116 lines
2.6 KiB
C
116 lines
2.6 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include "main.h"
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#include <pwd.h>
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#include <security/pam_appl.h>
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#include <security/pam_misc.h>
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int main(int argc, char** argv) {
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if(argc <= 1) {
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printf("insufficient\n");
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return 0;
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}
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uid_t uid = getuid();
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Config config = load_config();
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struct passwd* pwd = getpwuid(uid);
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char* user = pwd->pw_name;
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int result = validate(user);
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if(result) {
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return 2;
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}
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char* cmd = argv[1];
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char* args[argc];
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for(int i = 0; i < argc-1; i++) {
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args[i] = malloc(strlen(argv[i+1]));
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strcpy(args[i], argv[i+1]);
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}
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args[argc-1] = NULL;
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if(allowed(uid, &config)) {
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setuid(geteuid());
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setgid(getegid());
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int x = execvp(cmd, args);
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return x;
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} else {
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fprintf(stderr, "nope\n");
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return 1;
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}
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}
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int validate(char* user) {
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pam_handle_t *pamh = NULL;
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struct pam_conv conv = {misc_conv, NULL};
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int status = pam_start("udo", user, &conv, &pamh);
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if(status != PAM_SUCCESS) {
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printf("bad: %d\n", status);
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return 1;
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}
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status = pam_authenticate(pamh, 0);
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if(status != PAM_SUCCESS) {
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printf("wrong: %d\n", status);
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return 1;
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}
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status = pam_acct_mgmt(pamh, 0);
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if (pam_end(pamh,status) != PAM_SUCCESS) {
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pamh = NULL;
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exit(2);
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}
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if(status != PAM_SUCCESS) {
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printf("don't: %d\n", status);
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return 1;
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}
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return 0;
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}
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int allowed(uid_t uid, Config* config) {
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for(int i = 0; i < config->len; i++) {
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if(config->uids[i] == uid) {
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return 1;
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}
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}
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return 0;
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}
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Config load_config() {
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FILE* fp = fopen("/etc/udo.conf", "r");
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char* contents = malloc(CHUNK_SIZE + 1);
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int offset = 0;
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char buf[CHUNK_SIZE];
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int read = CHUNK_SIZE;
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while(read == CHUNK_SIZE) {
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read = fread(buf, 1, CHUNK_SIZE, fp);
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memcpy(contents + offset, buf, read);
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offset += read;
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if(read == CHUNK_SIZE) {
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contents = realloc(contents, offset + CHUNK_SIZE + 1);
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}
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}
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fclose(fp);
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contents[offset] = '\0';
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Config config;
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config.uids = malloc(1 * sizeof(uid_t));
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config.len = 0;
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char* ctx;
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char* word = strtok_r(contents, " ", &ctx);
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while(word != NULL) {
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uid_t uid = atoi(word);
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config.uids = realloc(config.uids, (config.len+1) * sizeof(uid_t));
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config.uids[config.len++] = uid;
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word = strtok_r(NULL, "\n", &ctx);
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}
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return config;
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}
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