diff -Nru opensc-0.13.0/debian/changelog opensc-0.13.0/debian/changelog
--- opensc-0.13.0/debian/changelog	2013-08-25 06:47:46.000000000 +0200
+++ opensc-0.13.0/debian/changelog	2014-01-11 13:03:11.000000000 +0100
@@ -1,3 +1,9 @@
+opensc (0.13.0-3ubuntu2) trusty; urgency=low
+
+  * Fix regression which causes authentication failure in Firefox. (LP: #1252254)
+
+ -- Jean-Louis Dupond <jean-louis@dupond.be>  Sat, 11 Jan 2014 13:02:29 +0100
+
 opensc (0.13.0-3ubuntu1) saucy; urgency=low
 
   * Merge from Debian. Remaining changes:
diff -Nru opensc-0.13.0/debian/patches/0001-pkcs15-regression-in-e35febe-compute-cert-length.patch opensc-0.13.0/debian/patches/0001-pkcs15-regression-in-e35febe-compute-cert-length.patch
--- opensc-0.13.0/debian/patches/0001-pkcs15-regression-in-e35febe-compute-cert-length.patch	1970-01-01 01:00:00.000000000 +0100
+++ opensc-0.13.0/debian/patches/0001-pkcs15-regression-in-e35febe-compute-cert-length.patch	2013-11-18 13:38:31.000000000 +0100
@@ -0,0 +1,114 @@
+From cc5a171ddcc8e49b2252135daac9ad3aa6d66ae7 Mon Sep 17 00:00:00 2001
+From: Viktor Tarasov <viktor.tarasov@gmail.com>
+Date: Tue, 25 Dec 2012 20:05:45 +0100
+Subject: [PATCH] pkcs15: regression in e35febe: compute cert length
+
+parse_x509_cert() reviewed.
+Now certificate's DER data are allocated and the DER data length is determined in one place.
+
+https://github.com/OpenSC/OpenSC/pull/114
+https://github.com/OpenSC/OpenSC/commit/e35febe
+---
+ src/libopensc/pkcs15-cert.c | 37 +++++++++++++++++++------------------
+ 1 file changed, 19 insertions(+), 18 deletions(-)
+
+diff --git a/src/libopensc/pkcs15-cert.c b/src/libopensc/pkcs15-cert.c
+index 86bea25..9b08aac 100644
+--- a/src/libopensc/pkcs15-cert.c
++++ b/src/libopensc/pkcs15-cert.c
+@@ -34,13 +34,13 @@
+ #include "pkcs15.h"
+ 
+ static int
+-parse_x509_cert(sc_context_t *ctx, const u8 *buf, size_t buflen, struct sc_pkcs15_cert *cert)
++parse_x509_cert(sc_context_t *ctx, struct sc_pkcs15_der *der, struct sc_pkcs15_cert *cert)
+ {
+ 	int r;
+ 	struct sc_algorithm_id sig_alg;
+-	struct sc_pkcs15_pubkey  * pubkey = NULL;
+-	u8 *serial = NULL;
+-	size_t serial_len = 0;
++	struct sc_pkcs15_pubkey *pubkey = NULL;
++	unsigned char *serial = NULL, *buf =  der->value;
++	size_t serial_len = 0, data_len = 0, buflen = der->len;
+ 	struct sc_asn1_entry asn1_version[] = {
+ 		{ "version", SC_ASN1_INTEGER, SC_ASN1_TAG_INTEGER, 0, &cert->version, NULL },
+ 		{ NULL, 0, 0, 0, NULL, NULL }
+@@ -87,30 +87,32 @@ parse_x509_cert(sc_context_t *ctx, const u8 *buf, size_t buflen, struct sc_pkcs1
+ 	if (obj == NULL)
+ 		LOG_TEST_RET(ctx, SC_ERROR_INVALID_ASN1_OBJECT, "X.509 certificate not found");
+ 
+-	cert->data.len = objlen + (obj - buf);
++	data_len = objlen + (obj - buf);
++	cert->data.value = malloc(data_len);
++	if (!cert->data.value)
++		LOG_FUNC_RETURN(ctx, SC_ERROR_OUT_OF_MEMORY);
++	memcpy(cert->data.value, buf, data_len);
++	cert->data.len = data_len;
++
+ 	r = sc_asn1_decode(ctx, asn1_cert, obj, objlen, NULL, NULL);
+ 	LOG_TEST_RET(ctx, r, "ASN.1 parsing of certificate failed");
+ 
+ 	cert->version++;
+ 
+-	if (pubkey) {
+-		cert->key = pubkey;
+-		pubkey = NULL;
+-	}
+-	else {
++	if (!pubkey)
+ 		LOG_TEST_RET(ctx, SC_ERROR_INVALID_ASN1_OBJECT, "Unable to decode subjectPublicKeyInfo from cert");
+-	}
++	cert->key = pubkey;
++
+ 	sc_asn1_clear_algorithm_id(&sig_alg);
+-	if (r < 0)
+-		return r;
+ 
+ 	if (serial && serial_len)   {
+ 		sc_format_asn1_entry(asn1_serial_number + 0, serial, &serial_len, 1);
+ 		r = sc_asn1_encode(ctx, asn1_serial_number, &cert->serial, &cert->serial_len);
+ 		free(serial);
++		LOG_TEST_RET(ctx, r, "ASN.1 encoding of serial failed");
+ 	}
+ 
+-	return r;
++	return SC_SUCCESS;
+ }
+ 
+ 
+@@ -125,7 +127,7 @@ sc_pkcs15_pubkey_from_cert(struct sc_context *ctx,
+ 	if (cert == NULL)
+ 		return SC_ERROR_OUT_OF_MEMORY;
+ 
+-	rv = parse_x509_cert(ctx, cert_blob->value, cert_blob->len, cert);
++	rv = parse_x509_cert(ctx, cert_blob, cert);
+ 
+ 	*out = cert->key;
+ 	cert->key = NULL;
+@@ -158,20 +160,19 @@ sc_pkcs15_read_certificate(struct sc_pkcs15_card *p15card, const struct sc_pkcs1
+ 		return SC_ERROR_OBJECT_NOT_FOUND;
+ 	}
+ 
+-
+ 	cert = malloc(sizeof(struct sc_pkcs15_cert));
+ 	if (cert == NULL) {
+ 		free(der.value);
+ 		return SC_ERROR_OUT_OF_MEMORY;
+ 	}
+ 	memset(cert, 0, sizeof(struct sc_pkcs15_cert));
+-	if (parse_x509_cert(p15card->card->ctx, der.value, der.len, cert)) {
++	if (parse_x509_cert(p15card->card->ctx, &der, cert)) {
+ 		free(der.value);
+ 		sc_pkcs15_free_certificate(cert);
+ 		return SC_ERROR_INVALID_ASN1_OBJECT;
+ 	}
++	free(der.value);
+ 
+-	cert->data = der;
+ 	*cert_out = cert;
+ 	return SC_SUCCESS;
+ }
+-- 
+1.8.1
+
diff -Nru opensc-0.13.0/debian/patches/series opensc-0.13.0/debian/patches/series
--- opensc-0.13.0/debian/patches/series	2013-07-18 05:05:02.000000000 +0200
+++ opensc-0.13.0/debian/patches/series	2014-01-11 13:02:19.000000000 +0100
@@ -0,0 +1 @@
+0001-pkcs15-regression-in-e35febe-compute-cert-length.patch