Ability to set user credentials from strings(s)

src/NATS.Client/ConnectionFactory.cs

@@ -104,6 +104,44 @@ public IConnection CreateConnection(string url, string jwt, string privateNkey,
             opts.SetUserCredentials(jwt, privateNkey);
             return CreateConnection(opts, reconnectOnConnect);
         }
+
+        /// <summary>
+        /// Attempt to connect to the NATS server referenced by <paramref name="url"/>
+        /// with NATS 2.0 the user jwt and nkey seed credentials provided directly in the string.
+        /// </summary>
+        /// <param name="url"></param>
+        /// <param name="credentialsText">The text containing the "-----BEGIN NATS USER JWT-----" block
+        /// and the text containing the "-----BEGIN USER NKEY SEED-----" block</param>
+        /// <param name="reconnectOnConnect"></param>
+        /// <returns></returns>
+        public IConnection CreateConnectionWithCredentials(string url, string credentialsText, bool reconnectOnConnect = false)
+        {
+            Options opts = GetDefaultOptions(url);
+            opts.SetUserCredentialsFromString(credentialsText);
+            return CreateConnection(opts, reconnectOnConnect);
+        }
+
+        /// <summary>
+        /// Attempt to connect to the NATS server referenced by <paramref name="url"/>
+        /// with NATS 2.0 the user jwt and nkey seed credentials provided directly via strings.
+        /// </summary>
+        /// <remarks>
+        /// <para><paramref name="url"/>
+        /// Comma seperated arrays are also supported, e.g. <c>&quot;urlA, urlB&quot;</c>.</para>
+        /// </remarks>
+        /// <param name="url">A string containing the URL (or URLs) to the NATS Server. See the Remarks
+        /// section for more information.</param>
+        /// <param name="userJwtText">The text containing the "-----BEGIN NATS USER JWT-----" block</param>
+        /// <param name="nkeySeedText">The text containing the "-----BEGIN USER NKEY SEED-----" block or the seed begining with "SU".
+        /// May be the same as the jwt string if they are chained.</param>
+        /// <param name="reconnectOnConnect"></param>
+        /// <returns></returns>
+        public IConnection CreateConnectionWithCredentials(string url, string userJwtText, string nkeySeedText, bool reconnectOnConnect = false)
+        {
+            Options opts = GetDefaultOptions(url);
+            opts.SetUserCredentialsFromStrings(userJwtText, nkeySeedText);
+            return CreateConnection(opts, reconnectOnConnect);
+        }
 
         /// <summary>
         /// Retrieves the default set of client options.

src/NATS.Client/DefaultUserJWTHandler.cs

@@ -12,6 +12,7 @@
 // limitations under the License.
 
 using System.IO;
+using System.Security;
 
 namespace NATS.Client
 {
@@ -56,33 +57,19 @@ public DefaultUserJWTHandler(string jwtFilePath, string credsFilePath)
         /// <returns>The encoded JWT</returns>
         public static string LoadUserFromFile(string path)
         {
-            string text = null;
-            string line = null;
-            StringReader reader = null;
-            try
+            string text = File.ReadAllText(path).Trim();
+            if (string.IsNullOrEmpty(text))
             {
-                text = File.ReadAllText(path).Trim();
-                if (string.IsNullOrEmpty(text)) throw new NATSException("Credentials file is empty");
-
-                reader = new StringReader(text);
-                for (line = reader.ReadLine(); line != null; line = reader.ReadLine())
-                {
-                    if (line.Contains("-----BEGIN NATS USER JWT-----"))
-                    {
-                        return reader.ReadLine();
-                    }
-                    Nkeys.Wipe(line);
-                }
-                throw new NATSException("Credentials file does not contain a JWT");
+                throw new NATSException("Credentials file is empty");
             }
-            finally
+            string user = JWTHandlerUtils.LoadUser(text);
+            if (user == null)
             {
-                Nkeys.Wipe(text);
-                Nkeys.Wipe(line);
-                reader?.Dispose();
+                throw new NATSException("Credentials file does not contain a JWT");
             }
+            return user;
         }
-
+        
         /// <summary>
         /// Generates a NATS Ed25519 keypair, used to sign server nonces, from a 
         /// private credentials file.
@@ -91,47 +78,23 @@ public static string LoadUserFromFile(string path)
         /// <returns>A NATS Ed25519 KeyPair</returns>
         public static NkeyPair LoadNkeyPairFromSeedFile(string path)
         {
-            NkeyPair kp = null;
-            string text = null;
-            string line = null;
-            string seed = null;
             StringReader reader = null;
-
             try
             {
-                text = File.ReadAllText(path).Trim();
-                if (string.IsNullOrEmpty(text)) throw new NATSException("Credentials file is empty");
-
-                // if it's a nk file, it only has the nkey
-                if (text.StartsWith("SU"))
+                string text = File.ReadAllText(path).Trim();
+                if (string.IsNullOrEmpty(text))
                 {
-                    kp = Nkeys.FromSeed(text);
-                    return kp;
+                    throw new NATSException("Credentials file is empty");
                 }
-
-                // otherwise assume it's a creds file.
-                reader = new StringReader(text);
-                for (line = reader.ReadLine(); line != null; line = reader.ReadLine())
-                {
-                    if (line.Contains("-----BEGIN USER NKEY SEED-----"))
-                    {
-                        seed = reader.ReadLine();
-                        kp = Nkeys.FromSeed(seed);
-                        Nkeys.Wipe(seed);
-                    }
-                    Nkeys.Wipe(line);
-                }
-
+                NkeyPair kp = JWTHandlerUtils.LoadNkeyPair(text);
                 if (kp == null)
+                {
                     throw new NATSException("Seed not found in credentials file.");
-                else
-                    return kp;
+                }
+                return kp;
             }
             finally
             {
-                Nkeys.Wipe(line);
-                Nkeys.Wipe(text);
-                Nkeys.Wipe(seed);
                 reader?.Dispose();
             }
         }

