Update Identity Credential HAL docs. (a7bdc955) · Commits · e / os / android_hardware_interfaces

identity/aidl/android/hardware/identity/CipherSuite.aidl

+8 −6

Original line number	Diff line number	Diff line
		@@ -24,13 +24,15 @@ package android.hardware.identity;
		enum CipherSuite {
		/**
		* Specifies that the cipher suite that will be used to secure communications between the reader
		* is:
		* and the prover is using the following primitives
		*
		* - ECDHE with HKDF-SHA-256 for key agreement.
		* - AES-256 with GCM block mode for authenticated encryption (nonces are incremented by
		* one for every message).
		* - ECDSA with SHA-256 for signing (used for signing session transcripts to defeat
		* man-in-the-middle attacks), signing keys are not ephemeral.
		* - ECKA-DH (Elliptic Curve Key Agreement Algorithm - Diffie-Hellman, see BSI TR-03111)
		* - HKDF-SHA-256 (see RFC 5869)
		* - AES-256-GCM (see NIST SP 800-38D)
		* - HMAC-SHA-256 (see RFC 2104)
		*
		* The exact way these primitives are combined to derive the session key is specified in
		* section 9.2.1.4 of ISO/IEC 18013-5 (see description of cipher suite '1').
		*
		* At present this is the only supported cipher suite and it is mandatory for all
		* implementations to support it.

identity/aidl/android/hardware/identity/IIdentityCredential.aidl

+45 −16

Original line number	Diff line number	Diff line
		@@ -48,6 +48,8 @@ interface IIdentityCredential {
		* with the reader. The reason for generating the key pair in the secure environment is so that
		* the secure environment knows what public key to expect to find in the session transcript.
		*
		* The generated key must be an EC key using the P-256 curve.
		*
		* This method may only be called once per instance. If called more than once, STATUS_FAILED
		* will be returned.
		*
		@@ -61,7 +63,8 @@ interface IIdentityCredential {
		* This method may only be called once per instance. If called more than once, STATUS_FAILED
		* will be returned.
		*
		* @param publicKey contains the reader's ephemeral public key, in uncompressed form.
		* @param publicKey contains the reader's ephemeral public key, in uncompressed
		* form (e.g. 0x04 \|\| X \|\| Y).
		*/
		void setReaderEphemeralPublicKey(in byte[] publicKey);

		@@ -82,9 +85,9 @@ interface IIdentityCredential {
		* This method be called after createEphemeralKeyPair(), setReaderEphemeralPublicKey(),
		* createAuthChallenge() and before startRetrieveEntry(). This method call is followed by
		* multiple calls of startRetrieveEntryValue(), retrieveEntryValue(), and finally
		* finishRetrieval().This whole process is called a "credential presentation".
		* finishRetrieval().
		*
		* It is permissible to perform multiple credential presentations using the same instance (e.g.
		* It is permissible to perform data retrievals multiple times using the same instance (e.g.
		* startRetrieval(), then multiple calls of startRetrieveEntryValue(), retrieveEntryValue(),
		* then finally finishRetrieval()) but if this is done, the sessionTranscript parameter
		* must be identical for each startRetrieval() invocation. If this is not the case, this call
		@@ -148,6 +151,8 @@ interface IIdentityCredential {
		* EReaderKeyBytes = #6.24(bstr .cbor EReaderKey.Pub)
		* ItemsRequestBytes = #6.24(bstr .cbor ItemsRequest)
		*
		* EReaderKey.Pub = COSE_Key ; Ephemeral public key provided by reader
		*
		* The public key corresponding to the key used to made signature, can be found in the
		* 'x5chain' unprotected header element of the COSE_Sign1 structure (as as described
		* in 'draft-ietf-cose-x509-04'). There will be at least one certificate in said element
		@@ -220,13 +225,11 @@ interface IIdentityCredential {
		*
		* It is permissible to keep retrieving values if an access control check fails.
		*
		* @param nameSpace is the namespace of the element, e.g. "org.iso.18013"
		* @param nameSpace is the namespace of the element, e.g. "org.iso.18013.5.1"
		*
		* @param name is the name of the element.
		* @param name is the name of the element, e.g. "driving_privileges".
		*
		* @param entrySize is the size of the entry value, if it's a text string or a byte string.
		* It must be zero if the entry value is an integer or boolean. If this requirement
		* is not met the call fails with STATUS_INVALID_DATA.
		* @param entrySize is the size of the entry value encoded in CBOR.
		*
		* @param accessControlProfileIds specifies the set of access control profiles that can
		* authorize access to the provisioned element. If an identifier of a profile
		@@ -260,14 +263,12 @@ interface IIdentityCredential {
		* @param out mac is empty if signingKeyBlob or the sessionTranscript passed to
		* startRetrieval() is empty. Otherwise it is a COSE_Mac0 with empty payload
		* and the detached content is set to DeviceAuthentication as defined below.
		* The key used for the MAC operation is EMacKey and is derived as follows:
		*
		* KDF(ECDH(SDeviceKey.Priv, EReaderKey.Pub))
		*
		* where SDeviceKey.Priv is the key identified by signingKeyBlob. The KDF
		* and ECDH functions shall be the same as the ciphersuite selected and
		* passed to IIdentityStore.getCredential(). The EMacKey shall be derived
		* using a salt of 0x00.
		* This code is produced by using the key agreement and key derivation function
		* from the ciphersuite with the authentication private key and the reader
		* ephemeral public key to compute a shared message authentication code (MAC)
		* key, then using the MAC function from the ciphersuite to compute a MAC of
		* the authenticated data. See section 9.2.3.5 of ISO/IEC 18013-5 for details
		* of this operation.
		*
		* DeviceAuthentication = [
		* "DeviceAuthentication",
		@@ -308,6 +309,34 @@ interface IIdentityCredential {
		/**
		* Generate a key pair to be used for signing session data and retrieved data items.
		*
		* The generated key must be an EC key using the P-256 curve.
		*
		* This method shall return just a single X.509 certificate which is signed by CredentialKey.
		* When combined with the certificate chain returned at provisioning time by
		* getAttestationCertificate() on IWritableIdentityCredential (for the credential key), this
		* forms a chain all the way from the root of trust to the generated key.
		*
		* The public part of a signing key is usually included in issuer-signed data and is
		* used for anti-cloning purposes or as a mechanism for the issuer to attest to data
		* generated on the device.
		*
		* The following non-optional fields for the X.509 certificate shall be set as follows:
		*
		* - version: INTEGER 2 (means v3 certificate).
		*
		* - serialNumber: INTEGER 1 (fixed value: same on all certs).
		*
		* - signature: must be set to ECDSA.
		*
		* - subject: CN shall be set to "Android Identity Credential Authentication Key".
		*
		* - issuer: shall be set to "credentialStoreName (credentialStoreAuthorName)" using the
		* values returned in HardwareInformation.
		*
		* - validity: should be from current time and one year in the future.
		*
		* - subjectPublicKeyInfo: must contain attested public key.
		*
		* @param out signingKeyBlob contains an encrypted copy of the newly-generated private
		* signing key.
		*

