Add support for OpenSSL PKCS#8 private key format

README.md

@@ -96,19 +96,36 @@ The main types provided by this library are:
 ## Public Key Authentication
 
 **SSH.NET** supports the following private key formats:
-* RSA in OpenSSL PEM ("BEGIN RSA PRIVATE KEY") and ssh.com ("BEGIN SSH2 ENCRYPTED PRIVATE KEY") format
-* DSA in OpenSSL PEM ("BEGIN DSA PRIVATE KEY") and ssh.com ("BEGIN SSH2 ENCRYPTED PRIVATE KEY") format
-* ECDSA 256/384/521 in OpenSSL PEM format ("BEGIN EC PRIVATE KEY")
-* ECDSA 256/384/521, ED25519 and RSA in OpenSSH key format ("BEGIN OPENSSH PRIVATE KEY")
-
-Private keys in OpenSSL PEM and ssh.com format can be encrypted using one of the following cipher methods:
+* RSA in
+  * OpenSSL traditional PEM format ("BEGIN RSA PRIVATE KEY")
+  * OpenSSL PKCS#8 PEM format ("BEGIN PRIVATE KEY", "BEGIN ENCRYPTED PRIVATE KEY")
+  * ssh.com format ("BEGIN SSH2 ENCRYPTED PRIVATE KEY")
+  * OpenSSH key format ("BEGIN OPENSSH PRIVATE KEY")
+* DSA in
+  * OpenSSL traditional PEM format ("BEGIN DSA PRIVATE KEY")
+  * OpenSSL PKCS#8 PEM format ("BEGIN PRIVATE KEY", "BEGIN ENCRYPTED PRIVATE KEY")
+  * ssh.com format ("BEGIN SSH2 ENCRYPTED PRIVATE KEY")
+* ECDSA 256/384/521 in
+  * OpenSSL traditional PEM format ("BEGIN EC PRIVATE KEY")
+  * OpenSSL PKCS#8 PEM format ("BEGIN PRIVATE KEY", "BEGIN ENCRYPTED PRIVATE KEY")
+  * OpenSSH key format ("BEGIN OPENSSH PRIVATE KEY")
+* ED25519 in
+  * OpenSSL PKCS#8 PEM format ("BEGIN PRIVATE KEY", "BEGIN ENCRYPTED PRIVATE KEY")
+  * OpenSSH key format ("BEGIN OPENSSH PRIVATE KEY")
+
+Private keys in OpenSSL traditional PEM format can be encrypted using one of the following cipher methods:
 * DES-EDE3-CBC
 * DES-EDE3-CFB
 * DES-CBC
 * AES-128-CBC
 * AES-192-CBC
 * AES-256-CBC
 
+Private keys in OpenSSL PKCS#8 PEM format can be encrypted using any cipher method BouncyCastle supports.
+
+Private keys in ssh.com format can be encrypted using one of the following cipher methods:
+* 3des-cbc
+
 Private keys in OpenSSH key format can be encrypted using one of the following cipher methods:
 * 3des-cbc
 * aes128-cbc

src/Renci.SshNet/PrivateKeyConnectionInfo.cs

@@ -22,7 +22,7 @@ public class PrivateKeyConnectionInfo : ConnectionInfo, IDisposable
         /// <param name="host">Connection host.</param>
         /// <param name="username">Connection username.</param>
         /// <param name="keyFiles">Connection key files.</param>
-        public PrivateKeyConnectionInfo(string host, string username, params PrivateKeyFile[] keyFiles)
+        public PrivateKeyConnectionInfo(string host, string username, params IPrivateKeySource[] keyFiles)
             : this(host, DefaultPort, username, ProxyTypes.None, string.Empty, 0, string.Empty, string.Empty, keyFiles)
         {
         }

src/Renci.SshNet/PrivateKeyFile.cs

@@ -1,15 +1,21 @@
-#nullable enable
+#nullable enable
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Formats.Asn1;
 using System.Globalization;
 using System.IO;
 using System.Numerics;
 using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
 
