diff options
Diffstat (limited to 'Crypto/src/asn1/Asn1Sequence.cs')
| -rw-r--r-- | Crypto/src/asn1/Asn1Sequence.cs | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/Crypto/src/asn1/Asn1Sequence.cs b/Crypto/src/asn1/Asn1Sequence.cs new file mode 100644 index 000000000..3131ead84 --- /dev/null +++ b/Crypto/src/asn1/Asn1Sequence.cs @@ -0,0 +1,255 @@ +using System; +using System.Collections; +using System.IO; + +using Org.BouncyCastle.Utilities; +using Org.BouncyCastle.Utilities.Collections; + +namespace Org.BouncyCastle.Asn1 +{ + public abstract class Asn1Sequence + : Asn1Object, IEnumerable + { + private readonly IList seq; + + /** + * return an Asn1Sequence from the given object. + * + * @param obj the object we want converted. + * @exception ArgumentException if the object cannot be converted. + */ + public static Asn1Sequence GetInstance( + object obj) + { + if (obj == null || obj is Asn1Sequence) + { + return (Asn1Sequence)obj; + } + else if (obj is byte[]) + { + try + { + return Asn1Sequence.GetInstance(Asn1Object.FromByteArray((byte[])obj)); + } + catch (IOException e) + { + throw new ArgumentException("Failed to construct sequence from byte[]", e); + } + } + + throw new ArgumentException("Unknown object in GetInstance: " + obj.GetType().FullName, "obj"); + } + + /** + * Return an ASN1 sequence from a tagged object. There is a special + * case here, if an object appears to have been explicitly tagged on + * reading but we were expecting it to be implicitly tagged in the + * normal course of events it indicates that we lost the surrounding + * sequence - so we need to add it back (this will happen if the tagged + * object is a sequence that contains other sequences). If you are + * dealing with implicitly tagged sequences you really <b>should</b> + * be using this method. + * + * @param obj the tagged object. + * @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 Asn1Sequence GetInstance( + Asn1TaggedObject obj, + bool explicitly) + { + Asn1Object inner = obj.GetObject(); + + if (explicitly) + { + if (!obj.IsExplicit()) + throw new ArgumentException("object implicit - explicit expected."); + + return (Asn1Sequence) inner; + } + + // + // constructed object which appears to be explicitly tagged + // when it should be implicit means we have to add the + // surrounding sequence. + // + if (obj.IsExplicit()) + { + if (obj is BerTaggedObject) + { + return new BerSequence(inner); + } + + return new DerSequence(inner); + } + + if (inner is Asn1Sequence) + { + return (Asn1Sequence) inner; + } + + throw new ArgumentException("Unknown object in GetInstance: " + obj.GetType().FullName, "obj"); + } + + protected internal Asn1Sequence( + int capacity) + { + seq = Platform.CreateArrayList(capacity); + } + + public virtual IEnumerator GetEnumerator() + { + return seq.GetEnumerator(); + } + + [Obsolete("Use GetEnumerator() instead")] + public IEnumerator GetObjects() + { + return GetEnumerator(); + } + + private class Asn1SequenceParserImpl + : Asn1SequenceParser + { + private readonly Asn1Sequence outer; + private readonly int max; + private int index; + + public Asn1SequenceParserImpl( + Asn1Sequence outer) + { + this.outer = outer; + this.max = outer.Count; + } + + public IAsn1Convertible ReadObject() + { + if (index == max) + return null; + + Asn1Encodable obj = outer[index++]; + + if (obj is Asn1Sequence) + return ((Asn1Sequence)obj).Parser; + + if (obj is Asn1Set) + return ((Asn1Set)obj).Parser; + + // NB: Asn1OctetString implements Asn1OctetStringParser directly +// if (obj is Asn1OctetString) +// return ((Asn1OctetString)obj).Parser; + + return obj; + } + + public Asn1Object ToAsn1Object() + { + return outer; + } + } + + public virtual Asn1SequenceParser Parser + { + get { return new Asn1SequenceParserImpl(this); } + } + + /** + * return the object at the sequence position indicated by index. + * + * @param index the sequence number (starting at zero) of the object + * @return the object at the sequence position indicated by index. + */ + public virtual Asn1Encodable this[int index] + { + get { return (Asn1Encodable) seq[index]; } + } + + [Obsolete("Use 'object[index]' syntax instead")] + public Asn1Encodable GetObjectAt( + int index) + { + return this[index]; + } + + [Obsolete("Use 'Count' property instead")] + public int Size + { + get { return Count; } + } + + public virtual int Count + { + get { return seq.Count; } + } + + protected override int Asn1GetHashCode() + { + int hc = Count; + + foreach (object o in this) + { + hc *= 17; + if (o == null) + { + hc ^= DerNull.Instance.GetHashCode(); + } + else + { + hc ^= o.GetHashCode(); + } + } + + return hc; + } + + protected override bool Asn1Equals( + Asn1Object asn1Object) + { + Asn1Sequence other = asn1Object as Asn1Sequence; + + if (other == null) + return false; + + if (Count != other.Count) + return false; + + IEnumerator s1 = GetEnumerator(); + IEnumerator s2 = other.GetEnumerator(); + + while (s1.MoveNext() && s2.MoveNext()) + { + Asn1Object o1 = GetCurrent(s1).ToAsn1Object(); + Asn1Object o2 = GetCurrent(s2).ToAsn1Object(); + + if (!o1.Equals(o2)) + return false; + } + + return true; + } + + private Asn1Encodable GetCurrent(IEnumerator e) + { + Asn1Encodable encObj = (Asn1Encodable)e.Current; + + // unfortunately null was allowed as a substitute for DER null + if (encObj == null) + return DerNull.Instance; + + return encObj; + } + + protected internal void AddObject( + Asn1Encodable obj) + { + seq.Add(obj); + } + + public override string ToString() + { + return CollectionUtilities.ToString(seq); + } + } +} |