Add an OrderedDictionary implementation for algorithm priorities

src/Renci.SshNet/Common/Extensions.cs

@@ -358,5 +358,30 @@ internal static string Join(this IEnumerable<string> values, string separator)
             // which is not available on all targets.
             return string.Join(separator, values);
         }
+
+#if NETFRAMEWORK || NETSTANDARD2_0
+        internal static bool TryAdd<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key, TValue value)
+        {
+            if (!dictionary.ContainsKey(key))
+            {
+                dictionary.Add(key, value);
+                return true;
+            }
+
+            return false;
+        }
+
+        internal static bool Remove<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key, out TValue value)
+        {
+            if (dictionary.TryGetValue(key, out value))
+            {
+                _ = dictionary.Remove(key);
+                return true;
+            }
+
+            value = default;
+            return false;
+        }
+#endif
     }
 }

src/Renci.SshNet/ConnectionInfo.cs

@@ -50,42 +50,40 @@ public class ConnectionInfo : IConnectionInfoInternal
         /// <summary>
         /// Gets supported key exchange algorithms for this connection.
         /// </summary>
-        public IDictionary<string, Func<IKeyExchange>> KeyExchangeAlgorithms { get; private set; }
+        public IOrderedDictionary<string, Func<IKeyExchange>> KeyExchangeAlgorithms { get; }
 
         /// <summary>
         /// Gets supported encryptions for this connection.
         /// </summary>
-#pragma warning disable CA1859 // Use concrete types when possible for improved performance
-        public IDictionary<string, CipherInfo> Encryptions { get; private set; }
-#pragma warning restore CA1859 // Use concrete types when possible for improved performance
+        public IOrderedDictionary<string, CipherInfo> Encryptions { get; }
 
         /// <summary>
         /// Gets supported hash algorithms for this connection.
         /// </summary>
-        public IDictionary<string, HashInfo> HmacAlgorithms { get; private set; }
+        public IOrderedDictionary<string, HashInfo> HmacAlgorithms { get; }
 
         /// <summary>
         /// Gets supported host key algorithms for this connection.
         /// </summary>
-        public IDictionary<string, Func<byte[], KeyHostAlgorithm>> HostKeyAlgorithms { get; private set; }
+        public IOrderedDictionary<string, Func<byte[], KeyHostAlgorithm>> HostKeyAlgorithms { get; }
 
         /// <summary>
         /// Gets supported authentication methods for this connection.
         /// </summary>
-        public IList<AuthenticationMethod> AuthenticationMethods { get; private set; }
+        public IList<AuthenticationMethod> AuthenticationMethods { get; }
 
         /// <summary>
         /// Gets supported compression algorithms for this connection.
         /// </summary>
-        public IDictionary<string, Func<Compressor>> CompressionAlgorithms { get; private set; }
+        public IOrderedDictionary<string, Func<Compressor>> CompressionAlgorithms { get; }
 
         /// <summary>
         /// Gets the supported channel requests for this connection.
         /// </summary>
         /// <value>
         /// The supported channel requests for this connection.
         /// </value>
-        public IDictionary<string, RequestInfo> ChannelRequests { get; private set; }
+        public IDictionary<string, RequestInfo> ChannelRequests { get; }
 
         /// <summary>
         /// Gets a value indicating whether connection is authenticated.
@@ -101,48 +99,48 @@ public class ConnectionInfo : IConnectionInfoInternal
         /// <value>
         /// The connection host.
         /// </value>
-        public string Host { get; private set; }
+        public string Host { get; }
 
         /// <summary>
         /// Gets connection port.
         /// </summary>
         /// <value>
         /// The connection port. The default value is 22.
         /// </value>
-        public int Port { get; private set; }
+        public int Port { get; }
 
         /// <summary>
         /// Gets connection username.
         /// </summary>
-        public string Username { get; private set; }
+        public string Username { get; }
 
         /// <summary>
         /// Gets proxy type.
         /// </summary>
         /// <value>
         /// The type of the proxy.
         /// </value>
-        public ProxyTypes ProxyType { get; private set; }
+        public ProxyTypes ProxyType { get; }
 
