Debug Your Infrastructure
Get Instant Solutions for Kubernetes, Databases, Docker and more
AWS SNS Access to the specified KMS key is denied.
Understanding AWS SNS
Amazon Simple Notification Service (SNS) is a fully managed messaging service provided by AWS. It is designed to enable applications, end-users, and devices to instantly send and receive notifications from the cloud. SNS supports a variety of messaging protocols, including HTTP/HTTPS, email, SMS, and AWS Lambda.
Identifying the Symptom
When working with AWS SNS, you might encounter an error message stating KMSAccessDenied. This error indicates that access to the specified AWS Key Management Service (KMS) key is denied. This typically occurs when attempting to publish a message to an SNS topic that is encrypted with a KMS key.
Observed Error
The error message appears as follows:
{
"Error": {
"Code": "KMSAccessDenied",
"Message": "Access to the specified KMS key is denied."
}
}
Explaining the Issue
The KMSAccessDenied error occurs when the IAM role or user attempting to publish to the SNS topic does not have the necessary permissions to use the KMS key. KMS keys are used to encrypt messages for security purposes, and access to these keys is controlled through IAM policies and key policies.
Root Cause
The root cause of this issue is typically insufficient permissions in the KMS key policy or the IAM policy associated with the user or role. The key policy must explicitly allow the necessary actions for the IAM entity.
Steps to Fix the Issue
To resolve the KMSAccessDenied error, follow these steps:
Step 1: Verify IAM Permissions
Ensure that the IAM user or role has the necessary permissions to use the KMS key. The following IAM policy snippet grants the required permissions:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"kms:Encrypt",
"kms:Decrypt",
"kms:GenerateDataKey"
],
"Resource": "arn:aws:kms:region:account-id:key/key-id"
}
]
}
Step 2: Update the KMS Key Policy
Modify the KMS key policy to allow the IAM user or role to perform the necessary actions. Here is an example of a key policy statement:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::account-id:user/username"
},
"Action": "kms:*",
"Resource": "*"
}
]
}
Step 3: Test the Configuration
After updating the IAM and key policies, test the configuration by attempting to publish a message to the SNS topic again. Ensure that the error is resolved and that the message is successfully published.
Additional Resources
For more information on AWS SNS and KMS, refer to the following resources:
Master
AWS SNS Access to the specified KMS key is denied.
debugging in Minutes
— Grab the Ultimate Cheatsheet
(Perfect for DevOps & SREs)
🚀 Tired of Noisy Alerts?
Try Doctor Droid — your AI SRE that auto-triages alerts, debugs issues, and finds the root cause for you.
Heading
MORE ISSUES
Backed by
