1 files changed, 104 insertions, 0 deletions
diff --git a/libfreerdp/crypto/der.c b/libfreerdp/crypto/der.c
new file mode 100644
index 0000000..5fcbf4a
--- /dev/null
+++ b/libfreerdp/crypto/der.c
@@ -0,0 +1,104 @@
+/**
+ * FreeRDP: A Remote Desktop Protocol Implementation
+ * ASN.1 Basic Encoding Rules (DER)
+ *
+ * Copyright 2011 Samsung, Author Jiten Pathy
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *	 http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <freerdp/config.h>
+
+#include <winpr/crt.h>
+
+#include <freerdp/crypto/der.h>
+
+int _der_skip_length(int length)
+{
+	if (length > 0x7F && length <= 0xFF)
+		return 2;
+	else if (length > 0xFF)
+		return 3;
+	else
+		return 1;
+}
+
+int der_write_length(wStream* s, int length)
+{
+	if (length > 0x7F && length <= 0xFF)
+	{
+		Stream_Write_UINT8(s, 0x81);
+		Stream_Write_UINT8(s, length);
+		return 2;
+	}
+	else if (length > 0xFF)
+	{
+		Stream_Write_UINT8(s, 0x82);
+		Stream_Write_UINT16_BE(s, length);
+		return 3;
+	}
+	else
+	{
+		Stream_Write_UINT8(s, length);
+		return 1;
+	}
+}
+
+int der_get_content_length(int length)
+{
+	if (length > 0x81 && length <= 0x102)
+		return length - 3;
+	else if (length > 0x102)
+		return length - 4;
+	else
+		return length - 2;
+}
+
+int der_skip_contextual_tag(int length)
+{
+	return _der_skip_length(length) + 1;
+}
+
+int der_write_contextual_tag(wStream* s, BYTE tag, int length, BOOL pc)
+{
+	Stream_Write_UINT8(s, (ER_CLASS_CTXT | ER_PC(pc)) | (ER_TAG_MASK & tag));
+	return der_write_length(s, length) + 1;
+}
+
+static void der_write_universal_tag(wStream* s, BYTE tag, BOOL pc)
+{
+	Stream_Write_UINT8(s, (ER_CLASS_UNIV | ER_PC(pc)) | (ER_TAG_MASK & tag));
+}
+
+int der_skip_octet_string(int length)
+{
+	return 1 + _der_skip_length(length) + length;
+}
+
+void der_write_octet_string(wStream* s, BYTE* oct_str, int length)
+{
+	der_write_universal_tag(s, ER_TAG_OCTET_STRING, FALSE);
+	der_write_length(s, length);
+	Stream_Write(s, oct_str, length);
+}
+
+int der_skip_sequence_tag(int length)
+{
+	return 1 + _der_skip_length(length);
+}
+
+int der_write_sequence_tag(wStream* s, int length)
+{
+	Stream_Write_UINT8(s, (ER_CLASS_UNIV | ER_CONSTRUCT) | (ER_TAG_MASK & ER_TAG_SEQUENCE));
+	return der_write_length(s, length) + 1;
+}