My code have a error,but I don't know how to check it,anyone can help me ? 3Q

char* MDString (char* string)
{
    MD5_CTX context;
    unsigned char digest[16];
    char output1[32];
    static char output[33] = {""};
    unsigned int len = strlen(string);
    int i;

    MD5Init(&context);
    MD5Update(&context, (unsigned char*)string, len);
    MD5Final(digest, &context);
    
    for (i = 0; i < 16; i++)
    {
        sprintf(&(output1[2*i]),"%02x",(unsigned char)digest[i]);
        sprintf(&(output1[2*i+1]),"%02x",(unsigned char)(digest[i]<<4));
    }

    for(i=0;i<=32;i++)
        output[i] = output1[i];

    return output;
}