+using Org.BouncyCastle.Asn1.EdEC;
+using Org.BouncyCastle.Asn1.Pkcs;
+using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Pkcs;
+
 using Renci.SshNet.Common;
 using Renci.SshNet.Security;
 using Renci.SshNet.Security.Cryptography;
@@ -36,12 +42,12 @@ namespace Renci.SshNet
     ///         <description>ECDSA 256/384/521 in OpenSSL PEM and OpenSSH key format</description>
     ///     </item>
     ///     <item>
-    ///         <description>ED25519 in OpenSSH key format</description>
+    ///         <description>ED25519 in OpenSSL PEM and OpenSSH key format</description>
     ///     </item>
     /// </list>
     /// </para>
     /// <para>
-    /// The following encryption algorithms are supported for OpenSSL PEM and ssh.com format:
+    /// The following encryption algorithms are supported for OpenSSL traditional PEM:
     /// <list type="bullet">
     ///     <item>
     ///         <description>DES-EDE3-CBC</description>
@@ -62,6 +68,19 @@ namespace Renci.SshNet
     ///         <description>AES-256-CBC</description>
     ///     </item>
     /// </list>
+    /// </para>
+    /// <para>
+    /// Private keys in OpenSSL PKCS#8 PEM format can be encrypted using any cipher method BouncyCastle supports.
+    /// </para>
+    /// <para>
+    /// The following encryption algorithms are supported for ssh.com format:
+    /// <list type="bullet">
+    ///     <item>
+    ///         <description>3des-cbc</description>
+    ///     </item>
+    /// </list>
+    /// </para>
+    /// <para>
     /// The following encryption algorithms are supported for OpenSSH format:
     /// <list type="bullet">
     ///     <item>
@@ -99,7 +118,7 @@ namespace Renci.SshNet
     /// </remarks>
     public partial class PrivateKeyFile : IPrivateKeySource, IDisposable
     {
-        private const string PrivateKeyPattern = @"^-+ *BEGIN (?<keyName>\w+( \w+)*) PRIVATE KEY *-+\r?\n((Proc-Type: 4,ENCRYPTED\r?\nDEK-Info: (?<cipherName>[A-Z0-9-]+),(?<salt>[A-F0-9]+)\r?\n\r?\n)|(Comment: ""?[^\r\n]*""?\r?\n))?(?<data>([a-zA-Z0-9/+=]{1,80}\r?\n)+)(\r?\n)?-+ *END \k<keyName> PRIVATE KEY *-+";
+        private const string PrivateKeyPattern = @"^-+ *BEGIN (?<keyName>\w+( \w+)*) *-+\r?\n((Proc-Type: 4,ENCRYPTED\r?\nDEK-Info: (?<cipherName>[A-Z0-9-]+),(?<salt>[A-F0-9]+)\r?\n\r?\n)|(Comment: ""?[^\r\n]*""?\r?\n))?(?<data>([a-zA-Z0-9/+=]{1,80}\r?\n)+)(\r?\n)?-+ *END \k<keyName> *-+";
 
 #if NET7_0_OR_GREATER
         private static readonly Regex PrivateKeyRegex = GetPrivateKeyRegex();
@@ -233,6 +252,11 @@ private void Open(Stream privateKey, string? passPhrase)
             }
 
             var keyName = privateKeyMatch.Result("${keyName}");
+            if (!keyName.EndsWith("PRIVATE KEY", StringComparison.Ordinal))
+            {
+                throw new SshException("Invalid private key file.");
+            }
+
             var cipherName = privateKeyMatch.Result("${cipherName}");
             var salt = privateKeyMatch.Result("${salt}");
             var data = privateKeyMatch.Result("${data}");
@@ -288,7 +312,7 @@ private void Open(Stream privateKey, string? passPhrase)
 
