xref: /aosp_15_r20/system/keymint/common/src/keyblob/keyblob.cddl (revision 9860b7637a5f185913c70aa0caabe3ecb78441e4)

; encrypted_key_material is AES-GCM encrypted with:
; - key derived as described below
; - plaintext is the CBOR-serialization of `KeyMaterial`
; - nonce value is fixed, all zeroes
; - no additional data
;
; Key derivation uses HKDF (RFC 5869) with HMAC-SHA256 to generate an AES-256 key:
; - input keying material = a root key held in hardware
; - salt = absent
; - info = the following three or four chunks of context data concatenated:
;    - content of `EncryptedKeyBlob.key_derivation_input` (a random nonce)
;    - CBOR-serialization of `EncryptedKeyBlob.characteristics`
;    - CBOR-serialized array of additional hidden `KeyParam` items associated with the key, specifically:
;        - [Tag_ApplicationId, bstr] if required
;        - [Tag_ApplicationData, bstr] if required
;        - [Tag_RootOfTrust, bstr .cbor RootOfTrustInfo]
;    - (if secure storage is available) CBOR serialization of the `SecureDeletionData` structure, with:
;        - `factory_reset_secret` always populated
;        - `secure_deletion_secret` populated with:
;           - all zeroes (if `EncryptedKeyBlob.secure_deletion_slot` is empty)
;           - the contents of the slot (if `EncryptedKeyBlob.secure_deletion_slot` is non-empty)
EncryptedKeyBlob = &(
    [0, EncryptedKeyBlobV1] ; Version::V1
)
Version = &(
    Version_V1: 0,
)
EncryptedKeyBlobV1 = [
    characteristics: [* KeyCharacteristics],
    key_derivation_input: bstr .size 32,
    kek_context: bstr,
    encrypted_key_material: #6.16(Cose_Encrypt0),
    secure_deletion_slot: [? SecureDeletionSlot],
]
KeyCharacteristics = [
    security_level: SecurityLevel,
    authorizations: [* KeyParam],
]
Cose_Encrypt0 = [ protected: bstr, unprotected: { * (int / tstr) => any }, ciphertext: bstr / nil ]
KeyMaterial = &(
  ; For each variant the `bool` second entry indicates whether the bstr for the key material
  ; is opaque (true), or explicit (false).
  [32, bool, bstr], ; Algorithm_Aes
  [33, bool, bstr], ; Algorithm_TripleDes
  [128, bool, bstr], ; Algorithm_Hmac
  ; An explicit RSA key is in the form of an ASN.1 DER encoding of a PKCS#1 `RSAPrivateKey`
  ; structure, as specified by RFC 3447 sections A.1.2 and 3.2.
  [1, bool, bstr], ; Algorithm_Rsa
  ; An explicit EC key for a NIST curve is in the form of an ASN.1 DER encoding of a
  ; `ECPrivateKey` structure, as specified by RFC 5915 section 3.
  ; An explicit EC key for curve 25519 is the raw key bytes.
  [3, bool, [EcCurve, CurveType, bstr]], ; Algorithm_Ec
)
SecureDeletionSlot = int
SecureDeletionData = [
    factory_reset_secret: bstr .size 32,
    secure_deletion_secret: bstr .size 16,
]
RootOfTrustInfo = [
    verified_boot_key: bstr,
    device_boot_locked: bool,
    verified_boot_state: VerifiedBootState,
]
VerifiedBootState = &(
    VerifiedBootState_Verified: 0,
    VerifiedBootState_SelfSigned: 1,
    VerifiedBootState_Unverified: 2,
    VerifiedBootState_Failed: 3,
)
SecurityLevel = &(
    SecurityLevel_Software: 0,
    SecurityLevel_TrustedEnvironment: 1,
    SecurityLevel_Strongbox: 2,
    SecurityLevel_Keystore: 100,
)
KeyParam = &(
    [268435458, Algorithm], ; Tag_Algorithm
    [536870916, BlockMode], ; Tag_BlockMode