src/NATS.Client/JWTHandlerUtils.cs

@@ -0,0 +1,72 @@
+// Copyright 2019-2024 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.IO;
+using System.Security;
+
+namespace NATS.Client
+{
+    public class JWTHandlerUtils
+    {
+        public static string LoadUser(string text)
+        {
+            StringReader reader = null;
+            try
+            {
+                reader = new StringReader(text);
+                for (string line = reader.ReadLine(); line != null; line = reader.ReadLine())
+                {
+                    if (line.Contains("-----BEGIN NATS USER JWT-----"))
+                    {
+                        return reader.ReadLine();
+                    }
+                }
+
+                return null;
+            }
+            finally
+            {
+                reader?.Dispose();
+            }
+        }
+
+        public static NkeyPair LoadNkeyPair(string nkeySeed)
+        {
+            StringReader reader = null;
+            try
+            {
+                // if it's a nk file, it only has the nkey
+                if (nkeySeed.StartsWith("SU"))
+                {
+                    return Nkeys.FromSeed(nkeySeed);
+                }
+
+                // otherwise assume it's a creds file.
+                reader = new StringReader(nkeySeed);
+                for (string line = reader.ReadLine(); line != null; line = reader.ReadLine())
+                {
+                    if (line.Contains("-----BEGIN USER NKEY SEED-----"))
+                    {
+                        return Nkeys.FromSeed(reader.ReadLine());
+                    }
+                }
+
+                return null;
+            }
+            finally
+            {
+                reader?.Dispose();
+            }
+        }
+    }
+}

src/NATS.Client/NKeys.cs

@@ -283,9 +283,10 @@ public static void Wipe(ref byte[] src)
         /// <param name="src">string to wipe</param>
         public static void Wipe(string src)
         {
-            // best effort to wipe.
-            if (src != null && src.Length > 0)
-                src.Remove(0);
+            // This code commented out b/c string.remove does not touch the original string.
+            // There is not way to really wipe the contents of a string.
+            // if (src != null && src.Length > 0)
+                // src.Remove(0);
         }
 
         internal static byte[] DecodeSeed(byte[] raw)

src/NATS.Client/Options.cs

@@ -173,6 +173,31 @@ public void SetUserCredentials(string credentialsPath, string privateKeyPath)
             UserSignatureEventHandler = handler.DefaultUserSignatureHandler;
         }
 
