KeyStoreException: Keystore key generation failed

[fleficher]

Describe the bug?

We have several Crashlytics reports showing crashes from the com.okta.authfoundation library.
When updating credentials:

Fatal Exception: java.security.ProviderException: Keystore key generation failed
       at android.security.keystore2.AndroidKeyStoreKeyGeneratorSpi.engineGenerateKey(AndroidKeyStoreKeyGeneratorSpi.java:413)
       at javax.crypto.KeyGenerator.generateKey(KeyGenerator.java:612)
       at com.okta.authfoundation.util.AndroidKeystoreUtil.getOrCreateAesKey(AndroidKeystoreUtil.kt:56)
       at com.okta.authfoundation.util.AesEncryptionHandler.encryptString(AesEncryptionHandler.kt:44)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invokeSuspend(EncryptionTokenProvider.kt:61)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invoke(EncryptionTokenProvider.kt:103)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invoke(EncryptionTokenProvider.kt:103)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invokeSuspend(Preferences.kt:358)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invoke(Preferences.kt:18)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invoke(Preferences.kt:18)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invokeSuspend(PreferenceDataStore.java:94)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invokeSuspend(PreferenceDataStore.java:94)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)

Caused by android.security.KeyStoreException: -22 (internal Keystore code: -22 message: system/security/keystore2/src/security_level.rs:622

Caused by:
    0: system/security/keystore2/src/security_level.rs:620: While generating Key without explicit attestation key.
    1: Error::Km(r#KEY_EXPORT_OPTIONS_INVALID))
       at android.security.KeyStore2.getKeyStoreException(KeyStore2.java:386)
       at android.security.KeyStoreSecurityLevel.handleExceptions(KeyStoreSecurityLevel.java:57)
       at android.security.KeyStoreSecurityLevel.generateKey(KeyStoreSecurityLevel.java:145)
       at android.security.keystore2.AndroidKeyStoreKeyGeneratorSpi.engineGenerateKey(AndroidKeyStoreKeyGeneratorSpi.java:400)
       at javax.crypto.KeyGenerator.generateKey(KeyGenerator.java:612)
       at com.okta.authfoundation.util.AndroidKeystoreUtil.getOrCreateAesKey(AndroidKeystoreUtil.kt:56)
       at com.okta.authfoundation.util.AesEncryptionHandler.encryptString(AesEncryptionHandler.kt:44)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invokeSuspend(EncryptionTokenProvider.kt:61)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invoke(EncryptionTokenProvider.kt:103)
       at com.okta.authfoundation.client.EncryptionTokenProvider$setDeviceToken$2.invoke(EncryptionTokenProvider.kt:103)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invokeSuspend(Preferences.kt:358)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invoke(Preferences.kt:18)
       at androidx.datastore.preferences.core.PreferencesKt$edit$2.invoke(Preferences.kt:18)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invokeSuspend(PreferenceDataStore.java:94)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invokeSuspend(PreferenceDataStore.java:94)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.preferences.core.PreferenceDataStore$updateData$2.invoke(PreferenceDataStore.java:137)
       at androidx.datastore.core.DataStoreImpl$transformAndWrite$2$newData$1.invokeSuspend(DataStoreImpl.java:331)

And getting credentials:

Fatal Exception: java.security.InvalidKeyException: Keystore operation failed
       at android.security.keystore2.KeyStoreCryptoOperationUtils.getInvalidKeyException(KeyStoreCryptoOperationUtils.java:128)
       at android.security.keystore2.KeyStoreCryptoOperationUtils.getExceptionForCipherInit(KeyStoreCryptoOperationUtils.java:152)
       at android.security.keystore2.AndroidKeyStoreCipherSpiBase.ensureKeystoreOperationInitialized(AndroidKeyStoreCipherSpiBase.java:354)
       at android.security.keystore2.AndroidKeyStoreCipherSpiBase.engineInit(AndroidKeyStoreCipherSpiBase.java:185)
       at javax.crypto.Cipher.tryTransformWithProvider(Cipher.java:3003)
       at javax.crypto.Cipher.tryCombinations(Cipher.java:2910)
       at javax.crypto.Cipher$SpiAndProviderUpdater.updateAndGetSpiAndProvider(Cipher.java:2815)
       at javax.crypto.Cipher.chooseProvider(Cipher.java:792)
       at javax.crypto.Cipher.init(Cipher.java:1162)
       at javax.crypto.Cipher.init(Cipher.java:1103)
       at com.okta.authfoundation.credential.DefaultTokenEncryptionHandler.rsaDecrypt(TokenEncryptionHandler.kt:290)
       at com.okta.authfoundation.credential.DefaultTokenEncryptionHandler.decrypt(TokenEncryptionHandler.kt:279)
       at com.okta.authfoundation.credential.RoomTokenStorage.getTokenFromEntity(RoomTokenStorage.kt:151)
       at com.okta.authfoundation.credential.RoomTokenStorage.getToken(RoomTokenStorage.kt:146)
       at com.okta.authfoundation.credential.RoomTokenStorage$getToken$1.invokeSuspend(RoomTokenStorage.kt:13)

Caused by android.security.KeyStoreException: -22 (internal Keystore code: -22 message: system/security/keystore2/src/security_level.rs:358: Failed to begin operation.

