/// <summary>
/// Initializes a new instance of the <see cref="RsaCertificate"/> class
/// for a signed certificate. This constructor is intended to be used
/// when creating a new certificate from within an application.
/// </summary>
/// <param name="parameters">The cryptographic RSA parameters. Be sure not to
/// include any private parameters.</param>
/// <param name="embeddedData">The embedded data or null if none.</param>
/// <param name="signCertificateCallback">The callback method to be invoked after
/// the hash value was calculated from the cryptographic RSA parameters in order
/// to get the signature determined from that hash value.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="signature"/> is null.</exception>
public RsaCertificate(RSAParameters parameters, IEnumerable <byte> embeddedData,
Func <IHash, RsaSignature> signCertificateCallback)
{
if (signCertificateCallback == null)
{
throw new ArgumentNullException(nameof(signCertificateCallback));
}
this.parameters = parameters;
this.EmbeddedData = embeddedData?.ToArray();
// Compute preliminary hash which does not include a signature.
this.Hash = Helpers.ComputeRsaHash(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: embeddedData);
this.Signature = signCertificateCallback.Invoke(this.Hash);
// Re-compute hash which now includes the signature.
this.HashWithSignature = Helpers.ComputeRsaHashWithSignature(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: embeddedData,
signature: this.Signature);
}
/// <summary>
/// Signs a certificate by its hash value.
/// </summary>
/// <param name="certificate">The certificate to sign.</param>
/// <returns>The signed certificate.</returns>
/// <exception cref="ArgumentNullException">Thrown if
/// <paramref name="certificate"/> is null.</exception>
public RsaCertificate Sign(RsaCertificate certificate)
{
if (certificate == null)
{
throw new ArgumentNullException(nameof(certificate));
}
// Create copy of RSA cryptographic parameters before creating the certificate
// with these data to avoid manipulation of references of cryptographic parameters
// via reflection or such.
var rsaParameters = certificate.CreateRsa().ExportParameters(false);
// Replace certificate by one with the same cryptographic RSA parameters
// but no signature.
var unsignedCertificate = new RsaCertificate(rsaParameters);
var signature = new RsaSignature(
signerCertificateHash: this.DeriveCertificate().Hash,
signature: this.rsa.SignHash(
unsignedCertificate.Hash.Hash.ToArray(),
unsignedCertificate.Hash.Name,
RSASignaturePadding.Pkcs1));
var signedCertificate = new RsaCertificate(rsaParameters, this.EmbeddedData, signature);
return(signedCertificate);
}
/// <summary>
/// Initializes a new instance of the <see cref="RsaKey"/> class.
/// </summary>
/// <param name="parameters">The cryptographic RSA parameters.</param>
/// <param name="signature">The cryptographic RSA signature.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="signature"/> is null.</exception>
public RsaKey(RSAParameters parameters, RsaSignature signature)
{
this.parameters = parameters;
this.signature = signature ?? throw new ArgumentNullException(nameof(signature));
this.Hash = Helpers.ComputeRsaHash(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: null);
this.rsa = this.CreateRsa();
}
/// <summary>
/// Initializes a new instance of the <see cref="RsaKey"/> class.
/// </summary>
/// <param name="parameters">The cryptographic RSA parameters.</param>
/// <param name="embeddedData">The embedded data or null if none.</param>
/// <param name="signature">The cryptographic RSA signature.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="signature"/> is null.</exception>
public RsaKey(RSAParameters parameters, IEnumerable <byte> embeddedData,
RsaSignature signature)
{
this.parameters = parameters;
this.EmbeddedData = embeddedData?.ToArray();
this.signature = signature ?? throw new ArgumentNullException(nameof(signature));
this.Hash = Helpers.ComputeRsaHash(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: embeddedData);
this.rsa = this.CreateRsa();
}
/// <summary>
/// Initializes a new instance of the <see cref="RsaCertificate"/> class
/// for a signed certificate. This constructor is intended to be used
/// when loading an existing certificate from a file or the like.
/// </summary>
/// <param name="parameters">The cryptographic RSA parameters. Be sure not to
/// include any private parameters.</param>
/// <param name="signature">The RSA signature.</param>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="signature"/> is null.</exception>
public RsaCertificate(RSAParameters parameters, RsaSignature signature)
{
this.parameters = parameters;
this.Signature = signature ?? throw new ArgumentNullException(nameof(signature));
this.Hash = Helpers.ComputeRsaHash(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: null);
this.HashWithSignature = Helpers.ComputeRsaHashWithSignature(
rsaParameters: parameters,
includePrivateParameters: false,
embeddedData: null,
signature: this.Signature);
}
/// <summary>
/// Computes the hash of certain parameters used in RSA certificates and keys.
/// </summary>
/// <param name="rsaParameters">The cryptographic RSA parameters.</param>
/// <param name="includePrivateParameters">true to include cryptographic RSA private parameters,
/// false to include only public ones.</param>
/// <param name="embeddedData">The embedded data to consider for computing
/// the hash.</param>
/// <param name="signature">The cryptographic RSA signature.</param>
/// <returns>The hash.</returns>
public static IHash ComputeRsaHashWithSignature(RSAParameters rsaParameters, bool includePrivateParameters,
IEnumerable <byte> embeddedData, RsaSignature signature)
{
using (var stream = new MemoryStream())
{
var data = new List <byte[]>();
data.Add(rsaParameters.Exponent);
data.Add(rsaParameters.Modulus);
if (includePrivateParameters)
{
data.Add(new byte[] { 0x01 });
data.Add(rsaParameters.D);
data.Add(rsaParameters.DP);
data.Add(rsaParameters.DQ);
data.Add(rsaParameters.InverseQ);
data.Add(rsaParameters.P);
data.Add(rsaParameters.Q);
}
else
{
data.Add(new byte[] { 0x00 });
}
if (embeddedData != null)
{
data.Add(new byte[] { 0x01 });
data.Add(Sha512Hash.Compute(embeddedData.ToArray()).Hash.ToArray());
}
else
{
data.Add(new byte[] { 0x00 });
}
if (signature != null)
{
data.Add(new byte[] { 0x01 });
data.Add(signature.Hash.Hash.ToArray());
}
else
{
data.Add(new byte[] { 0x00 });
}
int i = 0;
foreach (var d in data)
{
var iBytes = BitConverter.GetBytes(i);
if (!BitConverter.IsLittleEndian)
{
iBytes = iBytes.Reverse().ToArray();
}
stream.Write(iBytes, 0, iBytes.Length);
var info = d;
if (!BitConverter.IsLittleEndian)
{
info = info.Reverse().ToArray();
}
stream.Write(info, 0, info.Length);
}
stream.Position = 0;
return(Sha512Hash.Compute(stream));
}
}
