I am trying to setup minimal permissions for doing aws rds copy-db-snapshot with a KMS encryption key:
$ aws rds copy-db-snapshot --source-db-snapshot-identifier rds-backup-share-
mysql --target-db-snapshot-identifier rds-backup-share-mysql-reencrypted --kms-key-id <kms-arn>
(Everything within <> is stripped out by me and contains valid values.)
Unfortunately I get this error:
An error occurred (KMSKeyNotAccessibleFault) when calling the CopyDBSnapshot operation: The target snapshot KMS key [<kms-arn>] does not exist, is not enabled or you do not have permissions to access it.
Currently I allow these actions:
"Action": [
"kms:ReEncrypt*",
"kms:ListKeys",
"kms:ListAliases",
"kms:GenerateDataKey*",
"kms:Encrypt",
"kms:DescribeKey",
"kms:Decrypt"
],
It works if I replace it with kms:*{code}, so it must be a permission issue.
I tried to figure out the correct permissions with CloudTrail, but it just contains the same unhelpful error message.
So my actual questions:
Edit: This is the is the bottom part of the log output with --debug enabled:
2017-08-22 17:15:37,521 - MainThread - botocore.endpoint - DEBUG - Sending http request: <PreparedRequest [POST]>
2017-08-22 17:15:37,522 - MainThread - botocore.vendored.requests.packages.urllib3.connectionpool - INFO - Starting new HTTPS connection (1): rds.eu-west-1.amazonaws.com
2017-08-22 17:15:37,927 - MainThread - botocore.vendored.requests.packages.urllib3.connectionpool - DEBUG - "POST / HTTP/1.1" 400 437
2017-08-22 17:15:37,934 - MainThread - botocore.parsers - DEBUG - Response headers: {'x-amzn-requestid': 'c097fe4e-874c-11e7-a56a-9d1acedaf516', 'content-type': 'text/xml', 'content-length': '437', 'date': 'Tue, 22 Aug 2017 15:15:37 GMT', 'connection': 'close'}
2017-08-22 17:15:37,936 - MainThread - botocore.parsers - DEBUG - Response body:
b'<ErrorResponse xmlns="http://rds.amazonaws.com/doc/2014-10-31/">\n <Error>\n <Type>Sender</Type>\n <Code>KMSKeyNotAccessibleFault</Code>\n <Message>The target snapshot KMS key [<kms-arn>] does not exist, is not enabled or you do not have permissions to access it. </Message>\n </Error>\n <RequestId>c097fe4e-874c-11e7-a56a-9d1acedaf516</RequestId>\n</ErrorResponse>\n'
2017-08-22 17:15:37,938 - MainThread - botocore.hooks - DEBUG - Event needs-retry.rds.CopyDBSnapshot: calling handler <botocore.retryhandler.RetryHandler object at 0x7f9c7ce84860>
2017-08-22 17:15:37,939 - MainThread - botocore.retryhandler - DEBUG - No retry needed.
2017-08-22 17:15:37,952 - MainThread - awscli.clidriver - DEBUG - Exception caught in main()
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/awscli/clidriver.py", line 200, in main
return command_table[parsed_args.command](remaining, parsed_args)
File "/usr/lib/python3.6/site-packages/awscli/clidriver.py", line 338, in __call__
return command_table[parsed_args.operation](remaining, parsed_globals)
File "/usr/lib/python3.6/site-packages/awscli/clidriver.py", line 508, in __call__
call_parameters, parsed_globals)
File "/usr/lib/python3.6/site-packages/awscli/clidriver.py", line 627, in invoke
client, operation_name, parameters, parsed_globals)
File "/usr/lib/python3.6/site-packages/awscli/clidriver.py", line 639, in _make_client_call
**parameters)
File "/usr/lib/python3.6/site-packages/botocore/client.py", line 310, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/usr/lib/python3.6/site-packages/botocore/client.py", line 599, in _make_api_call
raise error_class(parsed_response, operation_name)
botocore.errorfactory.KMSKeyNotAccessibleFault: An error occurred (KMSKeyNotAccessibleFault) when calling the CopyDBSnapshot operation: The target snapshot KMS key [<kms-arn>] does not exist, is not enabled or you do not have permissions to access it.
2017-08-22 17:15:37,955 - MainThread - awscli.clidriver - DEBUG - Exiting with rc 255
An error occurred (KMSKeyNotAccessibleFault) when calling the CopyDBSnapshot operation: The target snapshot KMS key [<kms-arn>] does not exist, is not enabled or you do not have permissions to access it.
FTR: I did a cross-post to the AWS forum: https://forums.aws.amazon.com/thread.jspa?messageID=801745
Now, I figured it out by trial and error. Since I don't like to do the same task more than once, I automated it (see script below).
This are the required permissions for copying a RDS snapshot:
["kms:CreateGrant","kms:DescribeKey"]
This is the script I used. Maybe it is useful for other people which have a similar problem. It is hacked together, so don't expect it to work out of the box.
#!/bin/bash
set -euo pipefail
unknown=(
kms:CancelKeyDeletion
kms:CreateAlias
kms:CreateAlias
kms:CreateGrant
kms:CreateKey
kms:Decrypt
kms:DeleteAlias
kms:DeleteAlias
kms:DescribeKey
kms:DisableKey
kms:DisableKeyRotation
kms:EnableKey
kms:EnableKeyRotation
kms:Encrypt
kms:GenerateRandom
kms:GenerateDataKey
kms:GenerateDataKeyWithoutPlaintext
kms:GetKeyPolicy
kms:GetKeyRotationStatus
kms:ListAliases
kms:ListGrants
kms:ListKeyPolicies
kms:ListKeys
kms:ListRetirableGrants
kms:PutKeyPolicy
kms:ReEncryptFrom
kms:ReEncryptTo
kms:RetireGrant
kms:RevokeGrant
kms:ScheduleKeyDeletion
kms:UpdateAlias
kms:UpdateAlias
kms:UpdateKeyDescription
)
required=()
KEY_ID=86a6300d-38f9-4892-b7a1-d8f821e8438c
export AWS_DEFAULT_OUTPUT=json
function check_copy {
permissions=$( echo -n "${required[*]} ${unknown[*]}" | jq -R -s 'split(" ")' )
policy=$( aws kms \
get-key-policy \
--key-id ${KEY_ID} \
--policy-name default \
| jq ".Policy" -r \
| jq ".Statement[1].Action |= ${permissions}"
)
aws kms \
put-key-policy \
--key-id ${KEY_ID} \
--policy-name default \
--policy "${policy}"
aws rds \
delete-db-snapshot \
--db-snapshot-identifier rds-backup-share-mysql-reencrypted \
|| true
(
set -x
AWS_ACCESS_KEY_ID=XXX \
AWS_SECRET_ACCESS_KEY=XXX \
aws rds \
copy-db-snapshot \
--source-db-snapshot-identifier rds-backup-share-mysql \
--target-db-snapshot-identifier rds-backup-share-mysql-reencrypted \
--kms-key-id alias/rds-snapshot-share \
|| return 1
aws rds \
wait db-snapshot-completed \
--db-snapshot-identifier rds-backup-share-mysql-reencrypted
) || return 1
return 0
}
check_copy
while [ ${#unknown[@]} -gt 0 ]
do
removed=${unknown[0]}
unknown=(${unknown[@]:1})
if ! check_copy
then
required+=($removed)
fi
echo "Required permissions so far: ${required[*]}"
echo "Unknown permissions so far: ${unknown[*]}"
done
echo -n "Minimal permissions: "
echo -n "${required[*]}" | jq -R -s -c 'split(" ")'