diff options
Diffstat (limited to 'decrypt.c')
| -rw-r--r-- | decrypt.c | 41 |
1 files changed, 24 insertions, 17 deletions
@@ -1,36 +1,43 @@ #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <unistd.h> int main(int argc, char** argv) { - if(argc==0) { + /* We need a file to encrypt */ + if(argc==1) { fprintf(stderr, "Arguments fool!"); return 1; } + /* Now lets open that file */ FILE* file = fopen(argv[1], "r"); - fseek(file, 0, SEEK_END); - int length = ftell(file); - fseek(file, 0, SEEK_SET); - char filearr[length]; - fread(filearr, length, 1, file); - fclose(file); + /* And a temporary file to hold the encrypted data */ + char tpath[255] = "/tmp/"; + strcat(tpath, argv[1]); + FILE* temp = fopen(tpath, "w"); + /* Now we need the passphrase. Get it */ printf("Enter Passphrase:\n"); - char passphrase[81]; - fgets(passphrase, 81, stdin); + char passphrase[255]; + fgets(passphrase, 255, stdin); int passlen = strlen(passphrase) - 1; - int i=0,j=0; - for(i=0;i<length;i++) { + int c,j=0; + /* Now we encrypt! */ + while((c=fgetc(file)) != EOF) { if(j==passlen) { - j=0; - i--; + fputc(c-passphrase[0], temp); + j=1; } else { - filearr[i] -= passphrase[j]; + fputc(c-passphrase[j], temp); j++; } } - file = fopen(argv[1], "w"); - fwrite(filearr, 1, length, file); - fflush(file); + /* Close the files */ + fflush(temp); + fclose(temp); fclose(file); + /* Move the file back */ + char cmd[255]; + sprintf(cmd, "%s %s %s", "/bin/mv", tpath, argv[1]); + system(cmd); return 0; } |