/// <summary>
/// Verifies the data given as parameter with the given public key.
/// </summary>
/// <remarks>
/// <para>The function calculates a message digest over the given signature
/// data and verifies the digest with the digest stored in the
/// signature packet.</para>
/// <para>The results of the verify operation are directly stored
/// in the SignatureStatus property of this class.</para>
/// </remarks>
/// <param name="bSignedData">The data that is to be verified.</param>
/// <param name="pkpKey">The key that is to verify the signature</param>
public void Verify(byte[] bSignedData, PublicKeyPacket pkpKey)
{
System.Security.Cryptography.HashAlgorithm haVerifyer;
AsymmetricCipher acVerifyer;
switch (this.HashAlgorithm) {
case HashAlgorithms.MD5:
haVerifyer = System.Security.Cryptography.MD5.Create();
break;
case HashAlgorithms.SHA1:
haVerifyer = System.Security.Cryptography.SHA1.Create();
break;
default:
throw(new System.Exception("Currently only MD5 and SHA1 are implemented as hash algorithms!"));
}
switch (this.SignatureAlgorithm) {
case AsymAlgorithms.DSA:
acVerifyer = new SharpPrivacy.SharpPrivacyLib.Cipher.DSA();
break;
case AsymAlgorithms.RSA_Encrypt_Sign:
case AsymAlgorithms.RSA_Sign_Only:
acVerifyer = new SharpPrivacy.SharpPrivacyLib.Cipher.RSA();
break;
default:
throw(new System.Exception("Currently only DSA and RSA are implemented as signature algorithms!"));
}
byte[] bSignature = new byte[0];
int iCounter = 0;
if (this.Version <= SignaturePacketVersionNumbers.v3) {
bSignature = new byte[5];
bSignature[iCounter++] = (byte)this.SignatureType;
long lTime = (dtTimeCreated.Ticks - new DateTime(1970, 1, 1).Ticks)/10000000;
bSignature[iCounter++] = (byte)((lTime >> 24) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 16) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lTime & 0xFF);
} else {
//Hashed Subpackets Length
int lHashedSubPacketLength = 0;
for (int i=0; i<this.HashedSubPackets.Length; i++) {
lHashedSubPacketLength += this.HashedSubPackets[i].Generate().Length;
}
bSignature = new byte[lHashedSubPacketLength + 12];
bSignature[iCounter++] = 4; // Version
bSignature[iCounter++] = (byte)this.SignatureType;
bSignature[iCounter++] = (byte)this.SignatureAlgorithm;
bSignature[iCounter++] = (byte)this.HashAlgorithm;
//Hashed Subpackets
bSignature[iCounter++] = (byte)((lHashedSubPacketLength >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lHashedSubPacketLength & 0xFF);
for (int i=0; i<this.HashedSubPackets.Length; i++) {
byte[] bSubPacket = this.HashedSubPackets[i].Generate();
Array.Copy(bSubPacket, 0, bSignature, iCounter, bSubPacket.Length);
iCounter += bSubPacket.Length;
}
//Final Trailer of 6 bytes
bSignature[iCounter++] = 0x04;
bSignature[iCounter++] = 0xFF;
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 24) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 16) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 8) & 0xFF);
bSignature[iCounter++] = (byte)((lHashedSubPacketLength+6) & 0xFF);
}
byte[] bData = new byte[bSignedData.Length + bSignature.Length];
Array.Copy(bSignedData, bData, bSignedData.Length);
Array.Copy(bSignature, 0, bData, bSignedData.Length, bSignature.Length);
byte[] bHash = haVerifyer.ComputeHash(bData);
BigInteger biHash = new BigInteger(bHash);
//PKCS1 Encode the hash
if (this.SignatureAlgorithm != AsymAlgorithms.DSA) {
// We encode the MD in this way:
// 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
// PAD consists of FF bytes.
