diff --git a/fixtures/login.defs b/fixtures/login.defs new file mode 100644 index 0000000000000..62f203471656f --- /dev/null +++ b/fixtures/login.defs @@ -0,0 +1,341 @@ +# +# /etc/login.defs - Configuration control definitions for the login package. +# +# Three items must be defined: MAIL_DIR, ENV_SUPATH, and ENV_PATH. +# If unspecified, some arbitrary (and possibly incorrect) value will +# be assumed. All other items are optional - if not specified then +# the described action or option will be inhibited. +# +# Comment lines (lines beginning with "#") and blank lines are ignored. +# +# Modified for Linux. --marekm + +# REQUIRED for useradd/userdel/usermod +# Directory where mailboxes reside, _or_ name of file, relative to the +# home directory. If you _do_ define MAIL_DIR and MAIL_FILE, +# MAIL_DIR takes precedence. +# +# Essentially: +# - MAIL_DIR defines the location of users mail spool files +# (for mbox use) by appending the username to MAIL_DIR as defined +# below. +# - MAIL_FILE defines the location of the users mail spool files as the +# fully-qualified filename obtained by prepending the user home +# directory before $MAIL_FILE +# +# NOTE: This is no more used for setting up users MAIL environment variable +# which is, starting from shadow 4.0.12-1 in Debian, entirely the +# job of the pam_mail PAM modules +# See default PAM configuration files provided for +# login, su, etc. +# +# This is a temporary situation: setting these variables will soon +# move to /etc/default/useradd and the variables will then be +# no more supported +MAIL_DIR /var/mail +#MAIL_FILE .mail + +# +# Enable logging and display of /var/log/faillog login failure info. +# This option conflicts with the pam_tally PAM module. +# +FAILLOG_ENAB yes + +# +# Enable display of unknown usernames when login failures are recorded. +# +# WARNING: Unknown usernames may become world readable. +# See #290803 and #298773 for details about how this could become a security +# concern +LOG_UNKFAIL_ENAB no + +# +# Enable logging of successful logins +# +LOG_OK_LOGINS no + +# +# Enable "syslog" logging of su activity - in addition to sulog file logging. +# SYSLOG_SG_ENAB does the same for newgrp and sg. +# +SYSLOG_SU_ENAB yes +SYSLOG_SG_ENAB yes + +# +# If defined, all su activity is logged to this file. +# +#SULOG_FILE /var/log/sulog + +# +# If defined, file which maps tty line to TERM environment parameter. +# Each line of the file is in a format something like "vt100 tty01". +# +#TTYTYPE_FILE /etc/ttytype + +# +# If defined, login failures will be logged here in a utmp format +# last, when invoked as lastb, will read /var/log/btmp, so... +# +FTMP_FILE /var/log/btmp + +# +# If defined, the command name to display when running "su -". For +# example, if this is defined as "su" then a "ps" will display the +# command is "-su". If not defined, then "ps" would display the +# name of the shell actually being run, e.g. something like "-sh". +# +SU_NAME su + +# +# If defined, file which inhibits all the usual chatter during the login +# sequence. If a full pathname, then hushed mode will be enabled if the +# user's name or shell are found in the file. If not a full pathname, then +# hushed mode will be enabled if the file exists in the user's home directory. +# +HUSHLOGIN_FILE .hushlogin +#HUSHLOGIN_FILE /etc/hushlogins + +# +# *REQUIRED* The default PATH settings, for superuser and normal users. +# +# (they are minimal, add the rest in the shell startup files) +ENV_SUPATH PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin +ENV_PATH PATH=/usr/local/bin:/usr/bin:/bin:/foo + +# +# Terminal permissions +# +# TTYGROUP Login tty will be assigned this group ownership. +# TTYPERM Login tty will be set to this permission. +# +# If you have a "write" program which is "setgid" to a special group +# which owns the terminals, define TTYGROUP to the group number and +# TTYPERM to 0620. Otherwise leave TTYGROUP commented out and assign +# TTYPERM to either 622 or 600. +# +# In Debian /usr/bin/bsd-write or similar programs are setgid tty +# However, the default and recommended value for TTYPERM is still 0600 +# to not allow anyone to write to anyone else console or terminal + +# Users can still allow other people to write them by issuing +# the "mesg y" command. + +TTYGROUP tty +TTYPERM 0600 + +# +# Login configuration initializations: +# +# ERASECHAR Terminal ERASE character ('\010' = backspace). +# KILLCHAR