[Breaking] Drop support for RSA PKCS#1 PEM keys in favor of the OpenSSH format.

README.md

@@ -521,12 +521,9 @@ class SshConnectionClosedException : SshConnectionException
 
 This section lists the currently supported algorithms. If you would like support for other algorithms, you can request it with an issue in the repository. If the requested algorithm is considered insecure by current practice, it is unlikely to be added.
 
-Supported private key formats:
-- RSA in `RSA PRIVATE KEY`
-- RSA, ECDSA, ED25519 in `OPENSSH PRIVATE KEY` (`openssh-key-v1`)
-
-Supported private key encryption cyphers:
-- OpenSSH Keys `OPENSSH PRIVATE KEY` (`openssh-key-v1`)
+Supported private key formats*:
+- RSA, ECDSA, ED25519 in `OPENSSH PRIVATE KEY` (`openssh-key-v1`) with encryption:
+  - none
   - aes[128|192|256]-[cbc|ctr]
   - aes[128|256]-gcm@openssh.com
   - chacha20-poly1305@openssh.com
@@ -569,6 +566,8 @@ Authentications:
 - gssapi-with-mic (`KerberosCredential`)
 - none (`NoCredential`)
 
+*: Please convert your keys (using `ssh-keygen`, `PuttyGen`, ...) to a supported format rather than suggesting the library should support an additional format. If you can motivate why the library should support a additional format, open an issue to request support.
+
 ## Design
 
 * Since SSH is a network protocol, the APIs are asynchronous and implemented using C# `async` and .NET's `Task`/`ValueTask`.

src/Tmds.Ssh/PrivateKeyParser.cs

@@ -73,8 +73,6 @@ internal static PrivateKey ParsePrivateKey(ReadOnlyMemory<char> rawKey, Func<str
 
         switch (keyFormat)
         {
-            case "-----BEGIN RSA PRIVATE KEY-----":
-                return ParseRsaPkcs1PemKey(keyData, metadata);
             case "-----BEGIN OPENSSH PRIVATE KEY-----":
                 return ParseOpenSshKey(keyData, passwordPrompt);
             default:

test/Tmds.Ssh.Tests/PrivateKeyCredentialTests.cs

@@ -73,32 +73,6 @@ public async Task CtorWithRawKey()
         Assert.NotNull(privateKey);
     }
 
-    [Fact]
-    public async Task Pkcs1RsaKey()
-    {
-        await RunWithKeyConversion(_sshServer.TestUserIdentityFile, async (string localKey) =>
-        {
-            await EncryptSshKey(localKey, "PEM", null, null);
-            return new PrivateKeyCredential(localKey);
-        }, async (c) => await c.ConnectAsync());
-    }
-
-    [Fact]
-    public async Task FailPkcs1EncryptedRsaKey()
-    {
-        await RunWithKeyConversion(_sshServer.TestUserIdentityFile, async (string localKey) =>
-        {
-            await EncryptSshKey(localKey, "PEM", null, null);
-            await RunBinary("openssl", "pkey", "-in", localKey, "-inform", "PEM", "-out", $"{localKey}.rsa", "-traditional", "-aes256", "-passout", $"pass:{TestPassword}");
-            File.Move($"{localKey}.rsa", localKey, overwrite: true);
-            return new PrivateKeyCredential(localKey, TestPassword);
-        }, async (SshClient client) =>
-        {
-            var exc = await Assert.ThrowsAnyAsync<ConnectFailedException>(() => client.ConnectAsync());
-            Assert.IsType<PrivateKeyLoadException>(exc.InnerException);
-        });
-    }
-
     [Theory]
     [InlineData(null)]
     [InlineData("aes128-cbc")]