byte[] bASN = new byte[0];
switch (this.HashAlgorithm) {
case HashAlgorithms.MD5:
bASN = new byte[] {0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10};
break;
case HashAlgorithms.SHA1:
bASN = new byte[] {0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
0x2b, 0x0E, 0x03, 0x02, 0x1A, 0x05,
0x00, 0x04, 0x14};
break;
}
int iFrameSize = (pkpKey.KeyMaterial[0].bitCount() + 7) / 8;
byte[] bFrame = new byte[iFrameSize];
int iASNCounter = 0;
bFrame[iASNCounter++] = 0;
bFrame[iASNCounter++] = 1;
int iFFLength = iFrameSize - bHash.Length - bASN.Length - 3;
for (int i=0; i<iFFLength; i++) {
bFrame[iASNCounter++] = 0xFF;
}
bFrame[iASNCounter++] = 0;
Array.Copy(bASN, 0, bFrame, iASNCounter, bASN.Length);
iASNCounter += bASN.Length;
Array.Copy(bHash, 0, bFrame, iASNCounter, bHash.Length);
biHash = new BigInteger(bFrame);
}
if (acVerifyer.Verify(this.Signature, biHash, pkpKey)) {
ssSignatureStatus = SignatureStatusTypes.Valid;
} else {
ssSignatureStatus = SignatureStatusTypes.Invalid;
}
}
private BigInteger[][] GenerateRSAEncryptionKey(int iKeySize)
{
RSA rsaKeyGenerator = new RSA();
BigInteger[][] biEncryptionKey = rsaKeyGenerator.Generate(iKeySize);
return biEncryptionKey;
}
/// <summary>
/// Signes the data given as parameter with the given secret key.
/// The given password has to fit the given key.
/// </summary>
/// <remarks>
/// <para>The function calculates a message digest over the given signature
/// data and signes the digest with the given key.</para>
/// <para>The results of the signature operation are directly stored
/// in the Signature property of this class.</para>
/// </remarks>
/// <param name="bSignedData">The data that is to be signed.</param>
/// <param name="skpKey">The key that is to sign the data</param>
/// <param name="strPassphrase">The passphrase that is neccessary to
/// decrypt the given key.</param>
public void Sign(byte[] bSignedData, SecretKeyPacket skpKey, string strPassphrase)
{
System.Security.Cryptography.HashAlgorithm haSigner;
AsymmetricCipher acSigner;
this.SignatureAlgorithm = skpKey.PublicKey.Algorithm;
switch (this.HashAlgorithm) {
case HashAlgorithms.MD5:
haSigner = System.Security.Cryptography.MD5.Create();
break;
case HashAlgorithms.SHA1:
haSigner = System.Security.Cryptography.SHA1.Create();
break;
default:
throw(new System.Exception("Currently only MD5 and SHA1 are implemented as hash algorithms!"));
}
switch (this.SignatureAlgorithm) {
case AsymAlgorithms.DSA:
acSigner = new SharpPrivacy.SharpPrivacyLib.Cipher.DSA();
break;
case AsymAlgorithms.RSA_Encrypt_Sign:
case AsymAlgorithms.RSA_Sign_Only:
acSigner = new SharpPrivacy.SharpPrivacyLib.Cipher.RSA();
break;
default:
throw(new System.Exception("Currently only DSA and RSA are implemented as signature algorithms!"));
}
byte[] bSignature = new byte[0];
int iCounter = 0;
if (this.Version <= SignaturePacketVersionNumbers.v3) {
bSignature = new byte[5];
bSignature[iCounter++] = (byte)this.SignatureType;
long lTime = (dtTimeCreated.Ticks - new DateTime(1970, 1, 1).Ticks)/10000000;
bSignature[iCounter++] = (byte)((lTime >> 24) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 16) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lTime & 0xFF);
} else {
// Add Issuer KeyID Subpacket if it's not there.
