Ytukyg

When I run my lambda code, I get the following error:

The ciphertext refers to a customer master key that does not exist, does not exist in this region, or you are not allowed to access.

I have mostly followed this to create the stack using aws-sam-cli, and the relevant sections of the template are below the code.

The relevant code is:

const ssm = new AWS.SSM();

const param = {

    Name: "param1",

    WithDecryption: true

};

const secret = await ssm.getParameter(param).promise();

The relevant part of the template.yaml file is:

KeyAlias:

    Type: AWS::KMS::Alias

    Properties:

      AliasName: 'param1Key'

      TargetKeyId: !Ref Key

Key:

    Type: AWS::KMS::Key

    Properties:

      KeyPolicy:

        Id: default

        Statement:

        - Effect: Allow

          Principal:

            AWS: !Sub arn:aws:iam::${AWS::AccountId}:root

          Action:

          - 'kms:Create*'

          - 'kms:Encrypt'

          - 'kms:Describe*'

          - 'kms:Enable*'

          - 'kms:List*'

          - 'kms:Put*'

          - 'kms:Update*'

          - 'kms:Revoke*'

          - 'kms:Disable*'

          - 'kms:Get*'

          - 'kms:Delete*'

          - 'kms:ScheduleKeyDeletion'

          - 'kms:CancelKeyDeletion'

          Resource: '*'

          Sid: Allow root account all permissions except to decrypt the key

        Version: 2012-10-17



LambdaFunction:

    Type: AWS::Serverless::Function

    Properties:

      CodeUri: ../

      Handler: app.lambda

      Runtime: nodejs8.10

      Policies:

      - DynamoDBReadPolicy:

          TableName: !Ref Table

      - KMSDecryptPolicy:

          KeyId: !Ref Key

      - Statement:

         - Action:

           - "ssm:GetParameter"

           Effect: Allow

           Resource: !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/param1"

Does the KMSDecryptPolicy not allow the use of the key? What am I missing? Thanks!

EDIT: Changing the template to below works, but I'd really like to use the KMSDecryptPolicy in the lambda definition if possible.

LambdaFunction:

    Type: AWS::Serverless::Function

    Properties:

      CodeUri: ../

      Handler: app.lambda

      Runtime: nodejs8.10

      Policies:

      - DynamoDBReadPolicy:

          TableName: !Ref Table

      - KMSDecryptPolicy:

          KeyId: !Ref Key

      - Statement:

         - Action:

           - "ssm:GetParameter"

           Effect: Allow

           Resource: !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/param1"



Key:

    Type: AWS::KMS::Key

    Properties:

      KeyPolicy:

        Id: default

        Statement:

        - Effect: Allow

          Principal:

            AWS: !Sub arn:aws:iam::${AWS::AccountId}:root

          Action:

          - 'kms:Create*'

          - 'kms:Encrypt'

          - 'kms:Describe*'

          - 'kms:Enable*'

          - 'kms:List*'

          - 'kms:Put*'

          - 'kms:Update*'

          - 'kms:Revoke*'

          - 'kms:Disable*'

          - 'kms:Get*'

          - 'kms:Delete*'

          - 'kms:ScheduleKeyDeletion'

          - 'kms:CancelKeyDeletion'

          Resource: '*'

          Sid: Allow root account all permissions except to decrypt the key

        - Sid: 'Allow use of the key for decryption by the LambdaFunction'

          Effect: Allow

          Principal:

            AWS: !GetAtt LambdaFunctionRole.Arn

          Action:

          - 'kms:Decrypt'

          Resource: '*'        

        Version: 2012-10-17