Caused by:
    0: system/security/keystore2/src/security_level.rs:868
    1: system/security/keystore2/src/utils.rs:200: Calling km_op.
    2: Error::Km(r#KEY_EXPORT_OPTIONS_INVALID))
       at android.security.KeyStore2.getKeyStoreException(KeyStore2.java:386)
       at android.security.KeyStoreSecurityLevel.createOperation(KeyStoreSecurityLevel.java:120)
       at android.security.keystore2.AndroidKeyStoreCipherSpiBase.ensureKeystoreOperationInitialized(AndroidKeyStoreCipherSpiBase.java:349)
       at android.security.keystore2.AndroidKeyStoreCipherSpiBase.engineInit(AndroidKeyStoreCipherSpiBase.java:185)
       at javax.crypto.Cipher.tryTransformWithProvider(Cipher.java:3003)
       at javax.crypto.Cipher.tryCombinations(Cipher.java:2910)
       at javax.crypto.Cipher$SpiAndProviderUpdater.updateAndGetSpiAndProvider(Cipher.java:2815)
       at javax.crypto.Cipher.chooseProvider(Cipher.java:792)
       at javax.crypto.Cipher.init(Cipher.java:1162)
       at javax.crypto.Cipher.init(Cipher.java:1103)
       at com.okta.authfoundation.credential.DefaultTokenEncryptionHandler.rsaDecrypt(TokenEncryptionHandler.kt:290)
       at com.okta.authfoundation.credential.DefaultTokenEncryptionHandler.decrypt(TokenEncryptionHandler.kt:279)
       at com.okta.authfoundation.credential.RoomTokenStorage.getTokenFromEntity(RoomTokenStorage.kt:151)
       at com.okta.authfoundation.credential.RoomTokenStorage.getToken(RoomTokenStorage.kt:146)
       at com.okta.authfoundation.credential.RoomTokenStorage$getToken$1.invokeSuspend(RoomTokenStorage.kt:13)

What is expected to happen?

Application doesn't crash

What is the actual behavior?

Application crashes

Reproduction Steps?

Didn't find reproduction steps for this crash, but it seems to happen when we request a new token with Credentials.refreshToken() or calling Credentials.getDefaultAsync()

Additional Information?

No response

SDK Version and Artifact(s) used.

2.0.3

Build Information

No response

[justinpapezsonos]

Similarly, we have >70,000 Sentry reports in the last four days showing crashes stemming from the com.okta.authfoundation library. The problematic code resides within AesEncryptionHandler.kt, specifically the encryptString function.

fun encryptString(string: String): String {
    val aesKey = AndroidKeystoreUtil.getOrCreateAesKey(encryptionKeySpec)
    val cipher = getCipher().apply { init(Cipher.ENCRYPT_MODE, aesKey) }
    val encryptedStringByteArray = cipher.doFinal(string.toByteArray())
    val encryptedString = Base64.encodeToString(encryptedStringByteArray, Base64.NO_WRAP)
    return Base64.encodeToString(cipher.iv, Base64.NO_WRAP) + SEPARATOR + encryptedString
}

There seems to be no error handling for either the call to AndroidKeystoreUtil.getOrCreateAesKey(encryptionKeySpec) (which throws KeyStoreException if the keystore has not been initialized) or the call to init(Cipher.ENCRYPT_MODE, aesKey) (which throws InvalidKeyException if the given key is inappropriate for initializing the cipher, requires algorithm parameters that cannot be determined from the given key, or if the given key has a keysize that exceeds the maximum allowable keysize).

On our end, we ultimately call into this code from one of two entry points:

• Credential.kt's setDefaultAsync function (setDefaultCredentialId ➡️ aesEncryptionHandler.encryptString)
• AuthFoundationDefaults.kt's tokenStorageFactory function (getTokenStorageFactory ➡️ RoomTokenStorage.getInstance ➡️ createInstance ➡️ migrateIfNeeded ➡️ migrate ➡️ setDefaultCredentialId ➡️ aesEncryptionHandler.encryptString)

IMHO, these APIs should handle these errors gracefully in addition to providing fallback mechanisms when/where applicable.