diff options
Diffstat (limited to 'ext/ipp/sources/ippcp/pcpgfpxstuff.c')
-rw-r--r-- | ext/ipp/sources/ippcp/pcpgfpxstuff.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/ext/ipp/sources/ippcp/pcpgfpxstuff.c b/ext/ipp/sources/ippcp/pcpgfpxstuff.c new file mode 100644 index 0000000..ecb4cfe --- /dev/null +++ b/ext/ipp/sources/ippcp/pcpgfpxstuff.c @@ -0,0 +1,77 @@ +/******************************************************************************* +* Copyright 2010-2018 Intel Corporation +* All Rights Reserved. +* +* If this software was obtained under the Intel Simplified Software License, +* the following terms apply: +* +* The source code, information and material ("Material") contained herein is +* owned by Intel Corporation or its suppliers or licensors, and title to such +* Material remains with Intel Corporation or its suppliers or licensors. The +* Material contains proprietary information of Intel or its suppliers and +* licensors. The Material is protected by worldwide copyright laws and treaty +* provisions. No part of the Material may be used, copied, reproduced, +* modified, published, uploaded, posted, transmitted, distributed or disclosed +* in any way without Intel's prior express written permission. No license under +* any patent, copyright or other intellectual property rights in the Material +* is granted to or conferred upon you, either expressly, by implication, +* inducement, estoppel or otherwise. Any license under such intellectual +* property rights must be express and approved by Intel in writing. +* +* Unless otherwise agreed by Intel in writing, you may not remove or alter this +* notice or any other notice embedded in Materials by Intel or Intel's +* suppliers or licensors in any way. +* +* +* If this software was obtained under the Apache License, Version 2.0 (the +* "License"), the following terms apply: +* +* 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. +*******************************************************************************/ + +/* +// Intel(R) Integrated Performance Primitives. Cryptography Primitives. +// Internal operations over GF(p) extension. +// +// Context: +// cpGFpGetOptimalWinSize() +// +*/ + +#include "owncp.h" +#include "pcpbnumisc.h" +#include "pcpgfpxstuff.h" +#include "gsscramble.h" + +static int div_upper(int a, int d) +{ return (a+d-1)/d; } + +static int getNumOperations(int bitsize, int w) +{ + int n_overhead = (1<<w) -1; + int n_ops = div_upper(bitsize, w) + n_overhead; + return n_ops; +} + +int cpGFpGetOptimalWinSize(int bitsize) +{ + int w_opt = 1; + int n_opt = getNumOperations(bitsize, w_opt); + int w_trial; + for(w_trial=w_opt+1; w_trial<=IPP_MAX_EXPONENT_NUM; w_trial++) { + int n_trial = getNumOperations(bitsize, w_trial); + if(n_trial>=n_opt) break; + w_opt = w_trial; + n_opt = n_trial; + } + return w_opt; +} |