try {
ulong lTestForKeyID = this.KeyID;
} catch (Exception) {
SignatureSubPacket sspIssuerKeyID = new SignatureSubPacket();
sspIssuerKeyID.Type = SignatureSubPacketTypes.IssuerKeyID;
sspIssuerKeyID.KeyID = this.lKeyID;
this.AddSubPacket(sspIssuerKeyID, true);
}
// Add TimeCreated Subpacket if it's not there.
try {
this.FindSignatureCreationTime();
} catch (Exception) {
SignatureSubPacket sspCreationTime = new SignatureSubPacket();
sspCreationTime.Type = SignatureSubPacketTypes.SignatureCreationTime;
sspCreationTime.TimeCreated = DateTime.Now;
this.AddSubPacket(sspCreationTime, true);
}
//Hashed Subpackets Length
int lHashedSubPacketLength = 0;
for (int i=0; i<this.HashedSubPackets.Length; i++) {
lHashedSubPacketLength += this.HashedSubPackets[i].Generate().Length;
}
bSignature = new byte[lHashedSubPacketLength + 12];
bSignature[iCounter++] = 4; // Version
bSignature[iCounter++] = (byte)this.SignatureType;
bSignature[iCounter++] = (byte)this.SignatureAlgorithm;
bSignature[iCounter++] = (byte)this.HashAlgorithm;
//Hashed
bSignature[iCounter++] = (byte)((lHashedSubPacketLength >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lHashedSubPacketLength & 0xFF);
for (int i=0; i<this.HashedSubPackets.Length; i++) {
byte[] bSubPacket = this.HashedSubPackets[i].Generate();
Array.Copy(bSubPacket, 0, bSignature, iCounter, bSubPacket.Length);
iCounter += bSubPacket.Length;
}
//Final Trailer of 6 bytes
bSignature[iCounter++] = 0x04;
bSignature[iCounter++] = 0xFF;
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 24) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 16) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength+6) >> 8) & 0xFF);
bSignature[iCounter++] = (byte)((lHashedSubPacketLength+6) & 0xFF);
}
byte[] bData = new byte[bSignedData.Length + bSignature.Length];
Array.Copy(bSignedData, bData, bSignedData.Length);
Array.Copy(bSignature, 0, bData, bSignedData.Length, bSignature.Length);
byte[] bHash = haSigner.ComputeHash(bData);
BigInteger biHash = new BigInteger(bHash);
//PKCS1 Encode the hash
if (this.SignatureAlgorithm != AsymAlgorithms.DSA) {
// We encode the MD in this way:
// 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
// PAD consists of FF bytes.
byte[] bASN = new byte[0];
switch (this.HashAlgorithm) {
case HashAlgorithms.MD5:
bASN = new byte[] {0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10};
break;
case HashAlgorithms.SHA1:
bASN = new byte[] {0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
0x2b, 0x0E, 0x03, 0x02, 0x1A, 0x05,
0x00, 0x04, 0x14};
break;
}
int iFrameSize = (skpKey.PublicKey.KeyMaterial[0].bitCount() + 7) / 8;
byte[] bFrame = new byte[iFrameSize];
int iASNCounter = 0;
bFrame[iASNCounter++] = 0;
bFrame[iASNCounter++] = 1;
int iFFLength = iFrameSize - bHash.Length - bASN.Length - 3;
for (int i=0; i<iFFLength; i++)
bFrame[iASNCounter++] = 0xFF;
bFrame[iASNCounter++] = 0;
Array.Copy(bASN, 0, bFrame, iASNCounter, bASN.Length);
iASNCounter += bASN.Length;
Array.Copy(bHash, 0, bFrame, iASNCounter, bHash.Length);
biHash = new BigInteger(bFrame);
}
sSignedHash16Bit = (ushort)((bHash[0] << 8) + bHash[1]);
biSignature = acSigner.Sign(biHash, skpKey, strPassphrase);
this.bIsUpdated = true;
}
/// <summary>
/// Encryptes the session key stored in the SessionKey property
/// and saves the results in the EncryptedSessionKey property.
