PBC库传入参数文件问题

た入场券 2022-06-17 04:07 286阅读 0赞

**配置不同类型的椭圆曲线，需要修改配对类型。**

**PBC的param目录下有好多种：**

**![Center][]**

PBC手册是这样写的

**Chapter 5. Param functions**

Pairings are initialized from pairing parameters, which are objects of type pbc\_param\_t. Some applications can ignore this data type because pairing\_init\_set\_str() handles it behind the scenes:it reads a string as a pbc\_param\_t, then initializes a pairing with these parameters.

*  int pbc\_param\_init\_set\_str(pbc\_param\_t par, const char \*s)

Initializes pairing parameters from the string s. Returns 0 if successful, 1 otherwise.

*  int pbc\_param\_init\_set\_buf(pbc\_param\_t par, const char \*s, size\_t len)

Same, but read at most len bytes. If len is 0, it behaves as the previous function. Returns 0 if successful,

*  void pbc\_param\_out\_str(FILE \*stream, pbc\_param\_t p)

Write pairing parameters to ’stream’ in a text format.

*  void pbc\_param\_clear(pbc\_param\_t p)

Clear p. Call after p is no longer needed.

可以使用的有以下三种：

（1）Windows下直接调用的只有A，D,F三种类型的曲线

pairing_t pairing;
    a_param_input(pairing);

（2）产生动态配参数

pairing_t pairing;
    a_param_t w;
    a_param_init(w);
    a_param_gen(w,160,512);//取160bit，512bit最佳
    pairing_init_a_param(pairing,w);
    
     
     
     
     
     （3）自己写的一个pbc_new.h头文件
     #include <stdio.h>
    #include "pbc.h"
    static inline void pbc_demo_pairing_init(pairing_t pairing, char* filename) {  
    	char s[16384];  
    	FILE *fp;  
    	unsigned int count;
    	fp = fopen(filename, "r");  
    	if (!fp){  
          printf("error opening %s", filename);  
    	}  
          count = fread(s, 1, 16384, fp);  
    	if (!count){  
          printf("input error");  
    	 }  
    	fclose(fp);  
    	pairing_init_inp_buf(pairing, s, count); } 
     主函数main（）里的调用代码：
     #define F_PATH "d:\\a.param" 我放在D盘根目录下
    	//char* c_filepath = "d:\\a.param";  
        pbc_demo_pairing_init(pairing, F_PATH);  //pbc_new.h

[Center]: /images/20220617/98711073b06a43dd8754c8551c4dde2e.png