* Added three new helper utility files to OpenSim.Framework. MultipartForm is used for constructing multipart/form-data requests. UntrustedWebRequest places sanity checks and policy on requests to HTTP endpoints that are not in the same trust domain (useful for Hypergrid, OpenID, etc). WebUtil contains misc. functions for managing URLs and network streams

3 files changed, 650 insertions, 0 deletions

diff --git a/OpenSim/Framework/MultipartForm.cs b/OpenSim/Framework/MultipartForm.cs
new file mode 100644
index 0000000..8ba6d22
--- /dev/null
+++ b/OpenSim/Framework/MultipartForm.cs
@@ -0,0 +1,117 @@
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.IO;
+using System.Text;
+
+namespace OpenSim.Framework
+{
+    public static class MultipartForm
+    {
+        #region Helper Classes
+
+        public abstract class Element
+        {
+            public string Name;
+        }
+
+        public class File : Element
+        {
+            public string Filename;
+            public string ContentType;
+            public byte[] Data;
+
+            public File(string name, string filename, string contentType, byte[] data)
+            {
+                Name = name;
+                Filename = filename;
+                ContentType = contentType;
+                Data = data;
+            }
+        }
+
+        public class Parameter : Element
+        {
+            public string Value;
+
+            public Parameter(string name, string value)
+            {
+                Name = name;
+                Value = value;
+            }
+        }
+
+        #endregion Helper Classes
+
+        public static HttpWebResponse Post(HttpWebRequest request, List<Element> postParameters)
+        {
+            string boundary = Boundary();
+
+            // Set up the request properties
+            request.Method = "POST";
+            request.ContentType = "multipart/form-data; boundary=" + boundary;
+
+            #region Stream Writing
+
+            using (MemoryStream formDataStream = new MemoryStream())
+            {
+                foreach (var param in postParameters)
+                {
+                    if (param is File)
+                    {
+                        File file = (File)param;
+
+                        // Add just the first part of this param, since we will write the file data directly to the Stream
+                        string header = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"; filename=\"{2}\";\r\nContent-Type: {3}\r\n\r\n",
+                            boundary,
+                            file.Name,
+                            !String.IsNullOrEmpty(file.Filename) ? file.Filename : "tempfile",
+                            file.ContentType);
+
+                        formDataStream.Write(Encoding.UTF8.GetBytes(header), 0, header.Length);
+                        formDataStream.Write(file.Data, 0, file.Data.Length);
+                    }
+                    else
+                    {
+                        Parameter parameter = (Parameter)param;
+
+                        string postData = string.Format("--{0}\r\nContent-Disposition: form-data; name=\"{1}\"\r\n\r\n{2}\r\n",
+                            boundary,
+                            parameter.Name,
+                            parameter.Value);
+                        formDataStream.Write(Encoding.UTF8.GetBytes(postData), 0, postData.Length);
+                    }
+                }
+
+                // Add the end of the request
+                byte[] footer = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");
+                formDataStream.Write(footer, 0, footer.Length);
+
+                request.ContentLength = formDataStream.Length;
+
+                // Copy the temporary stream to the network stream
+                formDataStream.Seek(0, SeekOrigin.Begin);
+                using (Stream requestStream = request.GetRequestStream())
+                    formDataStream.CopyTo(requestStream, (int)formDataStream.Length);
+            }
+
+            #endregion Stream Writing
+
+            return request.GetResponse() as HttpWebResponse;
+        }
+
+        private static string Boundary()
+        {
+            Random rnd = new Random();
+            string formDataBoundary = String.Empty;
+
+            while (formDataBoundary.Length < 15)
+                formDataBoundary = formDataBoundary + rnd.Next();
+
+            formDataBoundary = formDataBoundary.Substring(0, 15);
+            formDataBoundary = "-----------------------------" + formDataBoundary;
+
+            return formDataBoundary;
+        }
+    }
+}
diff --git a/OpenSim/Framework/UntrustedWebRequest.cs b/OpenSim/Framework/UntrustedWebRequest.cs
new file mode 100644
index 0000000..1af7c41
--- /dev/null
+++ b/OpenSim/Framework/UntrustedWebRequest.cs
@@ -0,0 +1,203 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Net.Security;
+using System.Text;
+using log4net;
+
+namespace OpenSim.Framework
+{
