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Diffstat (limited to 'crypto/src/tsp/TSPUtil.cs')
| -rw-r--r-- | crypto/src/tsp/TSPUtil.cs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/crypto/src/tsp/TSPUtil.cs b/crypto/src/tsp/TSPUtil.cs new file mode 100644 index 000000000..1026914f4 --- /dev/null +++ b/crypto/src/tsp/TSPUtil.cs @@ -0,0 +1,202 @@ +using System; +using System.Collections; +using System.IO; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Asn1.CryptoPro; +using Org.BouncyCastle.Asn1.Nist; +using Org.BouncyCastle.Asn1.Oiw; +using Org.BouncyCastle.Asn1.Pkcs; +using Org.BouncyCastle.Asn1.TeleTrust; +using Org.BouncyCastle.Asn1.X509; +using Org.BouncyCastle.Cms; +using Org.BouncyCastle.Crypto; +using Org.BouncyCastle.Security; +using Org.BouncyCastle.Utilities; +using Org.BouncyCastle.Utilities.Collections; +using Org.BouncyCastle.X509; + +namespace Org.BouncyCastle.Tsp +{ + public class TspUtil + { + private static ISet EmptySet = CollectionUtilities.ReadOnly(new HashSet()); + private static IList EmptyList = CollectionUtilities.ReadOnly(Platform.CreateArrayList()); + + private static readonly IDictionary digestLengths = Platform.CreateHashtable(); + private static readonly IDictionary digestNames = Platform.CreateHashtable(); + + static TspUtil() + { + digestLengths.Add(PkcsObjectIdentifiers.MD5.Id, 16); + digestLengths.Add(OiwObjectIdentifiers.IdSha1.Id, 20); + digestLengths.Add(NistObjectIdentifiers.IdSha224.Id, 28); + digestLengths.Add(NistObjectIdentifiers.IdSha256.Id, 32); + digestLengths.Add(NistObjectIdentifiers.IdSha384.Id, 48); + digestLengths.Add(NistObjectIdentifiers.IdSha512.Id, 64); + digestLengths.Add(TeleTrusTObjectIdentifiers.RipeMD128.Id, 16); + digestLengths.Add(TeleTrusTObjectIdentifiers.RipeMD160.Id, 20); + digestLengths.Add(TeleTrusTObjectIdentifiers.RipeMD256.Id, 32); + digestLengths.Add(CryptoProObjectIdentifiers.GostR3411.Id, 32); + + digestNames.Add(PkcsObjectIdentifiers.MD5.Id, "MD5"); + digestNames.Add(OiwObjectIdentifiers.IdSha1.Id, "SHA1"); + digestNames.Add(NistObjectIdentifiers.IdSha224.Id, "SHA224"); + digestNames.Add(NistObjectIdentifiers.IdSha256.Id, "SHA256"); + digestNames.Add(NistObjectIdentifiers.IdSha384.Id, "SHA384"); + digestNames.Add(NistObjectIdentifiers.IdSha512.Id, "SHA512"); + digestNames.Add(PkcsObjectIdentifiers.Sha1WithRsaEncryption.Id, "SHA1"); + digestNames.Add(PkcsObjectIdentifiers.Sha224WithRsaEncryption.Id, "SHA224"); + digestNames.Add(PkcsObjectIdentifiers.Sha256WithRsaEncryption.Id, "SHA256"); + digestNames.Add(PkcsObjectIdentifiers.Sha384WithRsaEncryption.Id, "SHA384"); + digestNames.Add(PkcsObjectIdentifiers.Sha512WithRsaEncryption.Id, "SHA512"); + digestNames.Add(TeleTrusTObjectIdentifiers.RipeMD128.Id, "RIPEMD128"); + digestNames.Add(TeleTrusTObjectIdentifiers.RipeMD160.Id, "RIPEMD160"); + digestNames.Add(TeleTrusTObjectIdentifiers.RipeMD256.Id, "RIPEMD256"); + digestNames.Add(CryptoProObjectIdentifiers.GostR3411.Id, "GOST3411"); + } + + + /** + * Fetches the signature time-stamp attributes from a SignerInformation object. + * Checks that the MessageImprint for each time-stamp matches the signature field. + * (see RFC 3161 Appendix A). + * + * @param signerInfo a SignerInformation to search for time-stamps + * @return a collection of TimeStampToken objects + * @throws TSPValidationException + */ + public static ICollection GetSignatureTimestamps( + SignerInformation signerInfo) + { + IList timestamps = Platform.CreateArrayList(); + + Asn1.Cms.AttributeTable unsignedAttrs = signerInfo.UnsignedAttributes; + if (unsignedAttrs != null) + { + foreach (Asn1.Cms.Attribute tsAttr in unsignedAttrs.GetAll( + PkcsObjectIdentifiers.IdAASignatureTimeStampToken)) + { + foreach (Asn1Encodable asn1 in