diff --git a/ykcs11/Makefile.am b/ykcs11/Makefile.am
index d93c75c..f94ef82 100644
--- a/ykcs11/Makefile.am
+++ b/ykcs11/Makefile.am
@@ -39,8 +39,9 @@ libykcs11_la_SOURCES += slot_vendors.c slot_vendor.h
 libykcs11_la_SOURCES += token_vendors.c token_vendor.h
 libykcs11_la_SOURCES += mechanisms.c mechanisms.h
 libykcs11_la_SOURCES += yubico_slot.c yubico_slot.h yubico_token.c yubico_token.h
-libykcs11_la_SOURCES += utils.h utils.c
-libykcs11_la_SOURCES += obj_types.h objects.h objects.c
+libykcs11_la_SOURCES += utils.c utils.h
+libykcs11_la_SOURCES += openssl_utils.c openssl_utils.h
+libykcs11_la_SOURCES += objects.c objects.h obj_types.h
 
 #internal.h
 #libykcs11_la_SOURCES += error.c
@@ -54,6 +55,7 @@ EXTRA_libykcs11_la_DEPENDENCIES = ykcs11.map
 #libykcs11_la_LIBADD = $(OPENSSL_LIBS) $(PCSC_LIBS)
 #libykcs11_la_LIBADD += $(PCSC_WIN_LIBS) $(PCSC_MACOSX_LIBS)
 libykcs11_la_LIBADD = $(LIBNSPR) ../lib/libykpiv.la
+libykcs11_la_LIBADD += ../tool/libpiv_util.la
 
 libykcs11_la_LDFLAGS = -no-undefined
 libykcs11_la_LDFLAGS += -version-info $(LT_CURRENT):$(LT_REVISION):$(LT_AGE)
diff --git a/ykcs11/mechanisms.c b/ykcs11/mechanisms.c
index b63ea59..7eb0c69 100644
--- a/ykcs11/mechanisms.c
+++ b/ykcs11/mechanisms.c
@@ -40,7 +40,7 @@ CK_RV check_sign_mechanism(const ykcs11_session_t *s, const CK_MECHANISM_PTR m)
   if (token.get_token_mechanism_info(m->mechanism, &info) != CKR_OK)
     return CKR_MECHANISM_INVALID;
 
-  // TODO: also check that parametes make sens if any?
+  // TODO: also check that parametes make sense if any?
 
   CKR_OK;
 
@@ -84,3 +84,20 @@ CK_BBOOL is_RSA_mechanism(CK_MECHANISM_TYPE m) {
   // Not reached
   return CK_FALSE;
 }
+
+CK_RV do_sign_padding(CK_MECHANISM_PTR m, CK_BYTE_PTR in, CK_ULONG in_len,
+                      CK_BYTE_PTR out, CK_ULONG out_len, CK_ULONG key_len) {
+  switch (m->mechanism) {
+  case CKM_RSA_PKCS:
+    return do_pkcs_t1(in, in_len, out, out_len, key_len);
+
+  case CKM_RSA_PKCS_PSS:
+  case CKM_RSA_X_509:
+  case CKM_SHA1_RSA_PKCS:
+  case CKM_SHA256_RSA_PKCS:
+  case CKM_SHA384_RSA_PKCS:
+  case CKM_SHA512_RSA_PKCS:
+    return CKR_FUNCTION_FAILED;
+  }
+  
+}
diff --git a/ykcs11/mechanisms.h b/ykcs11/mechanisms.h
index f95565e..8a38121 100644
--- a/ykcs11/mechanisms.h
+++ b/ykcs11/mechanisms.h
@@ -7,4 +7,7 @@
 CK_RV check_sign_mechanism(const ykcs11_session_t *s, CK_MECHANISM_PTR m);
 CK_BBOOL is_RSA_mechanism(CK_MECHANISM_TYPE m);
 