+    /// <summary>
+    /// Used for requests to untrusted endpoints that may potentially be
+    /// malicious
+    /// </summary>
+    public static class UntrustedHttpWebRequest
+    {
+        /// <summary>Setting this to true will allow HTTP connections to localhost</summary>
+        private const bool DEBUG = true;
+
+        private static readonly ILog m_log =
+                LogManager.GetLogger(
+                System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+
+        private static readonly ICollection<string> allowableSchemes = new List<string> { "http", "https" };
+
+        /// <summary>
+        /// Creates an HttpWebRequest that is hardened against malicious
+        /// endpoints after ensuring the given Uri is safe to retrieve
+        /// </summary>
+        /// <param name="uri">Web location to request</param>
+        /// <returns>A hardened HttpWebRequest if the uri was determined to be safe</returns>
+        /// <exception cref="ArgumentNullException">If uri is null</exception>
+        /// <exception cref="ArgumentException">If uri is unsafe</exception>
+        public static HttpWebRequest Create(Uri uri)
+        {
+            return Create(uri, DEBUG, 1000 * 5, 1000 * 20, 10);
+        }
+
+        /// <summary>
+        /// Creates an HttpWebRequest that is hardened against malicious
+        /// endpoints after ensuring the given Uri is safe to retrieve
+        /// </summary>
+        /// <param name="uri">Web location to request</param>
+        /// <param name="allowLoopback">True to allow connections to localhost, otherwise false</param>
+        /// <param name="readWriteTimeoutMS">Read write timeout, in milliseconds</param>
+        /// <param name="timeoutMS">Connection timeout, in milliseconds</param>
+        /// <param name="maximumRedirects">Maximum number of allowed redirects</param>
+        /// <returns>A hardened HttpWebRequest if the uri was determined to be safe</returns>
+        /// <exception cref="ArgumentNullException">If uri is null</exception>
+        /// <exception cref="ArgumentException">If uri is unsafe</exception>
+        public static HttpWebRequest Create(Uri uri, bool allowLoopback, int readWriteTimeoutMS, int timeoutMS, int maximumRedirects)
+        {
+            if (uri == null)
+                throw new ArgumentNullException("uri");
+
+            if (!IsUriAllowable(uri, allowLoopback))
+                throw new ArgumentException("Uri " + uri + " was rejected");
+
+            HttpWebRequest httpWebRequest = (HttpWebRequest)HttpWebRequest.Create(uri);
+            httpWebRequest.MaximumAutomaticRedirections = maximumRedirects;
+            httpWebRequest.ReadWriteTimeout = readWriteTimeoutMS;
+            httpWebRequest.Timeout = timeoutMS;
+            httpWebRequest.KeepAlive = false;
+
+            return httpWebRequest;
+        }
+
+        public static string PostToUntrustedUrl(Uri url, string data)
+        {
+            try
+            {
+                byte[] requestData = System.Text.Encoding.UTF8.GetBytes(data);
+
+                HttpWebRequest request = Create(url);
+                request.Method = "POST";
+                request.ContentLength = requestData.Length;
+                request.ContentType = "application/x-www-form-urlencoded";
+
+                using (Stream requestStream = request.GetRequestStream())
+                    requestStream.Write(requestData, 0, requestData.Length);
+
+                using (WebResponse response = request.GetResponse())
+                {
+                    using (Stream responseStream = response.GetResponseStream())
+                        return responseStream.GetStreamString();
+                }
+            }
+            catch (Exception ex)
+            {
+                m_log.Warn("POST to untrusted URL " + url + " failed: " + ex.Message);
+                return null;
+            }
+        }
+
+        public static string GetUntrustedUrl(Uri url)
+        {
+            try
+            {
+                HttpWebRequest request = Create(url);
+
+                using (WebResponse response = request.GetResponse())
+                {
+                    using (Stream responseStream = response.GetResponseStream())
+                        return responseStream.GetStreamString();
+                }
+            }
+            catch (Exception ex)
+            {
+                m_log.Warn("GET from untrusted URL " + url + " failed: " + ex.Message);
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Determines whether a URI is allowed based on scheme and host name.
+        /// No requireSSL check is done here
+        /// </summary>
+        /// <param name="allowLoopback">True to allow loopback addresses to be used</param>
+        /// <param name="uri">The URI to test for whether it should be allowed.</param>
+        /// <returns>
+        ///     <c>true</c> if [is URI allowable] [the specified URI]; otherwise, <c>false</c>.
