Iot Hub - Connection failed suddenly beacuse of bad credential

Question

Iot Hub - Connection failed suddenly beacuse of bad credential

Winnie Cheng 0

We have multiple IoT devices created with self-defined key around 1-2 years ago and keep connecting to IoT Hub till 23/01/2024. All of a sudden, some of the devices disconnected due to bad credential. We have finished the certificate migration in last yeat Oct. So we don't think this should be the certificate issue. Also, we try to copy the crediential from azure poretal and test with Azure IoT device java SDK,

DeviceClient iotHubClient = new DeviceClient(DEVICE_CONNECTION_STR, protocol);

the following error was shown.

java.lang.IllegalArgumentException: Last encoded character (before the paddings if any) is a valid base 64 alphabet but not a possible value. Expected the discarded bits to be zero.
@org.apache.commons.codec.binary.Base64.validateCharacter(Base64.java:803)
org.apache.commons.codec.binary.Base64.decode(Base64.java:482)
org.apache.commons.codec.binary.BaseNCodec.decode(BaseNCodec.java:481)
org.apache.commons.codec.binary.Base64.decodeBase64(Base64.java:713)
com.microsoft.azure.sdk.iot.device.auth.SignatureHelper.decodeDeviceKeyBase64(SignatureHelper.java:56)
com.microsoft.azure.sdk.iot.device.auth.Signature.<init>(Signature.java:24)
com.microsoft.azure.sdk.iot.device.auth.IotHubSasToken.<init>(IotHubSasToken.java:81)
com.microsoft.azure.sdk.iot.device.auth.IotHubSasTokenSoftwareAuthenticationProvider.<init>(IotHubSasTokenSoftwareAuthenticationProvider.java:46)
com.microsoft.azure.sdk.iot.device.ClientConfiguration.configSasAuth(ClientConfiguration.java:160)
com.microsoft.azure.sdk.iot.device.ClientConfiguration.<init>(ClientConfiguration.java:202)
com.microsoft.azure.sdk.iot.device.InternalClient.<init>(InternalClient.java:48)
com.microsoft.azure.sdk.iot.device.DeviceClient.<init>(DeviceClient.java:81)
com.microsoft.azure.sdk.iot.device.DeviceClient.<init>(DeviceClient.java:60)
```Any help would be appreciated. Thanks

Winnie Cheng 0 Reputation points

2024-01-26T02:32:22.36+00:00
Thanks for your reply. We did notice that there would be a periodic deconnection when the SAS tokens renewed, but devices would usually reconnect within a few minutes. What we found is that the devices disconnected and unable to reconnect due to bad crediential. This means the credientials suddenly become invalid. Then we used the sample code provided in https://github.com/Azure/azure-iot-sdk-java/ to further verify.

DeviceClient client = new DeviceClient(DEVICE_CONNECTION_STR, protocol)

The DEVICE_CONNECTION_STR is the device connection string directly copied from azure portal. We found that the method can be called successfully with some of the crediential, but some will show the following error And for the base64 string checking, we found the connection string would pass the check if ising commons-codec: 1.15. However, it seems Azure iot SDK is using commons-codec:1.14.
So does it mean that Azure Iot Hub also using commons-codec:1.14 to do the checking which may cause the bad crediential error.

Thank you for any help you can provide.
LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2024-02-02T00:08:28.6433333+00:00

Hi @Winnie Cheng Just wanted to check if you are still experiencing this issue?
Winnie Cheng 0 Reputation points

2024-02-02T05:38:37.7766667+00:00

Yes. Still looking for solution

1 answer

Your answer

Winnie Cheng 0 Reputation points

2024-01-26T02:32:22.36+00:00

Thanks for your reply. We did notice that there would be a periodic deconnection when the SAS tokens renewed, but devices would usually reconnect within a few minutes. What we found is that the devices disconnected and unable to reconnect due to bad crediential. This means the credientials suddenly become invalid. Then we used the sample code provided in https://github.com/Azure/azure-iot-sdk-java/ to further verify.

DeviceClient client = new DeviceClient(DEVICE_CONNECTION_STR, protocol)

The DEVICE_CONNECTION_STR is the device connection string directly copied from azure portal. We found that the method can be called successfully with some of the crediential, but some will show the following error And for the base64 string checking, we found the connection string would pass the check if ising commons-codec: 1.15. However, it seems Azure iot SDK is using commons-codec:1.14.
So does it mean that Azure Iot Hub also using commons-codec:1.14 to do the checking which may cause the bad crediential error.

Thank you for any help you can provide.
LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2024-02-02T00:08:28.6433333+00:00

Hi @Winnie Cheng Just wanted to check if you are still experiencing this issue?
Winnie Cheng 0 Reputation points

2024-02-02T05:38:37.7766667+00:00

Yes. Still looking for solution

Answer 1

there is a library for Azure IoT error code troubleshooting https://learn.microsoft.com/en-us/azure/iot-hub/troubleshoot-error-codes you can review this document in addition to this Azure IoT device SDKs disconnect and then reconnect when they renew SAS tokens over the MQTT protocol. This can appear as periodic disconnects in logs. https://learn.microsoft.com/en-us/azure/iot-hub/iot-hub-troubleshoot-connectivity For the error code in Java Make sure that you're using the correct method for encoding and decoding Base64. Java provides java.util.Base64 for these operations. For decoding, use Base64.getDecoder().decode(string). You can use online Base64 validation tools to check if your Base64 string is valid.

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Iot Hub - Connection failed suddenly beacuse of bad credential

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