More Span-based Stream methods

5 files changed, 158 insertions, 6 deletions

diff --git a/crypto/src/asn1/Asn1OutputStream.cs b/crypto/src/asn1/Asn1OutputStream.cs
index 59178ea31..163e3848c 100644
--- a/crypto/src/asn1/Asn1OutputStream.cs
+++ b/crypto/src/asn1/Asn1OutputStream.cs
@@ -1,5 +1,10 @@
 using System;
 using System.IO;
+using System.Diagnostics;
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+using System.Buffers.Binary;
+using System.Numerics;
+#endif
 
 using Org.BouncyCastle.Utilities.IO;
 
@@ -73,15 +78,19 @@ namespace Org.BouncyCastle.Asn1
         {
             if (dl < 128)
             {
+                Debug.Assert(dl >= 0);
                 WriteByte((byte)dl);
                 return;
             }
 
 #if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-            Span<byte> stack = stackalloc byte[5];
+            Span<byte> encoding = stackalloc byte[5];
+            BinaryPrimitives.WriteUInt32BigEndian(encoding[1..], (uint)dl);
+            int leadingZeroBytes = BitOperations.LeadingZeroCount((uint)dl) / 8;
+            encoding[leadingZeroBytes] = (byte)(0x84 - leadingZeroBytes);
+            Write(encoding[leadingZeroBytes..]);
 #else
             byte[] stack = new byte[5];
-#endif
             int pos = stack.Length;
 
             do
@@ -94,9 +103,6 @@ namespace Org.BouncyCastle.Asn1
             int count = stack.Length - pos;
             stack[--pos] = (byte)(0x80 | count);
 
-#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-            Write(stack[pos..]);
-#else
             Write(stack, pos, count + 1);
 #endif
         }
diff --git a/crypto/src/asn1/ConstructedBitStream.cs b/crypto/src/asn1/ConstructedBitStream.cs
index 49f54fc1b..f089dac75 100644
--- a/crypto/src/asn1/ConstructedBitStream.cs
+++ b/crypto/src/asn1/ConstructedBitStream.cs
@@ -33,6 +33,9 @@ namespace Org.BouncyCastle.Asn1
         {
             Streams.ValidateBufferArguments(buffer, offset, count);
 
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+            return Read(buffer.AsSpan(offset, count));
+#else
             if (count < 1)
                 return 0;
 
@@ -75,8 +78,57 @@ namespace Org.BouncyCastle.Asn1
                     m_currentStream = m_currentParser.GetBitStream();
                 }
             }
+#endif
         }
 
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public override int Read(Span<byte> buffer)
+        {
+            if (buffer.IsEmpty)
+                return 0;
+
+            if (m_currentStream == null)
+            {
+                if (!m_first)
+                    return 0;
+
+                m_currentParser = GetNextParser();
+                if (m_currentParser == null)
+                    return 0;
+
+                m_first = false;
+                m_currentStream = m_currentParser.GetBitStream();
+            }
+
+            int totalRead = 0;
+
+            for (;;)
+            {
+                int numRead = m_currentStream.Read(buffer[totalRead..]);
+
+                if (numRead > 0)
+                {
+                    totalRead += numRead;
+
+                    if (totalRead == buffer.Length)
+                        return totalRead;
+                }
+                else
+                {
+                    m_padBits = m_currentParser.PadBits;
+                    m_currentParser = GetNextParser();
+                    if (m_currentParser == null)
+                    {
+                        m_currentStream = null;
+                        return totalRead;
+                    }
+
+                    m_currentStream = m_currentParser.GetBitStream();
+                }
+            }
+        }
+#endif
+
         public override int ReadByte()
         {
             if (m_currentStream == null)
diff --git a/crypto/src/asn1/ConstructedOctetStream.cs b/crypto/src/asn1/ConstructedOctetStream.cs
index 12aa14e74..d005f9fe7 100644
--- a/crypto/src/asn1/ConstructedOctetStream.cs
+++ b/crypto/src/asn1/ConstructedOctetStream.cs
@@ -1,3 +1,4 @@
+using System;
 using System.IO;
 
 using Org.BouncyCastle.Utilities;
@@ -22,6 +23,9 @@ namespace Org.BouncyCastle.Asn1
 		{
 			Streams.ValidateBufferArguments(buffer, offset, count);
 
