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/**
* 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;
}
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