/// </summary>
/// <remarks>This method also calles EncodeSessionKey so that it
/// does not have been called before calling EncryptSessionKey.
/// <p></p>
/// Please note: calling this function takes some time, because
/// asymmetrical encryption takes some time!
/// </remarks>
/// <param name="pkpPacket">An PublicKeyPacket to which
/// the sessionkey should be encrypted to.</param>
public void EncryptSessionKey(PublicKeyPacket pkpPacket)
{
EncodeSessionKey(pkpPacket.KeyMaterial[0].bitCount());
AsymmetricCipher acCipher = new RSA();
switch (aaPublicAlgorithm) {
case AsymAlgorithms.ElGama_Encrypt_Sign:
case AsymAlgorithms.ElGamal_Encrypt_Only:
acCipher = new ElGamal();
break;
case AsymAlgorithms.RSA_Encrypt_Only:
case AsymAlgorithms.RSA_Encrypt_Sign:
acCipher = new RSA();
break;
default:
throw new System.Exception("The chosen public key algorithm is not yet implemented!");
}
this.bIsUpdated = true;
biEncryptedSessionKey = acCipher.Encrypt(new BigInteger(this.bEncodedSessionKey), pkpPacket);
}
/// <summary>
/// Decrypts the session key stored in the EncryptedSessionKey
/// property and saves the decrypted key in the EncodedSessionKey
/// property.
/// </summary>
/// <remarks>This function also calls DecodeSessionKey so that the
/// decrypted and decoded sessionkey is stored in the
/// SessionKey property.</remarks>
/// <param name="tskKey">A transportable secret key that is used to
/// decrypt the encrypted session key.</param>
/// <param name="strPassphrase">The passphrase used to decrypt the
/// encrypted key material of the given transportable secret
/// key.</param>
public void DecryptSessionKey(TransportableSecretKey tskKey, string strPassphrase)
{
AsymmetricCipher acCipher = new RSA();
switch (aaPublicAlgorithm) {
case AsymAlgorithms.ElGama_Encrypt_Sign:
case AsymAlgorithms.ElGamal_Encrypt_Only:
acCipher = new ElGamal();
break;
case AsymAlgorithms.RSA_Encrypt_Only:
case AsymAlgorithms.RSA_Encrypt_Sign:
acCipher = new RSA();
break;
default:
throw new System.Exception("The chosen public key algorithm is not yet implemented!");
}
bool bFound = false;
SecretKeyPacket skpKey = new SecretKeyPacket();
IEnumerator ieSubkeys = tskKey.SubKeys.GetEnumerator();
while (ieSubkeys.MoveNext()) {
if (!(ieSubkeys.Current is SecretKeyPacket))
throw new System.Exception("Expected a secret key packet, but did not find one!");
skpKey = (SecretKeyPacket)ieSubkeys.Current;
if (skpKey.PublicKey.KeyID == lKeyID) {
bFound = true;
continue;
}
}
// check if the message was encrypted with the primary key
if (!bFound) {
if (tskKey.PrimaryKey.PublicKey.KeyID == lKeyID) {
skpKey = tskKey.PrimaryKey;
} else {
//theoretically we should never see this exception, as
//encrytped message makes sure we only get fitting secret
//keys, but just in case someone calls this directly, we
//throw an exception
throw new System.Exception("No fitting secret key found!");
}
}
BigInteger biKey = acCipher.Decrypt(this.biEncryptedSessionKey, skpKey, strPassphrase);
this.bEncodedSessionKey = biKey.getBytes();
DecodeSessionKey();
}
/// <summary>
/// Verifies the data given as parameter with the given public key.
/// </summary>
/// <remarks>
/// <para>The function calculates a message digest over the given signature
/// data and verifies the digest with the digest stored in the
/// signature packet.</para>
/// <para>The results of the verify operation are directly stored
/// in the SignatureStatus property of this class.</para>
/// </remarks>
/// <param name="bSignedData">The data that is to be verified.</param>
/// <param name="pkpKey">The key that is to verify the signature</param>
public void Verify(byte[] bSignedData, PublicKeyPacket pkpKey)
{
System.Security.Cryptography.HashAlgorithm haVerifyer;
AsymmetricCipher acVerifyer;
switch (this.HashAlgorithm)
{
case HashAlgorithms.MD5:
haVerifyer = System.Security.Cryptography.MD5.Create();
break;
case HashAlgorithms.SHA1:
haVerifyer = System.Security.Cryptography.SHA1.Create();
break;
default:
throw(new System.Exception("Currently only MD5 and SHA1 are implemented as hash algorithms!"));
}
switch (this.SignatureAlgorithm)
{
case AsymAlgorithms.DSA:
acVerifyer = new SharpPrivacy.SharpPrivacyLib.Cipher.DSA();
break;
case AsymAlgorithms.RSA_Encrypt_Sign:
case AsymAlgorithms.RSA_Sign_Only:
acVerifyer = new SharpPrivacy.SharpPrivacyLib.Cipher.RSA();
break;
default:
throw(new System.Exception("Currently only DSA and RSA are implemented as signature algorithms!"));
}
byte[] bSignature = new byte[0];
int iCounter = 0;
if (this.Version <= SignaturePacketVersionNumbers.v3)
{
bSignature = new byte[5];
bSignature[iCounter++] = (byte)this.SignatureType;
long lTime = (dtTimeCreated.Ticks - new DateTime(1970, 1, 1).Ticks) / 10000000;
bSignature[iCounter++] = (byte)((lTime >> 24) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 16) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lTime & 0xFF);
}
else
{
//Hashed Subpackets Length
int lHashedSubPacketLength = 0;
for (int i = 0; i < this.HashedSubPackets.Length; i++)
{
lHashedSubPacketLength += this.HashedSubPackets[i].Generate().Length;
}
bSignature = new byte[lHashedSubPacketLength + 12];
bSignature[iCounter++] = 4; // Version
bSignature[iCounter++] = (byte)this.SignatureType;
bSignature[iCounter++] = (byte)this.SignatureAlgorithm;
bSignature[iCounter++] = (byte)this.HashAlgorithm;
//Hashed Subpackets
bSignature[iCounter++] = (byte)((lHashedSubPacketLength >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lHashedSubPacketLength & 0xFF);
for (int i = 0; i < this.HashedSubPackets.Length; i++)
{
byte[] bSubPacket = this.HashedSubPackets[i].Generate();
Array.Copy(bSubPacket, 0, bSignature, iCounter, bSubPacket.Length);
iCounter += bSubPacket.Length;
}
//Final Trailer of 6 bytes
bSignature[iCounter++] = 0x04;
bSignature[iCounter++] = 0xFF;
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 24) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 16) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 8) & 0xFF);
bSignature[iCounter++] = (byte)((lHashedSubPacketLength + 6) & 0xFF);
}
byte[] bData = new byte[bSignedData.Length + bSignature.Length];
Array.Copy(bSignedData, bData, bSignedData.Length);
Array.Copy(bSignature, 0, bData, bSignedData.Length, bSignature.Length);
byte[] bHash = haVerifyer.ComputeHash(bData);
BigInteger biHash = new BigInteger(bHash);
//PKCS1 Encode the hash
if (this.SignatureAlgorithm != AsymAlgorithms.DSA)
{
// We encode the MD in this way:
// 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
// PAD consists of FF bytes.
