编写一个加密函数的程序

㈠ c++编写密码加密和解密函数

void encode(char * buff)
{
char *p=buff;
while(*p)
{
*p=255-*p;
p++;
}
}

㈡ c语言编写加密程序

#include <stdio.h>
#include <string.h>
#include "global.h"
#include "md5.h"

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char
[64]));
static void Encode PROTO_LIST
((unsigned char *, UINT4 *, unsigned int));
static void Decode PROTO_LIST
((UINT4 *, unsigned char *, unsigned int));
static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned
int));
static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));

static unsigned char PADDING[64] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

#define FF(a, b, c, d, x, s, ac) { (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); (a) = ROTATE_LEFT ((a), (s)); (a) += (b);}
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
}

void MD5Init (context)
MD5_CTX *context;
{
context->count[0] = context->count[1] = 0;
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}

void MD5Update (context, input, inputLen)
MD5_CTX *context;
unsigned char *input;
unsigned int inputLen;
{
unsigned int i, index, partLen;
index = (unsigned int)((context->count[0] >> 3) & 0x3F);
if ((context->count[0] += ((UINT4)inputLen << 3))< ((UINT4)inputLen << 3))
context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);
partLen = 64 - index;
if (inputLen >= partLen)
{
MD5_memcpy((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD5Transform (context->state, context->buffer);
for (i = partLen; i + 63 < inputLen; i += 64)
MD5Transform (context->state, &input[i]);
index = 0;
}
else
i = 0;
MD5_memcpy((POINTER)&context->buffer[index], (POINTER)&input[i],inputLen-i);
}

void MD5Final (digest, context)
unsigned char digest[16];
MD5_CTX *context;
{
unsigned char bits[8];
unsigned int index, padLen;
Encode (bits, context->count, 8);
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context, PADDING, padLen);
MD5Update (context, bits, 8);
Encode (digest, context->state, 16);
MD5_memset ((POINTER)context, 0, sizeof (*context));
}

static void MD5Transform (UINT4 state[4], unsigned char block[64])
{
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);
FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

/* Round 2 */
GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */

GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

/* Round 3 */
HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

/* Round 4 */
II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
MD5_memset ((POINTER)x, 0, sizeof (x));
}

static void Encode (output, input, len)
unsigned char *output;
UINT4 *input;
unsigned int len;
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
{
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
}
}

static void Decode (output, input, len)
UINT4 *output;
unsigned char *input;
unsigned int len;
{
unsigned int i, j;
for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |(((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

static void MD5_memcpy (output, input, len)
POINTER output;
POINTER input;
unsigned int len;
{
unsigned int i;
for (i = 0; i < len; i++)
output[i] = input[i];
}

static void MD5_memset (output, value, len)
POINTER output;
int value;
unsigned int len;
{
unsigned int i;
for (i = 0; i < len; i++)
((char *)output)[i] = (char)value;
}
#ifndef MD
#define MD 5
#endif

#define TEST_BLOCK_LEN 1000
#define TEST_BLOCK_COUNT 1000

static void MDString PROTO_LIST ((char *));
static void MDPrint PROTO_LIST ((unsigned char [16]));

#define MD_CTX MD5_CTX
#define MDInit MD5Init
#define MDUpdate MD5Update
#define MDFinal MD5Final

int main (int argc, char *argv[])
{
int i;
if (argc > 1)
{ MDString(argv[1]);
return (0);
}
}

static void MDString (char *string)
{
MD_CTX context;
unsigned char digest[16];
unsigned int len = strlen (string);

MDInit (&context);
MDUpdate (&context, string, len);
MDFinal (digest, &context);

printf ("MD%d (\"%s\") = ", MD, string);
MDPrint (digest);
printf ("\n");
}

static void MDPrint (unsigned char digest[16])
{
unsigned int i;
for (i = 0; i < 16; i++)
printf ("%02x", digest[i]);

}

㈢ 写一个java加密程序

publicclass_Test2
{
publicstaticvoidmain(String[]args)throwsFileNotFoundException,IOException
{
//为了便于理解,所以有的部分为了通俗写得不够好
Scannersc=newScanner(System.in);
Stringline=sc.nextLine();
line=encrypt(line);
System.out.println(line);
newFileOutputStream("d:\word.txt").write((line+"
").getBytes());

}
//该方法是将一行数据简单加密(恺撒加密)
privatestaticStringencrypt(Stringline){
char[]chars=line.toCharArray();
for(inti=0;i<chars.length;i++)
{
//由ASCII码表得知大写字母是65-90,小写字母是97-122
if((chars[i]>=65&&chars[i]<90)||(chars[i]>=97&&chars[i]<122))
{
chars[i]=(char)(chars[i]+1);
}
if(chars[i]==90)
{
chars[i]='a';
}
if(chars[i]==122)
{
chars[i]='A';
}
}
returnnewString(chars);
}
}

