mirror of
https://github.com/nzp-team/dquakeplus.git
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65 lines
832 B
C
65 lines
832 B
C
/*
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DATA Decrypt
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*/
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#include <stdlib.h>
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#include <ctype.h>
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char rotate(char c, int key)
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{
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int l = 'Z' - 'A';
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c += key % l;
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if(c < 'A')
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c += l;
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if(c > 'Z')
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c -= l;
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return c;
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}
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char encrypt(char c, int key)
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{
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if(c >= 'a' && c <= 'z')
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c = toupper(c);
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if(c >= 'A' && c <= 'Z')
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c = rotate(c, key);
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return c;
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}
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char decrypt(char c, int key)
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{
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if(c < 'A' || c > 'Z')
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return c;
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else
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return rotate(c, key);
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}
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char *strencrypt(char *s, int key, int len)
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{
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int i;
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char *result = malloc(len);
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for(i = 0; i < len; i++)
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{
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result[i] = encrypt(s[i], key);
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}
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return result;
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}
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char *strdecrypt(char *s, int key, int len)
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{
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int i;
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char *result = malloc(len);
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for(i = 0; i < len; i++)
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{
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result[i] = decrypt(s[i], -key);
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}
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return result;
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}
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