+        /// <summary>
+        /// Sets user credentials from text instead of a file using the NATS 2.0 security scheme.
+        /// </summary>
+        /// <param name="credentialsText">The text containing the "-----BEGIN NATS USER JWT-----" block
+        /// and the text containing the "-----BEGIN USER NKEY SEED-----" block</param>
+        public void SetUserCredentialsFromString(string credentialsText)
+        {
+            var handler = new StringUserJWTHandler(credentialsText, credentialsText);
+            UserJWTEventHandler = handler.DefaultUserJWTEventHandler;
+            UserSignatureEventHandler = handler.DefaultUserSignatureHandler;
+        }
+
+        /// <summary>
+        /// Sets user credentials from text instead of a file using the NATS 2.0 security scheme.
+        /// </summary>
+        /// <param name="userJwtText">The text containing the "-----BEGIN NATS USER JWT-----" block</param>
+        /// <param name="nkeySeedText">The text containing the "-----BEGIN USER NKEY SEED-----" block or the seed begining with "SU".
+        /// May be the same as the jwt string if they are chained.</param>
+        public void SetUserCredentialsFromStrings(string userJwtText, string nkeySeedText)
+        {
+            var handler = new StringUserJWTHandler(userJwtText, nkeySeedText);
+            UserJWTEventHandler = handler.DefaultUserJWTEventHandler;
+            UserSignatureEventHandler = handler.DefaultUserSignatureHandler;
+        }
+
         /// <summary>
         /// Sets user credentials using the NATS 2.0 security scheme.
         /// </summary>

src/NATS.Client/StringUserJWTHandler.cs

@@ -0,0 +1,93 @@
+// Copyright 2024 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.IO;
+using System.Security;
+
+namespace NATS.Client
+{
+    /// <summary>
+    /// TODO
+    /// </summary>
+    public class StringUserJWTHandler
+    {
+        /// <summary>
+        /// Gets the JWT file.
+        /// </summary>
+        public string UserJwt { get; }
+
+        /// <summary>
+        /// Gets the credentials files.
+        /// </summary>
+        public string NkeySeed { get; }
+
+        /// <summary>
+        /// Creates a static user jwt handler.
+        /// </summary>
+        /// <param name="credentialsText">The text containing the "-----BEGIN NATS USER JWT-----" block
+        /// and the text containing the "-----BEGIN USER NKEY SEED-----" block</param>
+        public StringUserJWTHandler(string credentialsText) : this(credentialsText, credentialsText) {}
+
+        /// <summary>
+        /// Creates a static user jwt handler.
+        /// </summary>
+        /// <param name="userJwt">The text containing the "-----BEGIN NATS USER JWT-----" block</param>
+        /// <param name="nkeySeed">The text containing the "-----BEGIN USER NKEY SEED-----" block or the seed begining with "SU".
+        /// May be the same as the jwt string if they are chained.</param>
+        public StringUserJWTHandler(string userJwt, string nkeySeed)
+        {
+            UserJwt = JWTHandlerUtils.LoadUser(userJwt);
+            if (UserJwt == null)
+            {
+                throw new NATSException("Credentials do not contain a JWT");
+            }
+
+            if (JWTHandlerUtils.LoadNkeyPair(nkeySeed) == null)
+            {
+                throw new NATSException("Seed not found.");
+            }
+            NkeySeed = nkeySeed;
+        }
+
+        /// <summary>
+        /// The default User JWT Event Handler.
+        /// </summary>
+        /// <param name="sender">Usually the connection.</param>
+        /// <param name="args">Arguments</param>
+        public void DefaultUserJWTEventHandler(object sender, UserJWTEventArgs args)
+        {
+            args.JWT = UserJwt;
+        }
+
+        /// <summary>
+        /// Utility method to signs the UserSignatureEventArgs server nonce from 
+        /// a private credentials file.
+        /// </summary>
+        /// <param name="args">Arguments</param>
+        public void SignNonce(UserSignatureEventArgs args)
+        {
+            // you have to load this every time b/c signing actually wipes data
+            args.SignedNonce = JWTHandlerUtils.LoadNkeyPair(NkeySeed).Sign(args.ServerNonce);
+        }
+
+        /// <summary>
+        /// The default User Signature event handler.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="args"></param>
+        public void DefaultUserSignatureHandler(object sender, UserSignatureEventArgs args)
+        {
+            SignNonce(args);
+        }
+    }
+}

src/Tests/IntegrationTests/IntegrationTests.csproj

@@ -103,6 +103,15 @@
     <None Update="config\tls_first.conf">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>
+    <None Update="config\certs\test.creds.nkey-seed-block.txt">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+    <None Update="config\certs\test.creds.nkey-seed-only.txt">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+    <None Update="config\certs\test.creds.user-block.txt">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 
 </Project>