# Default KMS key policy created in CloudTrail console
<a name="default-kms-key-policy"></a>

If you create an Amazon KMS key in the CloudTrail console, the following policies are automatically created for you. The policy allows these permissions:
+ Allows Amazon Web Services account (root) permissions for the KMS key.
+ Allows CloudTrail to encrypt log files and digest files under the KMS key and describe the KMS key.
+ Allows all users in the specified accounts to decrypt log files and digest files.
+ Allows all users in the specified account to create a KMS alias for the KMS key.
+ Enables cross-account log decryption for the account ID of the account that created the trail. 

**Topics**
+ [Default KMS key policy for trails](#default-kms-key-policy-trail)

## Default KMS key policy for trails
<a name="default-kms-key-policy-trail"></a>

The following is the default policy created for a Amazon KMS key that you use with a trail.

**Note**  
The policy includes a statement to allow cross accounts to decrypt log files and digest files with the KMS key.

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#### [ JSON ]

****  

```
{
    "Version":"2012-10-17",		 	 	 
    "Id": "Key policy created by CloudTrail",
    "Statement": [
        {
            "Sid": "Enable IAM user permissions",
            "Effect": "Allow",
            "Principal": {
                "AWS": [
                    "arn:aws-cn:iam::{{111111111111}}:root",
                    "arn:aws-cn:iam::{{111111111111}}:user/{{username}}"
                ]
            },
            "Action": "kms:*",
            "Resource": "*"
        },
        {
            "Sid": "Allow CloudTrail to encrypt logs",
            "Effect": "Allow",
            "Principal": {
                "Service": "cloudtrail.amazonaws.com"
             },
            "Action": "kms:GenerateDataKey*",
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                    "aws:SourceArn": "arn:aws-cn:cloudtrail:{{us-east-1}}:{{111111111111}}:trail/{{trail-name}}"
                },
                "StringLike": {
                    "kms:EncryptionContext:aws:cloudtrail:arn": "arn:aws-cn:cloudtrail:*:{{111111111111}}:trail/*"
                }
            }
        },
        {
            "Sid": "Allow CloudTrail to describe key",
            "Effect": "Allow",
            "Principal": {
                "Service": "cloudtrail.amazonaws.com"
             },
            "Action": "kms:DescribeKey",
            "Resource": "*"
        },
        {
            "Sid": "Allow principals in the account to decrypt log files",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
             },
            "Action": [
                "kms:Decrypt",
                "kms:ReEncryptFrom"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                    "kms:CallerAccount": "{{111111111111}}"
                },
                "StringLike": {
                    "kms:EncryptionContext:aws:cloudtrail:arn": "arn:aws-cn:cloudtrail:*:{{111111111111}}:trail/*"
                }
            }
        },
        {
            "Sid": "Enable cross account log decryption",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action": [
                "kms:Decrypt",
                "kms:ReEncryptFrom"
            ],
            "Resource": "*",
            "Condition": {
                "StringEquals": {
                    "kms:CallerAccount": "{{111111111111}}"
                },
                "StringLike": {
                    "kms:EncryptionContext:aws:cloudtrail:arn": "arn:aws-cn:cloudtrail:*:{{111111111111}}:trail/*"
                }
            }
        }
    ]
}
```

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