identity/aidl/android/hardware/identity/IIdentityCredentialStore.aidl

+17 −20

Original line number	Diff line number	Diff line
		@@ -55,8 +55,8 @@ import android.hardware.identity.CipherSuite;
		*
		* - For each namespase, a set of name/value pairs, each with an associated set of access control
		* profile IDs. Names are UTF-8 strings of up to 256 bytes in length (most should be much
		* shorter). Values stored must be encoed as valid CBOR (https://tools.ietf.org/html/rfc7049) and
		* the encoeded size is is limited to at most 512 KiB.
		* shorter). Values stored must be encoded as CBOR (https://tools.ietf.org/html/rfc7049) and
		* the encoded size is is limited to at most 512 KiB.
		*
		* - A set of access control profiles, each with a profile ID and a specification of the
		* conditions which satisfy the profile's requirements.
		@@ -108,7 +108,8 @@ import android.hardware.identity.CipherSuite;
		@VintfStability
		interface IIdentityCredentialStore {
		/**
		* Success.
		* Success. This is never returned but included for completeness and for use by code
		* using these statuses for internal use.
		*/
		const int STATUS_OK = 0;

		@@ -186,16 +187,19 @@ interface IIdentityCredentialStore {
		HardwareInformation getHardwareInformation();

		/**
		* createCredential creates a new Credential. When a Credential is created, two cryptographic
		* createCredential creates a new credential. When a credential is created, two cryptographic
		* keys are created: StorageKey, an AES key used to secure the externalized Credential
		* contents, and CredentialKeyPair, an EC key pair used to authenticate the store to the IA. In
		* addition, all of the Credential data content is imported and a certificate for the
		* CredentialKeyPair and a signature produced with the CredentialKeyPair are created. These
		* contents, and CredentialKey, an EC key pair used to authenticate the store to the IA.
		*
		* CredentialKey must be an EC key using the P-256 curve.
		*
		* In addition, all of the Credential data content is imported and a certificate for the
		* CredentialKey and a signature produced with the CredentialKey are created. These
		* latter values may be checked by an issuing authority to verify that the data was imported
		* into secure hardware and that it was imported unmodified.
		*
		* @param docType is an optional name (may be an empty string) that identifies the type of
		* credential being created, e.g. "org.iso.18013-5.2019.mdl" (the doc type of the ISO
		* credential being created, e.g. "org.iso.18013.5.1.mDL" (the doc type of the ISO
		* driving license standard).
		*
		* @param testCredential indicates if this is a test store. Test credentials must use an
		@@ -213,15 +217,8 @@ interface IIdentityCredentialStore {
		* Credential.
		*
		* The cipher suite used to communicate with the remote verifier must also be specified. Currently
		* only a single cipher-suite is supported and the details of this are as follow:
		*
		* - ECDHE with HKDF-SHA-256 for key agreement.
		* - AES-256 with GCM block mode for authenticated encryption (nonces are incremented by one
		* for every message).
		* - ECDSA with SHA-256 for signing (used for signing session transcripts to defeat
		* man-in-the-middle attacks), signing keys are not ephemeral.
		*
		* Support for other cipher suites may be added in a future version of this HAL.
		* only a single cipher-suite is supported. Support for other cipher suites may be added in a
		* future version of this HAL.
		*
		* This method fails with STATUS_INVALID_DATA if the passed in credentialData cannot be
		* decoded or decrypted.
		@@ -233,7 +230,7 @@ interface IIdentityCredentialStore {
		* return argument of the same name in finishAddingEntries(), in
		* IWritableIdentityCredential.
		*
		* @return an IIdentityCredential HIDL interface that provides operations on the Credential.
		* @return an IIdentityCredential interface that provides operations on the Credential.
		*/
		IIdentityCredential getCredential(in CipherSuite cipherSuite, in byte[] credentialData);
		}

