Which factors could be the cause of this failure?
(Choose two.)
The EC2 instance role does not have decrypt permissions on the AWS Key Management Service (AWS KMS) key used to encrypt the secret.
The EC2 instance role does not have read permissions to read the parameters in Parameter Store.
Parameter Store does not have permission to use AWS Key Management Service (AWS KMS) to decrypt the parameter.
The EC2 instance role does not have encrypt permissions on the AWS Key Management Service (AWS KMS) key associated with the secret.
The EC2 instance does not have any tags associated.
Explanations:
The EC2 instance role needs to have decrypt permissions on the AWS KMS key that is used to encrypt the secure string. If it lacks these permissions, the instance will be unable to decrypt the secure string stored in Parameter Store.
The EC2 instance role must have read permissions for AWS Systems Manager Parameter Store to access the parameters. Without these permissions, the instance will fail to read the secure string, regardless of KMS permissions.
Parameter Store itself does not require permission to use KMS; rather, it is the entity accessing the parameter (in this case, the EC2 instance role) that needs the necessary permissions.
The EC2 instance role does not need encrypt permissions on the KMS key used for the secure string; it only needs decrypt permissions. Encrypt permissions are only relevant for entities that need to create new encrypted secrets.
The presence or absence of tags on the EC2 instance does not affect its ability to access secure strings in Parameter Store. Tags are mainly used for resource management and billing purposes, not for permission control.
I figure that the answer is:
The EC2 instance role does not have decrypt permissions on the AWS Key Management Service (AWS KMS) key used to encrypt the secret.