+CK_RV do_sign_padding(CK_MECHANISM_PTR m, CK_BYTE_PTR in, CK_ULONG in_len,
+                      CK_BYTE_PTR out, CK_ULONG out_len, CK_ULONG key_len);
+
 #endif
diff --git a/ykcs11/obj_types.h b/ykcs11/obj_types.h
index a0f3c3c..1f0913f 100644
--- a/ykcs11/obj_types.h
+++ b/ykcs11/obj_types.h
@@ -103,12 +103,12 @@ typedef struct {
   X509 *data;
 } piv_cert_obj_t;
 
-typedef struct {
+typedef struct { // TODO: enough to use the public key for the parameters?
   CK_BBOOL todo;
 } piv_pvtk_obj_t;
 
 typedef struct {
-  CK_BBOOL todo;
+  EVP_PKEY *data;
 } piv_pubk_obj_t;
 
 typedef struct {
diff --git a/ykcs11/objects.c b/ykcs11/objects.c
index 19a749e..270e94d 100644
--- a/ykcs11/objects.c
+++ b/ykcs11/objects.c
@@ -3,6 +3,9 @@
 #include <ykpiv.h>
 #include <string.h>
 #include <stdlib.h>
+#include "openssl_utils.h"
+
+#define IS_CERT(x) (((x) >= PIV_CERT_OBJ_X509_PIV_AUTH && (x) <  PIV_CERT_OBJ_LAST) ? CK_TRUE : CK_FALSE)
 
 CK_RV get_doa(CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR template); // TODO: static?
 CK_RV get_coa(CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR template);
@@ -843,6 +846,38 @@ CK_RV get_puoa(CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR template) {
 
 }
 
+CK_ULONG piv_2_ykpiv(piv_obj_id_t id) {
+  // TODO: add retired keys
+  switch(id) {
+  case PIV_CERT_OBJ_X509_PIV_AUTH:
+    return YKPIV_OBJ_AUTHENTICATION;
+    
+  case PIV_CERT_OBJ_X509_CARD_AUTH:
+    return YKPIV_OBJ_CARD_AUTH;
+    
+  case PIV_CERT_OBJ_X509_DS:
+    return YKPIV_OBJ_SIGNATURE;
+    
+  case PIV_CERT_OBJ_X509_KM:
+    return YKPIV_OBJ_KEY_MANAGEMENT;
+
+  case PIV_PVTK_OBJ_PIV_AUTH:
+    return YKPIV_KEY_AUTHENTICATION;
+    
+  case PIV_PVTK_OBJ_CARD_AUTH:
+    return YKPIV_KEY_CARDAUTH;
+    
+  case PIV_PVTK_OBJ_DS:
+    return YKPIV_KEY_SIGNATURE;
+    
+  case PIV_PVTK_OBJ_KM:
+    return YKPIV_KEY_KEYMGM;
+
+  default:
+    return 0ul;
+  }
+}
+
 CK_RV get_attribute(ykcs11_session_t *s, CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR template) {
   CK_ULONG i;
 
@@ -851,6 +886,34 @@ CK_RV get_attribute(ykcs11_session_t *s, CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR
       return piv_objects[obj].get_attribute(obj, template);
     }
 
-
   return CKR_OBJECT_HANDLE_INVALID;
 }
+
+CK_RV get_available_certificate_ids(ykcs11_session_t *s, piv_obj_id_t *cert_ids, CK_ULONG n_certs) {
+  CK_ULONG i, j;
+
+  j = 0;
+  for (i = 0; i < s->slot->token->n_objects; i++)
+    if (IS_CERT(s->slot->token->objects[i]) == CK_TRUE)
+      cert_ids[j++] = s->slot->token->objects[i];
+
+  fprintf(stderr, "Just to check: %lu %lu\n", j, n_certs);
+
+  return CKR_OK;
+}
+
+CK_RV store_cert(piv_obj_id_t cert_id, CK_BYTE_PTR data, CK_ULONG len) {
+
+  CK_RV rv;
+
+  // Store the certificate as an object
+  rv = do_store_cert(data, len, &cert_objects[piv_objects[cert_id].sub_id].data);
+  if (rv != CKR_OK)
+    return rv;
+
+  // Extract and store the public key as an object
+  rv = do_store_pubk(cert_objects[piv_objects[cert_id].sub_id].data, &pubkey_objects[piv_objects[cert_id].sub_id].data);
+
+  return CKR_OK;
+}
+
diff --git a/ykcs11/objects.h b/ykcs11/objects.h
index 439361e..df0a60f 100644
--- a/ykcs11/objects.h
+++ b/ykcs11/objects.h
@@ -5,6 +5,10 @@
 
