c语言设计密码检测程序？

#include <stdio.h>

#define UC (1U<<1) // upper case

#define LC (1U<<2) // lower case

#define NUM (1U<<3) // 0-9

#define ALL (UC|LC|NUM)

int check(const char pass1[], const char pass2[])

{

const char *p = &pass1[0]

unsigned int flag = 0

if (strlen(pass1) <6 || strlen(pass1) >8)

{

printf("password length is 6 to 8.\n")

return 1

}

if (strcmp(pass1, pass2))

{

printf("the tow passwords are diffrence.\n")

return 2

}

while (*p)

{

if (*p >= 'a' &&*p <= 'z') flag |= LC

else if (*p >= 'A' &&*p <= 'Z') flag |= UC

else if (*p >= '0' &&*p <= '9') flag |= NUM

else

{

printf("in valid charactor: %c.\n", *p)

return 3

}

++p

}

if (flag == ALL) return 0

if ((flag &UC) == 0)

{

printf("lack of uppercase.\n")

}

if ((flag &LC) == 0)

{

printf("lack of lowercase.\n")

}

if ((flag &NUM) == 0)

{

printf("lack of number.\n")

}

return -1

}

int main(int argc, char *argv[])

{

char pass1[100]

char pass2[100]

do {

printf("input password:")

scanf("%s", pass1)

printf("repeat password:")

scanf("%s", pass2)

} while (check(pass1, pass2) != 0)

return 0

}

// playFair 加密 你参考下 ...

#include"stdio.h"

#include"string.h"

#include"stdlib.h"

#define x 50

char MiYao[x],PassWord[x],AddPass[x],Table[5][5],Map[25]

bool Visit[27]={false}

char English[27]="abcdefghijklmnopqrstuvwxyz"

void Input()

{

printf("请输入密钥:\t") scanf("%s",MiYao)

printf("请输入待加密密码:\t") scanf("%s",PassWord)

}

void Fun_5x5()

{

int count = 0,V =0

/*标记密钥内字符为: true*/

for(int i=0MiYao[i]!='\0'i++)

if(strchr(English,MiYao[i])!=NULL)

Visit[strchr(English,MiYao[i])-English] = true

/*执行密钥矩阵 *** 作 并标记已使用字符:true*/

for(int i=0i<5i++)

for(int j=0j<5j++)

{

if(count<strlen(MiYao))

Table[i][j] = MiYao[count++]

else

{

while(Visit[V] != false) V++

Table[i][j] = English[V]

Visit[V++] = true

}

}

puts("∞∞∞密钥矩阵为∞∞∞")

for(int i=0i<5i++)

{ for(int j=0j<5j++)

printf("%3c",Table[i][j])

puts("")

}

puts("∞∞∞∞∞∞∞∞∞∞∞")

}

int IsVisited(char ch)

{

return Visit[strchr(English,ch)-English] //false 未出现过

}

void TabletoMap()

{ int count=0

for(int i=0i<5i++)

for(int j=0j<5j++)

Map[count++]=Table[i][j]

Map[count]='\0'

}

void Judge()

{

int len = strlen(PassWord),i,j,k

memset(AddPass,0,sizeof(char))

/*一对对去字母,剩下单个字母,则不变化,直接放入加密串中.*/

if(len%2){

AddPass[len-1] = PassWord[len-1]

len -=1

}

/*一对中 密钥矩阵中 存在矩阵 eg.ab 先输出a同行顶点在输出b同行顶点*/

int row1,low1,row2,low2,a1,a2

for(i=0i<leni+=2)

{

char c1,c2

c1 = PassWord[i]

c2 = PassWord[i+1]

/*一对中 两字母相同 无变化*/

/*一对中 有字母不在密钥矩阵中 无变化*/

if(c1 == c2 || ( !IsVisited(c1)||!IsVisited(c2)))

{ AddPass[i] = c1

AddPass[i+1]=c2

}else{

a1 = strchr(Map,c1)-Map

row1 = a1/5 low1 = a1%5

a2 = strchr(Map,c2)-Map

row2 = a2/5 low2 = a2%5

/*一对中 字符出现在同行或同列 简单swap字符*/

if(row1 == row2 || low1 == low2)

{

AddPass[i] = c2

AddPass[i+1] = c1

}else{

AddPass[i] = Table[row1][low2]

AddPass[i+1] = Table[row2][low1]

}

}

}AddPass[len+1]='\0'

puts("加密后字符串:")

puts(AddPass)

puts("原串是:")

puts(PassWord)

}

int main()

{

Input()

Fun_5x5()

TabletoMap()

Judge()

return 0

}

C语言设计一个简单的加密解密程序如下：

加密程序代码：

#include<stdio.h>

main()

{

char

c,filename[20]

FILE

*fp1,*fp2

printf("请输入待加密的文件名:\n")

scanf("%s",filename)

fp1=fopen(filename,"r")

fp2=fopen("miwen.txt","w")

do

{

c=fgetc(fp1)

if(c>=32&&c<=126)

{

c=c-32

c=126-c

}

if(c!=-1)

fprintf(fp2,"%c",c)

}

while(c!=-1)

}

解密程序代码：

#include<stdio.h>

#include<string.h>

main()

{

char

c,filename[20]

char

yanzhengma[20]

FILE

*fp1,*fp2

printf("请输入待解密文件名:\n")

scanf("%s",filename)

printf("请输入验证码:\n")

scanf("%s",yanzhengma)

if(strcmp(yanzhengma,"shan")==0)

{

fp1=fopen(filename,"r")

fp2=fopen("yuanwen.txt","w")

do

{

c=fgetc(fp1)

if(c>=32&&c<=126)

{

c=126-c

c=32+c

}

if(c!=-1)

fprintf(fp2,"%c",c)

}

while(c!=-1)

}

else

{

printf("验证码错误！请重新输入:\n")

scanf("%s",filename)

}

}

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