    [536870918, PaddingMode], ; Tag_Padding
    [536870917, Digest], ; Tag_Digest
    [268435466, EcCurve], ; Tag_EcCurve
    [268436158, KeyOrigin], ; Tag_Origin
    [536870913, KeyPurpose], ; Tag_Purpose
    [805306371, KeySizeInBits], ; Tag_KeySize
    [1879048199, bstr], ; Tag_CallerNonce
    [805306376, int], ; Tag_MinMacLength
    [1342177480, RsaExponent], ; Tag_RsaPublicExponent
    [1879048394, true], ; Tag_IncludeUniqueId
    [536871115, Digest], ; Tag_RsaOaepMgfDigest
    [1879048494, true], ; Tag_BootloaderOnly
    [1879048495, true], ; Tag_RollbackResistance
    [1879048497, true], ; Tag_EarlyBootOnly
    [1610613136, DateTime], ; Tag_ActiveDatetime
    [1610613137, DateTime], ; Tag_OriginationExpireDatetime
    [1610613138, DateTime], ; Tag_UsageExpireDatetime
    [805306772, int], ; Tag_MaxUsesPerBoot
    [805306773, int], ; Tag_UsageCountLimit
    [805306869, int], ; Tag_UserId
    [-1610612234, int], ; Tag_UserSecureId
    [1879048695, true], ; Tag_NoAuthRequired
    [268435960, int], ; Tag_UserAuthType
    [805306873, int], ; Tag_AuthTimeout
    [1879048698, true], ; Tag_AllowWhileOnBody
    [1879048699, true], ; Tag_TrustedUserPresenceRequired
    [1879048700, true], ; Tag_TrustedConfirmationRequired
    [1879048701, true], ; Tag_UnlockedDeviceRequired
    [-1879047591, bstr], ; Tag_ApplicationId
    [-1879047492, bstr], ; Tag_ApplicationData
    [1610613437, DateTime], ; Tag_CreationDatetime
    [-1879047488, bstr], ; Tag_RootOfTrust
    [805307073, int], ; Tag_OsVersion
    [805307074, int], ; Tag_OsPatchlevel
    [-1879047484, bstr], ; Tag_AttestationChallenge
    [-1879047483, bstr], ; Tag_AttestationApplicationId
    [-1879047482, bstr], ; Tag_AttestationIdBrand
    [-1879047481, bstr], ; Tag_AttestationIdDevice
    [-1879047480, bstr], ; Tag_AttestationIdProduct
    [-1879047479, bstr], ; Tag_AttestationIdSerial
    [-1879047478, bstr], ; Tag_AttestationIdImei
    [-1879047469, bstr], ; Tag_AttestationIdSecondImei
    [-1879047477, bstr], ; Tag_AttestationIdMeid
    [-1879047476, bstr], ; Tag_AttestationIdManufacturer
    [-1879047475, bstr], ; Tag_AttestationIdModel
    [805307086, int], ; Tag_VendorPatchlevel
    [805307087, int], ; Tag_BootPatchlevel
    [1879048912, true], ; Tag_DeviceUniqueAttestation
    [1879048914, true], ; Tag_StorageKey
    [-1879047191, bstr], ; Tag_Nonce
    [805307371, int], ; Tag_MacLength
    [1879049196, true], ; Tag_ResetSinceIdRotation
    [-2147482642, bstr], ; Tag_CertificateSerial
    [-1879047185, bstr], ; Tag_CertificateSubject
    [1610613744, DateTime], ; Tag_CertificateNotBefore
    [1610613745, DateTime], ; Tag_CertificateNotAfter
    [805307378, int], ; Tag_MaxBootLevel
)
Tag = &(
    Tag_Invalid: 0,
    Tag_Purpose: 536870913,
    Tag_Algorithm: 268435458,
    Tag_KeySize: 805306371,
    Tag_BlockMode: 536870916,
    Tag_Digest: 536870917,
    Tag_Padding: 536870918,
    Tag_CallerNonce: 1879048199,
    Tag_MinMacLength: 805306376,
    Tag_EcCurve: 268435466,
    Tag_RsaPublicExponent: 1342177480,
    Tag_IncludeUniqueId: 1879048394,
    Tag_RsaOaepMgfDigest: 536871115,
    Tag_BootloaderOnly: 1879048494,
    Tag_RollbackResistance: 1879048495,
    Tag_HardwareType: 268435760,
    Tag_EarlyBootOnly: 1879048497,
    Tag_ActiveDatetime: 1610613136,
