172 lines
3.8 KiB
C
Executable File
172 lines
3.8 KiB
C
Executable File
/*
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* (C) Copyright 2012
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* wangflord@allwinnertech.com
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program;
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*
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*/
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/*
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A. 加密解密
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1. 密钥的产生
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1) 找出两个相异的大素数P和Q，令N＝P×Q，M＝（P－1）*（Q－1）。
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2) 找出与M互素的大数E，且E<M；用欧氏算法计算出大数D，使D×E≡1 MOD M。
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3) 丢弃P和Q，公开E，D和N。E和N即加密密钥(公钥)，D和N即解密密钥(私钥)。
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2. 加密的步骤
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1) 计算N的有效位数tn（以字节数计），将最高位的零忽略掉，令tn1＝tn－1。比如N＝0x012A05，其有效位数tn＝5，tn1＝4
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2) 将明文数据A分割成tn1位（以字节数计）的块，每块看成一个大数，块数记为bn。从而，保证了每块都小于N。
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3) 对A的每一块Ai进行Bi＝Ai^E MOD N运算。Bi就是密文数据的一块，将所有密文块合并起来，就得到了密文数据B。
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3. 解密的步骤
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1) 同加密的第一步。
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2) 将密文数据B分割成tn位（以字节数计）的块，每块看成一个大数，块数记为bn。
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3) 对B的每一块Bi进行Ci＝Bi^D MOD N运算。Ci就是密文数据的一块，将所有密文块合并起来，就得到了密文数据C。
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*/
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#include "signature.h"
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void rsa_dump(void);
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typedef struct public_key_pairs_t
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{
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unsigned public_key; // e
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unsigned divider; // n
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}
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public_key_pairs;
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typedef struct private_key_pairs_t
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{
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unsigned private_key; // d
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unsigned divider; // n
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}
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private_key_pairs;
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#define P (127)
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#define Q (401)
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#define N ((P) * (Q))
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#define M ((P-1) * (Q-1))
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#define E (53)
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public_key_pairs pblc_keys;
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private_key_pairs prvt_keys;
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static unsigned probe_gcd(unsigned divdend, unsigned divder)
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{
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unsigned ret = divdend % divder;
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while(ret)
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{
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divdend = divder;
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divder = ret;
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ret = divdend % divder;
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}
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return divder;
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}
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unsigned probe_high_level_power_mod(unsigned base_value, unsigned power, unsigned divider)
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{
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unsigned ret = 1;
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base_value %= divider;
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while(power > 0)
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{
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if(power & 1)
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{
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ret = (ret * base_value) % divider;
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}
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power /= 2;
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base_value = (base_value * base_value) % divider;
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}
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return ret;
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}
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unsigned rsa_init(void)
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{
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unsigned k;
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unsigned product;
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unsigned m_value;
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m_value = M;
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k = 1;
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if(probe_gcd(m_value, E) == 1) //e,M互质
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{
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do
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{
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product = M * k + 1;
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if(!(product % E))
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{
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pblc_keys.public_key = E;
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pblc_keys.divider = N;
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prvt_keys.private_key = product/E;
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prvt_keys.divider = N;
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#ifdef DEBUG_MODE
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rsa_dump();
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#endif
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return 0;
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}
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k ++;
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}
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while(1);
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}
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return -1;
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}
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void rsa_dump(void)
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{
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printf("base value\n");
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printf("M = %d(%d * %d), N = %d(%d * %d)\n", M, P-1, Q-1, N, P, Q);
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printf("public key: \n");
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printf("{e, n} = %d, %d\n", pblc_keys.public_key, pblc_keys.divider);
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printf("private key: \n");
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printf("{d, n} = %d, %d\n", prvt_keys.private_key, prvt_keys.divider);
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}
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void rsa_encrypt( unsigned *input, unsigned int length, unsigned *output )
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{
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unsigned int i;
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for(i=0;i<length;i++)
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{
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debug("rsa_encrypt %d start\n", i);
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output[i] = probe_high_level_power_mod(input[i], pblc_keys.public_key, pblc_keys.divider);
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debug("rsa_encrypt %d end\n", i);
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}
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return ;
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}
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void rsa_decrypt( unsigned *input, unsigned int length, unsigned *output )
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{
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unsigned int i;
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for(i=0;i<length;i++)
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{
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output[i] = probe_high_level_power_mod(input[i], prvt_keys.private_key, prvt_keys.divider);
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}
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return ;
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}
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