MACSec Redux


Good ol’ MACSec.

First, I posted a quick and dirty notes-for-myself, MACSec how-to for Juniper.

Then, I posted a similar MACSec howto for Cisco. So here’s a miscellany of different macsec implementations.

Let’s say you want to run your own router, because your Layer 8 & 9 specialists mandate it, here MACSec on linux.

Here’s a guy who did cisco-switch-to-cisco-switch macsec over an mpls link between a cisco and juniper router (because macsec works at layer 1 and thus you need to fake layer 1 via MLPS). So that’s a thing.

Here’s the Extreme Network’s MACSec implementation:

set macsec port mka enable tg.1.1
set macsec pre-shared-key port tg.1.1 ckn foo cak passphrase bar

HP switches macsec config

Brocade MACSec details and also a Brocade sample config of MACSec.

Cisco MACSec Notes


A while back I did notes for MACSec on Juniper devices and here’s the Cisco equivalent of the 802.1AE (“MAC Sec”) implementation

  1. Your Cisco device needs to be running either an IP Base or IP Services image. MACSec is not happening otherwise.
  2. switch# cts credentials id trustsec password mypassword
  3. en then, conf t, then int Gig1/1 (or whatever)
  4. switch(config-if)# cts man
    % Enabling macsec on Gi1/1 (may take a few seconds)…
    switch(config-if-cts-manual)#no propagate sgt
    switch(config-if-cts-manual)#sap pmk abc123 mode-list gcm-encrypt
    switch(config-if-cts-manual)#no shut

Where abc123 is your shared secret. I believe this is analogous to Juniper’s cak. You can do this to aggregated links (“port-channel” for you Cisco folks) but you have to do it before you aggregate the trunks together into a single logical interface. E.g., do this on Gig1/1 and Gig1/2 and then create int Port-channel1 (channel-group 1 mode on in the interface config)


mode-list options are:

  • gcm-encrypt (authentication and encryption)
  • gmac (auth, no encrypt)
  • null (encapsulation only; no auth, no encryption)



  • to use 802.1x (cts dot1x) as opposed to cts man above, you have to enable 802.1x globally on each device.
  • if you select gcm as the sap mode, you need an additional macsec license from cisco (as well as the ipbase or ipservices image/license). if you select gcm without the license, the interface goes into link-down state.


show cts credentials

show macsec summary

show macsec interface

show authentication sessions interface gigabitethernet1/1


Additional reading:

The actual Cisco doc (this is for a cat4500 but translates well most places) (here’s one for 3750/3560)


Newly published NSA documents show agency could grab all Skype traffic | Ars Technica


The full capture of voice traffic began in February of 2011 for “Skype in” and “Skype out” calls—calls between a Skype user and a land line or cellphone through a gateway to the public switched telephone network (PSTN), captured through warranted taps into Microsoft’s gateways. But in July of 2011, the NSA added the capability of capturing peer-to-peer Skype communications—meaning that the NSA gained the ability to capture peer-to-peer traffic and decrypt it using keys provided by Microsoft through the PRISM warrant request.

via Newly published NSA documents show agency could grab all Skype traffic | Ars Technica.

Juniper MACSec Notes


MACSec is kind of neat (TL;DR for the impatient: layer-1 crypto on links).

Media Access Control Security (MACsec) is an industry-standard security technology that provides secure communication for all traffic on Ethernet links. MACsec provides point-to-point security on Ethernet links between directly connected nodes and is capable of identifying and preventing most security threats, including denial of service, intrusion, man-in-the-middle, masquerading, passive wiretapping, and playback attacks. MACsec is standardized in IEEE 802.1AE.

MACsec allows you to secure an Ethernet link for almost all traffic, including frames from the Link Layer Discovery Protocol (LLDP), Link Aggregation Control Protocol (LACP), Dynamic Host Configuration Protocol (DHCP), Address Resolution Protocol (ARP), and other protocols that are not typically secured on an Ethernet link because of limitations with other security solutions. MACsec can be used in combination with other security protocols such as IP Security (IPsec) and Secure Sockets Layer (SSL) to provide end-to-end network security.

CLI config:

#create an association:
set security macsec connectivity-association ca1

#choose a mode (static cak recommended — see here for why)
set security macsec connectivity-association ca1 security-mode static-cak

#ckn needs to be a 64-digit number in hex, but any empty space is padded w/ 0’s
set security macsec connectivity-association ca1 pre-shared-key ckn deadbeef99

#cak needs to be a 32-digit number in hex, but any empty space is padded w/ 0’s
set security macsec connectivity-association ca1 pre-shared-key cak deadbeef11

# set to 255 to make it “less likely” to be chosen as key server, 0 for “more likely”
set security macsec connectivity-association ca1 mka key-server-priority 0

# set to 6000 for high-traffic environment. default to 2000.
set security macsec connectivity-association ca1 mka transmit-interval 6000

#this leaves headers unencrypted for troubleshooting, set to 0 for full encryption, set to 50 for unencrypted ipv6 headers
set security macsec connectivity-association ca1 offset 30

# replay protection, set to 0 to enforce all packets coming in order
set security macsec connectivity-association ca1 replay-protect replay-window-size 5

# exclude a protocol
set exclude-protocol lldp

#enable macsec
set security macsec interfaces xe-0/1/0 connectivity-association ca1

show security macsec statistics interface xe-0/1/0 detail

additional reading:
(Cisco version:


There’s a Cisco version of this here:

Categories : HowTo  Networking  Security

Google Online Security Blog: This POODLE bites: exploiting the SSL 3.0 fallback


Holder urges tech companies to leave device backdoors open for police – The Washington Post


Attorney General Eric H. Holder Jr. said on Tuesday that new forms of encryption capable of locking law enforcement officials out of popular electronic devices imperil investigations of kidnappers and sexual predators, putting children at increased risk.

via Holder urges tech companies to leave device backdoors open for police – The Washington Post.