 #include <stdio.h> // TODO: delete
 
+CK_ULONG piv_2_ykpiv(piv_obj_id_t id);
+
 CK_RV get_attribute(ykcs11_session_t *s, CK_OBJECT_HANDLE obj, CK_ATTRIBUTE_PTR template);
+CK_RV get_available_certificate_ids(ykcs11_session_t *s, piv_obj_id_t *cert_ids, CK_ULONG n_certs);
+CK_RV store_cert(piv_obj_id_t cert_id, CK_BYTE_PTR data, CK_ULONG len);
 
 #endif
diff --git a/ykcs11/openssl_utils.c b/ykcs11/openssl_utils.c
new file mode 100644
index 0000000..d139a99
--- /dev/null
+++ b/ykcs11/openssl_utils.c
@@ -0,0 +1,78 @@
+#include "openssl_utils.h"
+#include <stdbool.h>
+#include "../tool/util.h" // TODO: share this better?
+
+
+CK_RV do_store_cert(CK_BYTE_PTR data, CK_ULONG len, X509 **cert) {
+
+  const unsigned char *p = data; // Mandatory temp variable required by OpenSSL
+  int                 cert_len;
+  
+  /**cert = X509_new();
+  if (*cert == NULL)
+  return CKR_HOST_MEMORY;*/
+  //dump_hex(data, len, stderr, CK_TRUE);
+
+  if (*p++ != 0x70)
+    return CKR_FUNCTION_FAILED;
+
+  p += get_length(p, &cert_len);
+
+  *cert = d2i_X509(NULL, &p, cert_len);
+  if (*cert == NULL)
+    return CKR_FUNCTION_FAILED;
+
+  /*
+  BIO *STDout = BIO_new_fp(stderr, BIO_NOCLOSE);
+
+  X509_print_ex(STDout, *cert, 0, 0);
+
+  BIO_free(STDout);
+  */
+
+  return CKR_OK;
+
+}
+
+CK_RV free_cert(X509 *cert) {
+
+  X509_free((X509 *) cert);
+
+  return CKR_OK;
+}
+
+
+CK_RV do_store_pubk(X509 *cert, EVP_PKEY **key) {
+
+  *key = X509_get_pubkey(cert);
+
+  if (*key == NULL)
+    return CKR_FUNCTION_FAILED;
+
+  return CKR_OK;
+  
+}
+
+CK_RV free_key(EVP_PKEY *key) {
+
+  EVP_PKEY_free(key);
+  
+  return CKR_OK;
+  
+}
+/* #include <stdio.h> */
+/* #include <openssl/err.h> */
+/*   ERR_load_crypto_strings(); */
+/* //SSL_load_error_strings(); */
+CK_RV do_pkcs_t1(CK_BYTE_PTR in, CK_ULONG in_len, CK_BYTE_PTR out, CK_ULONG out_len, CK_ULONG key_len) {
+  fprintf(stderr, "Apply padding to %lu bytes and get %lu\n", in_len, key_len);
+
+
+  if (out_len < key_len)
+    CKR_BUFFER_TOO_SMALL;
+
+  if (RSA_padding_add_PKCS1_type_1(out, key_len, in, in_len) == 0)
+    return CKR_FUNCTION_FAILED;
+
+  return CKR_OK;
+}
diff --git a/ykcs11/openssl_utils.h b/ykcs11/openssl_utils.h
new file mode 100644
index 0000000..f9382d5
--- /dev/null
+++ b/ykcs11/openssl_utils.h
@@ -0,0 +1,17 @@
+#ifndef OPENSSL_UTIL_H
+#define OPENSSL_UTIL_H
+
+#include <openssl/x509.h>
+#include <openssl/evp.h>
+#include <openssl/rsa.h>
+#include "pkcs11t.h"
+
+CK_RV do_store_cert(CK_BYTE_PTR data, CK_ULONG len, X509 **cert);
+CK_RV free_cert(X509 *cert);
+
+CK_RV do_store_pubk(X509 *cert, EVP_PKEY **key);
+CK_RV free_key(EVP_PKEY *key);
+
+CK_RV do_pkcs_t1(CK_BYTE_PTR in, CK_ULONG in_len, CK_BYTE_PTR out, CK_ULONG out_len, CK_ULONG key_len);
+
+#endif
diff --git a/ykcs11/token_vendors.c b/ykcs11/token_vendors.c
index a19c18e..7fd1bfc 100644
--- a/ykcs11/token_vendors.c
+++ b/ykcs11/token_vendors.c
@@ -6,32 +6,34 @@ token_vendor_t get_token_vendor(vendor_id_t vid) {
 
