:Request signatures

1. Arrange the request parameters, including all common request parameters and operation-specific parameters except Signature, in alphabetical order.
   Note When you use the GET method to submit a request, the request parameters are included as a part of the URI. The request parameters in the URI are between the question mark (?) and the ampersand (&).
2. Encode the name and value of each request parameter. URL encode parameter names and values based on the UTF-8 character set. The URL encoding rules are described as follows:
   1. Uppercase letters, lowercase letters, digits, and some special characters such as hyphens (-), underscores (_), periods (.), and tildes (~) do not need to be encoded.
   2. Other characters must be percent encoded in the %XY format. XY represents the ASCII code of the characters in hexadecimal notation. For example, double quotation marks (") are encoded as %22.
   3. Extended UTF-8 characters are encoded in the %XY%ZA… format. Spaces must be encoded as %20. Do not encode spaces as plus signs (+).
      Note Generally, all the libraries that support URL encoding, such as java.net.URLEncoder, perform encoding based on the rule of the application/x-www-form-urlencoded MIME type. If this encoding method is used, replace the plus signs (+) in the encoded strings with %20, the asterisks (*) with %2A, and %7E with a tilde (~) to conform to the encoding rules.
3. Connect the encoded name and value of each parameter with an equal sign (=).
4. Arrange the encoded parameters in alphabetical order based on the first letter of the name of each parameter and connect the parameters with ampersands (&) to create a canonicalized query string.

StringToSign=
HTTPMethod + "&" +
percentEncode("/") + "&" +
percentEncode(CanonicalizedQueryString)

Note:

• HTTPMethod: specifies the HTTP method that is used to send a request, such as GET.
• percentEncode("/"): encodes the forward slashes (/) based on the URL encoding rules described in Step 1.ii. The encoded value of a forward slash (/) is %2F.
• percentEncode(CanonicalizedQueryString): encodes the canonicalized query string that is created in Step 1 based on the URL encoding rules described in Step 1.ii.