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/*
* Copyright (c) 2010 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.
*/
/*****************************************************************************
OSSLUtil.h
OpenSSL convenience functions
*****************************************************************************/
#include "config.h"
#include "log.h"
#include "OSSLUtil.h"
#include <openssl/asn1.h>
#include <openssl/err.h>
// Convert an OpenSSL BIGNUM to a ByteString
ByteString OSSL::bn2ByteString(const BIGNUM* bn)
{
ByteString rv;
if (bn != NULL)
{
rv.resize(BN_num_bytes(bn));
BN_bn2bin(bn, &rv[0]);
}
return rv;
}
// Convert a ByteString to an OpenSSL BIGNUM
BIGNUM* OSSL::byteString2bn(const ByteString& byteString)
{
if (byteString.size() == 0) return NULL;
return BN_bin2bn(byteString.const_byte_str(), byteString.size(), NULL);
}
#ifdef WITH_ECC
// Convert an OpenSSL EC GROUP to a ByteString
ByteString OSSL::grp2ByteString(const EC_GROUP* grp)
{
ByteString rv;
if (grp != NULL)
{
rv.resize(i2d_ECPKParameters(grp, NULL));
unsigned char *p = &rv[0];
i2d_ECPKParameters(grp, &p);
}
return rv;
}
// Convert a ByteString to an OpenSSL EC GROUP
EC_GROUP* OSSL::byteString2grp(const ByteString& byteString)
{
const unsigned char *p = byteString.const_byte_str();
return d2i_ECPKParameters(NULL, &p, byteString.size());
}
// POINT_CONVERSION_UNCOMPRESSED 0x04
// Convert an OpenSSL EC POINT in the given EC GROUP to a ByteString
ByteString OSSL::pt2ByteString(const EC_POINT* pt, const EC_GROUP* grp)
{
ByteString rv;
if (pt != NULL && grp != NULL)
{
size_t len = EC_POINT_point2oct(grp, pt, POINT_CONVERSION_UNCOMPRESSED, NULL, 0, NULL);
// Definite, short
if (len <= 0x7f)
{
rv.resize(2 + len);
rv[0] = V_ASN1_OCTET_STRING;
rv[1] = len & 0x7f;
EC_POINT_point2oct(grp, pt, POINT_CONVERSION_UNCOMPRESSED, &rv[2], len, NULL);
}
// Definite, long
else
{
// Get the number of length octets
ByteString length(len);
unsigned int counter = 0;
while (length[counter] == 0 && counter < (length.size()-1)) counter++;
ByteString lengthOctets(&length[counter], length.size() - counter);
rv.resize(len + 2 + lengthOctets.size());
rv[0] = V_ASN1_OCTET_STRING;
rv[1] = 0x80 | lengthOctets.size();
memcpy(&rv[2], &lengthOctets[0], lengthOctets.size());
EC_POINT_point2oct(grp, pt, POINT_CONVERSION_UNCOMPRESSED, &rv[2 + lengthOctets.size()], len, NULL);
}
}
return rv;
}
// Convert a ByteString to an OpenSSL EC POINT in the given EC GROUP
EC_POINT* OSSL::byteString2pt(const ByteString& byteString, const EC_GROUP* grp)
{
size_t len = byteString.size();
size_t controlOctets = 2;
if (len < controlOctets)
{
ERROR_MSG("Undersized EC point");
return NULL;
}
ByteString repr = byteString;
if (repr[0] != V_ASN1_OCTET_STRING)
{
ERROR_MSG("EC point tag is not OCTET STRING");
return NULL;
}
// Definite, short
if (repr[1] < 0x80)
{
if (repr[1] != (len - controlOctets))
{
if (repr[1] < (len - controlOctets))
{
ERROR_MSG("Underrun EC point");
}
else
{
ERROR_MSG("Overrun EC point");
}
return NULL;
}
}
// Definite, long
else
{
size_t lengthOctets = repr[1] & 0x7f;
controlOctets += lengthOctets;
if (controlOctets >= repr.size())
{
ERROR_MSG("Undersized EC point");
return NULL;
}
ByteString length(&repr[2], lengthOctets);
if (length.long_val() != (len - controlOctets))
{
if (length.long_val() < (len - controlOctets))
{
ERROR_MSG("Underrun EC point");
}
else
{
ERROR_MSG("Overrun EC point");
}
return NULL;
}
}
EC_POINT* pt = EC_POINT_new(grp);
if (!EC_POINT_oct2point(grp, pt, &repr[controlOctets], len - controlOctets, NULL))
{
ERROR_MSG("EC_POINT_oct2point failed: %s", ERR_error_string(ERR_get_error(), NULL));
EC_POINT_free(pt);
return NULL;
}
return pt;
}
#endif
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