㈣ 编写一个数据加密函数（用C编写）

这个问题并不难，两个数组很容易实现
main()
{
int i,a[4],b[4];
printf("请输入四个数字： ");
for(i=0;i<4;i++)
scanf("%d",a[i]);
b[0]=（a[3]+6）%8；
b[1]=（a[2]+6）%8；
b[2]=（a[1]+6）%8；
b[3]=（a[0]+6）%8；
printf("原数组是：")
for(i=0;i<4;i++)
printf("%d",a[i])
printf("加密后的数组是：")
for(i=0;i<4;i++)
printf("%d",b[i])
}

㈤ C语言编程：编写一个函数base64加密

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

constchar*chlist="+/";

intencode_string(char*str,unsignedintlength,char*stat){
	chars[103];
	inti,j;
	unsignedtemp;
	if(length<=0)return1;
	if(length>100)return2;
	str[length]='';
	strcpy(s,str);
	while(strlen(s)%3)strcat(s,"=");
	for(i=0,j=0;s[i];i+=3,j+=4){
		temp=s[i];
		temp=(temp<<8)+s[i+1];
		temp=(temp<<8)+s[i+2];
		stat[j+3]=chlist[temp&0X3F];
		temp>>=6;
		stat[j+2]=chlist[temp&0X3F];
		temp>>=6;
		stat[j+1]=chlist[temp&0X3F];
		temp>>=6;
		stat[j+0]=chlist[temp&0X3F];
	}
	stat[j]='';
	return0;
}

intIndex(charch){
	inti;
	for(i=0;chlist[i];++i){
		if(chlist[i]==ch)
			returni;
	}
	return-1;
}

voiddecode_string(char*s,char*t){
	unsignedtemp;
	inti,j,k,len=strlen(s);
	if(len%4){
		printf("无效数据。
");
		exit(2);
	}
	for(i=0,j=0;i<=len;i+=4,j+=3){
		temp=0;
		for(k=0;k<4;++k)
			temp=(temp<<6)+Index(s[i+k]);
		for(k=2;k>=0;--k){
			t[j+k]=temp&0XFF;
			temp>>=8;
		}
	}
	t[j+k]='';
}

intmain(){
	chars[100]="1a2a3s4dff5fj6u7M8B9P0O1U2";
	chart[150],u[100];
	printf("s=%s
",s);
	encode_string(s,strlen(s),t);
	printf("t=%s
",t);
	decode_string(t,u);
	printf("u=%s
",u);
	return0;
}

㈥ VB 加密与解密的程序代码

加密：

PrivateFunction JiaMi(ByVal varPass As String) As String '参数varPass是需要加密的文本内容

Dim varJiaMi As String * 20

Dim varTmp As Double

Dim strJiaMi As String

Dim I

For I = 1 To Len(varPass)

varTmp = AscW(Mid$(varPass, I, 1))

varJiaMi = Str$(((((varTmp * 1.5) / 5.6) * 2.7) * I))

strJiaMi = strJiaMi & varJiaMi

NextI

JiaMi = strJiaMi

EndFunction

解密函数：

PrivateFunction JieMi(ByVal varPass As String) As String '参数varPass是需要解密的密文内容

Dim varReturn As String * 20

Dim varConvert As Double

Dim varFinalPass As String

Dim varKey As Integer

Dim varPasslenth As Long

varPasslenth = Len(varPass)

For I = 1 To varPasslenth / 20

varReturn = Mid(varPass, (I - 1) * 20 + 1, 20)

varConvert = Val(Trim(varReturn))

varConvert = ((((varConvert / 1.5) * 5.6) / 2.7) / I)

varFinalPass = varFinalPass & ChrW(Val(varConvert))

NextI

JieMi = varFinalPass

EndFunction

(6)编写一个加密函数的程序扩展阅读：

注意事项

编写加密程序，将用户输入的一个英文句子加密为加密字符串，然后输出加密字符串。假设句子长度不超过100个字符。

根据给定的句子加密函数原型SentenceEncoding，编写函数SentenceEncoding调用给定的字符加密函数CharEncoding完成句子加密。

然后，编写主程序提示用户输入英文句子，然后调用函数SentenceEncoding对句子加密，最后输出加密后的句子。

字符加密规则为大写字母和小写字母均加密为其补码, 我们定义ASCII码值相加为’A’+’Z’即155的两个大写字母互为补码，ASCII码值相加为’a’+’z’即219的两个小写字母互为补码。

空格用@代替,句号以#代替,其它字符用句点代替。

函数原型：

void SentenceEncoding(char *soure,char *code);

功能：对待加密字符串source加密后保存加密字符串到code.

