Rule: KMS Key Decryption Restricted in IAM Customer Managed Policy

This rule ensures restricted KMS key decryption in IAM customer managed policy.

Rule	KMS key decryption should be restricted in IAM customer managed policy
Framework	HIPAA
Severity	✔ Medium

Rule Description:

The KMS key decryption should be restricted in the IAM customer managed policy for HIPAA compliance. This rule ensures that only specific IAM users or roles with the necessary permissions are allowed to decrypt data using a specific KMS (Key Management Service) key. By implementing this policy, organizations can restrict access to encrypted data and maintain the security and confidentiality required by the HIPAA (Health Insurance Portability and Accountability Act) regulations.

Troubleshooting Steps:

If the KMS key decryption is not restricted according to the IAM customer managed policy, it can lead to unauthorized access to sensitive data, which can result in non-compliance with HIPAA regulations. To troubleshoot any issues related to this policy, follow these steps:

1.

Check the IAM customer managed policy settings: Verify that the policy contains the necessary restrictions and permissions to control access to the KMS keys. Ensure that only authorized IAM users or roles have the required permissions for key decryption.

2.

Review the KMS key permissions: Double-check the permissions configured for the KMS key itself. Ensure that the IAM users or roles specified in the customer managed policy have the necessary permissions for the key decryption.

3.

Check IAM user or role associations: Confirm that the IAM users or roles associated with the KMS key are correctly defined in the customer managed policy. Ensure that any changes made to IAM user or role associations are reflected in the policy.

4.

Test decryption capabilities: Verify that only the authorized IAM users or roles can successfully decrypt data using the KMS key. Perform various test scenarios to ensure that the policy restrictions are effective and functioning as intended.

5.

Monitor access logs: Enable access logging for the KMS key and regularly review the logs to detect any unauthorized attempts to decrypt data. Analyzing the logs can help identify any potential issues or suspicious activities.

Necessary Codes:

Depending on the specific requirements and configurations of the organization's infrastructure, the following AWS CLI commands can be used to enforce the restriction on KMS key decryption in the IAM customer managed policy:

1.
To create an IAM policy that allows only specified IAM users or roles to decrypt a specific KMS key, use the following command:

aws iam create-policy --policy-name policy-name --policy-document '{
  "Version": "2012-10-17",
  "Statement": [
      {
          "Sid": "AllowDecrypt",
          "Effect": "Allow",
          "Action": "kms:Decrypt",
          "Resource": "arn:aws:kms:region:account-id:key/key-id",
          "Condition": {
              "StringEquals": {
                  "kms:EncryptionContextKeyName": "value"
              },
              "ArnEquals": {
                  "AWS:SourceArn": "arn:aws:iam::account-id:role/role-name"
              }
          }
      }
  ]
}'

Replace

policy-name

with the desired name for the policy,

region

with the AWS region,

account-id

with the AWS account ID,

key-id

with the KMS key ID,

value

with the encryption context key value, and

role-name

with the IAM role name.

1.
To attach the policy to the specific IAM user or role, use the following command:

aws iam attach-user-policy --user-name user-name --policy-arn policy-arn
aws iam attach-role-policy --role-name role-name --policy-arn policy-arn

Replace

user-name

role-name

with the IAM user or role name and

policy-arn

with the ARN (Amazon Resource Name) of the created policy.

Note: These commands are examples, and the specific values need to be replaced accordingly based on the organization's environment.

Step-by-step Guide for Remediation:

To remediate and enforce the KMS key decryption restriction in the IAM customer managed policy, follow these step-by-step instructions:

1.

Identify the specific KMS keys used for data encryption that require restricted decryption access.

2.

Create an IAM policy using the AWS CLI (Command-Line Interface) command provided above. Modify the command with the appropriate policy name, KMS key ARN, encryption context key name/value, and IAM role or user ARN.

3.

Attach the created policy to the IAM users or roles that need decryption access. Use the AWS CLI commands mentioned above, replacing the user or role name and policy ARN accordingly.

4.

Test the decryption capabilities using the restricted IAM users or roles to ensure they can decrypt data using the specified KMS key.

5.

Regularly monitor the access logs for the KMS keys to identify any unauthorized attempts or suspicious activities.

By following these steps, organizations can ensure that only authorized entities can decrypt data using the specified KMS key, complying with HIPAA regulations and maintaining a secure environment.

Rule: KMS Key Decryption Restricted in IAM Customer Managed Policy

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