C＃生成用于SSH身份验证的Ed25519私钥和公钥对

Question

我需要使用C＃在ssh隧道中生成用于认证的密钥对。唯一的约束是应为Ed25519的密码。我能够生成有效的公钥，但not生成有效的私钥（或者可能只是格式）。我已经尝试过使用BouncyCastle和NSec库生成它们，但均未成功。

这是我的一些尝试：

#### NSec ####
var creationParameters = new KeyCreationParameters
{
    ExportPolicy = KeyExportPolicies.AllowPlaintextArchiving
};
using (var key = Key.Create(SignatureAlgorithm.Ed25519, creationParameters))
{
    var blob = key.Export(KeyBlobFormat.PkixPrivateKeyText);
    result.PrivateKey = Convert.ToBase64String(blob);

    blob = key.Export(KeyBlobFormat.PkixPublicKeyText);
    result.PublicKey = string.Format("ssh-ed25519 {0} generated-key", Convert.ToBase64String(blob));
}


#### BouncyCastle ####
IAsymmetricCipherKeyPairGenerator gen;
KeyGenerationParameters param;
gen = new Ed25519KeyPairGenerator();
param = new Ed25519KeyGenerationParameters(new SecureRandom());
gen.Init(param);
AsymmetricCipherKeyPair pair = gen.GenerateKeyPair();
PrivateKeyInfo pkInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(pair.Private);
result.PrivateKey = Convert.ToBase64String(pkInfo.GetDerEncoded());
SubjectPublicKeyInfo info = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pair.Public);
result.PublicKey = Convert.ToBase64String(info.GetDerEncoded());

更具体地说，我希望从cmd获得类似以下结果的结果：

ssh-keygen -t ed25519 -f ssh-ed25519-private-key.pem

生成公共密钥，如：

ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICjTBKzEKElOtmjuYDaBsoF9UpsXUeLUmKuqiK86jv2A xxxxxx\xxxxxxx@xxxx

和私人喜欢：

-----BEGIN OPENSSH PRIVATE KEY-----
b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
QyNTUxOQAAACAo0wSsxChJTrZo7mA2gbKBfVKbF1Hi1JirqoivOo79gAAAAKgLape6C2qX
ugAAAAtzc2gtZWQyNTUxOQAAACAo0wSsxChJTrZo7mA2gbKBfVKbF1Hi1JirqoivOo79gA
AAAECRX7SDurbmPZzRMqYwONep7gk4ZCFp1Uj6hTpVbGWi0CjTBKzEKElOtmjuYDaBsoF9
UpsXUeLUmKuqiK86jv2AAAAAJWNnLWNvbnRyb2xzLXJkXGFtZW5lZ2F0QFcwNTItQU1lbm
VnYXQ=
-----END OPENSSH PRIVATE KEY-----

谢谢，安德里亚

Answer 1

我能够生成有效的公共密钥，但不能生成有效的私有密钥（或者可能仅是格式）。

这没有道理。

公钥实际上是大小为y^2 = x^3 + 486662*x^2 + x的有限域上由57896044618658097711785492504343953926634992332820282019728792003956564819949定义的椭圆曲线上的point（X，Y坐标）

只能通过生成器点G (9 , 14781619447589544791020593568409986887264606134616475288964881837755586237401)的标量乘法来获得公钥>

大量。因此，私钥实际上只是一个256位整数，一个数字。

以最原始的形式，私钥是256位随机值，上面的OpenSSH格式是base64编码的值，包括其他组件，例如：

"openssh-key-v1"0x00    # NULL-terminated "Auth Magic" string
32-bit length, "none"   # ciphername length and string
32-bit length, "none"   # kdfname length and string
32-bit length, nil      # kdf (0 length, no kdf)
32-bit 0x01             # number of keys, hard-coded to 1 (no length)
32-bit length, sshpub   # public key in ssh format
    32-bit length, keytype
    32-bit length, pub0
    32-bit length, pub1
32-bit length for rnd+prv+comment+pad
    64-bit dummy checksum?  # a random 32-bit int, repeated
    32-bit length, keytype  # the private key (including public)
    32-bit length, pub0     # Public Key parts
    32-bit length, pub1
    32-bit length, prv0     # Private Key parts
    ...                     # (number varies by type)
    32-bit length, comment  # comment string
    padding bytes 0x010203  # pad to blocksize
[我强烈建议您将switch设置为libsodium，这是与curve25519交互的标准，或者是[Twisted Edwards]签名重点变体ed25519。