             switch (keyName)
             {
-                case "RSA":
+                case "RSA PRIVATE KEY":
                     var rsaKey = new RsaKey(decryptedData);
                     _key = rsaKey;
                     _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-rsa", _key));
@@ -297,16 +321,17 @@ private void Open(Stream privateKey, string? passPhrase)
                     _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-256", _key, new RsaDigitalSignature(rsaKey, HashAlgorithmName.SHA256)));
 #pragma warning restore CA2000 // Dispose objects before losing scope
                     break;
-                case "DSA":
+                case "DSA PRIVATE KEY":
                     _key = new DsaKey(decryptedData);
                     _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-dss", _key));
                     break;
-                case "EC":
+                case "EC PRIVATE KEY":
                     _key = new EcdsaKey(decryptedData);
                     _hostAlgorithms.Add(new KeyHostAlgorithm(_key.ToString(), _key));
                     break;
-                case "OPENSSH":
-                    _key = ParseOpenSshV1Key(decryptedData, passPhrase);
+                case "PRIVATE KEY":
+                    var privateKeyInfo = PrivateKeyInfo.GetInstance(binaryData);
+                    _key = ParseOpenSslPkcs8PrivateKey(privateKeyInfo);
                     if (_key is RsaKey parsedRsaKey)
                     {
                         _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-rsa", _key));
@@ -315,13 +340,55 @@ private void Open(Stream privateKey, string? passPhrase)
                         _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-256", _key, new RsaDigitalSignature(parsedRsaKey, HashAlgorithmName.SHA256)));
 #pragma warning restore CA2000 // Dispose objects before losing scope
                     }
+                    else if (_key is DsaKey parsedDsaKey)
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-dss", _key));
+                    }
                     else
                     {
                         _hostAlgorithms.Add(new KeyHostAlgorithm(_key.ToString(), _key));
                     }
 
                     break;
-                case "SSH2 ENCRYPTED":
+                case "ENCRYPTED PRIVATE KEY":
+                    var encryptedPrivateKeyInfo = EncryptedPrivateKeyInfo.GetInstance(binaryData);
+                    privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(passPhrase?.ToCharArray(), encryptedPrivateKeyInfo);
+                    _key = ParseOpenSslPkcs8PrivateKey(privateKeyInfo);
+                    if (_key is RsaKey parsedRsaKey2)
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-rsa", _key));
+#pragma warning disable CA2000 // Dispose objects before losing scope
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-512", _key, new RsaDigitalSignature(parsedRsaKey2, HashAlgorithmName.SHA512)));
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-256", _key, new RsaDigitalSignature(parsedRsaKey2, HashAlgorithmName.SHA256)));
+#pragma warning restore CA2000 // Dispose objects before losing scope
+                    }
+                    else if (_key is DsaKey parsedDsaKey)
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-dss", _key));
+                    }
+                    else
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm(_key.ToString(), _key));
+                    }
+
+                    break;
+                case "OPENSSH PRIVATE KEY":
+                    _key = ParseOpenSshV1Key(decryptedData, passPhrase);
+                    if (_key is RsaKey parsedRsaKey3)
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("ssh-rsa", _key));
+#pragma warning disable CA2000 // Dispose objects before losing scope
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-512", _key, new RsaDigitalSignature(parsedRsaKey3, HashAlgorithmName.SHA512)));
+                        _hostAlgorithms.Add(new KeyHostAlgorithm("rsa-sha2-256", _key, new RsaDigitalSignature(parsedRsaKey3, HashAlgorithmName.SHA256)));
+#pragma warning restore CA2000 // Dispose objects before losing scope
+                    }
+                    else
+                    {
+                        _hostAlgorithms.Add(new KeyHostAlgorithm(_key.ToString(), _key));
+                    }
+
+                    break;
+                case "SSH2 ENCRYPTED PRIVATE KEY":
                     var reader = new SshDataReader(decryptedData);
                     var magicNumber = reader.ReadUInt32();
                     if (magicNumber != 0x3f6ff9eb)
@@ -488,8 +555,8 @@ private static byte[] DecryptKey(CipherInfo cipherInfo, byte[] cipherData, strin
         }
 
