# 使用临时URL进行授权访问 临时授权访问是指通过访问密钥、请求方法类型、请求参数等信息生成一个临时访问权限的URL，这个URL中会包含鉴权信息，您可以使用该URL进行访问OBS服务进行特定操作。在生成URL时，您需要指定URL的有效期。所有继承OBSBaseRequest的子类都能使用临时鉴权访问。 临时授权访问支持的操作以及相关信息见下表： | **操作名** | **OBS iOS SDK类名** | |:---|:---| | 创建桶 | OBSCreateBucketRequest | | 获取桶列表 | OBSListBucketsRequest | | 删除桶 | OBSDeleteBucketRequest | | 列举桶内对象 | OBSListObjectsRequest | | 列举桶内多版本对象 | OBSListObjectsVersionsRequest | | 列举分段上传任务 | OBSListMultipartUploadsRequest | | 获取桶元数据 | OBSGetBucketMetaDataRequest | | 获取桶区域位置 | OBSGetBucketMetaDataRequest | | 获取桶存量信息 | OBSGetBucketStorageInfoRequest | | 设置桶配额 | OBSSetBucketQuotaRequest | | 获取桶配额 | OBSGetBucketQuotaRequest | | 设置桶ACL | OBSSetBucketACLWithCannedACLRequest、OBSSetBucketACLWithPolicyRequest | | 获取桶ACL | OBSGetBucketACLRequest | | 开启/关闭桶日志 | OBSSetBucketLoggingRequest | | 查看桶日志 | OBSGetBucketLoggingRequest | | 设置桶策略 | OBSSetBucketPolicyRequest、OBSSetBucketPolicyWithStringRequest | | 查看桶策略 | OBSGetBucketPolicyRequest | | 删除桶策略 | OBSDeleteBucketPolicyRequest | | 设置生命周期规则 | OBSSetBucketLifecycleRequest | | 查看生命周期规则 | OBSGetBucketLifecycleRequest | | 删除生命周期规则 | OBSDeleteBucketLifecycleRequest | | 设置托管配置 | OBSSetBucketWebsiteRequest | | 查看托管配置 | OBSGetBucketWebsiteRequest | | 清除托管配置 | OBSDeleteBucketWebsiteRequest | | 设置桶多版本状态 | OBSSetBucketVersioningRequest | | 查看桶多版本状态 | OBSGetBucketVersioningRequest | | 设置跨域规则 | OBSSetBucketCORSRequest | | 查看跨域规则 | OBSGetBucketCORSRequest | | 删除跨域规则 | OBSDeleteBucketCORSRequest | | OPTIONS桶 | OBSOptionsBucketRequest | | 设置桶标签 | OBSSetBucketTaggingRequest | | 查看桶标签 | OBSGetBucketTaggingRequest | | 删除桶标签 | OBSDeleteBucketTaggingRequest | | 上传对象 | OBSPutObjectWithDataRequest、OBSPutObjectWithFileRequest | | 追加上传 | OBSAppendObjectWithFileRequest | | 下载对象 | OBSGetObjectToDataRequest | | 复制对象 | OBSCopyObjectRequest | | 删除对象 | OBSDeleteObjectRequest | | 批量删除对象 | OBSDeleteObjectsRequest | | 获取对象属性 | OBSGetObjectMetaDataRequest | | 设置对象ACL | OBSSetObjectACLRequest | | 查看对象ACL | OBSGetObjectACLRequest | | 初始化分段上传任务 | OBSInitiateMultipartUploadRequest | | 上传段 | OBSUploadPartWithDataRequest | | 复制段 | OBSCopyPartRequest | | 列举已上传的段 | OBSListPartsRequest | | 合并段 | OBSCompleteMultipartUploadRequest | | 取消分段上传任务 | OBSAbortMultipartUploadRequest | | OPTIONS对象 | OBSOptionsObjectRequest | | 恢复归档存储对象 | OBSRestoreObjectRequest | ![](https://support.huaweicloud.com/sdk-ios-devg-obs/public_sys-resources/caution_3.0-zh-cn.png) 如果遇到跨域报错、签名不匹配问题，请参考以下步骤排查问题： 1. 未配置跨域，需要在控制台配置CORS规则，请参考[配置桶允许跨域请求](https://support.huaweicloud.com/sdk-browserjs-devg-obs/obs_24_0107.html)。 2. 签名计算问题，请参考[URL中携带签名](https://support.huaweicloud.com/api-obs/obs_04_0011.html)排查签名参数是否正确；比如上传对象功能，后端将Content-Type参与计算签名生成授权URL，但是前端使用授权URL时没有设置Content-Type字段或者传入错误的值，此时会出现跨域错误。解决方案为：Content-Type字段前后端保持一致。 您可以通过createV2PreSignedURL生成授权访问的临时URL。以下代码展示了如何生成常用操作的URL： #### 列举对象 ``` static OBSClient *client; NSString *endPoint = @"https://your-endpoint"; // 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量AccessKeyID和SecretAccessKey。 // 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html char* ak_env = getenv("AccessKeyID"); char* sk_env = getenv("SecretAccessKey"); if (ak_env == NULL || sk_env == NULL) { NSLog(@"Error: AccessKeyID or SecretAccessKey environment variable not set"); return; } NSString *AK = [NSString stringWithUTF8String:ak_env]; NSString *SK = [NSString stringWithUTF8String:sk_env]; // 初始化身份验证 OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK]; //初始化服务配置 OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider]; // 初始化client client = [[OBSClient alloc] initWithConfiguration:conf]; OBSListObjectsRequest *request = [[OBSListObjectsRequest alloc] initWithBucketName:@"bucketname"]; // V2生成授权访问url [client createV2PreSignedURL:request expireAfter:3600 completionHandler:^(NSString *urlString, NSString *httpVerb, NSDictionary *signedHeaders) { NSLog(@"%@",urlString); }] ``` #### 获取对象 ``` static OBSClient *client; NSString *endPoint = @"https://your-endpoint"; // 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量AccessKeyID和SecretAccessKey。 // 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html char* ak_env = getenv("AccessKeyID"); char* sk_env = getenv("SecretAccessKey"); if (ak_env == NULL || sk_env == NULL) { NSLog(@"Error: AccessKeyID or SecretAccessKey environment variable not set"); return; } NSString *AK = [NSString stringWithUTF8String:ak_env]; NSString *SK = [NSString stringWithUTF8String:sk_env]; // 初始化身份验证 OBSStaticCredentialProvider *credentialProvider = [[OBSStaticCredentialProvider alloc] initWithAccessKey:AK secretKey:SK]; //初始化服务配置 OBSServiceConfiguration *conf = [[OBSServiceConfiguration alloc] initWithURLString:endPoint credentialProvider:credentialProvider]; // 初始化client client = [[OBSClient alloc] initWithConfiguration:conf]; OBSGetObjectToDataRequest *request = [[OBSGetObjectToDataRequest alloc] initWithBucketName:@"bucketname" objectKey:@"objectkey"]; // V2生成授权访问url [client createV2PreSignedURL:request expireAfter:3600 completionHandler:^(NSString *urlString, NSString *httpVerb, NSDictionary *signedHeaders) { NSLog(@"%@",urlString); }] ```