QueryStringAuthGenerator.cs

// This software code is made available "AS IS" without warranties of any        
// kind.  You may copy, display, modify and redistribute the software            
// code either by itself or as incorporated into your code; provided that        
// you do not remove any proprietary notices.  Your use of this software         
// code is at your own risk and you waive any claim against Amazon               
// Digital Services, Inc. or its affiliates with respect to your use of          
// this software code. (c) 2006 Amazon Digital Services, Inc. or its             
// affiliates.          



using System;
using System.Collections;
using System.Text;
using System.Web;

namespace com.CastRoller.AmazonS3DA
{
    /// This class mimics the behavior of AWSAuthConnection, except instead of actually performing
    /// the operation, QueryStringAuthGenerator will return URLs with query string parameters that
    /// can be used to do the same thing.  These parameters include an expiration date, so that
    /// if you hand them off to someone else, they will only work for a limited amount of time.
    public class QueryStringAuthGenerator
    {
        private string awsAccessKeyId;
        private string awsSecretAccessKey;
        private bool isSecure;
        private string server;
        private int port;

        private long expiresIn = NOT_SET;
        private long expires = NOT_SET;

        // by default, expire in 1 minute
        public static readonly long DEFAULT_EXPIRES_IN = 60 * 1000;

        // Sentinel to indicate when a date is not set
        private static readonly long NOT_SET = -1;

        public QueryStringAuthGenerator( string awsAccessKeyId, string awsSecretAccessKey ) :
            this( awsAccessKeyId, awsSecretAccessKey, true )
        {
        }

        public QueryStringAuthGenerator( string awsAccessKeyId, string awsSecretAccessKey,
                                         bool isSecure ) :
            this( awsAccessKeyId, awsSecretAccessKey, isSecure, Utils.Host )
        {
        }

        public QueryStringAuthGenerator( string awsAccessKeyId, string awsSecretAccessKey,
                                         bool isSecure, string server ) :
            this( awsAccessKeyId, awsSecretAccessKey, isSecure, server,
                  isSecure ? Utils.SecurePort : Utils.InsecurePort )
        {
        }

        public QueryStringAuthGenerator( string awsAccessKeyId, string awsSecretAccessKey,
                                         bool isSecure, string server, int port )
        {
            this.awsAccessKeyId = awsAccessKeyId;
            this.awsSecretAccessKey = awsSecretAccessKey;
            this.isSecure = isSecure;
            this.server = server;
            this.port = port;
            this.expiresIn = DEFAULT_EXPIRES_IN;
            this.expires = NOT_SET;
        }

        /// <summary>
        /// Sets/Gets the milliseconds since the Epoch that this
        /// expires at
        /// </summary>
        public long Expires {
            get {
                return expires;
            }
            set {
                expires = value;
                expiresIn = NOT_SET;
            }
        }

        public long ExpiresIn {
            get {
                return expiresIn;
            }
            set {
                expiresIn = value;
                expires = NOT_SET;
            }
        }

        public string createBucket( string bucket, SortedList headers, SortedList metadata )
        {
            return generateURL( "PUT", bucket, mergeMeta( headers, metadata ) );
        }

        public string listBucket(string bucket, string prefix, string marker,
                                  int maxKeys, SortedList headers)
        {
            return listBucket(bucket, prefix, marker, maxKeys, null, headers);
        }

        public string listBucket(string bucket, string prefix, string marker,
                                  int maxKeys, string delimiter, SortedList headers)
        {
            StringBuilder path = new StringBuilder(bucket);
            path.Append("?");
            if (prefix != null) path.Append("prefix=" + HttpUtility.UrlEncode(prefix) + "&");
            if (marker != null) path.Append("marker=" + HttpUtility.UrlEncode(marker) + "&");
            if (maxKeys != 0) path.Append("max-keys=" + maxKeys + "&");
            if (delimiter != null) path.Append("delimiter=" + HttpUtility.UrlEncode(delimiter) + "&");
            path.Remove(path.Length - 1, 1);

            return generateURL("GET", path.ToString(), headers);
        }

        public string deleteBucket( string bucket, SortedList headers )
        {
            return generateURL( "DELETE", bucket, headers );
        }

        public string put( string bucket, string key, S3Object obj, SortedList headers )
        {
            SortedList metadata = null;
            if ( obj != null )
            {
                metadata = obj.Metadata;
            }

            return generateURL("PUT", bucket + "/" + HttpUtility.UrlEncode(key), mergeMeta(headers, metadata));
        }

        public string get( string bucket, string key, SortedList headers )
        {
         //   return generateURL("GET", bucket + "/" + HttpUtility.UrlEncode(key), headers);
			return generateURL("GET", bucket + "/" + key, headers);

