GET'> HEAD'> PUT'> POST'> DELETE'> ]>

To discover whether your Object Storage system supports this feature, see . Alternatively, check with your service provider.A temporary URL gives users temporary access to objects. For example, a website might want to provide a link to download a large object in Object Storage, but the Object Storage account has no public access. The website can generate a URL that provides time-limited &GET; access to the object. When the web browser user clicks on the link, the browser downloads the object directly from Object Storage, eliminating the need for the website to act as a proxy for the request. Ask your cloud administrator to enable the temporary URL feature. For information, see Temporary URL in the OpenStack Configuration Reference. To use &POST; requests to upload objects to specific Object Storage locations, use form &POST; instead of temporary URL middleware. See .

A temporary URL is comprised of the URL for an object with added query parameters: The example shows these elements: Object URL Required. The full path URL to the object. temp_url_sig Required. An HMAC-SHA1 cryptographic signature that defines the allowed HTTP method, expiration date, full path to the object, and the secret key for the temporary URL. For more information about secret keys, see . For more information about signatures, see . temp_url_expires Required. An expiration date as a UNIX Epoch timestamp, which is an integer value. For example, 1390852007 represents Mon, 27 Jan 2014 19:46:47 GMT. For more information, see Epoch & Unix Timestamp Conversion Tools. filename Optional. Overrides the default file name. Object Storage generates a default file name for &GET; temporary URLs that is based on the object name. Object Storage returns this value in the Content-Disposition response header. Browsers can interpret this file name value as a file attachment to be saved.

Object Storage supports up to two secret keys. You set secret keys at the account level. To set these keys, set one or both of the following request headers to arbitrary values: X-Account-Meta-Temp-URL-Key X-Account-Meta-Temp-URL-Key-2 The arbitrary values serve as the secret keys. Object Storage checks signatures against both keys, if present, to enable key rotation without invalidating existing temporary URLs. For example, use the swift post command to set the secret key to MYKEY: $ swift post -m "X-Account-Meta-Temp-URL-Key: MYKEY" Changing these headers invalidates any previously generated temporary URLs within 60 seconds, which is the memcache time for the key.

Temporary URL middleware uses an HMAC-SHA1 cryptographic signature. This signature includes these elements: The allowed method. Typically, &GET; or &PUT;. Expiry time. In , the expiry time is set to 86400 seconds (or 1 day) into the future. The path. Starting with /v1/ onwards and including a container name and object. In , the path is /v1/my_account/container/object. Do not URL-encode the path at this stage. The secret key. Set as the X-Account-Meta-Temp-URL-Key header value. This sample Python code shows how to compute a signature for use with temporary URLs: import hmac from hashlib import sha1 from time import time method = 'GET' duration_in_seconds = 60*60*24 expires = int(time() + duration_in_seconds) path = '/v1/my_account/container/object' key = 'MYKEY' hmac_body = '%s\n%s\n%s' % (method, expires, path) signature = hmac.new(key, hmac_body, sha1).hexdigest() Do not URL-encode the path when you generate the HMAC-SHA1 signature. However, when you make the actual HTTP request, you should properly URL-encode the URL. The MYKEY value is the value you set in the X-Account-Meta-Temp-URL-Key request header on the account. For more information, see RFC 2104: HMAC: Keyed-Hashing for Message Authentication.

Object Storage provides the swift-temp-url script that auto-generates the temp_url_sig and temp_url_expires query parameters. For example, you might run this command: $ bin/swift-temp-url GET 3600 /v1/my_account/container/object MYKEY This command returns the path: /v1/my_account/container/object ?temp_url_sig=5c4cc8886f36a9d0919d708ade98bf0cc71c9e91 &temp_url_expires=1374497657 To create the temporary URL, prefix this path with the Object Storage storage host name. For example, prefix the path with https://swift-cluster.example.com, as follows: https://swift-cluster.example.com/v1/my_account/container/object ?temp_url_sig=5c4cc8886f36a9d0919d708ade98bf0cc71c9e91 &temp_url_expires=1374497657