   switch (vid) {
   case YUBICO:
-    v.get_token_label          = YUBICO_get_token_label;
-    v.get_token_manufacturer   = YUBICO_get_token_manufacturer;
-    v.get_token_model          = YUBICO_get_token_model;
-    v.get_token_flags          = YUBICO_get_token_flags;
-    v.get_token_version        = YUBICO_get_token_version;
-    v.get_token_serial         = YUBICO_get_token_serial;
-    v.get_token_mechanisms_num = YUBICO_get_token_mechanisms_num;
-    v.get_token_mechanism_list = YUBICO_get_token_mechanism_list;
-    v.get_token_mechanism_info = YUBICO_get_token_mechanism_info;
-    v.get_token_objects_num    = YUBICO_get_token_objects_num;
-    v.get_token_object_list    = YUBICO_get_token_object_list;
+    v.get_token_label           = YUBICO_get_token_label;
+    v.get_token_manufacturer    = YUBICO_get_token_manufacturer;
+    v.get_token_model           = YUBICO_get_token_model;
+    v.get_token_flags           = YUBICO_get_token_flags;
+    v.get_token_version         = YUBICO_get_token_version;
+    v.get_token_serial          = YUBICO_get_token_serial;
+    v.get_token_mechanisms_num  = YUBICO_get_token_mechanisms_num;
+    v.get_token_mechanism_list  = YUBICO_get_token_mechanism_list;
+    v.get_token_mechanism_info  = YUBICO_get_token_mechanism_info;
+    v.get_token_objects_num     = YUBICO_get_token_objects_num;
+    v.get_token_object_list     = YUBICO_get_token_object_list;
+    v.get_token_raw_certificate = YUBICO_get_token_raw_certificate;
     break;
 
   case UNKNOWN:
   default:
-    v.get_token_label          = NULL;
-    v.get_token_manufacturer   = NULL;
-    v.get_token_model          = NULL;
-    v.get_token_flags          = NULL;
-    v.get_token_version        = NULL;
-    v.get_token_serial         = NULL;
-    v.get_token_mechanisms_num = NULL;
-    v.get_token_mechanism_list = NULL;
-    v.get_token_mechanism_info = NULL;
-    v.get_token_objects_num    = NULL;
-    v.get_token_object_list    = NULL;
+    v.get_token_label           = NULL;
+    v.get_token_manufacturer    = NULL;
+    v.get_token_model           = NULL;
+    v.get_token_flags           = NULL;
+    v.get_token_version         = NULL;
+    v.get_token_serial          = NULL;
+    v.get_token_mechanisms_num  = NULL;
+    v.get_token_mechanism_list  = NULL;
+    v.get_token_mechanism_info  = NULL;
+    v.get_token_objects_num     = NULL;
+    v.get_token_object_list     = NULL;
+    v.get_token_raw_certificate = NULL;
   }
 