identity/aidl/android/hardware/identity/IWritableIdentityCredential.aidl

+44 −6

Original line number	Diff line number	Diff line
		@@ -60,12 +60,50 @@ interface IWritableIdentityCredential {
		* attestationApplicationId.
		*
		* - The teeEnforced field in the attestation extension must include
		* Tag::IDENTITY_CREDENTIAL_KEY. This tag indicates that the key is an Identity
		*
		* - Tag::IDENTITY_CREDENTIAL_KEY which indicates that the key is an Identity
		* Credential key (which can only sign/MAC very specific messages) and not an Android
		* Keystore key (which can be used to sign/MAC anything).
		*
		* - Tag::PURPOSE must be set to SIGN
		*
		* - Tag::KEY_SIZE must be set to the appropriate key size, in bits (e.g. 256)
		*
		* - Tag::ALGORITHM must be set to EC
		*
		* - Tag::NO_AUTH_REQUIRED must be set
		*
		* - Tag::DIGEST must be set to SHA_2_256
		*
		* - Tag::EC_CURVE must be set to P_256
		*
		* Additional authorizations may be needed in the softwareEnforced and teeEnforced
		* fields - the above is not an exhaustive list.
		* fields - the above is not an exhaustive list. Specifically, authorizations containing
		* information about the root of trust, OS version, verified boot state, and so on should
		* be included.
		*
		* Since the chain is required to be generated using Keymaster Attestation, the returned
		* certificate chain has the following properties:
		*
		* - The certificate chain is of at least length three.
		*
		* - The root of trust is the same as for Keymaster Attestation. This is usually
		* a certificate owned by Google but depending on the specific Android device it may
		* be another certificate.
		*
		* As with any user of attestation, the Issuing Authority (as a relying party) wishing
		* to issue a credential to a device using these APIs, must carefully examine the
		* returned certificate chain for all of the above (and more). In particular, the Issuing
		* Authority should check the root of trust, verified boot state, patch level,
		* application id, etc.
		*
		* This all depends on the needs of the Issuing Authority and the kind of credential but
		* in general an Issuing Authority should never issue a credential to a device without
		* verified boot enabled, to an unrecognized application, or if it appears the device
		* hasn't been updated for a long time.
		*
		* See https://github.com/google/android-key-attestation for an example of how to
		* examine attestations generated from Android devices.
		*
		* @param attestationApplicationId is the DER encoded value to be stored
		* in Tag::ATTESTATION_APPLICATION_ID. This schema is described in
		@@ -105,7 +143,7 @@ interface IWritableIdentityCredential {
		* be used to reference the profile. If this is not satisfied the call fails with
		* STATUS_INVALID_DATA.
		*
		* @param readerCertificate if non-empty, specifies a X.509 certificate (or chain of
		* @param readerCertificate if non-empty, specifies a single X.509 certificate (not a chain of
		* certificates) that must be used to authenticate requests (see the readerSignature
		* parameter in IIdentityCredential.startRetrieval).
		*
		@@ -142,7 +180,7 @@ interface IWritableIdentityCredential {
		* @param accessControlProfileIds specifies the set of access control profiles that can
		* authorize access to the provisioned element.
		*
		* @param nameSpace is the namespace of the element, e.g. "org.iso.18013"
		* @param nameSpace is the namespace of the element, e.g. "org.iso.18013.5.1"
		*
		* @param name is the name of the element.
		*

identity/aidl/android/hardware/identity/SecureAccessControlProfile.aidl

+1 −1

Original line number	Diff line number	Diff line
		@@ -29,7 +29,7 @@ parcelable SecureAccessControlProfile {
		/**
		* readerCertificate, if non-empty, specifies a single X.509 certificate (not a chain
		* of certificates) that must be used to authenticate requests. For details about how
		* this is done, see the readerSignature paremter of IIdentityCredential.startRetrieval.
		* this is done, see the readerSignature parameter of IIdentityCredential.startRetrieval.
		*/
		Certificate readerCertificate;