TL;DR: “we need to snoop on everything, for the kids”. Shameless, spineless, embarassing.

Categories : News  News  Privacy

IPSec Site-to-Site between a Palo Alto firewall and Cisco Router


Palo Alto side:

1. create a tunnel interface:

Network Tab > Interfaces > Tunnels
new tunnel: name it, assign it to a Virtual Router(cisco parlance: VRF) and Security Zone

2. create IKE phase 1: (cisco calls it isakemp)

Network > Network Profiles > IKE Crypto
create a new profile, name it: assign a DH Group, authentication, encryption and lifetime (DH group 2, sha1, aes128, 1 day)

3. create IKE phase 2: (cisco: “transform set”)

Network > Network Profiles > IPSec Crypto
Create a new profile
DH group (pfs/no-pfs)

4. specify peer:

Network > Network Profiles > IKE Gateway
name it, interface, peer type, peer IP, pre-shared key, exchange mode, define which IKE Crypto profile (phase2)

5. Add an IPSec Tunnel:

Network > IPSec Tunnels

General Tab:
Add tunnel, name it, choose which tunnel interface to use
Autokey (since they’re defined in your gateway/phase1/phase2
Choose gateway
choose IPSec Crypto Profile (phase2)

Proxy ID tab:
add the IP address/network

Cisco router side:

1. Configure Phase-1 (“isakmp”)

# conf t
(config)# crypto isakmp policy 1
(config-isakmp)# authentication pre-share
(config-isakmp)# encrypt aes128
(config-isakmp)# hash sha1
(config-isakmp)# group 2
(config-isakmp)# lifetime 86400
(config-isakmp)# exit
(config)# crypto isamp key <<key>> address <<peer address>>

Change <<key>> to your preshared key and <<peer address>> to the other system’s IP address (e.g. the public address on the interface of the palo alto FW)

NB: note that ISAKMP Phase 1 policy is defined globally. So if you have five different remote sites and configured five different ISAKMP Phase 1 policies (one for each remote router), when our router tries to negotiate a VPN tunnel with each site it will send all five policies and use the first match that is accepted by both ends.

2. configure phase-2 (“transform-set”, ACLs, crypto map)

2a. set an ACL to match the traffic that will be encrypted in the tunnel:

The format is:
(access-list ### permit ip <<source-network>> <<source-netmask>> <<destination-network>> <<destination-netmask>>)

(config)# access-list 100 permit ip

NB: If you’re NAT’ing outbound traffic, you need to disable NAT for the traffic that you want encrypted through the tunnel; deny via ACL, like so:

(config)# ip nat inside source list 100 interface fastethernet0/2 overload
(config)# access-list 100 deny ip
(config)# access-list 100 permit ip any

The deny applies specifically to traffic from 10./8 to 192.168.1./24 and then permits 10./8 going anywhere else.

2b. set the transform set (aka phase 2)

(config)# crypto ipsec transform-set IPSECSET esp-sha-hmac esp-aes
(cfg-crypto-trans)# exit

2c. set the crypto map to tie the elements together:

(config)# crypto map IPSECMAP 1 ipsec-isakmp
(config-crypto-map)# set transform-set IPSECSET
(config-crypto-map)# set peer <<peer address>>
(config-crypto-map)# match address 100
(config-crypto-map)# exit

3. Apply the crypto map to your outbound interface:

(config)# interface FastEthernet0/2
(if-config)# crypto map IPSECMAP

And you’re done.

useful commands:

show crypto isakmp policy
show crypto isakmp
show crypto isakmp detail
show crypto ipsec transform-set — shows you phase 2
show crypto map — shows complete crypto map
show crypto ipsec sa — shows how many packets encrypted/decryted/going through the tunnel

Categories : HowTo

Cory Doctrow on the need for easy to use security mechanisms


Cory Doctrow via The Guardian:

Technical people need our non-technical friends to adopt good privacy practices. Every communications session has at least two parties, the sender and the recipient(s), and your privacy can leak out of either end of the wire. It doesn’t matter if I keep all my email offline, encrypted on my laptop, if it all ends up in the inboxes of people who leave it sitting on Gmail’s servers.

So this is critical, and not just for “normal people”. Even technically sophisticated people often find it difficult to follow security protocol in their own communications and computing. Things that aren’t usable just don’t get used. Making crypto as easy as your favourite websites and apps is the only way to make privacy a reality for everyone.

via Privacy technology everyone can use would make us all more secure | Technology |


That’s all well and good, but how do you do it? If you’re reading this, it’s a safe bet you’re at least interested in the idea of data security. But how do you implement this among the nontechnical? It’s easy enough to tell a group of technical people “install PGP, encrypt and sign everything, don’t use weak keys” etc. But how do you get your mom to use it? Or the 62-year-old accountant that prefers to not have to deal with computers except to buy things online and email old friends or distant relatives?

Categories : News  Security

A Few Thoughts on Cryptographic Engineering: What’s the matter with PGP?


A Few Thoughts on Cryptographic Engineering: What’s the matter with PGP?.

TL;DR: keys suck, key management sucks, no perfect foward secrecy really sucks, implementation sucks, software sucks and we should rethink how to do this stuff slightly better.

If you’ve used PGP (or GPG), it’s hard to find fault with his arguments, though.

Categories : Security

ProtonMail Blog – News and Updates


ProtonMail Blog – News and Updates.

Just got access to the public beta of this; here’s to hoping others follow suit.

Categories : Security