   return v;
diff --git a/ykcs11/token_vendors.h b/ykcs11/token_vendors.h
index a57a6cd..4df53e0 100644
--- a/ykcs11/token_vendors.h
+++ b/ykcs11/token_vendors.h
@@ -15,21 +15,23 @@ typedef CK_RV (*get_t_serial_f)(CK_CHAR_PTR, CK_ULONG);
 typedef CK_RV (*get_t_mechanisms_num_f)(CK_ULONG_PTR);
 typedef CK_RV (*get_t_mechanism_list_f)(CK_MECHANISM_TYPE_PTR, CK_ULONG);
 typedef CK_RV (*get_t_mechanism_info_f)(CK_MECHANISM_TYPE, CK_MECHANISM_INFO_PTR);
-typedef CK_RV (*get_t_objects_num_f)(ykpiv_state *, CK_ULONG_PTR);
+typedef CK_RV (*get_t_objects_num_f)(ykpiv_state *, CK_ULONG_PTR, CK_ULONG_PTR);
 typedef CK_RV (*get_t_object_list_f)(ykpiv_state *, piv_obj_id_t *, CK_ULONG);
-
+typedef CK_RV (*get_t_raw_certificate_f)(ykpiv_state *, piv_obj_id_t, CK_BYTE_PTR, CK_ULONG);
+// TODO: replace all the common call with functions defined in .c that use libykpiv
 typedef struct {
-  get_t_label_f          get_token_label;
-  get_t_manufacturer_f   get_token_manufacturer;
-  get_t_model_f          get_token_model;
-  get_t_flags_f          get_token_flags;
-  get_t_version_f        get_token_version;
-  get_t_serial_f         get_token_serial;
-  get_t_mechanisms_num_f get_token_mechanisms_num;
-  get_t_mechanism_list_f get_token_mechanism_list;
-  get_t_mechanism_info_f get_token_mechanism_info;
-  get_t_objects_num_f    get_token_objects_num;
-  get_t_object_list_f    get_token_object_list;
+  get_t_label_f           get_token_label;
+  get_t_manufacturer_f    get_token_manufacturer;
+  get_t_model_f           get_token_model;
+  get_t_flags_f           get_token_flags;
+  get_t_version_f         get_token_version;
+  get_t_serial_f          get_token_serial;
+  get_t_mechanisms_num_f  get_token_mechanisms_num;
+  get_t_mechanism_list_f  get_token_mechanism_list;
+  get_t_mechanism_info_f  get_token_mechanism_info;
+  get_t_objects_num_f     get_token_objects_num;
+  get_t_object_list_f     get_token_object_list;
+  get_t_raw_certificate_f get_token_raw_certificate;
 } token_vendor_t;
 
 token_vendor_t get_token_vendor(vendor_id_t vid);
diff --git a/ykcs11/utils.c b/ykcs11/utils.c
index 09fdc55..add1aef 100644
--- a/ykcs11/utils.c
+++ b/ykcs11/utils.c
@@ -156,6 +156,8 @@ CK_RV create_token(CK_BYTE_PTR p, ykcs11_slot_t *slot) {
   memset(t_info->utcTime, ' ', sizeof(t_info->utcTime)); // No clock present, clear
 
   // TODO: also get token objects here? (and destroy on failure)
+  slot->token->objects = NULL;
+  slot->token->n_objects = 0;
   
   return CKR_OK;
 }
diff --git a/ykcs11/ykcs11.c b/ykcs11/ykcs11.c
index 46faef9..2ad268c 100644
--- a/ykcs11/ykcs11.c
+++ b/ykcs11/ykcs11.c
@@ -23,10 +23,12 @@
 #define PIV_MIN_PIN_LEN 6
 #define PIV_MAX_PIN_LEN 8
 
-#define YKCS11_MAX_SLOTS 16
+#define YKCS11_MAX_SLOTS       16
+#define YKCS11_MAX_SIG_BUF_LEN 1024
 
