From 1e4ec1b29d15684a305bbc9ab54c6c8321504e7b Mon Sep 17 00:00:00 2001

From: David Tardon <dtardon@redhat.com>

Date: Tue, 27 Oct 2020 10:31:05 +0100

Subject: [PATCH] shared/user-util: add compat forms of user name checking

 functions

New functions are called valid_user_group_name_compat() and

valid_user_group_name_or_id_compat() and accept dots in the user

or group name. No functional change except the tests.

(cherry picked from commit 1a29610f5fa1bcb2eeb37d2c6b79d8d1a6dbb865)

This completes previous partial cherry-pick of the same commit (commit

76176de0889c3e8b9b3a176da24e4f8dbbd380a3).

Related: #1848373

---

 src/basic/user-util.c     | 32 +++++++-------

 src/basic/user-util.h     | 16 ++++++-

 src/test/test-user-util.c | 91 +++++++++++++++++++++++++++++++++++++--

 3 files changed, 117 insertions(+), 22 deletions(-)

diff --git a/src/basic/user-util.c b/src/basic/user-util.c

index 40f4e45db6..03cbbc2503 100644

--- a/src/basic/user-util.c

+++ b/src/basic/user-util.c

@@ -576,7 +576,7 @@ int take_etc_passwd_lock(const char *root) {

         return fd;

 }

-bool valid_user_group_name(const char *u) {

+bool valid_user_group_name_full(const char *u, bool strict) {

         const char *i;

         long sz;

@@ -585,12 +585,12 @@ bool valid_user_group_name(const char *u) {

          *

          * - We require that names fit into the appropriate utmp field

          * - We don't allow empty user names

+         * - No dots or digits in the first character

          *

-         * Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.

+         * If strict==true, additionally:

+         * - We don't allow any dots (this conflicts with chown syntax which permits dots as user/group name separator)

          *

-         * jsynacek: We now allow dots in user names. The checks are not exhaustive as user names like "..." are allowed

-         * and valid according to POSIX, but can't be created using useradd. However, ".user" can be created. Let's not

-         * complicate the code by adding additional checks for weird corner cases like these,  as they don't really matter here.

+         * Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.

          */

         if (isempty(u))

@@ -598,16 +598,16 @@ bool valid_user_group_name(const char *u) {

         if (!(u[0] >= 'a' && u[0] <= 'z') &&

             !(u[0] >= 'A' && u[0] <= 'Z') &&

-            u[0] != '_' && u[0] != '.')

+            u[0] != '_')

                 return false;

-        for (i = u+1; *i; i++) {

-                if (!(*i >= 'a' && *i <= 'z') &&

-                    !(*i >= 'A' && *i <= 'Z') &&

-                    !(*i >= '0' && *i <= '9') &&

-                    !IN_SET(*i, '_', '-', '.'))

+        for (i = u+1; *i; i++)

+                if (!((*i >= 'a' && *i <= 'z') ||

+                      (*i >= 'A' && *i <= 'Z') ||

+                      (*i >= '0' && *i <= '9') ||

+                      IN_SET(*i, '_', '-') ||

+                      (!strict && *i == '.')))

                         return false;

-        }

         sz = sysconf(_SC_LOGIN_NAME_MAX);

         assert_se(sz > 0);

@@ -621,15 +621,15 @@ bool valid_user_group_name(const char *u) {

         return true;

 }

-bool valid_user_group_name_or_id(const char *u) {

+bool valid_user_group_name_or_id_full(const char *u, bool strict) {

-        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the right

-         * range, and not the invalid user ids. */

+        /* Similar as above, but is also fine with numeric UID/GID specifications, as long as they are in the

+         * right range, and not the invalid user ids. */

         if (isempty(u))

                 return false;

-        if (valid_user_group_name(u))

+        if (valid_user_group_name_full(u, strict))

                 return true;

         return parse_uid(u, NULL) >= 0;

diff --git a/src/basic/user-util.h b/src/basic/user-util.h

index b74f168859..5ad0b2a2f9 100644

--- a/src/basic/user-util.h

+++ b/src/basic/user-util.h

@@ -78,8 +78,20 @@ static inline bool userns_supported(void) {

         return access("/proc/self/uid_map", F_OK) >= 0;

 }

-bool valid_user_group_name(const char *u);

-bool valid_user_group_name_or_id(const char *u);

+bool valid_user_group_name_full(const char *u, bool strict);

