/// <summary>
/// Sign a public key.
/// </summary>
/// <remarks>
/// <para>Signs a public key using the specified secret key.</para>
/// <para>Most OpenPGP implementations use <see cref="OpenPgpKeyCertification.GenericCertification"/>
/// to make their "key signatures". Some implementations are known to use the other
/// certification types, but few differentiate between them.</para>
/// </remarks>
/// <param name="secretKey">The secret key to use for signing.</param>
/// <param name="publicKey">The public key to sign.</param>
/// <param name="digestAlgo">The digest algorithm.</param>
/// <param name="certification">The certification to give the signed key.</param>
/// <exception cref="System.ArgumentNullException">
/// <para><paramref name="secretKey"/> is <c>null</c>.</para>
/// <para>-or-</para>
/// <para><paramref name="publicKey"/> is <c>null</c>.</para>
/// </exception>
public void SignKey(PgpSecretKey secretKey, PgpPublicKey publicKey, DigestAlgorithm digestAlgo = DigestAlgorithm.Sha1, OpenPgpKeyCertification certification = OpenPgpKeyCertification.GenericCertification)
{
if (secretKey == null)
{
throw new ArgumentNullException(nameof(secretKey));
}
if (publicKey == null)
{
throw new ArgumentNullException(nameof(publicKey));
}
var privateKey = GetPrivateKey(secretKey);
var signatureGenerator = new PgpSignatureGenerator(secretKey.PublicKey.Algorithm, GetHashAlgorithm(digestAlgo));
signatureGenerator.InitSign((int)certification, privateKey);
signatureGenerator.GenerateOnePassVersion(false);
var subpacketGenerator = new PgpSignatureSubpacketGenerator();
var subpacketVector = subpacketGenerator.Generate();
signatureGenerator.SetHashedSubpackets(subpacketVector);
var signedKey = PgpPublicKey.AddCertification(publicKey, signatureGenerator.Generate());
PgpPublicKeyRing keyring = null;
foreach (var ring in EnumeratePublicKeyRings())
{
foreach (PgpPublicKey key in ring.GetPublicKeys())
{
if (key.KeyId == publicKey.KeyId)
{
PublicKeyRingBundle = PgpPublicKeyRingBundle.RemovePublicKeyRing(PublicKeyRingBundle, ring);
keyring = PgpPublicKeyRing.InsertPublicKey(ring, signedKey);
break;
}
}
}
if (keyring == null)
{
keyring = new PgpPublicKeyRing(signedKey.GetEncoded());
}
Import(keyring);
}
