現(xiàn)在網(wǎng)上有的大部分都是理論

1、現(xiàn)在網(wǎng)上有的大部分都是理論，這里將給出一個簡單加密模塊的全部源程序（源代碼）至于 RSA 的理論網(wǎng)上一大把， 它是基于公鑰加密體制的一種算法。 這個實(shí)例主要是用來將某一重要文件綁定到一個 IP 地址上。把它拷貝下來，存為 CODE.C ，然后執(zhí)行GCC O CODE CODE.C然后用 ./ CODE E IP ADDRESS FILENAME對文件進(jìn)行加密?；蛴?/CODE D IP ADDRESS進(jìn)行解密整個過程中產(chǎn)生了兩個中間文件,至于什么文件,你去試一試就知道啦!#include "stdio.h"#include "string.h"int e

2、,d=1,n;main(int argc,char *argv)int ip,fai,p=43,q=59,ch1,i=0,j=0,edch,dech=0;char *num,*cha,ch,*file="index.html"FILE *fp,*fp2;if (argc<2)printf("paramater error!");exit(0);if (argc>3)file=argv3;/printf("%s,",file)e=iptoint(argv2);/printf("%s,%s",argv1,a

3、rgv2);switch (*argv1)case 'e':/printf("e=%d",e);if (fp2=fopen("encode.htm","w+")=NULL)printf("can't open file");exit(0);"code.c" 199L, 3571Cn=p*q;fai=(p-1)*(q-1);if(fp=fopen(file,"r")=NULL)printf("can't open giving file

4、");exit(0);elsewhile(ch1=fgetc(fp)!=EOF)edch=fmod(ch1,e,n);if (edch>0 && edch<10) fprintf(fp2,"%s","000"); fprintf(fp2,"%d",edch);else if (edch<100 && edch>10) fprintf(fp2,"%s","00"); fprintf(fp2,"%d",edch);

5、else if (edch<1000 && edch>100) fprintf(fp2,"%s","0"); fprintf(fp2,"%d",edch);else if (edch<10000 && edch>1000) fprintf(fp2,"%d",edch);else fputc('n',fp2);close(fp);close(fp2);break;case 'd':/ printf("d=%d"

6、,e);if (fp2=fopen("decode.html","w+")=NULL)if (fp2=fopen("decode.html","w+")=NULL)printf("can't open file");exit(0);n=p*q;fai=(p-1)*(q-1);while(d*e)%fai)!=1)d+;if(fp=fopen("encode.htm","r")=NULL)printf("can't open fil

7、e");exit(0);else i=0;/ printf("e=%d,d=%d,n=%d,",e,d,n);while(ch=fgetc(fp)!=EOF)if (i=4)/dech=(int)num0)*1000+(int)num1)*100+(int)num2)*10+(int)num3;/printf("yuan=%d,",dech);dech=fmod(dech,d,n);/printf("new=%d,",dech);fprintf(fp2,"%c",dech);i=0;dech=0;/swi

8、tch (ch)case '9':dech=dech*10+9;break;case '1':dech=dech*10+1;break;case '2':dech=dech*10+2;break;case '3':dech=dech*10+3;break;case '4':dech=dech*10+4;break;case '3':dech=dech*10+3;break;case '4':dech=dech*10+4;break;case '5':dech=dech

9、*10+5;break;case '6':dech=dech*10+6;break;case '7':dech=dech*10+7;break;case '8':dech=dech*10+8;break;default:dech=dech*10;/ printf("dech=%d,",dech);numi=ch;i+;dech=fmod(dech,d,n);fprintf(fp2,"%c",dech);close(fp);close(fp2);break;default:printf("Usage

10、:code option.Ip Address.n"); printf("List information about the optionn"); printf("e bind ip address to index.htmln");printf("d decode from the encodeing file to index2.html");int iptoint(ip)char *ip;int i,ei=0,len;int prime=0;len=strlen(ip);len=strlen(ip);for(i=0;i<len;i+)if(ipi>'0' && ipi<'9')ei=ei+i*(int)ipi);ei=ei/1000+(ei/100)%10+(ei/10)%10+ei%10;/printf("%d",ei);/len=ei/2;/while(prime=0)/indent: Standard input:2: Error:Unexpected end of filewhile (ei % 2)= 0) | (ei % 3) = 0) ei=ei+1;/* prime=1;for