AWS SDK Version 3 for .NET
API Reference

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Create a signed URL allowing access to a resource that would usually require authentication.

Namespace: Amazon.S3
Assembly: AWSSDK.S3.dll
Version: 3.x.y.z

Syntax

C#
public virtual String GetPreSignedURL(
         GetPreSignedUrlRequest request
)
Parameters
request
Type: Amazon.S3.Model.GetPreSignedUrlRequest

The GetPreSignedUrlRequest that defines the parameters of the operation.

Return Value
Type: String
A string that is the signed http request.

Exceptions

Remarks

When using query string authentication you create a query, specify an expiration time for the query, sign it with your signature, place the data in an HTTP request, and distribute the request to a user or embed the request in a web page.

A PreSigned URL can be generated for GET, PUT, DELETE and HEAD operations on your bucketName, keys, and versions.

Examples

The following examples show how to create various different pre-signed URLs.

The code sample shows a GetContents function. This will be referred to in subsequent samples to test out the generated URL.

GetContents function


public static string GetContents(string path)
{
    HttpWebRequest request = HttpWebRequest.Create(path) as HttpWebRequest;
    HttpWebResponse response = request.GetResponse() as HttpWebResponse; 

    using (Stream stream = response.GetResponseStream())
    using (StreamReader reader = new StreamReader(stream))
    {
        return reader.ReadToEnd();
    }
}
        
        

The first example creates a URL that will allow a third party to retrieve an object from S3 for a period of 5 minutes.

GetPreSignedURL sample 1


// Create a client
AmazonS3Client client = new AmazonS3Client();

// Create a CopyObject request
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest
{
    BucketName = "SampleBucket",
    Key = "Item1",
    Expires = DateTime.Now.AddMinutes(5)
};

// Get path for request
string path = client.GetPreSignedURL(request);

// Test by getting contents
string contents = GetContents(path);

                

The following example creates a URL that will allow a third party to retrieve an object from S3 for a period of 5 minutes, and it also sets the headers to specific content, caching and encoding values.

GetPreSignedURL sample 2


// Create a client
AmazonS3Client client = new AmazonS3Client();

// Create a CopyObject request
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest
{
    BucketName = "SampleBucket",
    Key = "Item1",
    Expires = DateTime.Now.AddMinutes(5)
};
request.ResponseHeaderOverrides.ContentType = "text/xml+zip";
request.ResponseHeaderOverrides.ContentDisposition = "attachment; filename=dispName.pdf";
request.ResponseHeaderOverrides.CacheControl = "No-cache";
request.ResponseHeaderOverrides.ContentLanguage = "mi, en";
request.ResponseHeaderOverrides.Expires = "Thu, 01 Dec 1994 16:00:00 GMT";
request.ResponseHeaderOverrides.ContentEncoding = "x-gzip";

// Get path for request
string path = client.GetPreSignedURL(request);

// Test by getting contents
string contents = GetContents(path);

                

This example creates a URL that will allow a third party to list all objects in a specific bucket. This URL will also expire in 5 minutes.
The URL response will be the XML response for a ListBucket request.

GetPreSignedURL sample 3


// Create a client
AmazonS3Client client = new AmazonS3Client();

// Create a CopyObject request
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest
{
    BucketName = "SampleBucket",
    Expires = DateTime.Now.AddMinutes(5)
};

// Get path for request
string path = client.GetPreSignedURL(request);

// Retrieve objects
string allObjects = GetContents(path);

                

This example creates a URL that will allow a third party to list all of the owner's buckets. This URL will also expire in 5 minutes.
The URL response will be the XML response for a ListBuckets request.

GetPreSignedURL sample 4


// Create a client
AmazonS3Client client = new AmazonS3Client();

// Create a CopyObject request
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest
{
    Expires = DateTime.Now.AddMinutes(5)
};

// Get path for request
string path = client.GetPreSignedURL(request);

// Retrieve buckets
string allBuckets = GetContents(path);

                

This final example creates a URL that allows a third party to put an object, then uses it to upload sample content. The URL is set to expire in 10 days.

GetPreSignedURL sample 5


// Create a client
AmazonS3Client client = new AmazonS3Client();

// Create a CopyObject request
GetPreSignedUrlRequest request = new GetPreSignedUrlRequest
{
    BucketName = "SampleBucket",
    Key = "Item1",
    Verb = HttpVerb.PUT,
    Expires = DateTime.Now.AddDays(10)
};

// Get path for request
string path = client.GetPreSignedURL(request);

// Prepare data
byte[] data = UTF8Encoding.UTF8.GetBytes("Sample text.");

// Configure request
HttpWebRequest httpRequest = WebRequest.Create(path) as HttpWebRequest;
httpRequest.Method = "PUT";
httpRequest.ContentLength = data.Length;

// Write data to stream
Stream requestStream = httpRequest.GetRequestStream();
requestStream.Write(data, 0, data.Length);
requestStream.Close();

// Issue request
HttpWebResponse response = httpRequest.GetResponse() as HttpWebResponse;

                

Version Information

.NET Standard:
Supported in: 1.3

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Windows Phone 8.1
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms