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Diffstat (limited to 'Crypto/src/openpgp/PgpSignature.cs')
| -rw-r--r-- | Crypto/src/openpgp/PgpSignature.cs | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/Crypto/src/openpgp/PgpSignature.cs b/Crypto/src/openpgp/PgpSignature.cs new file mode 100644 index 000000000..cbe0d83b4 --- /dev/null +++ b/Crypto/src/openpgp/PgpSignature.cs @@ -0,0 +1,422 @@ +using System; +using System.IO; +using Org.BouncyCastle.Asn1; + +using Org.BouncyCastle.Crypto; +using Org.BouncyCastle.Security; +using Org.BouncyCastle.Utilities; +using Org.BouncyCastle.Utilities.Date; + +namespace Org.BouncyCastle.Bcpg.OpenPgp +{ + /// <remarks>A PGP signature object.</remarks> + public class PgpSignature + { + public const int BinaryDocument = 0x00; + public const int CanonicalTextDocument = 0x01; + public const int StandAlone = 0x02; + + public const int DefaultCertification = 0x10; + public const int NoCertification = 0x11; + public const int CasualCertification = 0x12; + public const int PositiveCertification = 0x13; + + public const int SubkeyBinding = 0x18; + public const int PrimaryKeyBinding = 0x19; + public const int DirectKey = 0x1f; + public const int KeyRevocation = 0x20; + public const int SubkeyRevocation = 0x28; + public const int CertificationRevocation = 0x30; + public const int Timestamp = 0x40; + + private readonly SignaturePacket sigPck; + private readonly int signatureType; + private readonly TrustPacket trustPck; + + private ISigner sig; + private byte lastb; // Initial value anything but '\r' + + internal PgpSignature( + BcpgInputStream bcpgInput) + : this((SignaturePacket)bcpgInput.ReadPacket()) + { + } + + internal PgpSignature( + SignaturePacket sigPacket) + : this(sigPacket, null) + { + } + + internal PgpSignature( + SignaturePacket sigPacket, + TrustPacket trustPacket) + { + if (sigPacket == null) + throw new ArgumentNullException("sigPacket"); + + this.sigPck = sigPacket; + this.signatureType = sigPck.SignatureType; + this.trustPck = trustPacket; + } + + private void GetSig() + { + this.sig = SignerUtilities.GetSigner( + PgpUtilities.GetSignatureName(sigPck.KeyAlgorithm, sigPck.HashAlgorithm)); + } + + /// <summary>The OpenPGP version number for this signature.</summary> + public int Version + { + get { return sigPck.Version; } + } + + /// <summary>The key algorithm associated with this signature.</summary> + public PublicKeyAlgorithmTag KeyAlgorithm + { + get { return sigPck.KeyAlgorithm; } + } + + /// <summary>The hash algorithm associated with this signature.</summary> + public HashAlgorithmTag HashAlgorithm + { + get { return sigPck.HashAlgorithm; } + } + + public void InitVerify( + PgpPublicKey pubKey) + { + lastb = 0; + if (sig == null) + { + GetSig(); + } + try + { + sig.Init(false, pubKey.GetKey()); + } + catch (InvalidKeyException e) + { + throw new PgpException("invalid key.", e); + } + } + + public void Update( + byte b) + { + if (signatureType == CanonicalTextDocument) + { + doCanonicalUpdateByte(b); + } + else + { + sig.Update(b); + } + } + + private void doCanonicalUpdateByte( + byte b) + { + if (b == '\r') + { + doUpdateCRLF(); + } + else if (b == '\n') + { + if (lastb != '\r') + { + doUpdateCRLF(); + } + } + else + { + sig.Update(b); + } + + lastb = b; + } + + private void doUpdateCRLF() + { + sig.Update((byte)'\r'); + sig.Update((byte)'\n'); + } + + public void Update( + params byte[] bytes) + { + Update(bytes, 0, bytes.Length); + } + + public void Update( + byte[] bytes, + int off, + int length) + { + if (signatureType == CanonicalTextDocument) + { + int finish = off + length; + + for (int i = off; i != finish; i++) + { + doCanonicalUpdateByte(bytes[i]); + } + } + else + { + sig.BlockUpdate(bytes, off, length); + } + } + + public bool Verify() + { + byte[] trailer = GetSignatureTrailer(); + sig.BlockUpdate(trailer, 0, trailer.Length); + + return sig.VerifySignature(GetSignature()); + } + + private void UpdateWithIdData( + int header, + byte[] idBytes) + { + this.Update( + (byte) header, + (byte)(idBytes.Length >> 24), + (byte)(idBytes.Length >> 16), + (byte)(idBytes.Length >> 8), + (byte)(idBytes.Length)); + this.Update(idBytes); + } + + private void UpdateWithPublicKey( + PgpPublicKey key) + { + byte[] keyBytes = GetEncodedPublicKey(key); + + this.Update( + (byte) 0x99, + (byte)(keyBytes.Length >> 8), + (byte)(keyBytes.Length)); + this.Update(keyBytes); + } + + /// <summary> + /// Verify the signature as certifying the passed in public key as associated + /// with the passed in user attributes. + /// </summary> + /// <param name="userAttributes">User attributes the key was stored under.</param> + /// <param name="key">The key to be verified.</param> + /// <returns>True, if the signature matches, false otherwise.