From 013161014b868e9162d0649a9945139e27faaa74 Mon Sep 17 00:00:00 2001
From: Klas Lindfors <klas@yubico.com>
Date: Mon, 3 Feb 2014 15:08:15 +0100
Subject: [PATCH] implement authenticate

---
 Makefile.am       |  6 +++--
 configure.ac      |  1 +
 yubico-piv-tool.c | 65 +++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index b973506..b8bc1cb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,12 +25,14 @@
 # for the parts of OpenSSL used as well as that of the covered work.
 
 AM_CFLAGS = $(WERROR_CFLAGS) $(WARN_CFLAGS)
-AM_CPPFLAGS = $(PCSC_CFLAGS)
+AM_CPPFLAGS = $(PCSC_CFLAGS) $(OPENSSL_CFLAGS)
+
+ACLOCAL_AMFLAGS = -I m4
 
 bin_PROGRAMS = yubico-piv-tool
 yubico_piv_tool_SOURCES = yubico-piv-tool.c
 yubico_piv_tool_SOURCES += cmdline.ggo cmdline.c cmdline.h
-yubico_piv_tool_LDADD = $(PCSC_LIBS)
+yubico_piv_tool_LDADD = $(PCSC_LIBS) $(OPENSSL_LIBS)
 
 cmdline.c cmdline.h: cmdline.ggo Makefile.am
 	gengetopt --input $^
diff --git a/configure.ac b/configure.ac
index 9b3d467..f90f63a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -38,6 +38,7 @@ AM_MISSING_PROG(HELP2MAN, help2man, $missing_dir)
 PKG_PROG_PKG_CONFIG
 
 PKG_CHECK_MODULES(PCSC, libpcsclite)
+PKG_CHECK_MODULES(OPENSSL, openssl)
 
 AC_ARG_ENABLE([gcc-warnings],
   [AS_HELP_STRING([--enable-gcc-warnings],
diff --git a/yubico-piv-tool.c b/yubico-piv-tool.c
index 3111f88..a6e5e34 100644
--- a/yubico-piv-tool.c
+++ b/yubico-piv-tool.c
@@ -32,6 +32,8 @@
 #include <stdbool.h>
 #include <string.h>
 
+#include <openssl/des.h>
+
 #ifdef __APPLE__
 #include <PCSC/wintypes.h>
 #else
@@ -136,10 +138,9 @@ static bool select_applet(SCARDHANDLE *card, int verbose) {
   unsigned long recv_len = sizeof(data);
   int sw;
 
-  apdu.st.cla = 0x00;
+  memset(apdu.raw, 0, sizeof(apdu));
   apdu.st.ins = 0xa4;
   apdu.st.p1 = 0x04;
-  apdu.st.p2 = 0x00;
   apdu.st.lc = AID_LEN;
   memcpy(apdu.st.data, aid, AID_LEN);
 
@@ -151,6 +152,62 @@ static bool select_applet(SCARDHANDLE *card, int verbose) {
   return false;
 }
 
+static bool authenticate(SCARDHANDLE *card, unsigned char *key, int verbose) {
+  APDU apdu;
+  unsigned char data[0xff];
+  unsigned char challenge[8];
+  unsigned long recv_len = sizeof(data);
+  int sw;
+
+  DES_key_schedule ks1, ks2, ks3;
+
+  {
+    DES_set_key_unchecked(key, &ks1);
+    DES_set_key_unchecked(key + 8, &ks2);
+    DES_set_key_unchecked(key + 16, &ks3);
+  }
+
+  {
+    memset(apdu.raw, 0, sizeof(apdu));
+    apdu.st.ins = 0x87;
+    apdu.st.p1 = 0x03; /* triple des */
+    apdu.st.p2 = 0x9b; /* management key */
+    apdu.st.lc = 0x04;
+    apdu.st.data[0] = 0x7c;
+    apdu.st.data[1] = 0x02;
+    apdu.st.data[2] = 0x80;
+    sw = send_data(card, apdu, 9, data, &recv_len, verbose);
+    if(sw != 0x9000) {
+      return false;
+    }
+    memcpy(challenge, data + 4, 8);
+    if(verbose) {
+      printf("received challenge:\n");
+      dump_hex(challenge, 8);
+    }
+  }
+
+  {
+    recv_len = 0xff;
+    memset(apdu.raw, 0, sizeof(apdu));
+    apdu.st.ins = 0x87;
+    apdu.st.p1 = 0x03; /* triple des */
+    apdu.st.p2 = 0x9b; /* management key */
+    apdu.st.lc = 12;
+    apdu.st.data[0] = 0x7c;
+    apdu.st.data[1] = 10;
+    apdu.st.data[2] = 0x80;
+    apdu.st.data[3] = 8;
+    DES_ecb3_encrypt(challenge, apdu.st.data + 4, &ks1, &ks2, &ks3, 0);
+    sw = send_data(card, apdu, 17, data, &recv_len, verbose);
+  }
+
+  if(sw == 0x9000) {
+    return true;
+  }
+  return false;
+}
+
 int send_data(SCARDHANDLE *card, APDU apdu, unsigned int send_len, unsigned char *data, unsigned long *recv_len, int verbose) {
   long rc;
   int sw;
@@ -234,5 +291,9 @@ int main(int argc, char *argv[]) {
     return EXIT_FAILURE;
   }
 
+  if(authenticate(&card, key, args_info.verbose_flag) == false) {
+    return EXIT_FAILURE;
+  }
+
   return EXIT_SUCCESS;
 }