Try to make key acceptance logic clearer

[mirror/userdir-ldap.git] / ud-mailgate

diff --git a/ud-mailgate b/ud-mailgate
index 8439037..7edb3fd 100755 (executable)
--- a/ud-mailgate
+++ b/ud-mailgate
@@ -36,7 +36,6 @@ mailRHSBL = {}
 mailWhitelist = {}
 SeenList = {}
 DNS = {}
-SudoPasswd = {}
 ValidHostNames = [] # will be initialized in later
 
 SSHFingerprint = re.compile('^(\d+) ([0-9a-f\:]{47}) (.+)$')
@@ -324,10 +323,17 @@ def DoSSH(Str, Attrs, badkeys, uid):
    Match = SSHFingerprint.match(output)
    g = Match.groups()
 
-   if int(g[0]) < 1024:
+   if typekey == "ssh-rsa":
+      key_size_ok = (g[0]) >= 2048)
+   elif typekey == "ed25519":
+     key_size_ok = True
+   else:
+     key_size_ok = False
+
+   if not key_size_ok:
       try:
          # Body
-         Subst["__ERROR__"] = "SSH keysize %s is below limit 1024" % (g[0])
+         Subst["__ERROR__"] = "SSH key fails formal criteria.  We only accept RSA keys (>= 2048 bits) or ed25519 keys." % (g[0])
          ErrReply = TemplateSubst(Subst,open(TemplatesDir+"admin-info","r").read())
 
          Child = os.popen("/usr/sbin/sendmail -t","w")
@@ -339,7 +345,7 @@ def DoSSH(Str, Attrs, badkeys, uid):
          sys.exit(EX_TEMPFAIL)
 
       # And now break and stop processing input, which sends a reply to the user.
-      raise UDFormatError, "SSH keys must have at least 1024 bits, processing halted, NOTHING MODIFIED AT ALL"
+      raise UDFormatError, "SSH key fails formal criteria, NOTHING MODIFIED AT ALL"
    elif g[1] in badkeys:
       try:
          # Body
@@ -357,14 +363,11 @@ def DoSSH(Str, Attrs, badkeys, uid):
       # And now break and stop processing input, which sends a reply to the user.
       raise UDFormatError, "Submitted SSH Key known to be bad and insecure, processing halted, NOTHING MODIFIED AT ALL"
 
-   if (typekey == "dss"):
-      return "DSA keys not accepted anymore"
-
    global SeenKey;
    if SeenKey:
      Attrs.append((ldap.MOD_ADD,"sshRSAAuthKey",Str));
      return "SSH Key added "+FormatSSHAuth(Str);
-      
+
    Attrs.append((ldap.MOD_REPLACE,"sshRSAAuthKey",Str));
    SeenKey = 1;
    return "SSH Keys replaced with "+FormatSSHAuth(Str);
@@ -490,8 +493,8 @@ def DoRBL(Str,Attrs):
    return "%s replaced with %s" % (Key,Host)
 
 # Handle a ConfirmSudoPassword request
-def DoConfirmSudopassword(Str):
-   Match = re.compile('^confirm sudopassword ('+UUID_FORMAT+') ([a-z0-9.,*]+) ([0-9a-f]{40})$').match(Str)
+def DoConfirmSudopassword(Str, SudoPasswd):
+   Match = re.compile('^confirm sudopassword ('+UUID_FORMAT+') ([a-z0-9.,*-]+) ([0-9a-f]{40})$').match(Str)
    if Match == None:
       return None
 
@@ -499,12 +502,10 @@ def DoConfirmSudopassword(Str):
    hosts = Match.group(2)
    hmac = Match.group(3)
 
-   global SudoPasswd
    SudoPasswd[uuid] = (hosts, hmac)
    return "got confirm for sudo password %s on host(s) %s, auth code %s" % (uuid,hosts, hmac)
 