</returns> + public bool VerifyCertification( + PgpUserAttributeSubpacketVector userAttributes, + PgpPublicKey key) + { + UpdateWithPublicKey(key); + + // + // hash in the userAttributes + // + try + { + MemoryStream bOut = new MemoryStream(); + foreach (UserAttributeSubpacket packet in userAttributes.ToSubpacketArray()) + { + packet.Encode(bOut); + } + UpdateWithIdData(0xd1, bOut.ToArray()); + } + catch (IOException e) + { + throw new PgpException("cannot encode subpacket array", e); + } + + this.Update(sigPck.GetSignatureTrailer()); + + return sig.VerifySignature(this.GetSignature()); + } + + /// <summary> + /// Verify the signature as certifying the passed in public key as associated + /// with the passed in ID. + /// </summary> + /// <param name="id">ID the key was stored under.</param> + /// <param name="key">The key to be verified.</param> + /// <returns>True, if the signature matches, false otherwise.</returns> + public bool VerifyCertification( + string id, + PgpPublicKey key) + { + UpdateWithPublicKey(key); + + // + // hash in the id + // + UpdateWithIdData(0xb4, Strings.ToByteArray(id)); + + Update(sigPck.GetSignatureTrailer()); + + return sig.VerifySignature(GetSignature()); + } + + /// <summary>Verify a certification for the passed in key against the passed in master key.</summary> + /// <param name="masterKey">The key we are verifying against.</param> + /// <param name="pubKey">The key we are verifying.</param> + /// <returns>True, if the certification is valid, false otherwise.</returns> + public bool VerifyCertification( + PgpPublicKey masterKey, + PgpPublicKey pubKey) + { + UpdateWithPublicKey(masterKey); + UpdateWithPublicKey(pubKey); + + Update(sigPck.GetSignatureTrailer()); + + return sig.VerifySignature(GetSignature()); + } + + /// <summary>Verify a key certification, such as revocation, for the passed in key.</summary> + /// <param name="pubKey">The key we are checking.</param> + /// <returns>True, if the certification is valid, false otherwise.</returns> + public bool VerifyCertification( + PgpPublicKey pubKey) + { + if (SignatureType != KeyRevocation + && SignatureType != SubkeyRevocation) + { + throw new InvalidOperationException("signature is not a key signature"); + } + + UpdateWithPublicKey(pubKey); + + Update(sigPck.GetSignatureTrailer()); + + return sig.VerifySignature(GetSignature()); + } + + public int SignatureType + { + get { return sigPck.SignatureType; } + } + + /// <summary>The ID of the key that created the signature.</summary> + public long KeyId + { + get { return sigPck.KeyId; } + } + + [Obsolete("Use 'CreationTime' property instead")] + public DateTime GetCreationTime() + { + return CreationTime; + } + + /// <summary>The creation time of this signature.</summary> + public DateTime CreationTime + { + get { return DateTimeUtilities.UnixMsToDateTime(sigPck.CreationTime); } + } + + public byte[] GetSignatureTrailer() + { + return sigPck.GetSignatureTrailer(); + } + + /// <summary> + /// Return true if the signature has either hashed or unhashed subpackets. + /// </summary> + public bool HasSubpackets + { + get + { + return sigPck.GetHashedSubPackets() != null + || sigPck.GetUnhashedSubPackets() != null; + } + } + + public PgpSignatureSubpacketVector GetHashedSubPackets() + { + return createSubpacketVector(sigPck.GetHashedSubPackets()); + } + + public PgpSignatureSubpacketVector GetUnhashedSubPackets() + { + return createSubpacketVector(sigPck.GetUnhashedSubPackets()); + } + + private PgpSignatureSubpacketVector createSubpacketVector(SignatureSubpacket[] pcks) + { + return pcks == null ? null : new PgpSignatureSubpacketVector(pcks); + } + + public byte[] GetSignature() + { + MPInteger[] sigValues = sigPck.GetSignature(); + byte[] signature; + + if (sigValues != null) + { + if (sigValues.Length == 1) // an RSA signature + { + signature = sigValues[0].Value.ToByteArrayUnsigned(); + } + else + { + try + { + signature = new DerSequence( + new DerInteger(sigValues[0].Value), + new DerInteger(sigValues[1].Value)).GetEncoded(); + } + catch (IOException e) + { + throw new PgpException("exception encoding DSA sig.", e); + } + } + } + else + { + signature = sigPck.GetSignatureBytes(); + } + + return signature; + } + + // TODO Handle the encoding stuff by subclassing BcpgObject? + public byte[] GetEncoded() + { + MemoryStream bOut = new MemoryStream(); + + Encode(bOut); + + return bOut.ToArray(); + } + + public void Encode( + Stream outStream) + { + BcpgOutputStream bcpgOut = BcpgOutputStream.Wrap(outStream); + + bcpgOut.WritePacket(sigPck); + + if (trustPck != null) + { + bcpgOut.WritePacket(trustPck); + } + } + + private byte[] GetEncodedPublicKey( + PgpPublicKey pubKey) + { + try + { + return pubKey.publicPk.GetEncodedContents(); + } + catch (IOException e) + { + throw new PgpException("exception preparing key.", e); + } + } + } +} |