用c语言完整实现多表代换密码,在dev中运行
时间: 2024-09-15 08:02:49 浏览: 22
在C语言中,我们已经讨论了如何实现多表代换密码,特别是使用Caesar密码为例。完整的多表代换密码可以包含多种类型的替换表,比如Vigenère密码(基于字母的多次替换)。以下是Vigenère密码的一个简单实现,包括加密和解密函数,以及在命令行中运行的例子:
```c
#include <stdio.h>
#include <string.h>
// 假设我们的替换表是26个小写字母加上空格和其他特殊字符
const char ALPHABET[] = "abcdefghijklmnopqrstuvwxyz ";
const char ALPHABET_SIZE = sizeof(ALPHABET) - 1;
char shift(char c, int shift_amount) {
if ('a' <= c && c <= 'z') {
c = ((c - 'a' + shift_amount) % ALPHABET_SIZE) + 'a';
} else if (' ' <= c && c <= '/') { // 简单假设空格和特殊字符不变
c = c;
}
return c;
}
void vigenere_cipher_encrypt(char* plaintext, char* key, char* ciphertext) {
int key_length = strlen(key);
for (int i = 0; plaintext[i]; i++) {
ciphertext[i] = shift(plaintext[i], key[i%key_length] - 'a');
}
}
void vigenere_cipher_decrypt(char* ciphertext, char* key, char* plaintext) {
int key_length = strlen(key);
for (int i = 0; ciphertext[i]; i++) {
plaintext[i] = shift(ciphertext[i], 'a' - key[i%key_length]);
}
}
int main(int argc, char *argv[]) {
if (argc != 3) {
printf("Usage: %s [ENCRYPT|DECRYPT] [KEY]\n", argv[0]);
return 1;
}
char mode = strcmp(argv[1], "ENCRYPT") == 0 ? 1 : -1; // 1 for encrypt, -1 for decrypt
char* key = argv[2];
char input_buffer[100];
char output_buffer[100];
printf("Enter text to be %srypted: ", mode > 0 ? "en" : "de");
fgets(input_buffer, sizeof(input_buffer), stdin);
input_buffer[strlen(input_buffer)-1] = '\0'; // remove newline
if (mode > 0) {
vigenere_cipher_encrypt(input_buffer, key, output_buffer);
} else {
vigenere_cipher_decrypt(output_buffer, key, input_buffer);
}
printf("Result: %s\n", output_buffer);
return 0;
}
```
要在Dev环境中运行这个程序,你需要首先保存文件(如`vigenere_cipher.c`),然后编译并链接成可执行文件,例如:
```
gcc -o vigenere_cipher vigenere_cipher.c
```
接着你可以通过命令行运行它,提供加密或解密模式和密钥:
```
./vigenere_cipher ENCRYPT your_key
./vigenere_cipher DECRYPT your_key
```