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eperl_main.c  view on Meta::CPAN

    if ((stat(source, &st)) != 0) {
        PrintError(mode, source, NULL, NULL, "File `%s' not exists", source);
        CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
    }

    /*
     * Security Checks for the CGI modes
     */
    if (mode == MODE_CGI || mode == MODE_NPHCGI) {

        /*
         *
         *  == General Security ==
         *
         */

        /* general security check: allowed file extension */
        if (CGI_NEEDS_ALLOWED_FILE_EXT) {
            allow = FALSE;
            n = strlen(source);
            for (i = 0; allowed_file_ext[i] != NULL; i++) {
                k = strlen(allowed_file_ext[i]);
                if (strcmp(source+n-k, allowed_file_ext[i]) == 0) 
                    allow = TRUE;
            }
            if (!allow) {
                PrintError(mode, source, NULL, NULL, "File `%s' is not allowed to be interpreted by ePerl (wrong extension!)", source);
                CU(EX_OK);
            }
        }

        /*
         *
         *  == Perl Security ==
         *
         */

        /* perhaps force Taint mode */
        if (CGI_MODES_FORCE_TAINTING)
            fTaint = TRUE;

        /* perhaps force Warnings */
        if (CGI_MODES_FORCE_WARNINGS)
            fWarn = TRUE;

        /*
         *
         * == UID/GID switching ==
         *
         */

        /* we can only do a switching if we have euid == 0 (root) */
        if (geteuid() == 0) {

            fOkSwitch = TRUE;

            /* get our real user id (= caller uid) */
            uid = getuid();
    
            /* security check: valid caller uid */
            pw = getpwuid(uid);
            if (SETUID_NEEDS_VALID_CALLER_UID && pw == NULL) {
                if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                    PrintError(mode, source, NULL, NULL, "Invalid UID %d of caller", uid);
                    CU(EX_OK);
                }
                else
                    fOkSwitch = FALSE;
            }
            else {
                /* security check: allowed caller uid */
                if (SETUID_NEEDS_ALLOWED_CALLER_UID) {
                    allow = FALSE;
                    for (i = 0; allowed_caller_uid[i] != NULL; i++) {
                        if (isdigit(allowed_caller_uid[i][0]))
                            pw2 = getpwuid(atoi(allowed_caller_uid[i]));
                        else
                            pw2 = getpwnam(allowed_caller_uid[i]);
                        if (strcmp(pw->pw_name, pw2->pw_name) == 0) {
                            allow = TRUE;
                            break;
                        }
                    }
                    if (!allow) {
                        if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                            PrintError(mode, source, NULL, NULL, "UID %d of caller not allowed", uid);
                            CU(EX_OK);
                        }
                        else
                            fOkSwitch = FALSE;
                    }
                }
            }
    
            /* security check: valid owner UID */
            pw = getpwuid(st.st_uid);
            if (SETUID_NEEDS_VALID_OWNER_UID && pw == NULL) 
                if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                    PrintError(mode, source, NULL, NULL, "Invalid UID %d of owner", st.st_uid);
                    CU(EX_OK);
                }
                else
                    fOkSwitch = FALSE;
            else 
                uid = pw->pw_uid;
    
            /* security check: valid owner GID */
            gr = getgrgid(st.st_gid);
            if (SETUID_NEEDS_VALID_OWNER_GID && gr == NULL) 
                if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                    PrintError(mode, source, NULL, NULL, "Invalid GID %d of owner", st.st_gid);
                    CU(EX_OK);
                }
                else
                    fOkSwitch = FALSE;
            else 
                gid = gr->gr_gid;
    
            /* security check: file has to stay below owner homedir */
            if (fOkSwitch && SETUID_NEEDS_BELOW_OWNER_HOME) {
                /* preserve current working directory */
                cwd2 = getcwd(NULL, 1024);

