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Diffstat (limited to '')
| -rw-r--r-- | Crypto/src/asn1/DerObjectIdentifier.cs | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/Crypto/src/asn1/DerObjectIdentifier.cs b/Crypto/src/asn1/DerObjectIdentifier.cs new file mode 100644 index 000000000..7dc963729 --- /dev/null +++ b/Crypto/src/asn1/DerObjectIdentifier.cs @@ -0,0 +1,242 @@ +using System; +using System.IO; +using System.Text; +using System.Text.RegularExpressions; + +using Org.BouncyCastle.Math; + +namespace Org.BouncyCastle.Asn1 +{ + public class DerObjectIdentifier + : Asn1Object + { + private static readonly Regex OidRegex = new Regex(@"\A[0-2](\.[0-9]+)+\z"); + + private readonly string identifier; + + /** + * return an Oid from the passed in object + * + * @exception ArgumentException if the object cannot be converted. + */ + public static DerObjectIdentifier GetInstance( + object obj) + { + if (obj == null || obj is DerObjectIdentifier) + { + return (DerObjectIdentifier) obj; + } + + throw new ArgumentException("illegal object in GetInstance: " + obj.GetType().Name, "obj"); + } + + /** + * return an object Identifier from a tagged object. + * + * @param obj the tagged object holding the object we want + * @param explicitly true if the object is meant to be explicitly + * tagged false otherwise. + * @exception ArgumentException if the tagged object cannot + * be converted. + */ + public static DerObjectIdentifier GetInstance( + Asn1TaggedObject obj, + bool explicitly) + { + return GetInstance(obj.GetObject()); + } + + public DerObjectIdentifier( + string identifier) + { + if (identifier == null) + throw new ArgumentNullException("identifier"); + if (!OidRegex.IsMatch(identifier)) + throw new FormatException("string " + identifier + " not an OID"); + + this.identifier = identifier; + } + + // TODO Change to ID? + public string Id + { + get { return identifier; } + } + + public virtual DerObjectIdentifier Branch(string branchID) + { + return new DerObjectIdentifier(identifier + "." + branchID); + } + + /** + * Return true if this oid is an extension of the passed in branch, stem. + * @param stem the arc or branch that is a possible parent. + * @return true if the branch is on the passed in stem, false otherwise. + */ + public virtual bool On(DerObjectIdentifier stem) + { + string id = Id, stemId = stem.Id; + return id.Length > stemId.Length && id[stemId.Length] == '.' && id.StartsWith(stemId); + } + + internal DerObjectIdentifier( + byte[] bytes) + : this(MakeOidStringFromBytes(bytes)) + { + } + + private void WriteField( + Stream outputStream, + long fieldValue) + { + byte[] result = new byte[9]; + int pos = 8; + result[pos] = (byte)(fieldValue & 0x7f); + while (fieldValue >= (1L << 7)) + { + fieldValue >>= 7; + result[--pos] = (byte)((fieldValue & 0x7f) | 0x80); + } + outputStream.Write(result, pos, 9 - pos); + } + + private void WriteField( + Stream outputStream, + BigInteger fieldValue) + { + int byteCount = (fieldValue.BitLength + 6) / 7; + if (byteCount == 0) + { + outputStream.WriteByte(0); + } + else + { + BigInteger tmpValue = fieldValue; + byte[] tmp = new byte[byteCount]; + for (int i = byteCount-1; i >= 0; i--) + { + tmp[i] = (byte) ((tmpValue.IntValue & 0x7f) | 0x80); + tmpValue = tmpValue.ShiftRight(7); + } + tmp[byteCount-1] &= 0x7f; + outputStream.Write(tmp, 0, tmp.Length); + } + } + + internal override void Encode( + DerOutputStream derOut) + { + OidTokenizer tok = new OidTokenizer(identifier); + MemoryStream bOut = new MemoryStream(); + DerOutputStream dOut = new DerOutputStream(bOut); + + string token = tok.NextToken(); + int first = int.Parse(token); + + token = tok.NextToken(); + int second = int.Parse(token); + + WriteField(bOut, first * 40 + second); + + while (tok.HasMoreTokens) + { + token = tok.NextToken(); + if (token.Length < 18) + { + WriteField(bOut, Int64.Parse(token)); + } + else + { + WriteField(bOut, new BigInteger(token)); + } + } + + dOut.Dispose(); + + derOut.WriteEncoded(Asn1Tags.ObjectIdentifier, bOut.ToArray()); + } + + protected override int Asn1GetHashCode() + { + return identifier.GetHashCode(); + } + + protected override bool Asn1Equals( + Asn1Object asn1Object) + { + DerObjectIdentifier other = asn1Object as DerObjectIdentifier; + + if (other == null) + return false; + + return this.identifier.Equals(other.identifier); + } + + public override string ToString() + { + return identifier; + } + + private static string MakeOidStringFromBytes( + byte[] bytes) + { + StringBuilder objId = new StringBuilder(); + long value = 0; + BigInteger bigValue = null; + bool first = true; + + for (int i = 0; i != bytes.Length; i++) + { + int b = bytes[i]; + + if (value < 0x80000000000000L) + { + value = value * 128 + (b & 0x7f); + if ((b & 0x80) == 0) // end of number reached + { + if (first) + { + switch ((int)value / 40) + { + case 0: + objId.Append('0'); + break; + case 1: + objId.Append('1'); + value -= 40; + break; + default: + objId.Append('2'); + value -= 80; + break; + } + first = false; + } + + objId.Append('.'); + objId.Append(value); + value = 0; + } + } + else + { + if (bigValue == null) + { + bigValue = BigInteger.ValueOf(value); + } + bigValue = bigValue.ShiftLeft(7); + bigValue = bigValue.Or(BigInteger.ValueOf(b & 0x7f)); + if ((b & 0x80) == 0) + { + objId.Append('.'); + objId.Append(bigValue); + bigValue = null; + value = 0; + } + } + } + + return objId.ToString(); + } + } +} |