Terminal KILL character ('\025' = CTRL/U). +# UMASK Default "umask" value. +# +# The ERASECHAR and KILLCHAR are used only on System V machines. +# +# UMASK is the default umask value for pam_umask and is used by +# useradd and newusers to set the mode of the new home directories. +# 022 is the "historical" value in Debian for UMASK +# 027, or even 077, could be considered better for privacy +# There is no One True Answer here : each sysadmin must make up his/her +# mind. +# +# If USERGROUPS_ENAB is set to "yes", that will modify this UMASK default value +# for private user groups, i. e. the uid is the same as gid, and username is +# the same as the primary group name: for these, the user permissions will be +# used as group permissions, e. g. 022 will become 002. +# +# Prefix these values with "0" to get octal, "0x" to get hexadecimal. +# +ERASECHAR 0177 +KILLCHAR 025 +UMASK 022 + +# +# Password aging controls: +# +# PASS_MAX_DAYS Maximum number of days a password may be used. +# PASS_MIN_DAYS Minimum number of days allowed between password changes. +# PASS_WARN_AGE Number of days warning given before a password expires. +# +PASS_MAX_DAYS 99999 +PASS_MIN_DAYS 0 +PASS_WARN_AGE 7 + +# +# Min/max values for automatic uid selection in useradd +# +UID_MIN 1000 +UID_MAX 60000 +# System accounts +#SYS_UID_MIN 100 +#SYS_UID_MAX 999 + +# +# Min/max values for automatic gid selection in groupadd +# +GID_MIN 1000 +GID_MAX 60000 +# System accounts +#SYS_GID_MIN 100 +#SYS_GID_MAX 999 + +# +# Max number of login retries if password is bad. This will most likely be +# overriden by PAM, since the default pam_unix module has it's own built +# in of 3 retries. However, this is a safe fallback in case you are using +# an authentication module that does not enforce PAM_MAXTRIES. +# +LOGIN_RETRIES 5 + +# +# Max time in seconds for login +# +LOGIN_TIMEOUT 60 + +# +# Which fields may be changed by regular users using chfn - use +# any combination of letters "frwh" (full name, room number, work +# phone, home phone). If not defined, no changes are allowed. +# For backward compatibility, "yes" = "rwh" and "no" = "frwh". +# +CHFN_RESTRICT rwh + +# +# Should login be allowed if we can't cd to the home directory? +# Default in no. +# +DEFAULT_HOME yes + +# +# If defined, this command is run when removing a user. +# It should remove any at/cron/print jobs etc. owned by +# the user to be removed (passed as the first argument). +# +#USERDEL_CMD /usr/sbin/userdel_local + +# +# Enable setting of the umask group bits to be the same as owner bits +# (examples: 022 -> 002, 077 -> 007) for non-root users, if the uid is +# the same as gid, and username is the same as the primary group name. +# +# If set to yes, userdel will remove the user´s group if it contains no +# more members, and useradd will create by default a group with the name +# of the user. +# +USERGROUPS_ENAB yes + +# +# Instead of the real user shell, the program specified by this parameter +# will be launched, although its visible name (argv[0]) will be the shell's. +# The program may do whatever it wants (logging, additional authentification, +# banner, ...) before running the actual shell. +# +# FAKE_SHELL /bin/fakeshell + +# +# If defined, either full pathname of a file containing device names or +# a ":" delimited list of device names. Root logins will be allowed only +# upon these devices. +# +# This variable is used by login and su. +# +#CONSOLE /etc/consoles +#CONSOLE console:tty01:tty02:tty03:tty04 + +# +# List of groups to add to the user's supplementary group set +# when logging in on the console (as determined by the CONSOLE +# setting). Default is none. +# +# Use with caution - it is possible for users to gain permanent +# access to these groups, even when not logged in on the console. +# How to do it is left as an exercise for the reader... +# +# This variable is used by login and su. +# +#CONSOLE_GROUPS floppy:audio:cdrom + +# +# If set to "yes", new passwords will be encrypted using the MD5-based +# algorithm compatible with the one used by recent releases of FreeBSD. +# It supports passwords of unlimited length and longer salt strings. +# Set to "no" if you need to copy encrypted passwords to other systems +# which don't understand the new algorithm. Default is "no". +# +# This variable is deprecated. You should use ENCRYPT_METHOD. +# +#MD5_CRYPT_ENAB no + +# +# If set to MD5 , MD5-based algorithm will