         /// <summary>
         /// Gets proxy connection host.
         /// </summary>
-        public string ProxyHost { get; private set; }
+        public string ProxyHost { get; }
 
         /// <summary>
         /// Gets proxy connection port.
         /// </summary>
-        public int ProxyPort { get; private set; }
+        public int ProxyPort { get; }
 
         /// <summary>
         /// Gets proxy connection username.
         /// </summary>
-        public string ProxyUsername { get; private set; }
+        public string ProxyUsername { get; }
 
         /// <summary>
         /// Gets proxy connection password.
         /// </summary>
-        public string ProxyPassword { get; private set; }
+        public string ProxyPassword { get; }
 
         /// <summary>
         /// Gets or sets connection timeout.
@@ -347,7 +345,7 @@ public ConnectionInfo(string host, int port, string username, ProxyTypes proxyTy
             MaxSessions = 10;
             Encoding = Encoding.UTF8;
 
-            KeyExchangeAlgorithms = new Dictionary<string, Func<IKeyExchange>>
+            KeyExchangeAlgorithms = new OrderedDictionary<string, Func<IKeyExchange>>
                 {
                     { "mlkem768x25519-sha256", () => new KeyExchangeMLKem768X25519Sha256() },
                     { "sntrup761x25519-sha512", () => new KeyExchangeSNtruP761X25519Sha512() },
@@ -365,7 +363,7 @@ public ConnectionInfo(string host, int port, string username, ProxyTypes proxyTy
                     { "diffie-hellman-group1-sha1", () => new KeyExchangeDiffieHellmanGroup1Sha1() },
                 };
 
-            Encryptions = new Dictionary<string, CipherInfo>
+            Encryptions = new OrderedDictionary<string, CipherInfo>
                 {
                     { "aes128-ctr", new CipherInfo(128, (key, iv) => new AesCipher(key, iv, AesCipherMode.CTR, pkcs7Padding: false)) },
                     { "aes192-ctr", new CipherInfo(192, (key, iv) => new AesCipher(key, iv, AesCipherMode.CTR, pkcs7Padding: false)) },
@@ -379,7 +377,7 @@ public ConnectionInfo(string host, int port, string username, ProxyTypes proxyTy
                     { "3des-cbc", new CipherInfo(192, (key, iv) => new TripleDesCipher(key, iv, CipherMode.CBC, pkcs7Padding: false)) },
                 };
 
-            HmacAlgorithms = new Dictionary<string, HashInfo>
+            HmacAlgorithms = new OrderedDictionary<string, HashInfo>
                 {
                     /* Encrypt-and-MAC (encrypt-and-authenticate) variants */
                     { "hmac-sha2-256", new HashInfo(32*8, key => new HMACSHA256(key)) },
@@ -392,7 +390,7 @@ public ConnectionInfo(string host, int port, string username, ProxyTypes proxyTy
                 };
 
 #pragma warning disable SA1107 // Code should not contain multiple statements on one line
-            var hostAlgs = new Dictionary<string, Func<byte[], KeyHostAlgorithm>>();
+            var hostAlgs = new OrderedDictionary<string, Func<byte[], KeyHostAlgorithm>>();
             hostAlgs.Add("[email protected]", data => { var cert = new Certificate(data); return new CertificateHostAlgorithm("[email protected]", cert, hostAlgs); });
             hostAlgs.Add("[email protected]", data => { var cert = new Certificate(data); return new CertificateHostAlgorithm("[email protected]", cert, hostAlgs); });
             hostAlgs.Add("[email protected]", data => { var cert = new Certificate(data); return new CertificateHostAlgorithm("[email protected]", cert, hostAlgs); });
@@ -411,7 +409,7 @@ public ConnectionInfo(string host, int port, string username, ProxyTypes proxyTy
 #pragma warning restore SA1107 // Code should not contain multiple statements on one line
             HostKeyAlgorithms = hostAlgs;
 
