Skip to content

Debugging, Recording,
and Replaying Attestation Checks

Attestation failures often depend on the exact certificate chain, configuration, and revocation state present during verification. Warden Supreme can capture these inputs and replay the failed check offline.

The approach is the same whether you use Warden Supreme's integrated attestation flow or the raw makoto or roboto attestation checkers (see Usage without Integrated Clients): - Use Warden Supreme’s collectDebugInfo(...) on attestation errors to capture inputs, parsed fields, decisions, and failure reasons. - Persist the debug info object via serialize() / serializeCompact() to logs. - Enrich logs with device make/model, OS and patch levels, so OEM‑specific quirks can be correlated over time. - Replay collected debug statements offline to analyse attestation failures by invoking replay() on a collected debug statement (see Debugging Integrated Attestation).

Privacy Risks and Risk of Chasing Phantoms

Three restrictions apply when recording or sharing debug statements.

  • Attestation information is personally identifying data if the contained public key is associated with a person.
  • If you publicly paste a debug statement, it will contain your whole configuration, and it will leak information about your service, apps, and the environment of your backend that performs the attestation checks.
  • For actual debugging, only ever share debug statements in serializeCompact() format, not the human-readable serialize() output.
    • The serializeCompact() format uses a self-describing, forward-compatible multibase encoding.
    • This encoding is transport-safe. It survives Microsoft Outlook's sometimes creative way of "improving" message formatting, as well as "helpful" IDEs and editors being extra-smart when pasting.
    • We once lost a full day of debugging to encoding errors in transit. This is exactly why serializeCompact() is the way to record and share debug statements for analysis, while serialize() is for a human-readable representation.

Collecting Debug Info

Warden Supreme's integrated flow already offers a hook to collect debug statements: Whenever the actual attestation check fails (i.e., whenever onAttestationError() is called), a ready-made WardenDebugAttestationStatement is created and passed to this function. The callback provides two pieces of diagnostic information:

  1. The attestation error (as the receiver of this lambda)
  2. The debug statement, which can be exported for offline analysis

Warden roboto and makoto offer a collectDebugInfo() function to the same effect, creating a serializable debug statement. The difference is that you call it manually, and the right place and time to call it depends on how roboto or makoto are integrated. makoto produces a WardenDebugAttestationStatement directly, while roboto's collectDebugInfo() returns an AndroidDebugAttestationStatement. Both expose the same replay function and carry everything needed to replay the attestation check offline.

Debugging Integrated Attestation

Warden Supreme already contains code to load WardenDebugAttestationStatements and replay() them. Run the replay utility in an IDE to step through the attestation workflow and inspect the stack trace behind a failure:

  • Import this project into IntelliJ IDEA
  • Add a breakpoint here (line 19)
  • Run it in debug mode

Pass the debug-statement file as the single argument described in Diag.kt.

Debugging Raw Android Attestations

Stand-Alone Attestation Parser

To use androidAttestation­Extension on all platforms (e.g., to implement client-side checks on Android), include :supreme-common in your project, and you are ready to go!

A similar utility for printing the contents of an Android attestation statement lives in /utils/roboto-diag. It pretty-prints the leaf certificate's Android attestation extension and expects either:

  • -f path/to/leaf/certificate.pem
  • a base64-encoded certificate as the sole argument

It will then pretty-print the attestation extension's contents.

There is also a nullable androidAttestationExtension extension property on the Java X509Certificate and on Signum's X509Certificate class (and certificate chains). It exposes prettyPrint(), so you can peek into Android attestation extensions at any time. It even parses malformed values and prints their DER-encoded hex representation. The parser and renderer remain experimental, but they have been tested against thousands of attestation proofs captured from real devices. This corpus includes malformed values that Google's old and current parsers reject. Warden's parser retains these values and renders their DER representation where necessary, making it considerably more useful for investigating certificates encountered in production.