 #define YKCS11_SESSION_ID 5355104
 
+
 #if YKCS11_DBG
 #define DBG(x) D(x);
 #else
@@ -60,9 +62,10 @@ static struct {
   static CK_ULONG n_token_objects = 0;*/
 
 static struct {
-  CK_BBOOL         active;
-  CK_MECHANISM     mechanism;
-  CK_OBJECT_HANDLE key;
+  CK_BBOOL     active;
+  CK_MECHANISM mechanism;
+  CK_ULONG     key;
+  CK_BYTE      algo;
 } sign_info;
 
 extern CK_FUNCTION_LIST function_list; // TODO: check all return values
@@ -269,7 +272,7 @@ CK_DEFINE_FUNCTION(CK_RV, C_GetTokenInfo)(
   token = get_token_vendor(slots[slotID].token->vid);
 
   memcpy(pInfo, &slots[slotID].token->info, sizeof(CK_TOKEN_INFO));
-  
+
   // Overwrite value that are application specific
   pInfo->ulMaxSessionCount = CK_UNAVAILABLE_INFORMATION; // TODO: should this be 1?
   pInfo->ulSessionCount = CK_UNAVAILABLE_INFORMATION; // number of sessions that this application currently has open with the token
@@ -283,7 +286,7 @@ CK_DEFINE_FUNCTION(CK_RV, C_GetTokenInfo)(
   pInfo->ulFreePublicMemory = CK_UNAVAILABLE_INFORMATION;
   pInfo->ulTotalPrivateMemory = CK_UNAVAILABLE_INFORMATION;
   pInfo->ulFreePrivateMemory = CK_UNAVAILABLE_INFORMATION;
-  
+
   DOUT;
   return CKR_OK;
 }
@@ -430,9 +433,14 @@ CK_DEFINE_FUNCTION(CK_RV, C_OpenSession)(
   CK_SESSION_HANDLE_PTR phSession
 )
 {
-  DIN;
+  DIN; // TODO: pApplication and Notify
 
   token_vendor_t token;
+  CK_RV          rv;
+  piv_obj_id_t   *cert_ids;
+  CK_ULONG       i;
+  CK_BYTE        cert_data[2100];  // Max cert value for ykpiv
+  CK_ULONG       cert_len = sizeof(cert_data);
 
   if (piv_state == NULL) {
     DBG(("libykpiv is not initialized or already finalized"));
@@ -473,27 +481,7 @@ CK_DEFINE_FUNCTION(CK_RV, C_OpenSession)(
   session.slot = slots + slotID;
   //session.slot->info.slotID = slotID; // Redundant but required in CK_SESSION_INFO
 
-  // Get the number of token objects
-  if (token.get_token_objects_num(piv_state, &session.slot->token->n_objects) != CKR_OK) {
-    DBG(("Unable to retrieve number of token objects"));
-    return CKR_FUNCTION_FAILED;
-  }
-
-  // Get memory for the objects
-  session.slot->token->objects = malloc(sizeof(piv_obj_id_t) * session.slot->token->n_objects);
-  if (session.slot->token->objects == NULL) {
-    DBG(("Unable to allocate memory for token objects"));
-    return CKR_HOST_MEMORY;
-  }
-
-  // Store all the objects available in the token
-  if (token.get_token_object_list(piv_state,
-                                         session.slot->token->objects,
-                                         session.slot->token->n_objects) != CKR_OK) {
-    DBG(("Unable to retrieve token objects"));
-    return CKR_FUNCTION_FAILED;
-  }
-
+  // Store session flags
   if ((flags & CKF_RW_SESSION)) {
     // R/W Session
     session.info.state = CKS_RW_PUBLIC_SESSION; // Nobody has logged in, default session
@@ -506,13 +494,78 @@ CK_DEFINE_FUNCTION(CK_RV, C_OpenSession)(
   session.info.flags = flags;
   session.info.ulDeviceError = 0;
 
