/// <summary>
/// Writes the core.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="value">The value.</param>
protected override void WriteCore(Stream stream, RSAParameters value)
{
Requires.NotNull(stream, nameof(stream));
using var sequence = new MemoryStream();
if (KeyFormatter.HasPrivateKey(value))
{
// Only include the version element if this is a private key.
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, new byte[1]));
}
// Take care to always prepend a zero when an integer starts with a leading bit of 1,
// since the ASN.1 spec is that integers are encoded as two's complement, and these integers
// are always intended to be interpreted as positive.
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.Modulus !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.Exponent !)));
if (KeyFormatter.HasPrivateKey(value))
{
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.D !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.P !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.Q !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.DP !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.DQ !)));
sequence.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, PrependLeadingZero(value.InverseQ !)));
}
stream.WriteAsn1Element(new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Constructed, Asn.BerTag.Sequence, sequence.ToArray()));
}
/// <summary>
/// Reads a key from the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <returns>
/// The RSA Parameters of the key.
/// </returns>
/// <exception cref="System.ArgumentException">
/// Unexpected format.
/// or
/// Unexpected format.
/// or
/// Unexpected algorithm.
/// or
/// Unexpected format.
/// </exception>
protected override RSAParameters ReadCore(Stream stream)
{
var sequence = stream.ReadAsn1Elements().First();
if (sequence.Class != Asn.BerClass.Universal || sequence.PC != Asn.BerPC.Constructed || sequence.Tag != Asn.BerTag.Sequence)
{
throw new ArgumentException("Unexpected format.");
}
var elements = Asn.ReadAsn1Elements(sequence.Content).ToList();
if (elements.Count != 2 || elements[0].Class != Asn.BerClass.Universal || elements[0].PC != Asn.BerPC.Constructed || elements[0].Tag != Asn.BerTag.Sequence)
{
throw new ArgumentException("Unexpected format.");
}
var oid = Asn.ReadAsn1Elements(elements[0].Content).First();
if (!KeyFormatter.BufferEqual(Pkcs1KeyFormatter.RsaEncryptionObjectIdentifier, oid.Content))
{
throw new ArgumentException("Unexpected algorithm.");
}
if (elements[1].Class != Asn.BerClass.Universal || elements[1].PC != Asn.BerPC.Primitive || elements[1].Tag != Asn.BerTag.BitString || elements[1].Content[0] != 0)
{
throw new ArgumentException("Unexpected format.");
}
byte[] rsaPublicKey = TrimLeadingZero(elements[1].Content);
return(KeyFormatter.PublicKeyFilter(KeyFormatter.Pkcs1.Read(rsaPublicKey)));
}
/// <summary>
/// Reads a key from the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <returns>
/// The RSA Parameters of the key.