         /// <summary>
-        /// Parses an OpenSSH V1 key file (i.e. ED25519 key) according to the the key spec:
-        /// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key.
+        /// Parses an OpenSSH V1 key file according to the key spec:
+        /// <see href="https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key"/>.
         /// </summary>
         /// <param name="keyFileData">The key file data (i.e. base64 encoded data between the header/footer).</param>
         /// <param name="passPhrase">Passphrase or <see langword="null"/> if there isn't one.</param>
@@ -712,6 +779,81 @@ private static Key ParseOpenSshV1Key(byte[] keyFileData, string? passPhrase)
             return parsedKey;
         }
 
+        /// <summary>
+        /// Parses an OpenSSL PKCS#8 key file according to RFC5208:
+        /// <see href="https://www.rfc-editor.org/rfc/rfc5208#section-5"/>.
+        /// </summary>
+        /// <param name="privateKeyInfo">The <see cref="PrivateKeyInfo"/>.</param>
+        /// <returns>
+        /// The <see cref="Key"/>.
+        /// </returns>
+        /// <exception cref="SshException">Algorithm not supported.</exception>
+        private static Key ParseOpenSslPkcs8PrivateKey(PrivateKeyInfo privateKeyInfo)
+        {
+            var algorithmOid = privateKeyInfo.PrivateKeyAlgorithm.Algorithm;
+            var key = privateKeyInfo.PrivateKey.GetOctets();
+            if (algorithmOid.Equals(PkcsObjectIdentifiers.RsaEncryption))
+            {
+                return new RsaKey(key);
+            }
+
+            if (algorithmOid.Equals(X9ObjectIdentifiers.IdDsa))
+            {
+                var parameters = privateKeyInfo.PrivateKeyAlgorithm.Parameters.GetDerEncoded();
+                var parametersReader = new AsnReader(parameters, AsnEncodingRules.BER);
+                var sequenceReader = parametersReader.ReadSequence();
+                parametersReader.ThrowIfNotEmpty();
+
+                var p = sequenceReader.ReadInteger();
+                var q = sequenceReader.ReadInteger();
+                var g = sequenceReader.ReadInteger();
+                sequenceReader.ThrowIfNotEmpty();
+
+                var keyReader = new AsnReader(key, AsnEncodingRules.BER);
+                var x = keyReader.ReadInteger();
+                keyReader.ThrowIfNotEmpty();
+
+                var y = BigInteger.ModPow(g, x, p);
+
+                return new DsaKey(p, q, g, y, x);
+            }
+
+            if (algorithmOid.Equals(X9ObjectIdentifiers.IdECPublicKey))
+            {
+                var parameters = privateKeyInfo.PrivateKeyAlgorithm.Parameters.GetDerEncoded();
+                var parametersReader = new AsnReader(parameters, AsnEncodingRules.DER);
+                var curve = parametersReader.ReadObjectIdentifier();
+                parametersReader.ThrowIfNotEmpty();
+
+                var privateKeyReader = new AsnReader(key, AsnEncodingRules.DER);
+                var sequenceReader = privateKeyReader.ReadSequence();
+                privateKeyReader.ThrowIfNotEmpty();
+
+                var version = sequenceReader.ReadInteger();
+                if (version != BigInteger.One)
+                {
+                    throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, "EC version '{0}' is not supported.", version));
+                }
+
+                var privatekey = sequenceReader.ReadOctetString();
+
+                var publicKeyReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1, isConstructed: true));
+                var publickey = publicKeyReader.ReadBitString(out _);
+                publicKeyReader.ThrowIfNotEmpty();
+
+                sequenceReader.ThrowIfNotEmpty();
+
+                return new EcdsaKey(curve, publickey, privatekey.TrimLeadingZeros());
+            }
+
+            if (algorithmOid.Equals(EdECObjectIdentifiers.id_Ed25519))
+            {
+                return new ED25519Key(key);
+            }
+
+            throw new SshException(string.Format(CultureInfo.InvariantCulture, "Private key algorithm \"{0}\" is not supported.", algorithmOid));
+        }
+
         /// <summary>
         /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
         /// </summary>

