Merge "KeyMint VTS: ATTEST_KEY has no other purpose" am: a67b0441fe am: 02c4ee0dca am: 35392ef70e
Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1844276
Change-Id: Ia77411d469b6a291ec333ea27150c5eef8eb2ac1
diff --git a/security/keymint/aidl/android/hardware/security/keymint/KeyPurpose.aidl b/security/keymint/aidl/android/hardware/security/keymint/KeyPurpose.aidl
index e141e55..fd103ef 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/KeyPurpose.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/KeyPurpose.aidl
@@ -44,6 +44,10 @@
AGREE_KEY = 6,
/* Usable as an attestation signing key. Keys with this purpose must not have any other
- * purpose. */
+ * purpose; if they do, key generation/import must be rejected with
+ * ErrorCode::INCOMPATIBLE_PURPOSE. (Rationale: If key also included KeyPurpose::SIGN, then
+ * it could be used to sign arbitrary data, including any tbsCertificate, and so an
+ * attestation produced by the key would have no security properties.)
+ */
ATTEST_KEY = 7,
}
diff --git a/security/keymint/aidl/vts/functional/AttestKeyTest.cpp b/security/keymint/aidl/vts/functional/AttestKeyTest.cpp
index 73c3820..0fdf48d 100644
--- a/security/keymint/aidl/vts/functional/AttestKeyTest.cpp
+++ b/security/keymint/aidl/vts/functional/AttestKeyTest.cpp
@@ -175,6 +175,24 @@
}
/*
+ * AttestKeyTest.RsaAttestKeyMultiPurposeFail
+ *
+ * This test attempts to create an RSA attestation key that also allows signing.
+ */
+TEST_P(AttestKeyTest, RsaAttestKeyMultiPurposeFail) {
+ vector<uint8_t> attest_key_blob;
+ vector<KeyCharacteristics> attest_key_characteristics;
+ vector<Certificate> attest_key_cert_chain;
+ ASSERT_EQ(ErrorCode::INCOMPATIBLE_PURPOSE,
+ GenerateKey(AuthorizationSetBuilder()
+ .RsaSigningKey(2048, 65537)
+ .AttestKey()
+ .SetDefaultValidity(),
+ {} /* attestation signing key */, &attest_key_blob,
+ &attest_key_characteristics, &attest_key_cert_chain));
+}
+
+/*
* AttestKeyTest.RsaAttestedAttestKeys
*
* This test creates an RSA attestation key signed by factory keys, and varifies it can be
@@ -412,6 +430,24 @@
}
/*
+ * AttestKeyTest.EcAttestKeyMultiPurposeFail
+ *
+ * This test attempts to create an EC attestation key that also allows signing.
+ */
+TEST_P(AttestKeyTest, EcAttestKeyMultiPurposeFail) {
+ vector<uint8_t> attest_key_blob;
+ vector<KeyCharacteristics> attest_key_characteristics;
+ vector<Certificate> attest_key_cert_chain;
+ ASSERT_EQ(ErrorCode::INCOMPATIBLE_PURPOSE,
+ GenerateKey(AuthorizationSetBuilder()
+ .EcdsaSigningKey(EcCurve::P_256)
+ .AttestKey()
+ .SetDefaultValidity(),
+ {} /* attestation signing key */, &attest_key_blob,
+ &attest_key_characteristics, &attest_key_cert_chain));
+}
+
+/*
* AttestKeyTest.AlternateAttestKeyChaining
*
* This test creates a chain of multiple attest keys, in the order Ec - RSA - Ec - RSA ....
diff --git a/security/keymint/aidl/vts/functional/KeyMintTest.cpp b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
index 161531d..217ea0e 100644
--- a/security/keymint/aidl/vts/functional/KeyMintTest.cpp
+++ b/security/keymint/aidl/vts/functional/KeyMintTest.cpp
@@ -3352,6 +3352,26 @@
}
/*
+ * ImportKeyTest.RsaAttestMultiPurposeFail
+ *
+ * Verifies that importing an RSA key pair with purpose ATTEST_KEY+SIGN fails.
+ */
+TEST_P(ImportKeyTest, RsaAttestMultiPurposeFail) {
+ uint32_t key_size = 2048;
+ string key = rsa_2048_key;
+
+ ASSERT_EQ(ErrorCode::INCOMPATIBLE_PURPOSE,
+ ImportKey(AuthorizationSetBuilder()
+ .Authorization(TAG_NO_AUTH_REQUIRED)
+ .RsaSigningKey(key_size, 65537)
+ .AttestKey()
+ .Digest(Digest::SHA_2_256)
+ .Padding(PaddingMode::RSA_PSS)
+ .SetDefaultValidity(),
+ KeyFormat::PKCS8, key));
+}
+
+/*
* ImportKeyTest.EcdsaSuccess
*
* Verifies that importing and using an ECDSA P-256 key pair works correctly.
@@ -3470,6 +3490,22 @@
}
/*
+ * ImportKeyTest.EcdsaAttestMultiPurposeFail
+ *
+ * Verifies that importing and using an ECDSA P-256 key pair with purpose ATTEST_KEY+SIGN fails.
+ */
+TEST_P(ImportKeyTest, EcdsaAttestMultiPurposeFail) {
+ ASSERT_EQ(ErrorCode::INCOMPATIBLE_PURPOSE,
+ ImportKey(AuthorizationSetBuilder()
+ .Authorization(TAG_NO_AUTH_REQUIRED)
+ .EcdsaSigningKey(EcCurve::P_256)
+ .AttestKey()
+ .Digest(Digest::SHA_2_256)
+ .SetDefaultValidity(),
+ KeyFormat::PKCS8, ec_256_key));
+}
+
+/*
* ImportKeyTest.AesSuccess
*
* Verifies that importing and using an AES key works.