0x05, 0x38, 0x71, 0xc6, 0xdb, 0x53,
+];
+const POLICY_A_SHA512: [u8; 64] = [
+    0x1e, 0x3b, 0x76, 0x50, 0x2c, 0x8a, 0x14, 0x25, 0xaa, 0x0b, 0x7b, 0x3f, 0xc6, 0x46, 0xa1, 0xb0,
+    0xfa, 0xe0, 0x63, 0xb0, 0x3b, 0x53, 0x68, 0xf9, 0xc4, 0xcd, 0xde, 0xca, 0xff, 0x08, 0x91, 0xdd,
+    0x68, 0x2b, 0xac, 0x1a, 0x85, 0xd4, 0xd8, 0x32, 0xb7, 0x81, 0xea, 0x45, 0x19, 0x15, 0xde, 0x5f,
+    0xc5, 0xbf, 0x0d, 0xc4, 0xa1, 0x91, 0x7c, 0xd4, 0x2f, 0xa0, 0x41, 0xe3, 0xf9, 0x98, 0xe0, 0xee,
+];
+const POLICY_A_SM3_256: [u8; 32] = [
+    0xc6, 0x7f, 0x7d, 0x35, 0xf6, 0x6f, 0x3b, 0xec, 0x13, 0xc8, 0x9f, 0xe8, 0x98, 0x92, 0x1c, 0x65,
+    0x1b, 0x0c, 0xb5, 0xa3, 0x8a, 0x92, 0x69, 0x0a, 0x62, 0xa4, 0x3c, 0x00, 0x12, 0xe4, 0xfb, 0x8b,
+];
+const POLICY_C_SHA384: [u8; 48] = [
+    0xd6, 0x03, 0x2c, 0xe6, 0x1f, 0x2f, 0xb3, 0xc2, 0x40, 0xeb, 0x3c, 0xf6, 0xa3, 0x32, 0x37, 0xef,
+    0x2b, 0x6a, 0x16, 0xf4, 0x29, 0x3c, 0x22, 0xb4, 0x55, 0xe2, 0x61, 0xcf, 0xfd, 0x21, 0x7a, 0xd5,
+    0xb4, 0x94, 0x7c, 0x2d, 0x73, 0xe6, 0x30, 0x05, 0xee, 0xd2, 0xdc, 0x2b, 0x35, 0x93, 0xd1, 0x65,
+];
+const POLICY_C_SHA512: [u8; 64] = [
+    0x58, 0x9e, 0xe1, 0xe1, 0x46, 0x54, 0x47, 0x16, 0xe8, 0xde, 0xaf, 0xe6, 0xdb, 0x24, 0x7b, 0x01,
+    0xb8, 0x1e, 0x9f, 0x9c, 0x7d, 0xd1, 0x6b, 0x81, 0x4a, 0xa1, 0x59, 0x13, 0x87, 0x49, 0x10, 0x5f,
+    0xba, 0x53, 0x88, 0xdd, 0x1d, 0xea, 0x70, 0x2f, 0x35, 0x24, 0x0c, 0x18, 0x49, 0x33, 0x12, 0x1e,
+    0x2c, 0x61, 0xb8, 0xf5, 0x0d, 0x3e, 0xf9, 0x13, 0x93, 0xa4, 0x9a, 0x38, 0xc3, 0xf7, 0x3f, 0xc8,
+];
+const POLICY_C_SM3_256: [u8; 32] = [
+    0x2d, 0x4e, 0x81, 0x57, 0x8c, 0x35, 0x31, 0xd9, 0xbd, 0x1c, 0xdd, 0x7d, 0x02, 0xba, 0x29, 0x8d,
+    0x56, 0x99, 0xa3, 0xe3, 0x9f, 0xc3, 0x55, 0x1b, 0xfe, 0xff, 0xcf, 0x13, 0x2b, 0x49, 0xe1, 0x1d,
+];
 
 fn create_ak_public<IKC: IntoKeyCustomization>(
-    key_alg: AsymmetricAlgorithm,
+    key_alg: AsymmetricAlgorithmSelection,
     hash_alg: HashingAlgorithm,
     sign_alg: SignatureSchemeAlgorithm,
     key_customization: IKC,
@@ -50,7 +81,7 @@ fn create_ak_public<IKC: IntoKeyCustomization>(
     .build()?;
 
     let key_builder = match key_alg {
-        AsymmetricAlgorithm::Rsa => PublicBuilder::new()
+        AsymmetricAlgorithmSelection::Rsa(key_bits) => PublicBuilder::new()
             .with_public_algorithm(PublicAlgorithm::Rsa)
             .with_name_hashing_algorithm(hash_alg)
             .with_object_attributes(obj_attrs)
@@ -60,15 +91,15 @@ fn create_ak_public<IKC: IntoKeyCustomization>(
                         RsaSchemeAlgorithm::try_from(AlgorithmIdentifier::from(sign_alg))?,
                         Some(hash_alg),
                     )?)
-                    .with_key_bits(RsaKeyBits::Rsa2048)
+                    .with_key_bits(key_bits)
                     .with_exponent(RsaExponent::default())
                     .with_is_signing_key(obj_attrs.sign_encrypt())
                     .with_is_decryption_key(obj_attrs.decrypt())
                     .with_restricted(obj_attrs.restricted())
                     .build()?,
             )
             .with_rsa_unique_identifier(PublicKeyRsa::default()),
-        AsymmetricAlgorithm::Ecc => PublicBuilder::new()
+        AsymmetricAlgorithmSelection::Ecc(ecc_curve) => PublicBuilder::new()
             .with_public_algorithm(PublicAlgorithm::Ecc)
             .with_name_hashing_algorithm(hash_alg)
             .with_object_attributes(obj_attrs)
@@ -78,16 +109,17 @@ fn create_ak_public<IKC: IntoKeyCustomization>(
                     .with_ecc_scheme(EccScheme::create(
                         EccSchemeAlgorithm::try_from(AlgorithmIdentifier::from(sign_alg))?,
                         Some(hash_alg),
-                        Some(0),
+                        if sign_alg == SignatureSchemeAlgorithm::EcDaa {
+                            Some(0)
+                        } else {
+                            None
+                        },
                     )?)
-                    .with_curve(EccCurve::NistP192)
+                    .with_curve(ecc_curve)
                     .with_key_derivation_function_scheme(KeyDerivationFunctionScheme::Null)
                     .build()?,
-            ),
-        AsymmetricAlgorithm::Null => {
-            // TODO: Figure out what to with Null.
-            return Err(Error::local_error(WrapperErrorKind::UnsupportedParam));
-        }
+            )
+            .with_ecc_unique_identifier(EccPoint::default()),
     };
 