byte[] bASN = new byte[0];
switch (this.HashAlgorithm)
{
case HashAlgorithms.MD5:
bASN = new byte[] { 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10 };
break;
case HashAlgorithms.SHA1:
bASN = new byte[] { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
0x2b, 0x0E, 0x03, 0x02, 0x1A, 0x05,
0x00, 0x04, 0x14 };
break;
}
int iFrameSize = (pkpKey.KeyMaterial[0].bitCount() + 7) / 8;
byte[] bFrame = new byte[iFrameSize];
int iASNCounter = 0;
bFrame[iASNCounter++] = 0;
bFrame[iASNCounter++] = 1;
int iFFLength = iFrameSize - bHash.Length - bASN.Length - 3;
for (int i = 0; i < iFFLength; i++)
{
bFrame[iASNCounter++] = 0xFF;
}
bFrame[iASNCounter++] = 0;
Array.Copy(bASN, 0, bFrame, iASNCounter, bASN.Length);
iASNCounter += bASN.Length;
Array.Copy(bHash, 0, bFrame, iASNCounter, bHash.Length);
biHash = new BigInteger(bFrame);
}
if (acVerifyer.Verify(this.Signature, biHash, pkpKey))
{
ssSignatureStatus = SignatureStatusTypes.Valid;
}
else
{
ssSignatureStatus = SignatureStatusTypes.Invalid;
}
}
/// <summary>
/// Signes the data given as parameter with the given secret key.
/// The given password has to fit the given key.
/// </summary>
/// <remarks>
/// <para>The function calculates a message digest over the given signature
/// data and signes the digest with the given key.</para>
/// <para>The results of the signature operation are directly stored
/// in the Signature property of this class.</para>
/// </remarks>
/// <param name="bSignedData">The data that is to be signed.</param>
/// <param name="skpKey">The key that is to sign the data</param>
/// <param name="strPassphrase">The passphrase that is neccessary to
/// decrypt the given key.</param>
public void Sign(byte[] bSignedData, SecretKeyPacket skpKey, string strPassphrase)
{
System.Security.Cryptography.HashAlgorithm haSigner;
AsymmetricCipher acSigner;
this.SignatureAlgorithm = skpKey.PublicKey.Algorithm;
switch (this.HashAlgorithm)
{
case HashAlgorithms.MD5:
haSigner = System.Security.Cryptography.MD5.Create();
break;
case HashAlgorithms.SHA1:
haSigner = System.Security.Cryptography.SHA1.Create();
break;
default:
throw(new System.Exception("Currently only MD5 and SHA1 are implemented as hash algorithms!"));
}
switch (this.SignatureAlgorithm)
{
case AsymAlgorithms.DSA:
acSigner = new SharpPrivacy.SharpPrivacyLib.Cipher.DSA();
break;
case AsymAlgorithms.RSA_Encrypt_Sign:
case AsymAlgorithms.RSA_Sign_Only:
acSigner = new SharpPrivacy.SharpPrivacyLib.Cipher.RSA();
break;
default:
throw(new System.Exception("Currently only DSA and RSA are implemented as signature algorithms!"));
}
byte[] bSignature = new byte[0];
int iCounter = 0;
if (this.Version <= SignaturePacketVersionNumbers.v3)
{
bSignature = new byte[5];
bSignature[iCounter++] = (byte)this.SignatureType;
long lTime = (dtTimeCreated.Ticks - new DateTime(1970, 1, 1).Ticks) / 10000000;
bSignature[iCounter++] = (byte)((lTime >> 24) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 16) & 0xFF);
bSignature[iCounter++] = (byte)((lTime >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lTime & 0xFF);
}
else
{
// Add Issuer KeyID Subpacket if it's not there.
try {
ulong lTestForKeyID = this.KeyID;
} catch (Exception) {
SignatureSubPacket sspIssuerKeyID = new SignatureSubPacket();
sspIssuerKeyID.Type = SignatureSubPacketTypes.IssuerKeyID;
sspIssuerKeyID.KeyID = this.lKeyID;
this.AddSubPacket(sspIssuerKeyID, true);
}
// Add TimeCreated Subpacket if it's not there.