-            CompressionAlgorithms = new Dictionary<string, Func<Compressor>>
+            CompressionAlgorithms = new OrderedDictionary<string, Func<Compressor>>
                 {
                     { "none", null },
                     { "[email protected]", () => new ZlibOpenSsh() },

src/Renci.SshNet/IOrderedDictionary`2.cs

@@ -0,0 +1,149 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Renci.SshNet
+{
+    /// <summary>
+    /// Represents a collection of key/value pairs that are accessible by the key or index.
+    /// </summary>
+    /// <typeparam name="TKey">The type of the keys in the dictionary.</typeparam>
+    /// <typeparam name="TValue">The type of the values in the dictionary.</typeparam>
+    public interface IOrderedDictionary<TKey, TValue> :
+        IDictionary<TKey, TValue>, IReadOnlyDictionary<TKey, TValue>
+        where TKey : notnull
+    {
+        // Some members are redefined with 'new' to resolve ambiguities.
+
+        /// <summary>Gets or sets the value associated with the specified key.</summary>
+        /// <param name="key">The key of the value to get or set.</param>
+        /// <returns>The value associated with the specified key. If the specified key is not found, a get operation throws a <see cref="KeyNotFoundException"/>, and a set operation creates a new element with the specified key.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        /// <exception cref="KeyNotFoundException">The property is retrieved and <paramref name="key"/> does not exist in the collection.</exception>
+        /// <remarks>Setting the value of an existing key does not impact its order in the collection.</remarks>
+        new TValue this[TKey key] { get; set; }
+
+        /// <summary>Gets a collection containing the keys in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</summary>
+        new ICollection<TKey> Keys { get; }
+
+        /// <summary>Gets a collection containing the values in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</summary>
+        new ICollection<TValue> Values { get; }
+
+        /// <summary>Gets the number of key/value pairs contained in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</summary>
+        new int Count { get; }
+
+        /// <summary>Determines whether the <see cref="IOrderedDictionary{TKey, TValue}"/> contains the specified key.</summary>
+        /// <param name="key">The key to locate in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</param>
+        /// <returns><see langword="true"/> if the <see cref="IOrderedDictionary{TKey, TValue}"/> contains an element with the specified key; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        new bool ContainsKey(TKey key);
+
+        /// <summary>Determines whether the <see cref="IOrderedDictionary{TKey, TValue}"/> contains a specific value.</summary>
+        /// <param name="value">The value to locate in the <see cref="IOrderedDictionary{TKey, TValue}"/>. The value can be null for reference types.</param>
+        /// <returns><see langword="true"/> if the <see cref="IOrderedDictionary{TKey, TValue}"/> contains an element with the specified value; otherwise, <see langword="false"/>.</returns>
+        bool ContainsValue(TValue value);
+
+        /// <summary>Gets the key/value pair at the specified index.</summary>
+        /// <param name="index">The zero-based index of the pair to get.</param>
+        /// <returns>The element at the specified index.</returns>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is less than 0 or greater than or equal to <see cref="Count"/>.</exception>
+        KeyValuePair<TKey, TValue> GetAt(int index);
+
+        /// <summary>Determines the index of a specific key in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</summary>
+        /// <param name="key">The key to locate.</param>
+        /// <returns>The index of <paramref name="key"/> if found; otherwise, -1.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        int IndexOf(TKey key);
+
+        /// <summary>Inserts an item into the collection at the specified index.</summary>
+        /// <param name="index">The zero-based index at which item should be inserted.</param>
+        /// <param name="key">The key to insert.</param>
+        /// <param name="value">The value to insert.</param>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        /// <exception cref="ArgumentException">An element with the same key already exists in the <see cref="IOrderedDictionary{TKey, TValue}"/>.</exception>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is less than 0 or greater than <see cref="Count"/>.</exception>
+        void Insert(int index, TKey key, TValue value);
+
+        /// <summary>Removes the value with the specified key from the <see cref="IOrderedDictionary{TKey, TValue}"/> and copies the element to the value parameter.</summary>
+        /// <param name="key">The key of the element to remove.</param>
+        /// <param name="value">The removed element.</param>
+        /// <returns><see langword="true"/> if the element is successfully found and removed; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        bool Remove(TKey key, [MaybeNullWhen(false)] out TValue value);
+
+        /// <summary>Removes the key/value pair at the specified index.</summary>