src/Renci.SshNet/Security/Cryptography/EcdsaKey.cs

@@ -204,7 +204,7 @@ public EcdsaKey(SshKeyData publicKeyData)
         /// <summary>
         /// Initializes a new instance of the <see cref="EcdsaKey"/> class.
         /// </summary>
-        /// <param name="curve">The curve name.</param>
+        /// <param name="curve">The curve name or oid.</param>
         /// <param name="publickey">Value of publickey.</param>
         /// <param name="privatekey">Value of privatekey.</param>
         public EcdsaKey(string curve, byte[] publickey, byte[] privatekey)
@@ -266,24 +266,27 @@ private static Impl Import(string curve_oid, byte[] publickey, byte[]? privateke
 #endif
         }
 
-        private static string GetCurveOid(string curve_s)
+        private static string GetCurveOid(string curve)
         {
-            if (string.Equals(curve_s, "nistp256", StringComparison.OrdinalIgnoreCase))
+            if (string.Equals(curve, "nistp256", StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(curve, ECDSA_P256_OID_VALUE))
             {
                 return ECDSA_P256_OID_VALUE;
             }
 
-            if (string.Equals(curve_s, "nistp384", StringComparison.OrdinalIgnoreCase))
+            if (string.Equals(curve, "nistp384", StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(curve, ECDSA_P384_OID_VALUE))
             {
                 return ECDSA_P384_OID_VALUE;
             }
 
-            if (string.Equals(curve_s, "nistp521", StringComparison.OrdinalIgnoreCase))
+            if (string.Equals(curve, "nistp521", StringComparison.OrdinalIgnoreCase) ||
+                string.Equals(curve, ECDSA_P521_OID_VALUE))
             {
                 return ECDSA_P521_OID_VALUE;
             }
 
-            throw new SshException("Unexpected Curve Name: " + curve_s);
+            throw new SshException("Unexpected Curve: " + curve);
         }
 
         /// <summary>

test/Data/Key.DSA.PKCS8.Encrypted.Aes.256.CBC.12345.txt

@@ -0,0 +1,12 @@
+-----BEGIN ENCRYPTED PRIVATE KEY-----
+MIIBrTBXBgkqhkiG9w0BBQ0wSjApBgkqhkiG9w0BBQwwHAQIjn9BgD9X0loCAggA
+MAwGCCqGSIb3DQIJBQAwHQYJYIZIAWUDBAEqBBB3Zthr23nQDulzKryFEUTFBIIB
+UDW8/IR0K5DRScH4Cl7HOoK20aR+TmUOGczE027RL++iosgk5rYUpIKn0pxIKM0U
+StFGTqLz3G+bEh/Bm2Vt03Qv0Q2QZoX2e1Vktt32X2cLBNzGWfEpLuCD4vG8QDRW
+uGkE1NHxJKQTJWQt/gwGituyhMThGoE3ZcuqeLmRlhUSgRccO6WJ2HkNOW7TM5RB
+QbeBXmYB1H5S3FjpRAvd2p9dEzDsyquQaltFM4kekIxGjwiw5WSd+KsCGXFLa2Y2
+OXvcjRIIqGBJr+xvEVA86TNTfad+sKGqGUFszRmnGXA+VxEZju2OCpVhxTLEMX4Q
+2vYz9i8jE78tpx7C6PTKoJe5FTdlTatvWvYD5cvcbazPUjuZbraI9ha4XvNtERGC
+J0voz/7yeuNkW1ofxTUOu+snGhySC4AXkC44eZG4wUPfuQAswP8dFiQi2BthgVyP
+kA==
+-----END ENCRYPTED PRIVATE KEY-----