+bool valid_user_group_name_or_id_full(const char *u, bool strict);

+static inline bool valid_user_group_name(const char *u) {

+        return valid_user_group_name_full(u, true);

+}

+static inline bool valid_user_group_name_or_id(const char *u) {

+        return valid_user_group_name_or_id_full(u, true);

+}

+static inline bool valid_user_group_name_compat(const char *u) {

+        return valid_user_group_name_full(u, false);

+}

+static inline bool valid_user_group_name_or_id_compat(const char *u) {

+        return valid_user_group_name_or_id_full(u, false);

+}

 bool valid_gecos(const char *d);

 bool valid_home(const char *p);

diff --git a/src/test/test-user-util.c b/src/test/test-user-util.c

index 04e86f5ac3..3a4211655d 100644

--- a/src/test/test-user-util.c

+++ b/src/test/test-user-util.c

@@ -131,6 +131,43 @@ static void test_uid_ptr(void) {

         assert_se(PTR_TO_UID(UID_TO_PTR(1000)) == 1000);

 }

+static void test_valid_user_group_name_compat(void) {

+        log_info("/* %s */", __func__);

+

+        assert_se(!valid_user_group_name_compat(NULL));

+        assert_se(!valid_user_group_name_compat(""));

+        assert_se(!valid_user_group_name_compat("1"));

+        assert_se(!valid_user_group_name_compat("65535"));

+        assert_se(!valid_user_group_name_compat("-1"));

+        assert_se(!valid_user_group_name_compat("-kkk"));

+        assert_se(!valid_user_group_name_compat("rööt"));

+        assert_se(!valid_user_group_name_compat("."));

+        assert_se(!valid_user_group_name_compat(".eff"));

+        assert_se(!valid_user_group_name_compat("foo\nbar"));

+        assert_se(!valid_user_group_name_compat("0123456789012345678901234567890123456789"));

+        assert_se(!valid_user_group_name_or_id_compat("aaa:bbb"));

+        assert_se(!valid_user_group_name_compat("."));

+        assert_se(!valid_user_group_name_compat(".1"));

+        assert_se(!valid_user_group_name_compat(".65535"));

+        assert_se(!valid_user_group_name_compat(".-1"));

+        assert_se(!valid_user_group_name_compat(".-kkk"));

+        assert_se(!valid_user_group_name_compat(".rööt"));

+        assert_se(!valid_user_group_name_or_id_compat(".aaa:bbb"));

+

+        assert_se(valid_user_group_name_compat("root"));

+        assert_se(valid_user_group_name_compat("lennart"));

+        assert_se(valid_user_group_name_compat("LENNART"));

+        assert_se(valid_user_group_name_compat("_kkk"));

+        assert_se(valid_user_group_name_compat("kkk-"));

+        assert_se(valid_user_group_name_compat("kk-k"));

+        assert_se(valid_user_group_name_compat("eff.eff"));

+        assert_se(valid_user_group_name_compat("eff."));

+

+        assert_se(valid_user_group_name_compat("some5"));

+        assert_se(!valid_user_group_name_compat("5some"));

+        assert_se(valid_user_group_name_compat("INNER5NUMBER"));

+}

+

 static void test_valid_user_group_name(void) {

         log_info("/* %s */", __func__);

@@ -141,9 +178,18 @@ static void test_valid_user_group_name(void) {

         assert_se(!valid_user_group_name("-1"));

         assert_se(!valid_user_group_name("-kkk"));

         assert_se(!valid_user_group_name("rööt"));

+        assert_se(!valid_user_group_name("."));

+        assert_se(!valid_user_group_name(".eff"));

         assert_se(!valid_user_group_name("foo\nbar"));

         assert_se(!valid_user_group_name("0123456789012345678901234567890123456789"));

         assert_se(!valid_user_group_name_or_id("aaa:bbb"));

+        assert_se(!valid_user_group_name("."));

+        assert_se(!valid_user_group_name(".1"));

+        assert_se(!valid_user_group_name(".65535"));

+        assert_se(!valid_user_group_name(".-1"));

+        assert_se(!valid_user_group_name(".-kkk"));

+        assert_se(!valid_user_group_name(".rööt"));

+        assert_se(!valid_user_group_name_or_id(".aaa:bbb"));

         assert_se(valid_user_group_name("root"));

         assert_se(valid_user_group_name("lennart"));