    Tag_OriginationExpireDatetime: 1610613137,
    Tag_UsageExpireDatetime: 1610613138,
    Tag_MinSecondsBetweenOps: 805306771,
    Tag_MaxUsesPerBoot: 805306772,
    Tag_UsageCountLimit: 805306773,
    Tag_UserId: 805306869,
    Tag_UserSecureId: -1610612234,
    Tag_NoAuthRequired: 1879048695,
    Tag_UserAuthType: 268435960,
    Tag_AuthTimeout: 805306873,
    Tag_AllowWhileOnBody: 1879048698,
    Tag_TrustedUserPresenceRequired: 1879048699,
    Tag_TrustedConfirmationRequired: 1879048700,
    Tag_UnlockedDeviceRequired: 1879048701,
    Tag_ApplicationId: -1879047591,
    Tag_ApplicationData: -1879047492,
    Tag_CreationDatetime: 1610613437,
    Tag_Origin: 268436158,
    Tag_RootOfTrust: -1879047488,
    Tag_OsVersion: 805307073,
    Tag_OsPatchlevel: 805307074,
    Tag_UniqueId: -1879047485,
    Tag_AttestationChallenge: -1879047484,
    Tag_AttestationApplicationId: -1879047483,
    Tag_AttestationIdBrand: -1879047482,
    Tag_AttestationIdDevice: -1879047481,
    Tag_AttestationIdProduct: -1879047480,
    Tag_AttestationIdSerial: -1879047479,
    Tag_AttestationIdImei: -1879047478,
    Tag_AttestationIdMeid: -1879047477,
    Tag_AttestationIdManufacturer: -1879047476,
    Tag_AttestationIdModel: -1879047475,
    Tag_VendorPatchlevel: 805307086,
    Tag_BootPatchlevel: 805307087,
    Tag_DeviceUniqueAttestation: 1879048912,
    Tag_IdentityCredentialKey: 1879048913,
    Tag_StorageKey: 1879048914,
    Tag_AttestationIdSecondImei: -1879047469,
    Tag_AssociatedData: -1879047192,
    Tag_Nonce: -1879047191,
    Tag_MacLength: 805307371,
    Tag_ResetSinceIdRotation: 1879049196,
    Tag_ConfirmationToken: -1879047187,
    Tag_CertificateSerial: -2147482642,
    Tag_CertificateSubject: -1879047185,
    Tag_CertificateNotBefore: 1610613744,
    Tag_CertificateNotAfter: 1610613745,
    Tag_MaxBootLevel: 805307378,
)
Algorithm = &(
    Algorithm_Rsa: 1,
    Algorithm_Ec: 3,
    Algorithm_Aes: 32,
    Algorithm_TripleDes: 33,
    Algorithm_Hmac: 128,
)
BlockMode = &(
    BlockMode_Ecb: 1,
    BlockMode_Cbc: 2,
    BlockMode_Ctr: 3,
    BlockMode_Gcm: 32,
)
Digest = &(
    Digest_None: 0,
    Digest_Md5: 1,
    Digest_Sha1: 2,
    Digest_Sha224: 3,
    Digest_Sha256: 4,
    Digest_Sha384: 5,
    Digest_Sha512: 6,
)
EcCurve = &(
    EcCurve_P224: 0,
    EcCurve_P256: 1,
    EcCurve_P384: 2,
    EcCurve_P521: 3,
    EcCurve_Curve25519: 4,
)
CurveType = &(
    CurveType_Nist: 0,
    CurveType_EdDsa: 1,
    CurveType_Xdh: 2,
)
KeyOrigin = &(
    KeyOrigin_Generated: 0,
    KeyOrigin_Derived: 1,
    KeyOrigin_Imported: 2,
    KeyOrigin_Reserved: 3,
    KeyOrigin_SecurelyImported: 4,
)
KeyPurpose = &(
    KeyPurpose_Encrypt: 0,
    KeyPurpose_Decrypt: 1,
    KeyPurpose_Sign: 2,
    KeyPurpose_Verify: 3,
    KeyPurpose_WrapKey: 5,
    KeyPurpose_AgreeKey: 6,
    KeyPurpose_AttestKey: 7,
)
HardwareAuthenticatorType = &(
    HardwareAuthenticatorType_None: 0,
    HardwareAuthenticatorType_Password: 1,
    HardwareAuthenticatorType_Fingerprint: 2,
    HardwareAuthenticatorType_Any: -1,
)
PaddingMode = &(
    PaddingMode_None: 1,
    PaddingMode_RsaOaep: 2,
    PaddingMode_RsaPss: 3,
    PaddingMode_RsaPkcs115Encrypt: 4,
    PaddingMode_RsaPkcs115Sign: 5,
    PaddingMode_Pkcs7: 64,
)
DateTime = int
KeySizeInBits = int
RsaExponent = int