The following software needs to be installed upfront: git, curl, ant, gpg. You can use either Homebrew or Macports to do that. For Homebrew use the following command: brew install git curl ant Further more install the Mac GPG tools which can be found here: https://gpgtools.org. Do not install gpg via Homebrew or MacPorts, this will obviously not work. (see http://support.gpgtools.org/discussions/problems/11470-smart-card-access)

It absolutely makes sense to rebuild the applet on your device to match your device ID. Yubikey does not do that in the factory setting. There you have a fixed ID which is all the same on all keys. To personalize that perform the following steps: 1. Create a new directory on your disk where we can put the required files, e.g. ~/tmp/yubikey-pgp mkdir -p ~/tmp/yubikey-pgp 2. Navigate to the previously created directory and download ykneo-openpgp: git clone https://github.com/Yubico/ykneo-openpgp.git 3. Now you need to download the Java Card Development Kit 2.2.2 from http://www.oracle.com/technetwork/java/javasebusiness/downloads/java-archive-downloads-javame-419430.html, select the kit for Linux (java_card_kit-2_2_2-linux.zip). MacOS should already have extracted the file, so that now you should have a folder java_card_kit-2_2_2-linux containing the extracted files. Put it in your ~/tmp/yubikey-pgp folder. 4. Now navigate to ~/tmp/yubikey-pgp/java_card_kit-2_2_2-linux/java_card_kit-2_2_2 and unzip the file java_card_kit-2_2_2-rr-bin-linux-do.zip: cd ~/tmp/yubikey-pgp/java_card_kit-2_2_2-linux/java_card_kit-2_2_2 unzip -d java_card_kit-2_2_2-rr-bin-linux-do java_card_kit-2_2_2-rr-bin-linux-do.zip ` 5. Next find out the serial number of your key by typing `ykinfo -H. You will get a hex code (after serial_hex:, write this down. 6. Navigate back to ~/tmp/yubikey-pgp/ykneo-openpgp : cd ~/tmp/yubikey-pgp/ykneo-openpgp 7. Change the hex code in the build.xml file to match your devices serial. Find the property APPLET_AID`and change the hex value starting from the 12th byte. One byte with the serial you have written down in step 5. The default values you find here are `0x00:0x00:0x01. In my case I replaced <property name="APPLET_AID" value="0xd2:0x76:0x00:0x01:0x24:0x01:0x02:0x00:0x00:0x00:0x00:0x00:0x00:0x01:0x00:0x00"/> with <property name="APPLET_AID" value="0xd2:0x76:0x00:0x01:0x24:0x01:0x02:0x00:0x00:0x00:0x00:0x37:0x83:0xb3:0x00:0x00"/> 8. Now you can build the files in ant: ant -DJAVACARD_HOME=../java_card_kit-2_2_2-linux/java_card_kit-2_2_2/java_card_kit-2_2_2-rr-bin-linux-do/ 9. The relevant created file can be found here: ~/tmp/yubikey-pgp/ykneo-openpgp/applet/bin/openpgpcard/javacard/openpgpcard.cap

For installation you need the Global Platform shell. 1. Download the archive containing the shell from http://sourceforge.net/projects/globalplatform/. The current version is 1.4.4, so in this instructions I will refer to the file gpshell-1.4.4.tar.gz. When you download the file, MacOS automatically should extract it, but not fully. You need to extract the tar part manually by clicking on the file. The result will be the folder gpsshell-1.4.4 which you now should move to ~/tmp/yubikey-pgp/. 2. Now navigate to this folder: cd ~/tmp/yubikey-pgp/gpsshell-1.4.4 3. Set the relevant library path so all libraries are found for compilation: export DYLD_LIBRARY_PATH=/opt/local/lib

If your yubikey shall not be recognized, disable secure input for your terminal (this applies to both Apple Terminal or iTerm, see https://github.com/Yubico/yubikey-personalization/issues/34).