一、在.net micro framework中增加LibTom加解密算法

素颜马尾好姑娘i 2022-08-05 00:52 119阅读 0赞

思路.按照.net的方式新建一个供C\#调用的C接口,然后通过C接口调用LibTom的加解密算法。

1、C\#调用C方法,请参考.net micro framework提供的资料进行

2、修改工程的dotNetMF.proj文件,然后把LibTom的必要文件加上,要添加那些文件可以，参考[使用Libtomcrypt RSA/ECC等加密算法到项目中][Libtomcrypt RSA_ECC]

3、然后重新编译固件,此时你会发现好多问题.

我遇到的问题及相关解决方式如下:

EXEC : error : L6915E: Library reports error: __use_no_semihosting_swi was requested, but _sys_open was referenced [C:\MF\PK\Solutions\NetduinoPlus2\TinyCLR\TinyCLR.proj]
    	EXEC : error : L6915E: Library reports error: __use_no_semihosting_swi was requested, but clock was referenced [C:\MF\PK\Solutions\NetduinoPlus2\TinyCLR\TinyCLR.proj]
    
    	A、在tomcrypt_custom.h中打开以下宏定义,主要不使用printf or getline，fprintf, assert, fopen, fclose这些函数,参考
    	http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka11357.html
    	/* clean the stack of functions which put private information on stack */
    	#define LTC_CLEAN_STACK 
    
    	/* disable all file related functions */
    	#define LTC_NO_FILE
    
    	/* disable all forms of ASM */
    	#define LTC_NO_ASM
    
    	/* disable FAST mode */
    	/* #define LTC_NO_FAST */
    
    	/* disable BSWAP on x86 */
    	 #define LTC_NO_BSWAP/
    	 
    	B、在tomcrypt_cfg.h中修改ARGTYPE的定义
    		/* type of argument checking, 0=default, 1=fatal and 2=error+continue, 3=nothing */
    	#ifndef ARGTYPE
    	   #define ARGTYPE  4
    	#endif
    
    	解决_sys_open这个Bug。
    	
    	B、rng_get_bytes.c文件中取消这个函数
    	/* on ANSI C platforms with 100 < CLOCKS_PER_SEC < 10000 */
    	#if	0//defined(CLOCKS_PER_SEC) && !defined(WINCE)
    
    	#define ANSI_RNG
    
    	static unsigned long rng_ansic(unsigned char *buf, unsigned long len, 
    								   void (*callback)(void))
    	{
    	   clock_t t1;
    	   int l, acc, bits, a, b;
    
    	   if (XCLOCKS_PER_SEC < 100 || XCLOCKS_PER_SEC > 10000) {
    		  return 0;
    	   }
    
    	   l = len;
    	   bits = 8;
    	   acc  = a = b = 0;
    	   while (len--) {
    		   if (callback != NULL) callback();
    		   while (bits--) {
    			  do {
    				 t1 = XCLOCK(); while (t1 == XCLOCK()) a ^= 1;
    				 t1 = XCLOCK(); while (t1 == XCLOCK()) b ^= 1;
    			  } while (a == b);
    			  acc = (acc << 1) | a;
    		   }
    		   *buf++ = acc; 
    		   acc  = 0;
    		   bits = 8;
    	   }
    	   acc = bits = a = b = 0;
    	   return l;
    	}
    
    	#endif

[Libtomcrypt RSA_ECC]: http://blog.csdn.net/lan120576664/article/details/46045831