/// </returns>
protected override RSAParameters ReadCore(Stream stream)
{
var universalConstructedSequence = stream.ReadAsn1Elements().Single();
var sequence = Asn.ReadAsn1Elements(universalConstructedSequence.Content).ToList();
KeyFormatter.VerifyFormat(sequence[0].Content.Length == 1 && sequence[0].Content[0] == 0x00, Strings.UnrecognizedVersion);
Asn.DataElement oid = Asn.ReadAsn1Elements(sequence[1].Content).First();
KeyFormatter.VerifyFormat(X509SubjectPublicKeyInfoFormatter.BufferEqual(oid.Content, Pkcs1KeyFormatter.RsaEncryptionObjectIdentifier), Strings.UnrecognizedObjectIdentifier);
return(KeyFormatter.Pkcs1.Read(sequence[2].Content));
}
/// <summary>
/// Writes a key to the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="parameters">The RSA parameters of the key.</param>
protected override void WriteCore(Stream stream, RSAParameters parameters)
{
var rootElement = new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
new Asn.DataElement( // Version 0
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.Integer,
new byte[] { 0x00 }),
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
new Asn.DataElement( // privateKeyAlgorithm
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.ObjectIdentifier,
Pkcs1KeyFormatter.RsaEncryptionObjectIdentifier),
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.Null,
new byte[0])),
new Asn.DataElement( // rsaPrivateKey
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.OctetString,
KeyFormatter.Pkcs1PrependZeros.Write(parameters, HasPrivateKey(parameters))),
new Asn.DataElement(
Asn.BerClass.ContextSpecific,
Asn.BerPC.Constructed,
Asn.BerTag.EndOfContent,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.ObjectIdentifier,
new byte[] { 0x55, 0x1d, 0x0f }),
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.SetAndSetOf,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.BitString,
new byte[] { 0x00, 0x10 })))));
Asn.WriteAsn1Element(stream, rootElement);
}
/// <summary>
/// Writes a key to the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <param name="parameters">The RSA parameters of the key.</param>
protected override void WriteCore(Stream stream, RSAParameters parameters)
{
var version0 = new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.Integer, new byte[] { 0x00 });
var privateKeyAlgorithm = new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.ObjectIdentifier, RsaEncryptionObjectIdentifier);
var rsaPrivateKey = new Asn.DataElement(Asn.BerClass.Universal, Asn.BerPC.Primitive, Asn.BerTag.OctetString, Pkcs1.Write(parameters, HasPrivateKey(parameters)));
var rootElement = new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
version0,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
privateKeyAlgorithm,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.Null,
Array.Empty <byte>())),
rsaPrivateKey,
new Asn.DataElement(
Asn.BerClass.ContextSpecific,
Asn.BerPC.Constructed,
Asn.BerTag.EndOfContent,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.Sequence,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.ObjectIdentifier,
new byte[] { 0x55, 0x1d, 0x0f }),
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Constructed,
Asn.BerTag.SetAndSetOf,
new Asn.DataElement(
Asn.BerClass.Universal,
Asn.BerPC.Primitive,
Asn.BerTag.BitString,
new byte[] { 0x00, 0x10 })))));
Asn.WriteAsn1Element(stream, rootElement);
}
/// <summary>
/// Reads a key from the specified stream.
/// </summary>
/// <param name="stream">The stream.</param>
/// <returns>
/// The RSA Parameters of the key.
/// </returns>
protected override RSAParameters ReadCore(Stream stream)
{
var keyBlobElement = Asn.ReadAsn1Elements(stream).First();
KeyFormatter.VerifyFormat(
keyBlobElement.Class == Asn.BerClass.Universal &&
keyBlobElement.PC == Asn.BerPC.Constructed &&
keyBlobElement.Tag == Asn.BerTag.Sequence);
stream = new MemoryStream(keyBlobElement.Content);
var sequence = Asn.ReadAsn1Elements(stream).ToList();
switch (sequence.Count)
{
case 2:
return(new RSAParameters
{
Modulus = sequence[0].Content,
Exponent = sequence[1].Content,
});
case 9:
KeyFormatter.VerifyFormat(sequence[0].Content.Length == 1 && sequence[0].Content[0] == 0, "Unsupported version.");
return(new RSAParameters
{
Modulus = sequence[1].Content,
Exponent = sequence[2].Content,
D = sequence[3].Content,
P = sequence[4].Content,
Q = sequence[5].Content,
DP = sequence[6].Content,
DQ = sequence[7].Content,
InverseQ = sequence[8].Content,
});
default:
throw KeyFormatter.FailFormat();
}
}
/// <summary>
/// Initializes a new instance of the <see cref="DataElement"/> struct.
/// </summary>
/// <param name="class">The class.</param>
/// <param name="pc">The PC.</param>
/// <param name="tag">The tag.</param>
/// <param name="nestedElements">The content.</param>
public DataElement(BerClass @class, BerPC pc, BerTag tag, params DataElement[] nestedElements)
: this(@class, pc, tag, Asn.WriteAsn1Elements(nestedElements))
{
}