+        /// </returns>
+        private static bool IsUriAllowable(Uri uri, bool allowLoopback)
+        {
+            if (!allowableSchemes.Contains(uri.Scheme))
+            {
+                m_log.WarnFormat("Rejecting URL {0} because it uses a disallowed scheme.", uri);
+                return false;
+            }
+
+            // Try to interpret the hostname as an IP address so we can test for internal
+            // IP address ranges.  Note that IP addresses can appear in many forms 
+            // (e.g. http://127.0.0.1, http://2130706433, http://0x0100007f, http://::1
+            // So we convert them to a canonical IPAddress instance, and test for all
+            // non-routable IP ranges: 10.*.*.*, 127.*.*.*, ::1
+            // Note that Uri.IsLoopback is very unreliable, not catching many of these variants.
+            IPAddress hostIPAddress;
+            if (IPAddress.TryParse(uri.DnsSafeHost, out hostIPAddress))
+            {
+                byte[] addressBytes = hostIPAddress.GetAddressBytes();
+
+                // The host is actually an IP address.
+                switch (hostIPAddress.AddressFamily)
+                {
+                    case System.Net.Sockets.AddressFamily.InterNetwork:
+                        if (!allowLoopback && (addressBytes[0] == 127 || addressBytes[0] == 10))
+                        {
+                            m_log.WarnFormat("Rejecting URL {0} because it is a loopback address.", uri);
+                            return false;
+                        }
+                        break;
+                    case System.Net.Sockets.AddressFamily.InterNetworkV6:
+                        if (!allowLoopback && IsIPv6Loopback(hostIPAddress))
+                        {
+                            m_log.WarnFormat("Rejecting URL {0} because it is a loopback address.", uri);
+                            return false;
+                        }
+                        break;
+                    default:
+                        m_log.WarnFormat("Rejecting URL {0} because it does not use an IPv4 or IPv6 address.", uri);
+                        return false;
+                }
+            }
+            else
+            {
+                // The host is given by name.  We require names to contain periods to
+                // help make sure it's not an internal address.
+                if (!allowLoopback && !uri.Host.Contains("."))
+                {
+                    m_log.WarnFormat("Rejecting URL {0} because it does not contain a period in the host name.", uri);
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        /// <summary>
+        /// Determines whether an IP address is the IPv6 equivalent of "localhost/127.0.0.1".
+        /// </summary>
+        /// <param name="ip">The ip address to check.</param>
+        /// <returns>
+        ///     <c>true</c> if this is a loopback IP address; <c>false</c> otherwise.
+        /// </returns>
+        private static bool IsIPv6Loopback(IPAddress ip)
+        {
+            if (ip == null)
+                throw new ArgumentNullException("ip");
+
+            byte[] addressBytes = ip.GetAddressBytes();
+            for (int i = 0; i < addressBytes.Length - 1; i++)
+            {
+                if (addressBytes[i] != 0)
+                    return false;
+            }
+
+            if (addressBytes[addressBytes.Length - 1] != 1)
+                return false;
+
+            return true;
+        }
+    }
+}
diff --git a/OpenSim/Framework/WebUtil.cs b/OpenSim/Framework/WebUtil.cs
new file mode 100644
index 0000000..d9782ff
--- /dev/null
+++ b/OpenSim/Framework/WebUtil.cs
@@ -0,0 +1,330 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.IO;
+using System.Net;
+using System.Net.Security;
+using System.Reflection;
+using System.Text;
+using System.Web;
+using log4net;
+using OpenSim.Framework.Servers.HttpServer;
+using OpenMetaverse.StructuredData;
+
+namespace OpenSim.Framework
+{
+    /// <summary>
+    /// Miscellaneous static methods and extension methods related to the web
+    /// </summary>
+    public static class WebUtil
+    {
+        private static readonly ILog m_log =
+                LogManager.GetLogger(
+                MethodBase.GetCurrentMethod().DeclaringType);
+
+        /// <summary>
+        /// Send LLSD to an HTTP client in application/llsd+json form
+        /// </summary>
+        /// <param name="response">HTTP response to send the data in</param>
+        /// <param name="body">LLSD to send to the client</param>
+        public static void SendJSONResponse(OSHttpResponse response, OSDMap body)
+        {
+            byte[] responseData = Encoding.UTF8.GetBytes(OSDParser.SerializeJsonString(body));
+
+            response.ContentEncoding = Encoding.UTF8;
+            response.ContentLength = responseData.Length;
+            response.ContentType = "application/llsd+json";
+            response.Body.Write(responseData, 0, responseData.Length);
+        }
+
+        /// <summary>
+        /// Send LLSD to an HTTP client in application/llsd+xml form
+        /// </summary>
+        /// <param name="response">HTTP response to send the data in</param>
+        /// <param name="body">LLSD to send to the client</param>
+        public static void SendXMLResponse(OSHttpResponse response, OSDMap body)
+        {
+            byte[] responseData = OSDParser.SerializeLLSDXmlBytes(body);
+
+            response.ContentEncoding = Encoding.UTF8;
+            response.ContentLength = responseData.Length;
+            response.ContentType = "application/llsd+xml";
+            response.Body.Write(responseData, 0, responseData.Length);
+        }
+
+        /// <summary>
+        /// Make a GET or GET-like request to a web service that returns LLSD
+        /// or JSON data
+        /// </summary>