be used for encrypting password +# If set to SHA256, SHA256-based algorithm will be used for encrypting password +# If set to SHA512, SHA512-based algorithm will be used for encrypting password +# If set to DES, DES-based algorithm will be used for encrypting password (default) +# Overrides the MD5_CRYPT_ENAB option +# +# Note: It is recommended to use a value consistent with +# the PAM modules configuration. +# +ENCRYPT_METHOD SHA512 + +# +# Only used if ENCRYPT_METHOD is set to SHA256 or SHA512. +# +# Define the number of SHA rounds. +# With a lot of rounds, it is more difficult to brute forcing the password. +# But note also that it more CPU resources will be needed to authenticate +# users. +# +# If not specified, the libc will choose the default number of rounds (5000). +# The values must be inside the 1000-999999999 range. +# If only one of the MIN or MAX values is set, then this value will be used. +# If MIN > MAX, the highest value will be used. +# +# SHA_CRYPT_MIN_ROUNDS 5000 +# SHA_CRYPT_MAX_ROUNDS 5000 + +################# OBSOLETED BY PAM ############## +# # +# These options are now handled by PAM. Please # +# edit the appropriate file in /etc/pam.d/ to # +# enable the equivelants of them. +# +############### + +#MOTD_FILE +#DIALUPS_CHECK_ENAB +#LASTLOG_ENAB +#MAIL_CHECK_ENAB +#OBSCURE_CHECKS_ENAB +#PORTTIME_CHECKS_ENAB +#SU_WHEEL_ONLY +#CRACKLIB_DICTPATH +#PASS_CHANGE_TRIES +#PASS_ALWAYS_WARN +#ENVIRON_FILE +#NOLOGINS_FILE +#ISSUE_FILE +#PASS_MIN_LEN +#PASS_MAX_LEN +#ULIMIT +#ENV_HZ +#CHFN_AUTH +#CHSH_AUTH +#FAIL_DELAY + +################# OBSOLETED ####################### +# # +# These options are no more handled by shadow. # +# # +# Shadow utilities will display a warning if they # +# still appear. # +# # +################################################### + +# CLOSE_SESSIONS +# LOGIN_STRING +# NO_PASSWORD_CONSOLE +# QMAIL_DIR + + + diff --git a/lib/srv/exec.go b/lib/srv/exec.go index 2fc1389c72816..4b2e16de34c2f 100644 --- a/lib/srv/exec.go +++ b/lib/srv/exec.go @@ -17,9 +17,11 @@ limitations under the License. package srv import ( + "bufio" "fmt" "io" "net" + "os" "os/exec" "os/user" "path/filepath" @@ -179,6 +181,7 @@ func prepareCommand(ctx *ctx) (*exec.Cmd, error) { } c.Env = []string{ "LANG=en_US.UTF-8", + getDefaultEnvPath(""), "HOME=" + osUser.HomeDir, "USER=" + osUserName, "SHELL=" + shell, @@ -322,3 +325,38 @@ func collectStatus(cmd *exec.Cmd, err error) (*execResult, error) { } return &execResult{code: status.ExitStatus(), command: cmd.Path}, nil } + +// getDefaultEnvPath returns the default value of PATH environment variable for +// new logins (prior to shell) +// +// Normally getDefaultEnvPath is set to "" (default /etc/login.defs is used) +// but for unit testing it takes any file +// +// Returns a strings which looks like "PATH=/usr/bin:/bin" +func getDefaultEnvPath(loginDefsPath string) string { + const emptyPath = "PATH=" + if loginDefsPath == "" { + loginDefsPath = "/etc/login.defs" + } + f, err := os.Open(loginDefsPath) + if err != nil { + log.Warn(err) + return emptyPath + } + defer f.Close() + + // read /etc/login.defs line by line: + scanner := bufio.NewScanner(f) + for scanner.Scan() { + line := strings.TrimSpace(scanner.Text()) + // skip comments and empty lines: + if line == "" || line[0] == '#' { + continue + } + fields := strings.Fields(line) + if len(fields) > 1 && fields[0] == "ENV_PATH" { + return strings.TrimSpace(fields[1]) + } + } + return emptyPath +} diff --git a/lib/srv/exec_test.go b/lib/srv/exec_test.go index 01f78bc3f2de2..67986ebd94fd3 100644 --- a/lib/srv/exec_test.go +++ b/lib/srv/exec_test.go @@ -54,6 +54,7 @@ func (s *ExecSuite) SetUpSuite(c *check.C) { func (s *ExecSuite) TestOSCommandPrep(c *check.C) { expectedEnv := []string{ "LANG=en_US.UTF-8", + getDefaultEnvPath(""), fmt.Sprintf("HOME=%s", s.usr.HomeDir), fmt.Sprintf("USER=%s", s.usr.Username), "SHELL=/bin/sh", @@ -92,6 +93,11 @@ func (s *ExecSuite) TestOSCommandPrep(c *check.C) { c.Assert(cmd.Args, check.DeepEquals, []string{"top"}) } +func (s *ExecSuite) TestLoginDefsParser(c *check.C) { + c.Assert(getDefaultEnvPath("../../fixtures/login.defs"), check.Equals, "PATH=/usr/local/bin:/usr/bin:/bin:/foo") + c.Assert(getDefaultEnvPath("bad/file"), check.Equals, "PATH=") +} + // implementation of ssh.Conn interface func (s *ExecSuite) User() string { return s.usr.Username } func (s *ExecSuite) SessionID() []byte { return []byte{1, 2, 3} }