# IAM：允许 IAM 用户自行管理 MFA 设备
<a name="reference_policies_examples_iam_mfa-selfmanage"></a>

此示例说明如何创建 IAM policy 以允许基于身份的用户自行管理其[多重身份验证（MFA）](id_credentials_mfa.md)设备。此策略授予有计划地通过 AWS API 或 AWS CLI 完成此操作的必要权限。

**注意**  
如果具有此策略的 IAM 用户未通过 MFA 进行身份验证，则此策略会拒绝对所有 AWS 操作（使用 MFA 进行身份验证所需的操作除外）的访问。如果为已登录 AWS 的用户添加这些权限，他们需要注销并重新登录才能看到这些更改。

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#### [ JSON ]

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```
{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Sid": "AllowListActions",
            "Effect": "Allow",
            "Action": [
                "iam:ListUsers",
                "iam:ListVirtualMFADevices"
            ],
            "Resource": "*"
        },
        {
            "Sid": "AllowUserToCreateVirtualMFADevice",
            "Effect": "Allow",
            "Action": [
                "iam:CreateVirtualMFADevice"
            ],
            "Resource": "arn:aws:iam::*:mfa/*"
        },
        {
            "Sid": "AllowUserToManageTheirOwnMFA",
            "Effect": "Allow",
            "Action": [
                "iam:EnableMFADevice",
                "iam:GetMFADevice",
                "iam:ListMFADevices",
                "iam:ResyncMFADevice"
            ],
            "Resource": "arn:aws:iam::*:user/${aws:username}"
        },
        {
            "Sid": "AllowUserToDeactivateTheirOwnMFAOnlyWhenUsingMFA",
            "Effect": "Allow",
            "Action": [
                "iam:DeactivateMFADevice"
            ],
            "Resource": [
                "arn:aws:iam::*:user/${aws:username}"
            ],
            "Condition": {
                "Bool": {
                    "aws:MultiFactorAuthPresent": "true"
                }
            }
        },
        {
            "Sid": "BlockMostAccessUnlessSignedInWithMFA",
            "Effect": "Deny",
            "NotAction": [
                "iam:CreateVirtualMFADevice",
                "iam:EnableMFADevice",
                "iam:ListMFADevices",
                "iam:ListUsers",
                "iam:ListVirtualMFADevices",
                "iam:ResyncMFADevice"
            ],
            "Resource": "*",
            "Condition": {
                "BoolIfExists": {
                    "aws:MultiFactorAuthPresent": "false"
                }
            }
        }
    ]
}
```

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