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Diffstat (limited to 'Crypto/src/asn1/Asn1Set.cs')
-rw-r--r-- | Crypto/src/asn1/Asn1Set.cs | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/Crypto/src/asn1/Asn1Set.cs b/Crypto/src/asn1/Asn1Set.cs new file mode 100644 index 000000000..f5b66495c --- /dev/null +++ b/Crypto/src/asn1/Asn1Set.cs @@ -0,0 +1,326 @@ +using System; +using System.Collections; + +using Org.BouncyCastle.Utilities; +using Org.BouncyCastle.Utilities.Collections; + +namespace Org.BouncyCastle.Asn1 +{ + abstract public class Asn1Set + : Asn1Object, IEnumerable + { + private readonly IList _set; + + /** + * return an ASN1Set from the given object. + * + * @param obj the object we want converted. + * @exception ArgumentException if the object cannot be converted. + */ + public static Asn1Set GetInstance( + object obj) + { + if (obj == null || obj is Asn1Set) + { + return (Asn1Set)obj; + } + + throw new ArgumentException("Unknown object in GetInstance: " + obj.GetType().FullName, "obj"); + } + + /** + * Return an ASN1 set 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 + * set - 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 sets 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 Asn1Set GetInstance( + Asn1TaggedObject obj, + bool explicitly) + { + Asn1Object inner = obj.GetObject(); + + if (explicitly) + { + if (!obj.IsExplicit()) + throw new ArgumentException("object implicit - explicit expected."); + + return (Asn1Set) inner; + } + + // + // constructed object which appears to be explicitly tagged + // and it's really implicit means we have to add the + // surrounding sequence. + // + if (obj.IsExplicit()) + { + return new DerSet(inner); + } + + if (inner is Asn1Set) + { + return (Asn1Set) inner; + } + + // + // in this case the parser returns a sequence, convert it + // into a set. + // + if (inner is Asn1Sequence) + { + Asn1EncodableVector v = new Asn1EncodableVector(); + Asn1Sequence s = (Asn1Sequence) inner; + + foreach (Asn1Encodable ae in s) + { + v.Add(ae); + } + + // TODO Should be able to construct set directly from sequence? + return new DerSet(v, false); + } + + throw new ArgumentException("Unknown object in GetInstance: " + obj.GetType().FullName, "obj"); + } + + protected internal Asn1Set( + int capacity) + { + _set = Platform.CreateArrayList(capacity); + } + + public virtual IEnumerator GetEnumerator() + { + return _set.GetEnumerator(); + } + + [Obsolete("Use GetEnumerator() instead")] + public IEnumerator GetObjects() + { + return GetEnumerator(); + } + + /** + * return the object at the set position indicated by index. + * + * @param index the set number (starting at zero) of the object + * @return the object at the set position indicated by index. + */ + public virtual Asn1Encodable this[int index] + { + get { return (Asn1Encodable) _set[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 _set.Count; } + } + + public virtual Asn1Encodable[] ToArray() + { + Asn1Encodable[] values = new Asn1Encodable[this.Count]; + for (int i = 0; i < this.Count; ++i) + { + values[i] = this[i]; + } + return values; + } + + private class Asn1SetParserImpl + : Asn1SetParser + { + private readonly Asn1Set outer; + private readonly int max; + private int index; + + public Asn1SetParserImpl( + Asn1Set 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 virtual Asn1Object ToAsn1Object() + { + return outer; + } + } + + public Asn1SetParser Parser + { + get { return new Asn1SetParserImpl(this); } + } + + 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) + { + Asn1Set other = asn1Object as Asn1Set; + + 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; + } + + /** + * return true if a <= b (arrays are assumed padded with zeros). + */ + private bool LessThanOrEqual( + byte[] a, + byte[] b) + { + int len = System.Math.Min(a.Length, b.Length); + for (int i = 0; i != len; ++i) + { + if (a[i] != b[i]) + { + return a[i] < b[i]; + } + } + return len == a.Length; + } + + protected internal void Sort() + { + if (_set.Count > 1) + { + bool swapped = true; + int lastSwap = _set.Count - 1; + + while (swapped) + { + int index = 0; + int swapIndex = 0; + byte[] a = ((Asn1Encodable) _set[0]).GetEncoded(); + + swapped = false; + + while (index != lastSwap) + { + byte[] b = ((Asn1Encodable) _set[index + 1]).GetEncoded(); + + if (LessThanOrEqual(a, b)) + { + a = b; + } + else + { + object o = _set[index]; + _set[index] = _set[index + 1]; + _set[index + 1] = o; + + swapped = true; + swapIndex = index; + } + + index++; + } + + lastSwap = swapIndex; + } + } + } + + protected internal void AddObject( + Asn1Encodable obj) + { + _set.Add(obj); + } + + public override string ToString() + { + return CollectionUtilities.ToString(_set); + } + } +} |