复制数据库快照的最小 KMS 权限

Question

我正在尝试设置使用 KMS 加密密钥执行 aws rds copy-db-snapshot 的最小权限：

$ 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>

（<> 中的所有内容都被我剥离并包含有效值。）

不幸的是我得到这个错误：

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.

目前我允许这些操作：

  "Action": [
    "kms:ReEncrypt*",
    "kms:ListKeys",
    "kms:ListAliases",
    "kms:GenerateDataKey*",
    "kms:Encrypt",
    "kms:DescribeKey",
    "kms:Decrypt"
  ],

换成kms:*{code}就可以了，肯定是权限问题

我试图通过 CloudTrail 找出正确的权限，但它只包含同样无用的错误消息。

所以我的实际问题是：

CopyDBSnapshot 的最小 KMS 权限是什么？
是否有通用的方法来确定所需的权限？通过谷歌搜索所需的权限来浪费我的时间总是很痛苦。

编辑： 这是启用 --debug 后日志输出的底部部分：

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：我跨post AWS 论坛：https://forums.aws.amazon.com/thread.jspa?messageID=801745

Answer 1

现在，我通过反复试验弄明白了。由于我不喜欢多次执行相同的任务，因此我将其自动化（请参阅下面的脚本）。

这是复制 RDS 快照所需的权限：

["kms:CreateGrant","kms:DescribeKey"]

这是我使用的脚本。也许它对其他有类似问题的人有用。它是一起破解的，所以不要指望它开箱即用。

#!/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(" ")'

Answer 2

我也在做一个 RDS 数据库快照的副本，但是使用 Powershell 并且我的数据库是 MS SQL。我遇到了同样的错误：

The target snapshot KMS key [<kms-arn>] does not exist, 
is not enabled or you do not have permissions to access it.

我在这里结束了我的搜索，检查了我的个人资料、证书、角色等......但一切似乎都很好。

我的错误是没有在 Copy-RDSDBSnapshot 中指定区域（在 Powershell 中；相当于 CLI 中的 copy-db-snapshot）。由于我正在为灾难恢复方案跨区域复制，因此我必须指定目标区域的 KmsKeyId（因为它将延迟源区域）。源区域 us-east-1 是我的默认区域，因此执行此操作无效，它因上述错误而失败，因为我没有指定任何内容，它在我的默认区域 us-east- 中运行1 因此它找不到 us-west-2 键，正如错误所说，它 "does not exist" 在那个区域，它与权限无关：

Copy-RDSDBSnapshot -SourceDBSnapshotIdentifier $dBSnapshotArn `
                   -SourceRegion 'us-east-1' `
                   -TargetDBSnapshotIdentifier $targetSnapshotName `
                   -KmsKeyId 'arn:aws:kms:us-west-2:xxxxx:key/xxxxx' `
                   -CopyTag $true -OptionGroupName 'myOptionGroup'

添加所谓的 "Common Parameter" Region 成功了：

Copy-RDSDBSnapshot -SourceDBSnapshotIdentifier $dBSnapshotArn `
                   -SourceRegion 'us-east-1' `
                   -TargetDBSnapshotIdentifier $targetSnapshotName `
                   -KmsKeyId 'arn:aws:kms:us-west-2:xxxxx:key/xxxxx' `
                   -CopyTag $true -OptionGroupName 'myOptionGroup' `
                   -Region 'us-west-2'  # <-- new line

Answer 3

我找到了另一个根本原因和另一个解决方案：

只需在目标区域创建然后删除 RDS！

AWS RDS 只是拒绝复制快照，无论我对密钥策略做了什么，直到我创建了一个小型的自动 RDS。现在任何密钥都有效 "out-of-box"，即使是新密钥也没有任何政策变化！

Answer 4

除了其他答案的权限外，请确保使用对称加密密钥。 AWS 错误并不清楚它们的含义，当您尝试使用非对称密钥执行某些应该使用对称密钥执行的操作时，会使用完全相同的错误消息。

复制数据库快照的最小 KMS 权限

Minimal KMS permissions to copy a database snapshot

amazon-web-services

amazon-rds

aws-kms