ssh: T4273: bugfix cipher and key-exchange multi nodes

After hardning the regex validator to be preceeded with ^ and ending with $
it was no longer possible to have a comma separated list as SSH ciphers. The
migrations cript is altered to migrate the previous comma separated list
to individual multi node entries - cipher and key-exchange always had been
multinodes - so this just re-arranges some values and does not break CLI
compatibility

(cherry picked from commit 61fa1c95164e4222e79b078b1a796f41397e0ee3)

3 files changed, 130 insertions, 16 deletions

diff --git a/interface-definitions/ssh.xml.in b/interface-definitions/ssh.xml.in
index e3b9d16e1..867037295 100644
--- a/interface-definitions/ssh.xml.in
+++ b/interface-definitions/ssh.xml.in
@@ -44,7 +44,7 @@
                 <list>3des-cbc aes128-cbc aes192-cbc aes256-cbc rijndael-cbc@lysator.liu.se aes128-ctr aes192-ctr aes256-ctr aes128-gcm@openssh.com aes256-gcm@openssh.com chacha20-poly1305@openssh.com</list>
               </completionHelp>
                 <constraint>
-                  <regex>^(3des-cbc|aes128-cbc|aes192-cbc|aes256-cbc|rijndael-cbc@lysator.liu.se|aes128-ctr|aes192-ctr|aes256-ctr|aes128-gcm@openssh.com|aes256-gcm@openssh.com|chacha20-poly1305@openssh.com)$</regex>
+                  <regex>(3des-cbc|aes128-cbc|aes192-cbc|aes256-cbc|rijndael-cbc@lysator.liu.se|aes128-ctr|aes192-ctr|aes256-ctr|aes128-gcm@openssh.com|aes256-gcm@openssh.com|chacha20-poly1305@openssh.com)</regex>
                 </constraint>
               <multi/>
             </properties>
@@ -70,7 +70,7 @@
               </completionHelp>
               <multi/>
               <constraint>
-                <regex>^(diffie-hellman-group1-sha1|diffie-hellman-group14-sha1|diffie-hellman-group14-sha256|diffie-hellman-group16-sha512|diffie-hellman-group18-sha512|diffie-hellman-group-exchange-sha1|diffie-hellman-group-exchange-sha256|ecdh-sha2-nistp256|ecdh-sha2-nistp384|ecdh-sha2-nistp521|curve25519-sha256|curve25519-sha256@libssh.org)$</regex>
+                <regex>(diffie-hellman-group1-sha1|diffie-hellman-group14-sha1|diffie-hellman-group14-sha256|diffie-hellman-group16-sha512|diffie-hellman-group18-sha512|diffie-hellman-group-exchange-sha1|diffie-hellman-group-exchange-sha256|ecdh-sha2-nistp256|ecdh-sha2-nistp384|ecdh-sha2-nistp521|curve25519-sha256|curve25519-sha256@libssh.org)</regex>
               </constraint>
             </properties>
           </leafNode>
@@ -102,7 +102,7 @@
                 <description>enable logging of failed login attempts</description>
               </valueHelp>
               <constraint>
-                <regex>^(quiet|fatal|error|info|verbose)$</regex>
+                <regex>(quiet|fatal|error|info|verbose)</regex>
               </constraint>
             </properties>
             <defaultValue>INFO</defaultValue>
@@ -115,7 +115,7 @@
                 <list>hmac-sha1 hmac-sha1-96 hmac-sha2-256 hmac-sha2-512 hmac-md5 hmac-md5-96 umac-64@openssh.com umac-128@openssh.com hmac-sha1-etm@openssh.com hmac-sha1-96-etm@openssh.com hmac-sha2-256-etm@openssh.com hmac-sha2-512-etm@openssh.com hmac-md5-etm@openssh.com hmac-md5-96-etm@openssh.com umac-64-etm@openssh.com umac-128-etm@openssh.com</list>
               </completionHelp>
               <constraint>
-                <regex>^(hmac-sha1|hmac-sha1-96|hmac-sha2-256|hmac-sha2-512|hmac-md5|hmac-md5-96|umac-64@openssh.com|umac-128@openssh.com|hmac-sha1-etm@openssh.com|hmac-sha1-96-etm@openssh.com|hmac-sha2-256-etm@openssh.com|hmac-sha2-512-etm@openssh.com|hmac-md5-etm@openssh.com|hmac-md5-96-etm@openssh.com|umac-64-etm@openssh.com|umac-128-etm@openssh.com)$</regex>
+                <regex>(hmac-sha1|hmac-sha1-96|hmac-sha2-256|hmac-sha2-512|hmac-md5|hmac-md5-96|umac-64@openssh.com|umac-128@openssh.com|hmac-sha1-etm@openssh.com|hmac-sha1-96-etm@openssh.com|hmac-sha2-256-etm@openssh.com|hmac-sha2-512-etm@openssh.com|hmac-md5-etm@openssh.com|hmac-md5-96-etm@openssh.com|umac-64-etm@openssh.com|umac-128-etm@openssh.com)</regex>
               </constraint>
               <multi/>
             </properties>
diff --git a/smoketest/configs/basic-vyos b/smoketest/configs/basic-vyos
new file mode 100644
index 000000000..493feed5b
--- /dev/null
+++ b/smoketest/configs/basic-vyos
@@ -0,0 +1,88 @@
+interfaces {
+    ethernet eth0 {
+        address 192.168.0.1/24
+        duplex auto
+        smp-affinity auto
+        speed auto
+    }
+    ethernet eth1 {
+        address 100.64.0.0/31
+        duplex auto
+        smp-affinity auto
+        speed auto
+    }
+    loopback lo {
+    }
+}
+protocols {
+    static {
+        route 0.0.0.0/0 {
+            next-hop 100.64.0.1 {
+            }
+        }
+    }
+}
+service {
+    dhcp-server {
+        shared-network-name LAN {
+            authoritative
+            subnet 192.168.0.0/24 {
+                default-router 192.168.0.1
+                dns-server 192.168.0.1
+                domain-name vyos.net
+                domain-search vyos.net
+                range LANDynamic {
+                    start 192.168.0.20
+                    stop 192.168.0.240
+                }
+            }
+        }
+    }
+    dns {
+        forwarding {
+            allow-from 192.168.0.0/16
+            cache-size 10000
+            dnssec off
+            listen-address 192.168.0.1
+        }
+    }
+    ssh {
+        ciphers aes128-ctr,aes192-ctr,aes256-ctr
+        ciphers chacha20-poly1305@openssh.com,rijndael-cbc@lysator.liu.se
+        listen-address 192.168.0.1
+        key-exchange curve25519-sha256@libssh.org
+        key-exchange diffie-hellman-group1-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group-exchange-sha256
+        port 22
+    }
+}
+system {
+    config-management {
+        commit-revisions 100
+    }
+    console {
+        device ttyS0 {
+            speed 115200
+        }
+    }
+    host-name vyos
+    login {
+        user vyos {
+            authentication {
+                encrypted-password $6$O5gJRlDYQpj$MtrCV9lxMnZPMbcxlU7.FI793MImNHznxGoMFgm3Q6QP3vfKJyOSRCt3Ka/GzFQyW1yZS4NS616NLHaIPPFHc0
+                plaintext-password ""
+            }
+        }
+    }
+    name-server 192.168.0.1
+    syslog {
+        global {
+            facility all {
+                level info
+            }
+        }
+    }
+    time-zone Europe/Berlin
+}
+/* Warning: Do not remove the following line. */
+/* === vyatta-config-version: "broadcast-relay@1:cluster@1:config-management@1:conntrack-sync@1:conntrack@1:dhcp-relay@2:dhcp-server@5:dns-forwarding@1:firewall@5:ipsec@5:l2tp@1:mdns@1:nat@4:ntp@1:pptp@1:qos@1:quagga@6:snmp@1:ssh@1:system@9:vrrp@2:wanloadbalance@3:webgui@1:webproxy@1:webproxy@2:zone-policy@1" === */
+/* Release version: 1.2.6 */
diff --git a/src/migration-scripts/ssh/1-to-2 b/src/migration-scripts/ssh/1-to-2
index bc8815753..31c40df16 100755
--- a/src/migration-scripts/ssh/1-to-2
+++ b/src/migration-scripts/ssh/1-to-2
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020 VyOS maintainers and contributors
+# Copyright (C) 2020-2022 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -30,26 +30,52 @@ file_name = argv[1]
 with open(file_name, 'r') as f:
     config_file = f.read()
 
