/// <summary>
/// Create a signed URL allowing access to a resource that would
/// usually require authentication.
/// </summary>
/// <remarks>
/// <para>
/// 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.
/// </para>
/// <para>
/// A PreSigned URL can be generated for GET, PUT, DELETE and HEAD
/// operations on your bucketName, keys, and versions.
/// </para>
/// </remarks>
/// <param name="request">The GetPreSignedUrlRequest that defines the
/// parameters of the operation.</param>
/// <returns>A string that is the signed http request.</returns>
/// <exception cref="T:System.ArgumentException" />
/// <exception cref="T:System.ArgumentNullException" />
public string GetPreSignedURL(GetPreSignedUrlRequest request)
{
if (Credentials == null)
{
throw new AmazonS3Exception("Credentials must be specified, cannot call method anonymously");
}
if (request == null)
{
throw new ArgumentNullException("request", "The PreSignedUrlRequest specified is null!");
}
if (!request.IsSetExpires())
{
throw new InvalidOperationException("The Expires specified is null!");
}
var aws4Signing = AWSConfigs.S3UseSignatureVersion4;
var region = AWS4Signer.DetermineRegion(Config);
if (aws4Signing && string.IsNullOrEmpty(region))
{
throw new InvalidOperationException("To use AWS4 signing, a region must be specified in the client configuration using the AuthenticationRegion or Region properties, or be determinable from the service URL.");
}
if (region.Equals(RegionEndpoint.CNNorth1.SystemName, StringComparison.OrdinalIgnoreCase))
{
aws4Signing = true;
}
var immutableCredentials = Credentials.GetCredentials();
var irequest = Marshall(request, immutableCredentials.AccessKey, immutableCredentials.Token, aws4Signing);
irequest.Endpoint = DetermineEndpoint(irequest);
ProcessRequestHandlers(irequest);
var metrics = new RequestMetrics();
string authorization;
if (aws4Signing)
{
var aws4Signer = new AWS4PreSignedUrlSigner();
var signingResult = aws4Signer.SignRequest(irequest,
this.Config,
metrics,
immutableCredentials.AccessKey,
immutableCredentials.SecretKey);
authorization = "&" + signingResult.ForQueryParameters;
}
else
{
signer.SignRequest(irequest, metrics, immutableCredentials.AccessKey, immutableCredentials.SecretKey);
authorization = irequest.Headers[S3QueryParameter.Authorization.ToString()];
authorization = authorization.Substring(authorization.IndexOf(":", StringComparison.Ordinal) + 1);
authorization = "&Signature=" + AmazonS3Util.UrlEncode(authorization, false);
}
Uri url = ComposeUrl(irequest, irequest.Endpoint);
string result = url.AbsoluteUri + authorization;
Protocol protocol = DetermineProtocol();
if (request.Protocol != protocol)
{
switch (protocol)
{
case Protocol.HTTP:
result = result.Replace("http://", "https://");
break;
case Protocol.HTTPS:
result = result.Replace("https://", "http://");
break;
}
}
return(result);
}