tsAttr.AttrValues) + { + try + { + Asn1.Cms.ContentInfo contentInfo = Asn1.Cms.ContentInfo.GetInstance( + asn1.ToAsn1Object()); + TimeStampToken timeStampToken = new TimeStampToken(contentInfo); + TimeStampTokenInfo tstInfo = timeStampToken.TimeStampInfo; + + byte[] expectedDigest = DigestUtilities.CalculateDigest( + GetDigestAlgName(tstInfo.MessageImprintAlgOid), + signerInfo.GetSignature()); + + if (!Arrays.ConstantTimeAreEqual(expectedDigest, tstInfo.GetMessageImprintDigest())) + throw new TspValidationException("Incorrect digest in message imprint"); + + timestamps.Add(timeStampToken); + } + catch (SecurityUtilityException) + { + throw new TspValidationException("Unknown hash algorithm specified in timestamp"); + } + catch (Exception) + { + throw new TspValidationException("Timestamp could not be parsed"); + } + } + } + } + + return timestamps; + } + + /** + * Validate the passed in certificate as being of the correct type to be used + * for time stamping. To be valid it must have an ExtendedKeyUsage extension + * which has a key purpose identifier of id-kp-timeStamping. + * + * @param cert the certificate of interest. + * @throws TspValidationException if the certicate fails on one of the check points. + */ + public static void ValidateCertificate( + X509Certificate cert) + { + if (cert.Version != 3) + throw new ArgumentException("Certificate must have an ExtendedKeyUsage extension."); + + Asn1OctetString ext = cert.GetExtensionValue(X509Extensions.ExtendedKeyUsage); + if (ext == null) + throw new TspValidationException("Certificate must have an ExtendedKeyUsage extension."); + + if (!cert.GetCriticalExtensionOids().Contains(X509Extensions.ExtendedKeyUsage.Id)) + throw new TspValidationException("Certificate must have an ExtendedKeyUsage extension marked as critical."); + + try + { + ExtendedKeyUsage extKey = ExtendedKeyUsage.GetInstance( + Asn1Object.FromByteArray(ext.GetOctets())); + + if (!extKey.HasKeyPurposeId(KeyPurposeID.IdKPTimeStamping) || extKey.Count != 1) + throw new TspValidationException("ExtendedKeyUsage not solely time stamping."); + } + catch (IOException) + { + throw new TspValidationException("cannot process ExtendedKeyUsage extension"); + } + } + + /// <summary> + /// Return the digest algorithm using one of the standard JCA string + /// representations rather than the algorithm identifier (if possible). + /// </summary> + internal static string GetDigestAlgName( + string digestAlgOID) + { + string digestName = (string) digestNames[digestAlgOID]; + + return digestName != null ? digestName : digestAlgOID; + } + + internal static int GetDigestLength( + string digestAlgOID) + { + if (!digestLengths.Contains(digestAlgOID)) + throw new TspException("digest algorithm cannot be found."); + + return (int)digestLengths[digestAlgOID]; + } + + internal static IDigest CreateDigestInstance( + String digestAlgOID) + { + string digestName = GetDigestAlgName(digestAlgOID); + + return DigestUtilities.GetDigest(digestName); + } + + internal static ISet GetCriticalExtensionOids(X509Extensions extensions) + { + if (extensions == null) + return EmptySet; + + return CollectionUtilities.ReadOnly(new HashSet(extensions.GetCriticalExtensionOids())); + } + + internal static ISet GetNonCriticalExtensionOids(X509Extensions extensions) + { + if (extensions == null) + return EmptySet; + + // TODO: should probably produce a set that imposes correct ordering + return CollectionUtilities.ReadOnly(new HashSet(extensions.GetNonCriticalExtensionOids())); + } + + internal static IList GetExtensionOids(X509Extensions extensions) + { + if (extensions == null) + return EmptyList; + + return CollectionUtilities.ReadOnly(Platform.CreateArrayList(extensions.GetExtensionOids())); + } + } +} |