-base = ['service', 'ssh', 'loglevel']
+base = ['service', 'ssh']
 config = ConfigTree(config_file)
 
 if not config.exists(base):
     # Nothing to do
     exit(0)
-else:
-    # red in configured loglevel and convert it to lower case
-    tmp = config.return_value(base).lower()
 
+path_loglevel = base + ['loglevel']
+if config.exists(path_loglevel):
+    # red in configured loglevel and convert it to lower case
+    tmp = config.return_value(path_loglevel).lower()
     # VyOS 1.2 had no proper value validation on the CLI thus the
     # user could use any arbitrary values - sanitize them
     if tmp not in ['quiet', 'fatal', 'error', 'info', 'verbose']:
         tmp = 'info'
+    config.set(path_loglevel, value=tmp)
+
+# T4273: migrate ssh cipher list to multi node
+path_ciphers = base + ['ciphers']
+if config.exists(path_ciphers):
+    tmp = []
+    # get curtrent cipher list - comma delimited
+    for cipher in config.return_values(path_ciphers):
+        tmp.extend(cipher.split(','))
+    # delete old cipher suite representation
+    config.delete(path_ciphers)
 
-    config.set(base, value=tmp)
+    for cipher in tmp:
+        config.set(path_ciphers, value=cipher, replace=False)
 
-    try:
-        with open(file_name, 'w') as f:
-            f.write(config.to_string())
-    except OSError as e:
-        print("Failed to save the modified config: {}".format(e))
-        exit(1)
+# T4273: migrate ssh key-exchange list to multi node
+path_kex = base + ['key-exchange']
+if config.exists(path_kex):
+    tmp = []
+    # get curtrent cipher list - comma delimited
+    for kex in config.return_values(path_kex):
+        tmp.extend(kex.split(','))
+    # delete old cipher suite representation
+    config.delete(path_kex)
+
+    for kex in tmp:
+        config.set(path_kex, value=kex, replace=False)
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print("Failed to save the modified config: {}".format(e))
+    exit(1)