                /* determine physical homedir of owner */
                pw = getpwuid(st.st_uid);
                if (chdir(pw->pw_dir) == -1) {
                    if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                        PrintError(mode, source, NULL, NULL, "Invalid homedir ``%s'' of file owner", pw->pw_dir);
                        CU(EX_OK);
                    }
                    else 
                        fOkSwitch = FALSE;
                }
                else {
                    dir_home = getcwd(NULL, 1024);

                    /* determine physical dir of file */
                    strcpy(dir_tmp, source);
                    if ((cp = strrchr(dir_tmp, '/')) == NULL) {
                        if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                            PrintError(mode, source, NULL, NULL, "Invalid script ``%s'': no absolute path", source);
                            CU(EX_OK);
                        }
                        else 
                            fOkSwitch = FALSE;
                    }
                    else {
                        *cp = NUL;
                        if (chdir(dir_tmp) == -1) {
                            if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                                PrintError(mode, source, NULL, NULL, "Invalid script ``%s'': cannot chdir to its location", source);
                                CU(EX_OK);
                            }
                            else 
                                fOkSwitch = FALSE;
                        }
                        else {
                            dir_script = getcwd(NULL, 1024);
        
                            /* dir_home has to be a prefix of dir_script */
                            if (strncmp(dir_script, dir_home, strlen(dir_home)) < 0) {
                                if (DO_FOR_FAILED_STEP == STOP_AND_ERROR) {
                                    PrintError(mode, source, NULL, NULL, "Invalid script ``%s'': does not stay below homedir of owner", source);
                                    CU(EX_OK);
                                }
                                else 
                                    fOkSwitch = FALSE;
                            }
            
                            free(dir_script);
                        }
                    }
                    free(dir_home);
                }

                /* restore original cwd */
                chdir(cwd2);
        
                free(cwd2);
            }
    
            if (fOkSwitch && uid != 0 && gid != 0) {
                /* switch to new uid/gid */
                if (((setgid(gid)) != 0) || (initgroups(pw->pw_name,gid) != 0)) {
                    PrintError(mode, source, NULL, NULL, "Unable to set GID %d: setgid/initgroups failed", gid);

eperl_main.c  view on Meta::CPAN

        setuid(uid);
#endif
#ifdef HAVE_SETEGID
        setegid(uid);
#else
        /* HP/UX and others eliminate the effective GID with setgid(gid) ! */
        setgid(gid);
#endif
    }

    /* read source file into internal buffer */
    if ((cpBuf = ePerl_ReadSourceFile(source, &cpBuf, &nBuf)) == NULL) {
        PrintError(mode, source, NULL, NULL, "Cannot open source file `%s' for reading\n%s", source, ePerl_GetError);
        CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
    }

    /* strip shebang prefix */
    if (strncmp(cpBuf, "#!", 2) == 0) {
        for (cpScript = cpBuf;
             (*cpScript != ' ' && *cpScript != '\t' && *cpScript != '\n') && (cpScript-cpBuf < nBuf);
             cpScript++)
            ;
        for (cpScript = cpBuf;
             *cpScript != '\n' && (cpScript-cpBuf < nBuf);
             cpScript++)
            ;
        cpScript++;
    }
    else
        cpScript = cpBuf;

    /* now set the additional env vars */
    env = mysetenv(env, "SCRIPT_SRC_PATH", "%s", abspath(source));
    env = mysetenv(env, "SCRIPT_SRC_PATH_FILE", "%s", filename(source));
    env = mysetenv(env, "SCRIPT_SRC_PATH_DIR", "%s", abspath(dirname(source)));
    if ((cpPath = getenv("PATH_INFO")) != NULL) {
        if ((cpHost = getenv("SERVER_NAME")) == NULL)
            cpHost = "localhost";
        cpPort = getenv("SERVER_PORT");
        if (strcmp(cpPort, "80") == 0)
            cpPort = NULL;
        sprintf(ca, "http://%s%s%s%s", 
                cpHost, cpPort != NULL ? ":" : "", cpPort != NULL ? cpPort : "", cpPath);
        env = mysetenv(env, "SCRIPT_SRC_URL", "%s", ca);
        env = mysetenv(env, "SCRIPT_SRC_URL_FILE", "%s", filename(ca));
        env = mysetenv(env, "SCRIPT_SRC_URL_DIR", "%s", dirname(ca));
    }
    else {
        env = mysetenv(env, "SCRIPT_SRC_URL", "file://%s", abspath(source));
        env = mysetenv(env, "SCRIPT_SRC_URL_FILE", "%s", filename(source));
        env = mysetenv(env, "SCRIPT_SRC_URL_DIR", "file://%s", abspath(source));
    }

