C 代码 将 Atbash 替换密码应用于文本字符串atbash.rar

# include <stdio.h> # include <stdlib.h> # include <string.h> # include <time.h> # include "atbash.h" /******************************************************************************/ char *atbash_encrypt ( char *plain ) /******************************************************************************/ /* Purpose: atbash_encrypt() encrypts a string using the ATBASH code. Discussion: Only the alphabetic characters will be encrypted. Licensing: This code is distributed under the GNU LGPL license. Modified: 20 October 2018 Author: John Burkardt Input: char *PLAIN, the string to be encrypted. Output: char *ATBASH_ENCRYPT, the encrypted version of the string. */ { char *crypt; char *crypt_pointer; /* Create space for the encrypted string. */ crypt = ( char * ) malloc ( ( strlen ( plain ) + 1 ) * sizeof ( char ) ); crypt_pointer = crypt; /* Convert plain text characters to unsigned integers, and reverse the index. */ while ( *plain != '\0' ) { if ( 'a' <= *plain && *plain <= 'z' ) { *crypt_pointer = 'a' + 'z' - *plain; } else if ( 'A' <= *plain && *plain <= 'Z' ) { *crypt_pointer = 'A' + 'Z' - *plain; } else { *crypt_pointer = *plain; } plain++; crypt_pointer++; } *crypt_pointer = '\0'; return crypt; }