login: T2050: retrieve home directory for SSH keys from OS and not guess it

We should not rely on the home dir value stored in user['home_dir'] as if a
crazy user will choose username root or any other system user this will fail.

Should be deny using root at all?

1 files changed, 14 insertions, 10 deletions

diff --git a/src/conf_mode/system-login.py b/src/conf_mode/system-login.py
index 23152fee0..a7fb8ee8f 100755
--- a/src/conf_mode/system-login.py
+++ b/src/conf_mode/system-login.py
@@ -265,15 +265,19 @@ def apply(login):
             uid = getpwnam(user['name']).pw_uid
             gid = getpwnam(user['name']).pw_gid
 
+            # we should not rely on the home dir value stored in user['home_dir']
+            # as if a crazy user will choose username root or any other system
+            # user this will fail. should be deny using root at all?
+            home_dir = getpwnam(user['name']).pw_dir
             # install ssh keys
-            key_dir = '{}/.ssh'.format(user['home_dir'])
-            if not os.path.isdir(key_dir):
-                os.mkdir(key_dir)
-                os.chown(key_dir, uid, gid)
-                os.chmod(key_dir, S_IRWXU | S_IRGRP | S_IXGRP)
-
-            key_file = key_dir + '/authorized_keys';
-            with open(key_file, 'w') as f:
+            ssh_key_dir = home_dir + '/.ssh'
+            if not os.path.isdir(ssh_key_dir):
+                os.mkdir(ssh_key_dir)
+                os.chown(ssh_key_dir, uid, gid)
+                os.chmod(ssh_key_dir, S_IRWXU | S_IRGRP | S_IXGRP)
+
+            ssh_key_file = ssh_key_dir + '/authorized_keys';
+            with open(ssh_key_file, 'w') as f:
                 f.write("# Automatically generated by VyOS\n")
                 f.write("# Do not edit, all changes will be lost\n")
 
@@ -285,8 +289,8 @@ def apply(login):
                     line += '{} {} {}\n'.format(id['type'], id['key'], id['name'])
                     f.write(line)
 
-            os.chown(key_file, uid, gid)
-            os.chmod(key_file, S_IRUSR | S_IWUSR)
+            os.chown(ssh_key_file, uid, gid)
+            os.chmod(ssh_key_file, S_IRUSR | S_IWUSR)
 
         except Exception as e:
             raise ConfigError('Adding user "{}" raised an exception: {}'.format(user['name'], e))