@@ -151,14 +197,47 @@ static void test_valid_user_group_name(void) {

         assert_se(valid_user_group_name("_kkk"));

         assert_se(valid_user_group_name("kkk-"));

         assert_se(valid_user_group_name("kk-k"));

-        assert_se(valid_user_group_name(".moo"));

-        assert_se(valid_user_group_name("eff.eff"));

+        assert_se(!valid_user_group_name("eff.eff"));

+        assert_se(!valid_user_group_name("eff."));

         assert_se(valid_user_group_name("some5"));

         assert_se(!valid_user_group_name("5some"));

         assert_se(valid_user_group_name("INNER5NUMBER"));

 }

+static void test_valid_user_group_name_or_id_compat(void) {

+        log_info("/* %s */", __func__);

+

+        assert_se(!valid_user_group_name_or_id_compat(NULL));

+        assert_se(!valid_user_group_name_or_id_compat(""));

+        assert_se(valid_user_group_name_or_id_compat("0"));

+        assert_se(valid_user_group_name_or_id_compat("1"));

+        assert_se(valid_user_group_name_or_id_compat("65534"));

+        assert_se(!valid_user_group_name_or_id_compat("65535"));

+        assert_se(valid_user_group_name_or_id_compat("65536"));

+        assert_se(!valid_user_group_name_or_id_compat("-1"));

+        assert_se(!valid_user_group_name_or_id_compat("-kkk"));

+        assert_se(!valid_user_group_name_or_id_compat("rööt"));

+        assert_se(!valid_user_group_name_or_id_compat("."));

+        assert_se(!valid_user_group_name_or_id_compat(".eff"));

+        assert_se(valid_user_group_name_or_id_compat("eff.eff"));

+        assert_se(valid_user_group_name_or_id_compat("eff."));

+        assert_se(!valid_user_group_name_or_id_compat("foo\nbar"));

+        assert_se(!valid_user_group_name_or_id_compat("0123456789012345678901234567890123456789"));

+        assert_se(!valid_user_group_name_or_id_compat("aaa:bbb"));

+

+        assert_se(valid_user_group_name_or_id_compat("root"));

+        assert_se(valid_user_group_name_or_id_compat("lennart"));

+        assert_se(valid_user_group_name_or_id_compat("LENNART"));

+        assert_se(valid_user_group_name_or_id_compat("_kkk"));

+        assert_se(valid_user_group_name_or_id_compat("kkk-"));

+        assert_se(valid_user_group_name_or_id_compat("kk-k"));

+

+        assert_se(valid_user_group_name_or_id_compat("some5"));

+        assert_se(!valid_user_group_name_or_id_compat("5some"));

+        assert_se(valid_user_group_name_or_id_compat("INNER5NUMBER"));

+}

+

 static void test_valid_user_group_name_or_id(void) {

         log_info("/* %s */", __func__);

@@ -172,6 +251,10 @@ static void test_valid_user_group_name_or_id(void) {

         assert_se(!valid_user_group_name_or_id("-1"));

         assert_se(!valid_user_group_name_or_id("-kkk"));

         assert_se(!valid_user_group_name_or_id("rööt"));

+        assert_se(!valid_user_group_name_or_id("."));

+        assert_se(!valid_user_group_name_or_id(".eff"));

+        assert_se(!valid_user_group_name_or_id("eff.eff"));

+        assert_se(!valid_user_group_name_or_id("eff."));

         assert_se(!valid_user_group_name_or_id("foo\nbar"));

         assert_se(!valid_user_group_name_or_id("0123456789012345678901234567890123456789"));

         assert_se(!valid_user_group_name_or_id("aaa:bbb"));

@@ -182,8 +265,6 @@ static void test_valid_user_group_name_or_id(void) {

         assert_se(valid_user_group_name_or_id("_kkk"));

         assert_se(valid_user_group_name_or_id("kkk-"));

         assert_se(valid_user_group_name_or_id("kk-k"));

-        assert_se(valid_user_group_name_or_id(".moo"));

-        assert_se(valid_user_group_name_or_id("eff.eff"));

         assert_se(valid_user_group_name_or_id("some5"));

         assert_se(!valid_user_group_name_or_id("5some"));

@@ -286,7 +367,9 @@ int main(int argc, char*argv[]) {

         test_parse_uid();

         test_uid_ptr();

+        test_valid_user_group_name_compat();

         test_valid_user_group_name();

+        test_valid_user_group_name_or_id_compat();

         test_valid_user_group_name_or_id();

         test_valid_gecos();

         test_valid_home();