iot credentials for aws 403 debug

Step 1: Verify IAM Policies and Roles

Ensure that the IAM policies and roles associated with the IoT thing are correctly configured.

1. Policy Attached to the Certificate:

Make sure the IoT policy attached to the certificate allows the iot:AssumeRoleWithCertificate action. Here is an example IoT policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iot:AssumeRoleWithCertificate",
      "Resource": "arn:aws:iot:your-region:your-account-id:rolealias/YourRoleAlias"
    }
  ]
}

2. IAM Role and Role Alias:

Ensure that the IAM role associated with the role alias has the necessary permissions to generate the AWS credentials. The role should have a trust relationship with the IoT service and policies allowing access to the required AWS services.

Trust Relationship:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "iot.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

IAM Policy example:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:ListBucket",
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Resource": [
        "arn:aws:s3:::your-bucket",
        "arn:aws:s3:::your-bucket/*"
      ]
    }
  ]
}

Step 2: Check IoT Policy and Role Alias

Ensure that the role alias is correctly configured and mapped to the appropriate IAM role.

1. Describe the Role Alias:

Use the AWS CLI to describe the role alias and verify the IAM role associated with it:

aws iot describe-role-alias --role-alias YourRoleAlias

2. Verify Role Alias Configuration:

Check the output to confirm that the correct IAM role is associated with the role alias.

Step 3: CloudWatch Logs

AWS IoT does not directly log the authorization details in CloudWatch, but you can enable AWS IoT logging to get more details.

1. Enable IoT Logging:

Enable logging for AWS IoT Core to get more detailed logs.

aws iot set-v2-logging-options --role-arn arn:aws:iam::your-account-id:role/your-iot-logging-role --default-log-level DEBUG --disable-all-logs

2. Check CloudWatch Log Groups:

After enabling IoT logging, check the CloudWatch logs for your IoT Core. The log group would typically be named /aws/iot/your-region.

aws logs describe-log-groups --log-group-name-prefix /aws/iot/

Thank you Oleksii and ladybug—

In this case I'd forgotten to give the iot client the iot:AssumeRoleWithCertificate privilege. The request succeeds after.

I moved the iam policy to a cdk stack and can no longer authenticate. Again, I'm getting an opaque 403 error

I tried enabling logging as you suggest but I'm getting an error stating that iot cannot assume the iam role. Please see below and help me.

aws iot describe-role-alias --role-alias jhartman-appliance-role
{
    "roleAliasDescription": {
        "roleAlias": "jhartman-appliance-role",
        "roleAliasArn": "arn:aws:iot:us-east-1:XXXXXXXXXXXX:rolealias/jhartman-appliance-role",
        "roleArn": "arn:aws:iam::443721045540:role/jhartman-appliance-role",
        "owner": "443721045540",
        "credentialDurationSeconds": 3600,
        "creationDate": "2024-07-27T11:49:25.466000-04:00",
        "lastModifiedDate": "2024-07-27T11:49:25.466000-04:00"
    }
}

aws iam get-role --role-name jhartman-appliance-role
{
    "Role": {
        "Path": "/",
        "RoleName": "jhartman-appliance-role",
        "RoleId": "AROAWOT6V2YSCIA4YSEXF",
        "Arn": "arn:aws:iam::XXXXXXXXXXXX:role/jhartman-appliance-role",
        "CreateDate": "2024-07-27T16:05:51+00:00",
        "AssumeRolePolicyDocument": {
            "Version": "2012-10-17",
            "Statement": [
                {
                    "Effect": "Allow",
                    "Principal": {
                        "Service": "credentials.iot.amazonaws.com"
                    },
                    "Action": "sts:AssumeRole"
                },
                {
                    "Effect": "Allow",
                    "Principal": {
                        "Service": "iot.amazonaws.com"
                    },
                    "Action": "sts:AssumeRole"
                }
            ]
        },
        "Description": "",
        "MaxSessionDuration": 3600,
        "RoleLastUsed": {}
    }
}

aws iot set-v2-logging-options --role-arn arn:aws:iam::443721045540:role/jhartman-appliance-role --default-log-level DEBUG --disable-all-logs

An error occurred (InvalidRequestException) when calling the SetV2LoggingOptions operation: AWS IoT (iot.amazonaws.com) is unable to assume role (sts:AssumeRole) on resource: arn:aws:iam::443721045540:role/jhartman-appliance-role.  If the role was just created or updated, please try again in a few seconds.

Why can't iot assume the role? Also perhaps the same root cause is resulting in the 403 errors I'm seeing.

Please take a look on this https://docs.aws.amazon.com/pt_br/iot/latest/developerguide/diagnosing-connectivity-issues.html

Logging is not happening still though. After experiencing additional 403 responses, there are no logs:

aws logs describe-log-groups --log-group-name-prefix /aws/iot/
{
    "logGroups": []
}