1 files changed, 145 insertions, 0 deletions
diff --git a/SoftHSMv2/src/lib/crypto/DerUtil.cpp b/SoftHSMv2/src/lib/crypto/DerUtil.cpp
new file mode 100644
index 0000000..1117b2e
--- /dev/null
+++ b/SoftHSMv2/src/lib/crypto/DerUtil.cpp
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2018 SURFnet bv
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*****************************************************************************
+ DerUtil.h
+
+ DER encoding convenience functions
+ *****************************************************************************/
+
+#include "config.h"
+#include "DerUtil.h"
+
+// Convert a raw ByteString to a DER encoded octet string
+ByteString DERUTIL::raw2Octet(const ByteString& byteString)
+{
+	ByteString header;
+	size_t len = byteString.size();
+
+	// Definite, short
+	if (len < 0x80)
+ 	{
+		header.resize(2);
+		header[0] = (unsigned char)0x04;
+		header[1] = (unsigned char)(len & 0x7F);
+	}
+	// Definite, long
+	else
+	{
+		// Count significate bytes
+		size_t bytes = sizeof(size_t);
+		for(; bytes > 0; bytes--)
+		{
+			size_t value = len >> ((bytes - 1) * 8);
+			if (value & 0xFF) break;
+		}
+
+		// Set header data
+		header.resize(2 + bytes);
+		header[0] = (unsigned char)0x04;
+		header[1] = (unsigned char)(0x80 | bytes);
+		for (size_t i = 1; i <= bytes; i++)
+		{
+			header[2+bytes-i] = (unsigned char) (len & 0xFF);
+			len >>= 8;
+		}
+	}
+
+	return header + byteString;
+}
+
+// Convert a DER encoded octet string to a raw ByteString
+ByteString DERUTIL::octet2Raw(const ByteString& byteString)
+{
+	ByteString rv;
+	ByteString repr = byteString;
+	size_t len = repr.size();
+	size_t controlOctets = 2;
+
+	if (len < controlOctets)
+	{
+		ERROR_MSG("Undersized octet string");
+
+		return rv;
+	}
+
+	if (repr[0] != 0x04)
+	{
+		ERROR_MSG("ByteString is not an octet string");
+
+		return rv;
+	}
+
+	// Definite, short
+	if (repr[1] < 0x80)
+	{
+		if (repr[1] != (len - controlOctets))
+		{
+			if (repr[1] < (len - controlOctets))
+			{
+				ERROR_MSG("Underrun octet string");
+			}
+			else
+			{
+				ERROR_MSG("Overrun octet string");
+			}
+
+			return rv;
+		}
+	}
+	// Definite, long
+	else
+	{
+		size_t lengthOctets = repr[1] & 0x7f;
+		controlOctets += lengthOctets;
+
+		if (controlOctets >= repr.size())
+		{
+			ERROR_MSG("Undersized octet string");
+
+			return rv;
+		}
+
+		ByteString length(&repr[2], lengthOctets);
+
+		if (length.long_val() != (len - controlOctets))
+                {
+			if (length.long_val() < (len - controlOctets))
+			{
+				ERROR_MSG("Underrun octet string");
+			}
+			else
+			{
+				ERROR_MSG("Overrun octet string");
+			}
+
+			return rv;
+		}
+	}
+
+	return repr.substr(controlOctets, len - controlOctets);
+}
+