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#include "lib4.h"
#include "lib3.h"
#include "lib2.h"
#include "lib.h"
/**
* encrypt always with the same key, same nonce?
*
**/
int aes_ctr_edit(char *ciphertext, int ciphertext_length, int offset, char *newtext)
{
// do not allow greater ciphertexts
if((strlen(newtext)+offset) > ciphertext_length)
return 1;
// insert newtext at offset and reencrpyt
char *plaintext = malloc(ciphertext_length);
aes_ctr(ciphertext, ciphertext_length, plaintext, key, nonce);
memcpy(&plaintext[offset], newtext, strlen(newtext));
aes_ctr(plaintext, ciphertext_length, ciphertext, key, nonce);
return 0;
}
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