+        public static OSDMap ServiceRequest(string url, string httpVerb)
+        {
+            string errorMessage;
+
+            try
+            {
+                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
+                request.Method = httpVerb;
+
+                using (WebResponse response = request.GetResponse())
+                {
+                    using (Stream responseStream = response.GetResponseStream())
+                    {
+                        try
+                        {
+                            string responseStr = responseStream.GetStreamString();
+                            OSD responseOSD = OSDParser.Deserialize(responseStr);
+                            if (responseOSD.Type == OSDType.Map)
+                                return (OSDMap)responseOSD;
+                            else
+                                errorMessage = "Response format was invalid.";
+                        }
+                        catch
+                        {
+                            errorMessage = "Failed to parse the response.";
+                        }
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                m_log.Warn("GET from URL " + url + " failed: " + ex.Message);
+                errorMessage = ex.Message;
+            }
+
+            return new OSDMap { { "Message", OSD.FromString("Service request failed. " + errorMessage) } };
+        }
+
+        /// <summary>
+        /// POST URL-encoded form data to a web service that returns LLSD or
+        /// JSON data
+        /// </summary>
+        public static OSDMap PostToService(string url, NameValueCollection data)
+        {
+            string errorMessage;
+
+            try
+            {
+                string queryString = BuildQueryString(data);
+                byte[] requestData = System.Text.Encoding.UTF8.GetBytes(queryString);
+
+                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
+                request.Method = "POST";
+                request.ContentLength = requestData.Length;
+                request.ContentType = "application/x-www-form-urlencoded";
+
+                using (Stream requestStream = request.GetRequestStream())
+                    requestStream.Write(requestData, 0, requestData.Length);
+
+                using (WebResponse response = request.GetResponse())
+                {
+                    using (Stream responseStream = response.GetResponseStream())
+                    {
+                        try
+                        {
+                            string responseStr = responseStream.GetStreamString();
+                            OSD responseOSD = OSDParser.Deserialize(responseStr);
+                            if (responseOSD.Type == OSDType.Map)
+                                return (OSDMap)responseOSD;
+                            else
+                                errorMessage = "Response format was invalid.";
+                        }
+                        catch
+                        {
+                            errorMessage = "Failed to parse the response.";
+                        }
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                m_log.Warn("POST to URL " + url + " failed: " + ex.Message);
+                errorMessage = ex.Message;
+            }
+
+            return new OSDMap { { "Message", OSD.FromString("Service request failed. " + errorMessage) } };
+        }
+
+        #region Uri
+
+        /// <summary>
+        /// Combines a Uri that can contain both a base Uri and relative path
+        /// with a second relative path fragment
+        /// </summary>
+        /// <param name="uri">Starting (base) Uri</param>
+        /// <param name="fragment">Relative path fragment to append to the end
+        /// of the Uri</param>
+        /// <returns>The combined Uri</returns>
+        /// <remarks>This is similar to the Uri constructor that takes a base
+        /// Uri and the relative path, except this method can append a relative
+        /// path fragment on to an existing relative path</remarks>
+        public static Uri Combine(this Uri uri, string fragment)
+        {
+            string fragment1 = uri.Fragment;
+            string fragment2 = fragment;
+
+            if (!fragment1.EndsWith("/"))
+                fragment1 = fragment1 + '/';
+            if (fragment2.StartsWith("/"))
+                fragment2 = fragment2.Substring(1);
+
+            return new Uri(uri, fragment1 + fragment2);
+        }
+
+        /// <summary>
+        /// Combines a Uri that can contain both a base Uri and relative path
+        /// with a second relative path fragment. If the fragment is absolute,
+        /// it will be returned without modification
+        /// </summary>
+        /// <param name="uri">Starting (base) Uri</param>
+        /// <param name="fragment">Relative path fragment to append to the end
+        /// of the Uri, or an absolute Uri to return unmodified</param>
+        /// <returns>The combined Uri</returns>
+        public static Uri Combine(this Uri uri, Uri fragment)
+        {
+            if (fragment.IsAbsoluteUri)
+                return fragment;
+
+            string fragment1 = uri.Fragment;
+            string fragment2 = fragment.ToString();
+
+            if (!fragment1.EndsWith("/"))
+                fragment1 = fragment1 + '/';
+            if (fragment2.StartsWith("/"))
+                fragment2 = fragment2.Substring(1);
+
+            return new Uri(uri, fragment1 + fragment2);
+        }
+
+        /// <summary>
+        /// Appends a query string to a Uri that may or may not have existing 
+        /// query parameters
+        /// </summary>
+        /// <param name="uri">Uri to append the query to</param>
+        /// <param name="query">Query string to append. Can either start with ?