Example of a Pretty-Printed Attestation Record from an Emulator

AttestationKeyDescription(
  attestationVersion = 3
  attestationSecurityLevel = TRUSTED_ENVIRONMENT
  keyMintVersion = 41
  keyMintSecurityLevel = TRUSTED_ENVIRONMENT
  attestationChallenge = b5a4a68423c5d2f610328b3dcc8b408d352afc78fb7eb0d4803bd9ef581654eb
  uniqueId = 
  softwareEnforced =
    AuthorizationList(
      purpose = null
      algorithm = null
      keySize = null
      blockMode = null
      digest = null
      padding = null
      callerNonce = false
      minMacLength = null
      ecCurve = null
      rsaPublicExponent = null
      mgfDigest = null
      rollbackResistance = false
      earlyBootOnly = false
      activeDateTime = null
      originationExpireDateTime = null
      usageExpireDateTime = null
      usageCountLimit = null
      userSecureId = null
      noAuthRequired = false
      userAuthType = null
      authTimeout = null
      allowWhileOnBody = false
      trustedUserPresenceRequired = false
      trustedConfirmationRequired = false
      unlockedDeviceRequired = false
      allApplications = false
      creationDateTime = CreationDateTime(intValue=1752703332000, timestamp=2025-07-16T22:02:12Z)
      origin = null
      rollbackResistant = null
      rootOfTrust = null
      osVersion = null
      osPatchLevel = null
      attestationApplicationId = 
        AttestationApplicationId(
          packageInfos = [
            AttestationPackageInfo(packageName='at.asitplus.atttest', version=1)
          ]
          signatureDigests = [
            34b9762c4d6c90d48431940c57bde7314258b26420efe16ac7f7274f0d330ad5
          ]
        )
      attestationIdBrand = null
      attestationIdDevice = null
      attestationIdProduct = null
      attestationIdSerial = null
      attestationIdImei = null
      attestationIdMeid = null
      attestationIdManufacturer = null
      attestationIdModel = null
      vendorPatchLevel = null
      bootPatchLevel = null
      deviceUniqueAttestation = false
      attestationIdSecondImei = null
      moduleHash = null
    )
  hardwareEnforced =
    AuthorizationList(
      purpose = [
        - SIGN
        - VERIFY
      ]
      algorithm = EC
      keySize = KeySize(intValue=256)
      blockMode = null
      digest = [
        - SHA_2_256
      ]
      padding = null
      callerNonce = false
      minMacLength = null
      ecCurve = P_256
      rsaPublicExponent = null
      mgfDigest = null
      rollbackResistance = false
      earlyBootOnly = false
      activeDateTime = null
      originationExpireDateTime = null
      usageExpireDateTime = null
      usageCountLimit = null
      userSecureId = null
      noAuthRequired = false
      userAuthType = UserAuth(authTypes=[FINGERPRINT], intValue=2)
      authTimeout = null
      allowWhileOnBody = false
      trustedUserPresenceRequired = false
      trustedConfirmationRequired = false
      unlockedDeviceRequired = false
      allApplications = false
      creationDateTime = null
      origin = GENERATED
      rollbackResistant = null
      rootOfTrust = 
        RootOfTrust(
          verifiedBootKeyDigest=c2224571c9cd5c89200a7311b1e37aa9cf751e2e19753e8d3702bca00be1d42c
          deviceLocked=true
          verifiedBootState=Verified
          verifiedBootHash=d415abd0e620d3e8a942a62920195ad893ff0515ab8236931a156bc1f49de444
        )
      osVersion = OsVersion(major=13, minor=0, sub=0, intValue=130000)
      osPatchLevel = OsPatchLevel(year=2025, month=MAY, intValue=202505)
      attestationApplicationId = null
      attestationIdBrand = null
      attestationIdDevice = null
      attestationIdProduct = null
      attestationIdSerial = null
      attestationIdImei = null
      attestationIdMeid = null
      attestationIdManufacturer = null
      attestationIdModel = null
      vendorPatchLevel = PatchLevel(year=2025, month=MAY, day=1, intValue=20250501)
      bootPatchLevel = PatchLevel(year=2025, month=MAY, day=1, intValue=20250501)
      deviceUniqueAttestation = false
      attestationIdSecondImei = null
      moduleHash = null
    )
)