try {
this.FindSignatureCreationTime();
} catch (Exception) {
SignatureSubPacket sspCreationTime = new SignatureSubPacket();
sspCreationTime.Type = SignatureSubPacketTypes.SignatureCreationTime;
sspCreationTime.TimeCreated = DateTime.Now;
this.AddSubPacket(sspCreationTime, true);
}
//Hashed Subpackets Length
int lHashedSubPacketLength = 0;
for (int i = 0; i < this.HashedSubPackets.Length; i++)
{
lHashedSubPacketLength += this.HashedSubPackets[i].Generate().Length;
}
bSignature = new byte[lHashedSubPacketLength + 12];
bSignature[iCounter++] = 4; // Version
bSignature[iCounter++] = (byte)this.SignatureType;
bSignature[iCounter++] = (byte)this.SignatureAlgorithm;
bSignature[iCounter++] = (byte)this.HashAlgorithm;
//Hashed
bSignature[iCounter++] = (byte)((lHashedSubPacketLength >> 8) & 0xFF);
bSignature[iCounter++] = (byte)(lHashedSubPacketLength & 0xFF);
for (int i = 0; i < this.HashedSubPackets.Length; i++)
{
byte[] bSubPacket = this.HashedSubPackets[i].Generate();
Array.Copy(bSubPacket, 0, bSignature, iCounter, bSubPacket.Length);
iCounter += bSubPacket.Length;
}
//Final Trailer of 6 bytes
bSignature[iCounter++] = 0x04;
bSignature[iCounter++] = 0xFF;
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 24) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 16) & 0xFF);
bSignature[iCounter++] = (byte)(((lHashedSubPacketLength + 6) >> 8) & 0xFF);
bSignature[iCounter++] = (byte)((lHashedSubPacketLength + 6) & 0xFF);
}
byte[] bData = new byte[bSignedData.Length + bSignature.Length];
Array.Copy(bSignedData, bData, bSignedData.Length);
Array.Copy(bSignature, 0, bData, bSignedData.Length, bSignature.Length);
byte[] bHash = haSigner.ComputeHash(bData);
BigInteger biHash = new BigInteger(bHash);
//PKCS1 Encode the hash
if (this.SignatureAlgorithm != AsymAlgorithms.DSA)
{
// We encode the MD in this way:
// 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
// PAD consists of FF bytes.
byte[] bASN = new byte[0];
switch (this.HashAlgorithm)
{
case HashAlgorithms.MD5:
bASN = new byte[] { 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D,
0x02, 0x05, 0x05, 0x00, 0x04, 0x10 };
break;
case HashAlgorithms.SHA1:
bASN = new byte[] { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
0x2b, 0x0E, 0x03, 0x02, 0x1A, 0x05,
0x00, 0x04, 0x14 };
break;
}
int iFrameSize = (skpKey.PublicKey.KeyMaterial[0].bitCount() + 7) / 8;
byte[] bFrame = new byte[iFrameSize];
int iASNCounter = 0;
bFrame[iASNCounter++] = 0;
bFrame[iASNCounter++] = 1;
int iFFLength = iFrameSize - bHash.Length - bASN.Length - 3;
for (int i = 0; i < iFFLength; i++)
{
bFrame[iASNCounter++] = 0xFF;
}
bFrame[iASNCounter++] = 0;
Array.Copy(bASN, 0, bFrame, iASNCounter, bASN.Length);
iASNCounter += bASN.Length;
Array.Copy(bHash, 0, bFrame, iASNCounter, bHash.Length);
biHash = new BigInteger(bFrame);
}
sSignedHash16Bit = (ushort)((bHash[0] << 8) + bHash[1]);
biSignature = acSigner.Sign(biHash, skpKey, strPassphrase);
this.bIsUpdated = true;
}
