Apart from the issues addressed by the currently unmerged PR #5, I found an undefined behavior issue in pointer-struct.c which might cause the program to reject valid input.

The issue is that the gen_password() function allocates and initializes a string to hold the generated password, but it does not add a null terminator:

int gen_password(struct userinfo* info){
    int count = strlen(info->username);
    int x = 0;
    char * pass = malloc(count);
    for(x = 0; x < count; x++){
        pass[x] = ((char)info->username[x] + (char)info->key)^ (char)info->realKey;
        pass[x] = pass[x] - 0x13;
    }
    info->password = pass;
    return 0;
}

The main() function then calls strlen() on that string, which is undefined behavior due to the string not being null-terminated:

for(pwordLen = 0; pwordLen < strlen(info.password);pwordLen++ ){

This might cause the loop to iterate too many times, breaking the logic.

edit: Session 3's files binary suffers from the same issue. However, the source code for it, file.c, was fixed in this commit, so the binary just needs to be rebuilt.