test/Data/Key.DSA.PKCS8.txt

@@ -0,0 +1,9 @@
+-----BEGIN PRIVATE KEY-----
+MIIBSgIBADCCASsGByqGSM44BAEwggEeAoGBALVl3fae2O4qwsAK95SUShX0KMUN
+P+yl/uT3lGH9T/ZptnHSlrTxnTWXCl0g91KEeCaEnDDhLxm4aCv1Ag4B/yvcM4u3
+4qkmaNLy2LiAxiqdobZcNG61Pqwqd5IDkp38LBsn8tmb12xu9NalpUfOiSEB1cyC
+r4zFZMrm0wtdyJQVAhUArvojZKn/2DgGI2Kx0ghxZlgHxGECgYAOVJ434UAR3Hn6
+lA5nWNfFOuUVH3W7nJaP0FQJiIPx7GUbdxO9qtDNTbWkWL3c9qx5+B7Ole4xM7cv
+yXPrNQUYDHCFlS+Ue2x3IeJrkdfZkH9ePP25y5A0J4/c+8XXvQaj4zA5nfw13oy5
+Ptyd7d3Kq5tEDM8KiVdIhwkXjUA3PQQWAhQYRjs5PgIpnqG/euBPPh7EDZcnXg==
+-----END PRIVATE KEY-----

test/Data/Key.ECDSA.PKCS8.Encrypted.Aes.256.CBC.12345.txt

@@ -0,0 +1,7 @@
+-----BEGIN ENCRYPTED PRIVATE KEY-----
+MIHsMFcGCSqGSIb3DQEFDTBKMCkGCSqGSIb3DQEFDDAcBAithDR1n5wCYQICCAAw
+DAYIKoZIhvcNAgkFADAdBglghkgBZQMEASoEEMSzAQ3FSZ5hQHbmb7K9aB0EgZCS
+RVfVmMp1SBllrUMvdMEz5Zwvthaa1/M3Mc6MEVEzgROEXY3X+ywECU9q18aIOct+
+m5bmFcRcwoxo/hj6fsnmeH567KRfnN4Al219azq5ccwTr68y8tasYsZHOFCkn3ve
+Hkzu0+gylHZGWqo5TWif9O9DrII/KszsoX86jJxhORwqCnxMmKQQ/gGvexpAYJA=
+-----END ENCRYPTED PRIVATE KEY-----

test/Data/Key.ECDSA.PKCS8.txt

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgR2poUqAkEiJtWPJS
+HW/tjfkvAhAmuhx1NpgUvCXuIHShRANCAARAPkw7+f3KpINOzPDNWkCkvHlJAV5w
+Tll8OSDGpV0dB5ybUEA+jNnh4oY2EqfvaFPv2YuWn0ddf6g0Ry5VPzcf
+-----END PRIVATE KEY-----

test/Data/Key.OPENSSH.ED25519.PKCS8.Encrypted.Aes.256.CBC.12345.txt

@@ -0,0 +1,6 @@
+-----BEGIN ENCRYPTED PRIVATE KEY-----
+MIGbMFcGCSqGSIb3DQEFDTBKMCkGCSqGSIb3DQEFDDAcBAhiAnoQd2VMZwICCAAw
+DAYIKoZIhvcNAgkFADAdBglghkgBZQMEASoEENed/l3AFuDblxDnswMZXDcEQIpo
+fCVdEbDerN0Rrh9i+Ymu+qpEqGlc6jycwR3rPtyL9jy0k5kauBxRn3Z5uCSlGzJL
+JXxlMR+DWG6QDJdxrHI=
+-----END ENCRYPTED PRIVATE KEY-----