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+			return Read(buffer.AsSpan(offset, count));
+#else
 			if (count < 1)
                 return 0;
 
@@ -63,8 +67,56 @@ namespace Org.BouncyCastle.Asn1
 					m_currentStream = next.GetOctetStream();
 				}
 			}
+#endif
 		}
 
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+		public override int Read(Span<byte> buffer)
+		{
+			if (buffer.IsEmpty)
+                return 0;
+
+			if (m_currentStream == null)
+			{
+				if (!m_first)
+					return 0;
+
+                Asn1OctetStringParser next = GetNextParser();
+                if (next == null)
+                    return 0;
+
+				m_first = false;
+				m_currentStream = next.GetOctetStream();
+			}
+
+			int totalRead = 0;
+
+			for (;;)
+			{
+				int numRead = m_currentStream.Read(buffer[totalRead..]);
+
+				if (numRead > 0)
+				{
+					totalRead += numRead;
+
+					if (totalRead == buffer.Length)
+						return totalRead;
+				}
+				else
+				{
+                    Asn1OctetStringParser next = GetNextParser();
+                    if (next == null)
+					{
+						m_currentStream = null;
+						return totalRead;
+					}
+
+					m_currentStream = next.GetOctetStream();
+				}
+			}
+		}
+#endif
+
 		public override int ReadByte()
 		{
 			if (m_currentStream == null)
diff --git a/crypto/src/asn1/DefiniteLengthInputStream.cs b/crypto/src/asn1/DefiniteLengthInputStream.cs
index ed5bd2446..89f0d5a62 100644
--- a/crypto/src/asn1/DefiniteLengthInputStream.cs
+++ b/crypto/src/asn1/DefiniteLengthInputStream.cs
@@ -79,6 +79,27 @@ namespace Org.BouncyCastle.Asn1
             return numRead;
         }
 
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public override int Read(Span<byte> buffer)
+        {
+            if (_remaining == 0)
+                return 0;
+
+            int toRead = System.Math.Min(buffer.Length, _remaining);
+            int numRead = _in.Read(buffer[..toRead]);
+
+            if (numRead < 1)
+                throw new EndOfStreamException("DEF length " + _originalLength + " object truncated by " + _remaining);
+
+            if ((_remaining -= numRead) == 0)
+            {
+                SetParentEofDetect();
+            }
+
+            return numRead;
+        }
+#endif
+
         internal void ReadAllIntoByteArray(byte[] buf)
         {
             if (_remaining != buf.Length)
diff --git a/crypto/src/asn1/IndefiniteLengthInputStream.cs b/crypto/src/asn1/IndefiniteLengthInputStream.cs
index 1c8bd9a15..e192e9e8b 100644
--- a/crypto/src/asn1/IndefiniteLengthInputStream.cs
+++ b/crypto/src/asn1/IndefiniteLengthInputStream.cs
@@ -57,7 +57,28 @@ namespace Org.BouncyCastle.Asn1
 			return numRead + 1;
 		}
 
-		public override int ReadByte()
+#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        public override int Read(Span<byte> buffer)
+        {
+            // Only use this optimisation if we aren't checking for 00
+            if (_eofOn00 || buffer.Length <= 1)
+                return base.Read(buffer);
+
+            if (_lookAhead < 0)
+                return 0;
+
+            int numRead = _in.Read(buffer[1..]);
+            if (numRead <= 0)
+                throw new EndOfStreamException();
+
+            buffer[0] = (byte)_lookAhead;
+            _lookAhead = RequireByte();
+
+            return numRead + 1;
+        }
+#endif
+
+        public override int ReadByte()
 		{
             if (_eofOn00 && _lookAhead <= 0)
             {