参数：char *soure，指向待加密句子的字符串指针；

char *code 指向加密字符串的字符串指针；

字符加密函数代码。

㈦ 用C语言设计一个文件加密与解密程序

c语言文件加密和解密方法如下：

1、首先打开VC++6.0；

4、声明头文件

#include<stdio.h>

#include<stdlib.h>

#include<string.h>

首先写个加密函数，算法就是简介里说的;

voidEncryptFile(FILE*sfp,FILE*dfp,charpwd)
{
charch;
if(sfp==0||dfp==0)
{
printf("ERROR! ");
return;
}
while((ch=fgetc(sfp))!=EOF)
{
if((ch>='a')&&(ch<='z'))
{
ch=(ch-'a'+1)%26+'a';
ch=ch^pwd;
}
if((ch>='A')&&(ch<='Z'))
{
ch=(ch-'A'+1)%26+'A';
ch=ch^pwd;
}
fputc(ch,dfp);
}
}

写解密子函数：与加密的过程相反;

voidDecryptFile(FILE*sfp,FILE*dfp,charpwd)
{
charch;
while((ch=fgetc(sfp))!=EOF)
{
if((ch>='a')&&(ch<='z'))
{
ch=ch^pwd;
ch=(ch-'a'+25)%26+'a';
}
if((ch>='A')&&(ch<='Z'))
{
ch=ch^pwd;
ch=(ch-'A'+25)%26+'A';
}
fputc(ch,dfp);
}
}

输出函数，输出文件内容
voidOutputFile(FILE*fp)
{
charch;
while((ch=fgetc(fp))!=EOF)
putchar(ch);
}
主函数，主要调用这几个函数
intmain()
{
/*用户输入的要加密的文件名*/
charsfilename[20];
/*用户输入加密后保存的文件名*/
chardfilename[20];
/*用来保存密码字符*/
charpwd;
FILE*sfp,*dfp;

printf(": ");
/*得到要加密的文件名*/
gets(sfilename);
/*得到加密后你要的文件名*/
printf(": ");
gets(dfilename);
/*得到加密字符*/
printf("PleaseinputyourPassword: ");
//scanf("%c",&pwd);
pwd=getch();
/*屏幕以*来表示输入的加密字符*/
printf("* ");
/*以只读方式打开要加密的文件*/
if((sfp=fopen(sfilename,"r"))==0)
{
printf("Can'topenthefile:%s ",sfilename);
exit(0);
}
/*输出要加密的文件*/
printf(": ");
OutputFile(sfp);
/*建立加密后的文件*/
if((dfp=fopen(dfilename,"w+"))==0)
{
printf("Can'topenorcreatethefile:%s ",dfilename);
//exit(0);
}
/*文件加密*/
fseek(sfp,0L,SEEK_SET);
EncryptFile(sfp,dfp,pwd);
printf(" Encryptedthefilesuccessfully! ");
/*输出加密后的文件*/
printf(": ");
fseek(dfp,0L,SEEK_SET);
OutputFile(dfp);
fclose(sfp);
fclose(dfp);
getch();
return0;
}

㈧ c语言编写字符串加密函数 不要写得太难啊

#include<stdio.h>
#include<ctype.h>

char*encrypt(char*text){
charc;
char*p=text;
for(;*text;++text){
c=*text;
if(isdigit(c))
*text='0'+'9'-c;
elseif(islower(c)){
c=c+3;
if(c>'z')
c=c-26;
*text=c;
}elseif(isupper(c)){
c=c+3;
if(c>'Z')
c=c-26;
*text=c;
}
}
returnp;
}

intmain(){
chartext[100];
printf("输入明文:");
scanf("%s",text);
printf("密文:%s
",encrypt(text));
getchar();
}

㈨ C语言编程：编写一个函数实现篱笆加密

intfence_cipher(unsignedchar*data,intdata_length,intn)
{
unsignedchar*ret;
inti,j,k=0;

if(data_length<=0||strlen((constchar*)data)==0){
return2;
}

if(n<=1||n>=data_length){
return1;
}

ret=(unsignedchar*)calloc(1,data_length+1);
if(ret==NULL){
return3;
}

for(i=0;i<n;i++)
{
for(j=0;j*(n+1)<data_length;j++)
{
if(j*(n+1)-i>=0){
ret[k++]=data[j*(n+1)-i];
}

if(i!=0&&i!=n-1&&j*(n+1)+i<data_length){
ret[k++]=data[j*(n+1)+i];
}

}
}

ret[k]='';

strncpy((char*)data,(char*)ret,data_length);
free(ret);
return0;

}