     let key_builder = if let Some(ref k) = key_customization {
@@ -99,6 +131,38 @@ fn create_ak_public<IKC: IntoKeyCustomization>(
     key_builder.build()
 }
 
+// extracts the hashing and sysmmetric algorithm from parent and constructs the correct DigestList for OR policy
+fn session_config(
+    context: &mut Context,
+    parent: KeyHandle,
+) -> Result<(HashingAlgorithm, SymmetricDefinitionObject, DigestList)> {
+    let (parent_public, _, _) = context.read_public(parent)?;
+    let parent_hash_alg = parent_public.name_hashing_algorithm();
+    let parent_symmetric = parent_public
+        .symmetric_algorithm()
+        .ok_or_else(|| Error::local_error(WrapperErrorKind::InvalidParam))?;
+
+    let mut policy_digests = DigestList::new();
+
+    match parent_hash_alg {
+        HashingAlgorithm::Sha384 => {
+            policy_digests.add(Digest::try_from(POLICY_A_SHA384.as_slice())?)?;
+            policy_digests.add(Digest::try_from(POLICY_C_SHA384.as_slice())?)?;
+        }
+        HashingAlgorithm::Sha512 => {
+            policy_digests.add(Digest::try_from(POLICY_A_SHA512.as_slice())?)?;
+            policy_digests.add(Digest::try_from(POLICY_C_SHA512.as_slice())?)?;
+        }
+        HashingAlgorithm::Sm3_256 => {
+            policy_digests.add(Digest::try_from(POLICY_A_SM3_256.as_slice())?)?;
+            policy_digests.add(Digest::try_from(POLICY_C_SM3_256.as_slice())?)?;
+        }
+        _ => (),
+    };
+
+    Ok((parent_hash_alg, parent_symmetric, policy_digests))
+}
+
 /// This loads an Attestation Key previously generated under the Endorsement hierarchy
 pub fn load_ak(
     context: &mut Context,
@@ -107,14 +171,16 @@ pub fn load_ak(
     private: Private,
     public: Public,
 ) -> Result<KeyHandle> {
+    let (parent_hash_alg, parent_symmetric, policy_digests) = session_config(context, parent)?;
+
     let policy_auth_session = context
         .start_auth_session(
             None,
             None,
             None,
             SessionType::Policy,
-            Cipher::aes_128_cfb().try_into()?,
-            HashingAlgorithm::Sha256,
+            parent_symmetric.into(),
+            parent_hash_alg,
         )?
         .ok_or_else(|| Error::local_error(WrapperErrorKind::WrongValueFromTpm))?;
 
@@ -142,6 +208,13 @@ pub fn load_ak(
                 )
             })?;
 
+            if !policy_digests.is_empty() {
+                ctx.policy_or(
+                    PolicySession::try_from(policy_auth_session)?,
+                    policy_digests,
+                )?
+            }
+
             ctx.execute_with_session(Some(policy_auth_session), |ctx| {
                 ctx.load(parent, private, public)
             })
@@ -160,26 +233,22 @@ pub fn create_ak<IKC: IntoKeyCustomization>(
     context: &mut Context,
     parent: KeyHandle,
     hash_alg: HashingAlgorithm,
+    key_alg: AsymmetricAlgorithmSelection,
     sign_alg: SignatureSchemeAlgorithm,
     ak_auth_value: Option<Auth>,
     key_customization: IKC,
 ) -> Result<CreateKeyResult> {
-    let key_alg = AsymmetricAlgorithm::try_from(sign_alg).map_err(|e| {
-        // sign_alg is either HMAC or Null.
-        error!("Could not retrieve asymmetric algorithm for provided signature scheme");
-        e
-    })?;
-
     let ak_pub = create_ak_public(key_alg, hash_alg, sign_alg, key_customization)?;
+    let (parent_hash_alg, parent_symmetric, policy_digests) = session_config(context, parent)?;
 
     let policy_auth_session = context
         .start_auth_session(
             None,
             None,
             None,
             SessionType::Policy,
-            Cipher::aes_128_cfb().try_into()?,
-            HashingAlgorithm::Sha256,
+            parent_symmetric.into(),
+            parent_hash_alg,
         )?
         .ok_or_else(|| Error::local_error(WrapperErrorKind::WrongValueFromTpm))?;
 
@@ -207,6 +276,13 @@ pub fn create_ak<IKC: IntoKeyCustomization>(
                 )
             })?;
 
+            if !policy_digests.is_empty() {
+                ctx.policy_or(
+                    PolicySession::try_from(policy_auth_session)?,
+                    policy_digests,
+                )?
+            };
+
             ctx.execute_with_session(Some(policy_auth_session), |ctx| {
                 ctx.create(parent, ak_pub, ak_auth_value, None, None, None)
             })