94 lines
1.7 KiB
C++
94 lines
1.7 KiB
C++
#include <bits/termios.h>
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#include <os/ArgumentParser.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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static struct termios orig;
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void restore_terminal()
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{
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ioctl(fileno(stdin), TCSETS, &orig);
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}
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char* getpass()
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{
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fputs("Password: ", stdout);
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if (ioctl(fileno(stdin), TCGETS, &orig) < 0)
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{
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perror("ioctl(TCGETS)");
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return nullptr;
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}
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atexit(restore_terminal);
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struct termios tc = orig;
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tc.c_lflag &= ~ECHO;
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if (ioctl(fileno(stdin), TCSETS, &tc) < 0)
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{
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perror("ioctl(TCSETS)");
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return nullptr;
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}
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static char buf[1024];
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char* rc = fgets(buf, sizeof(buf), stdin);
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restore_terminal();
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putchar('\n');
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if (!rc)
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{
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perror("fgets");
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return nullptr;
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}
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char* newline = strrchr(rc, '\n');
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if (newline) *newline = 0;
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return buf;
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}
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int main(int argc, char** argv)
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{
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StringView name;
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if (geteuid() != 0)
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{
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fprintf(stderr, "su must be setuid root!\n");
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return 1;
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}
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os::ArgumentParser parser;
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parser.add_positional_argument(name, "name"_sv, true);
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parser.parse(argc, argv);
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struct passwd* entry = getpwnam(name.chars());
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if (!entry)
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{
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fprintf(stderr, "su: user %s not found!\n", name.chars());
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return 1;
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}
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if (getuid() != geteuid() && *entry->pw_passwd)
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{
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char* pass = getpass();
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if (!pass) return 1;
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if (strcmp(pass, entry->pw_passwd))
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{
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fprintf(stderr, "Wrong password!\n");
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return 1;
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}
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memset(pass, 0, strlen(pass));
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}
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setgid(entry->pw_gid);
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setuid(entry->pw_uid);
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execl(entry->pw_shell, entry->pw_shell, NULL);
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}
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