C language uses Des_ncbc_encrypt and segment errors (core dumps) to resolve __c language

1. Install SSL library files first

sudo apt-get install Libssl-dev

Introducing Header Files

#include <openssl/des.h>

2. Define calling Method

void Call_cbc () {Des_cblock key; Des_random_key (&key);   Random number algorithm produces 64 random bit des_string_to_key ("pass", &key);//String generates key Des_key_schedule schedule;

    Literal meaning is cipher table des_set_key_checked (&key, &schedule);
    printf ("CBC mode encryption and decryption: \ n"); unsigned char *input = "My name is Xuhuayong";//Encrypted input string long len = (strlen (input) +7)/8*8;//length printf ("Before Encryption:%d\n", Len
    );
    unsigned char *output= (char*) malloc (len);
    Des_cblock Ivec;
    memset ((char*) &ivec, 0, sizeof (IVEC));//ivec Clear 0 printf ("Before Encryption:%s\n", input);
    Des_ncbc_encrypt (input, output, strlen (input), &schedule, &ivec, Des_encrypt);
    printf ("Encrypted:");
    int i;
    for (i = 0; i < strlen (output); i++) printf ("%02x", output[i);//Print two-bit 16-digit printf ("\ n") per character;
    memset ((char*) &ivec, 0, sizeof (IVEC));           input= (char*) malloc (len);
    。。。。。。
    Des_ncbc_encrypt (output, input, Len, &schedule, &ivec, Des_decrypt);
printf ("After decryption:%s\n", input); }

If the above program does not annotate the sentence, there will be "paragraph error (core has been dumped)", meaning that the input pointer to a fixed allocation of space,

Content cannot be changed to raise a segment error, and the annotation section is allocated space again, you can assign a value.

For example:

unsigned char *input1 = "My name is Xuhuayong";//Encrypted input string
unsigned char input2[21] = "My name is Xuhuayong";//Encrypted input string
s trcpy (INPUT1, "ABCD");

strcpy use assignment also appears "segment error (Core dump)", but instead of allocating space for it or changing it to input2, there is no error.