-def FinishConfirmSudopassword(l, uid, Attrs):
-   global SudoPasswd
+def FinishConfirmSudopassword(l, uid, Attrs, SudoPasswd):
    result = "\n"
 
    if len(SudoPasswd) == 0:
@@ -520,7 +521,7 @@ def FinishConfirmSudopassword(l, uid, Attrs):
 
    newldap = []
    for entry in inldap:
-      Match = re.compile('^('+UUID_FORMAT+') (confirmed:[0-9a-f]{40}|unconfirmed) ([a-z0-9.,*]+) ([^ ]+)$').match(entry)
+      Match = re.compile('^('+UUID_FORMAT+') (confirmed:[0-9a-f]{40}|unconfirmed) ([a-z0-9.,*-]+) ([^ ]+)$').match(entry)
       if Match == None:
          raise UDFormatError, "Could not parse existing sudopasswd entry"
       uuid = Match.group(1)
@@ -582,6 +583,7 @@ def HandleChange(Reply,DnRecord,Key):
 
    Result = "";
    Attrs = [];
+   SudoPasswd = {}
    Show = 0;
    CommitChanges = 1
    for Line in Lines: 
@@ -599,7 +601,7 @@ def HandleChange(Reply,DnRecord,Key):
             badkeys = LoadBadSSH()
             Res = DoPosition(Line,Attrs) or DoDNS(Line,Attrs,DnRecord) or \
                   DoArbChange(Line,Attrs) or DoSSH(Line,Attrs,badkeys,GetAttr(DnRecord,"uid")) or \
-                  DoDel(Line,Attrs) or DoRBL(Line,Attrs) or DoConfirmSudopassword(Line)
+                  DoDel(Line,Attrs) or DoRBL(Line,Attrs) or DoConfirmSudopassword(Line, SudoPasswd)
       except:
          Res = None;
          Result = Result + "==> %s: %s\n" %(sys.exc_type,sys.exc_value);
@@ -615,17 +617,16 @@ def HandleChange(Reply,DnRecord,Key):
    # Connect to the ldap server
    l = connect_to_ldap_and_check_if_locked(DnRecord)
 
-   if CommitChanges == 1: # only if we are still good to go
+   if CommitChanges == 1 and len(SudoPasswd) > 0: # only if we are still good to go
       try:
-         Res = FinishConfirmSudopassword(l, GetAttr(DnRecord,"uid"), Attrs)
+         Res = FinishConfirmSudopassword(l, GetAttr(DnRecord,"uid"), Attrs, SudoPasswd)
          if not Res is None:
             Result = Result + Res + "\n";
       except Error, e:
          CommitChanges = 0
          Result = Result + "FinishConfirmSudopassword raised an error (%s) - no changes committed\n"%(e);
 
-   # Modify the record
-   if CommitChanges == 1:
+   if CommitChanges == 1 and len(Attrs) > 0:
       Dn = "uid=" + GetAttr(DnRecord,"uid") + "," + BaseDn;
       l.modify_s(Dn,Attrs);
 
@@ -752,8 +753,8 @@ try:
    # Get the email 
    ErrType = EX_PERMFAIL;
    ErrMsg = "Failed to understand the email or find a signature:";
-   email = email.parser.Parser().parse(sys.stdin);
-   Msg = GetClearSig(email);
+   mail = email.parser.Parser().parse(sys.stdin);
+   Msg = GetClearSig(mail);
 
    ErrMsg = "Message is not PGP signed:"
    if Msg[0].find("-----BEGIN PGP SIGNED MESSAGE-----") == -1 and \
@@ -802,8 +803,8 @@ try:
 
    # Determine the sender address
    ErrMsg = "A problem occured while trying to formulate the reply";
-   Sender = email['Reply-To']
-   if not Sender: Sender = email['From']
+   Sender = mail['Reply-To']
+   if not Sender: Sender = mail['From']
    if not Sender: raise UDFormatError, "Unable to determine the sender's address";
 
    # Formulate a reply