        }

        public string delete( string bucket, string key, SortedList headers )
        {
            return generateURL("DELETE", bucket + "/" + HttpUtility.UrlEncode(key), headers);
        }

        public string getBucketLogging(string bucket, SortedList headers)
        {
            return generateURL("GET", bucket + "?logging", headers);
        }

        public string putBucketLogging(string bucket, SortedList headers)
        {
            return generateURL("PUT", bucket + "?logging", headers);
        }

        public string getBucketACL(string bucket, SortedList headers)
        {
            return generateURL("GET", bucket + "?acl", headers);
        }

        public string getACL(string bucket, string key, SortedList headers)
        {
            return generateURL("GET", bucket + "/" + HttpUtility.UrlEncode(key) + "?acl", headers);
        }

        public string putBucketACL(string bucket, SortedList headers)
        {
            return generateURL("PUT", bucket + "?acl", headers);
        }

        public string putACL(string bucket, string key, SortedList headers)
        {
            return generateURL("PUT", bucket + "/" + HttpUtility.UrlEncode(key) + "?acl", headers);
        }

        public string listAllMyBuckets( SortedList headers )
        {
            return generateURL( "GET", "", headers );
        }

        public string makeBaseURL( string bucket, string key ) {
            StringBuilder buffer = new StringBuilder();
            if ( this.isSecure ) {
                buffer.Append( "https://" );
            } else {
                buffer.Append( "http://" );
            }
            buffer.Append(this.server).Append(":").Append(this.port).Append("/");
            if ( bucket != null ) {
                buffer.Append( bucket );
                if ( key != null ) {
                    buffer.Append( "/" );
                    buffer.Append( HttpUtility.UrlEncode(key) );
                }
            }
            return buffer.ToString();
        }

        private string generateURL( string method, string path, SortedList headers )
        {
            long expires = 0L;
            if ( this.expiresIn != NOT_SET )
            {
                expires = Utils.currentTimeMillis() + this.expiresIn;
            }
            else if ( this.expires != NOT_SET )
            {
                expires = this.expires;
            }
            else
            {
                throw new Exception( "Illegal expire state!" );
            }

            // convert to seconds
            expires /= 1000;

            string canonicalString = Utils.makeCanonicalString( method, path, headers, "" + expires );
            string encodedCanonical = Utils.encode( this.awsSecretAccessKey, canonicalString, true );

            StringBuilder builder = new StringBuilder();
            if ( this.isSecure ) {
                builder.Append( "https://" );
            } else {
                builder.Append( "http://" );
            }
            builder.Append( this.server ).Append( ":" ).Append( this.port ).Append( "/" ).Append( path );
            if ( path.IndexOf( "?" ) == -1 )
            {
                builder.Append( "?" );
            } else {
                builder.Append( "&" );
            }
            builder.Append( "Signature=" ).Append( encodedCanonical );
            builder.Append( "&Expires=" ).Append( expires );
            builder.Append( "&AWSAccessKeyId=" ).Append( this.awsAccessKeyId );

            return builder.ToString();
        }

        private SortedList mergeMeta( SortedList headers, SortedList metadata )
        {
            SortedList merged = new SortedList();
            if ( headers != null )
            {
                foreach ( string key in headers.Keys )
                {
                    merged.Add( key, headers[ key ] );
                }
            }

            if ( metadata != null )
            {
                foreach ( string key in metadata.Keys )
                {
                    string existing = merged[ key ] as string;
                    if ( existing != null )
                    {
                        existing += "," + metadata[ key ];
                    }
                    else
                    {
                        existing = metadata[ key ] as string;
                    }
                    merged.Add( key, existing );
                }
            }

            return merged;
        }
    }
}