    env = mysetenv(env, "SCRIPT_SRC_SIZE", "%d", nBuf);
    stat(source, &st);
    env = mysetenv(env, "SCRIPT_SRC_MODIFIED", "%d", st.st_mtime);
    cp = ctime(&(st.st_mtime));
    cp[strlen(cp)-1] = NUL;
    env = mysetenv(env, "SCRIPT_SRC_MODIFIED_CTIME", "%s", cp);
    env = mysetenv(env, "SCRIPT_SRC_MODIFIED_ISOTIME", "%s", isotime(&(st.st_mtime)));
    if ((pw = getpwuid(st.st_uid)) != NULL)
        env = mysetenv(env, "SCRIPT_SRC_OWNER", "%s", pw->pw_name);
    else
        env = mysetenv(env, "SCRIPT_SRC_OWNER", "unknown-uid-%d", st.st_uid);
    env = mysetenv(env, "VERSION_INTERPRETER", "%s", ePerl_WebID);
    env = mysetenv(env, "VERSION_LANGUAGE", "Perl/%s", AC_perl_vers);

    /* optionally run the ePerl preprocessor */
    if (fPP) {
        /* switch to directory where script stays */
        getcwd(cwd, MAXPATHLEN);
        strcpy(sourcedir, source);
        for (cp = sourcedir+strlen(sourcedir); cp > sourcedir && *cp != '/'; cp--)
            ;
        *cp = NUL;
        chdir(sourcedir);
        /* run the preprocessor */
        if ((cpBuf3 = ePerl_PP(cpScript, RememberedINC)) == NULL) {
            PrintError(mode, source, NULL, NULL, "Preprocessing failed for `%s': %s", source, ePerl_PP_GetError());
            CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
        }
        cpScript = cpBuf3;
        /* switch to previous dir */
        chdir(cwd);
    }

    /* convert bristled source to valid Perl code */
    if ((cpBuf2 = ePerl_Bristled2Plain(cpScript)) == NULL) {
        PrintError(mode, source, NULL, NULL, "Cannot convert bristled code file `%s' to pure HTML", source);
        CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
    }
    cpScript = cpBuf2;

    /* write buffer to temporary script file */
    strcpy(perlscript, mytmpfile("ePerl.script"));
#ifndef DEBUG_ENABLED
    unlink(perlscript);
#endif
    if ((fp = fopen(perlscript, "w")) == NULL) {
        PrintError(mode, source, NULL, NULL, "Cannot open Perl script file `%s' for writing", perlscript);
        CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
    }
    fwrite(cpScript, strlen(cpScript), 1, fp);
    fclose(fp); fp = NULL;

    /* in Debug mode output the script to the console */
    if (fDebug) {
        if ((fp = fopen("/dev/tty", "w")) == NULL) {
            PrintError(mode, source, NULL, NULL, "Cannot open /dev/tty for debugging message");
            CU(mode == MODE_FILTER ? EX_IOERR : EX_OK);
        }
        fprintf(fp, "----internally created Perl script-----------------------------------\n");
        fwrite(cpScript, strlen(cpScript)-1, 1, fp);
        if (cpScript[strlen(cpScript)-1] == '\n') 
            fprintf(fp, "%c", cpScript[strlen(cpScript)-1]);
        else 
            fprintf(fp, "%c\n", cpScript[strlen(cpScript)-1]);
        fprintf(fp, "----internally created Perl script-----------------------------------\n");
        fclose(fp); fp = NULL;
    }