+        /// or just containg key/value pairs</param>
+        /// <returns>String representation of the Uri with the query string
+        /// appended</returns>
+        public static string AppendQuery(this Uri uri, string query)
+        {
+            if (String.IsNullOrEmpty(query))
+                return uri.ToString();
+
+            if (query[0] == '?' || query[0] == '&')
+                query = query.Substring(1);
+
+            string uriStr = uri.ToString();
+
+            if (uriStr.Contains("?"))
+                return uriStr + '&' + query;
+            else
+                return uriStr + '?' + query;
+        }
+
+        #endregion Uri
+
+        #region NameValueCollection
+
+        /// <summary>
+        /// Convert a NameValueCollection into a query string. This is the
+        /// inverse of HttpUtility.ParseQueryString()
+        /// </summary>
+        /// <param name="parameters">Collection of key/value pairs to convert</param>
+        /// <returns>A query string with URL-escaped values</returns>
+        public static string BuildQueryString(NameValueCollection parameters)
+        {
+            List<string> items = new List<string>(parameters.Count);
+
+            foreach (string key in parameters.Keys)
+            {
+                foreach (string value in parameters.GetValues(key))
+                    items.Add(String.Concat(key, "=", HttpUtility.UrlEncode(value ?? String.Empty)));
+            }
+
+            return String.Join("&", items.ToArray());
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="collection"></param>
+        /// <param name="key"></param>
+        /// <returns></returns>
+        public static string GetOne(this NameValueCollection collection, string key)
+        {
+            string[] values = collection.GetValues(key);
+            if (values != null && values.Length > 0)
+                return values[0];
+
+            return null;
+        }
+
+        #endregion NameValueCollection
+
+        #region Stream
+
+        /// <summary>
+        /// Copies the contents of one stream to another, starting at the 
+        /// current position of each stream
+        /// </summary>
+        /// <param name="copyFrom">The stream to copy from, at the position 
+        /// where copying should begin</param>
+        /// <param name="copyTo">The stream to copy to, at the position where 
+        /// bytes should be written</param>
+        /// <param name="maximumBytesToCopy">The maximum bytes to copy</param>
+        /// <returns>The total number of bytes copied</returns>
+        /// <remarks>
+        /// Copying begins at the streams' current positions. The positions are
+        /// NOT reset after copying is complete.
+        /// </remarks>
+        public static int CopyTo(this Stream copyFrom, Stream copyTo, int maximumBytesToCopy)
+        {
+            byte[] buffer = new byte[4096];
+            int readBytes;
+            int totalCopiedBytes = 0;
+
+            while ((readBytes = copyFrom.Read(buffer, 0, Math.Min(4096, maximumBytesToCopy))) > 0)
+            {
+                int writeBytes = Math.Min(maximumBytesToCopy, readBytes);
+                copyTo.Write(buffer, 0, writeBytes);
+                totalCopiedBytes += writeBytes;
+                maximumBytesToCopy -= writeBytes;
+            }
+
+            return totalCopiedBytes;
+        }
+
+        /// <summary>
+        /// Converts an entire stream to a string, regardless of current stream
+        /// position
+        /// </summary>
+        /// <param name="stream">The stream to convert to a string</param>
+        /// <returns></returns>
+        /// <remarks>When this method is done, the stream position will be 
+        /// reset to its previous position before this method was called</remarks>
+        public static string GetStreamString(this Stream stream)
+        {
+            string value = null;
+
+            if (stream != null && stream.CanRead)
+            {
+                long rewindPos = -1;
+
+                if (stream.CanSeek)
+                {
+                    rewindPos = stream.Position;
+                    stream.Seek(0, SeekOrigin.Begin);
+                }
+
+                StreamReader reader = new StreamReader(stream);
+                value = reader.ReadToEnd();
+
+                if (rewindPos >= 0)
+                    stream.Seek(rewindPos, SeekOrigin.Begin);
+            }
+
+            return value;
+        }
+
+        #endregion Stream
+    }
+}