+        /// <param name="index">The zero-based index of the item to remove.</param>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is less than 0 or greater than or equal to <see cref="Count"/>.</exception>
+        void RemoveAt(int index);
+
+        /// <summary>Sets the key/value pair at the specified index.</summary>
+        /// <param name="index">The zero-based index at which to set the key/value pair.</param>
+        /// <param name="key">The key to store at the specified index.</param>
+        /// <param name="value">The value to store at the specified index.</param>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        /// <exception cref="ArgumentException">An element with the same key already exists at an index different to <paramref name="index"/>.</exception>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is less than 0 or greater than or equal to <see cref="Count"/>.</exception>
+        void SetAt(int index, TKey key, TValue value);
+
+        /// <summary>Sets the value for the key at the specified index.</summary>
+        /// <param name="index">The zero-based index at which to set the key/value pair.</param>
+        /// <param name="value">The value to store at the specified index.</param>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="index"/> is less than 0 or greater than or equal to <see cref="Count"/>.</exception>
+        void SetAt(int index, TValue value);
+
+        /// <summary>
+        /// Moves an existing key/value pair to the specified index in the collection.
+        /// </summary>
+        /// <param name="index">The current zero-based index of the key/value pair to move.</param>
+        /// <param name="newIndex">The zero-based index at which to set the key/value pair.</param>
+        /// <exception cref="ArgumentOutOfRangeException">
+        /// <paramref name="index"/> or <paramref name="newIndex"/> are less than 0 or greater than or equal to <see cref="Count"/>.
+        /// </exception>
+        void SetPosition(int index, int newIndex);
+
+        /// <summary>
+        /// Moves an existing key/value pair to the specified index in the collection.
+        /// </summary>
+        /// <param name="key">The key to move.</param>
+        /// <param name="newIndex">The zero-based index at which to set the key/value pair.</param>
+        /// <exception cref="KeyNotFoundException">The specified key does not exist in the collection.</exception>
+        /// <exception cref="ArgumentOutOfRangeException"><paramref name="newIndex"/> is less than 0 or greater than or equal to <see cref="Count"/>.</exception>
+        void SetPosition(TKey key, int newIndex);
+
+        /// <summary>Adds the specified key and value to the dictionary if the key doesn't already exist.</summary>
+        /// <param name="key">The key of the element to add.</param>
+        /// <param name="value">The value of the element to add. The value can be <see langword="null"/> for reference types.</param>
+        /// <returns><see langword="true"/> if the key didn't exist and the key and value were added to the dictionary; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        bool TryAdd(TKey key, TValue value);
+
+        /// <summary>Adds the specified key and value to the dictionary if the key doesn't already exist.</summary>
+        /// <param name="key">The key of the element to add.</param>
+        /// <param name="value">The value of the element to add. The value can be <see langword="null"/> for reference types.</param>
+        /// <param name="index">The index of the added or existing <paramref name="key"/>. This is always a valid index into the dictionary.</param>
+        /// <returns><see langword="true"/> if the key didn't exist and the key and value were added to the dictionary; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        bool TryAdd(TKey key, TValue value, out int index);
+
+        /// <summary>Gets the value associated with the specified key.</summary>
+        /// <param name="key">The key of the value to get.</param>
+        /// <param name="value">
+        /// When this method returns, contains the value associated with the specified key, if the key is found;
+        /// otherwise, the default value for the type of the value parameter.
+        /// </param>
+        /// <returns><see langword="true"/> if the <see cref="IOrderedDictionary{TKey, TValue}"/> contains an element with the specified key; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        new bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value);
+
+        /// <summary>Gets the value associated with the specified key.</summary>
+        /// <param name="key">The key of the value to get.</param>
+        /// <param name="value">
+        /// When this method returns, contains the value associated with the specified key, if the key is found;
+        /// otherwise, the default value for the type of the value parameter.
+        /// </param>
+        /// <param name="index">The index of <paramref name="key"/> if found; otherwise, -1.</param>
+        /// <returns><see langword="true"/> if the <see cref="IOrderedDictionary{TKey, TValue}"/> contains an element with the specified key; otherwise, <see langword="false"/>.</returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is <see langword="null"/>.</exception>
+        bool TryGetValue(TKey key, [MaybeNullWhen(false)] out TValue value, out int index);
+    }
+}