+  // Get the number of token objects
+  rv = token.get_token_objects_num(piv_state, &session.slot->token->n_objects, &session.slot->token->n_certs);
+  if (rv != CKR_OK) {
+    DBG(("Unable to retrieve number of token objects"));
+    return rv;
+  }
+
+  // Get memory for the objects
+  session.slot->token->objects = malloc(sizeof(piv_obj_id_t) * session.slot->token->n_objects);
+  if (session.slot->token->objects == NULL) {
+    DBG(("Unable to allocate memory for token object ids"));
+    return CKR_HOST_MEMORY;
+  }
+
+  // Get memory for the certificates
+  cert_ids = malloc(sizeof(piv_obj_id_t) * session.slot->token->n_certs);
+  if (cert_ids == NULL) {
+    DBG(("Unable to allocate memory for token certificate ids"));
+    return CKR_HOST_MEMORY;
+  }
+
+  // Save a list of all the available objects in the token // TODO: change behavior based on login status
+  rv = token.get_token_object_list(piv_state, session.slot->token->objects, session.slot->token->n_objects);
+  if (rv != CKR_OK) {
+    DBG(("Unable to retrieve token objects"));
+    goto failure;
+  }
+
+  // Get a list object ids for available certificates object from the session
+  rv = get_available_certificate_ids(&session, cert_ids, session.slot->token->n_certs); // TODO: better to get this from token? how?
+  if (rv != CKR_OK) {
+    DBG(("Unable to retrieve certificate ids from the session"));
+    goto failure;
+  }
+
+  // Get the actual certificate data from the token and store it as an X509 object
+  for (i = 0; i < session.slot->token->n_certs; i++) {
+    rv = token.get_token_raw_certificate(piv_state, cert_ids[i], cert_data, cert_len);
+    if (rv != CKR_OK) {
+      DBG(("Unable to get certificate data from token"));
+      goto failure;
+    }
+
+    rv = store_cert(cert_ids[i], cert_data, cert_len);
+    if (rv != CKR_OK) {
+      DBG(("Unable to store certificate data"));
+      goto failure;
+    }
+  }
+
   session.handle = YKCS11_SESSION_ID;
-  // TODO: KEEP TRACK OF THE APPLICATION
+  // TODO: KEEP TRACK OF THE APPLICATION (possble to steal a session?)
 
   *phSession = session.handle;
 
   DOUT;
   return CKR_OK;
+
+failure:
+  if (session.slot->token->objects != NULL) {
+    free(session.slot->token->objects);
+    session.slot->token->objects = NULL;
+  }
+
+  if (cert_ids != NULL) {
+    free(cert_ids);
+    cert_ids = NULL;
+  }
+
+  free_certs(); // TODO
+
+  return rv;
 }
 
 CK_DEFINE_FUNCTION(CK_RV, C_CloseSession)(
@@ -677,7 +730,9 @@ CK_DEFINE_FUNCTION(CK_RV, C_Login)(
     return CKR_USER_TYPE_INVALID; // TODO: only allow regular user for now
   }
 
-  DBG(("You win! %lu", tries))
+  DBG(("You win! %lu", tries));
+
+  // TODO: update session objects now that we're logged in ?
 
   DOUT;
   return CKR_OK;
@@ -856,9 +911,9 @@ CK_DEFINE_FUNCTION(CK_RV, C_FindObjectsInit)(
     // TODO: remove objects that don't match
   }
 
-  // TODO: do it properly here, jsut a test now
+  // TODO: do it properly here, just a test now
   //find_obj.objects = session.slot->token->objects + 3;
-  memmove(find_obj.objects, find_obj.objects + 3, sizeof(piv_obj_id_t) * (find_obj.num - 3));
+  memmove(find_obj.objects, find_obj.objects + 14, sizeof(piv_obj_id_t) * (find_obj.num - 14));
   find_obj.num = 1;
 
   DOUT;
@@ -1128,33 +1183,41 @@ CK_DEFINE_FUNCTION(CK_RV, C_SignInit)(
 
   DBG(("Trying to sign some data with mechanism %lu and key %lu", pMechanism->mechanism, hKey));
 
+  // Check if mechanism is supported
   if (check_sign_mechanism(&session, pMechanism) != CKR_OK) {
     DBG(("Mechanism %lu is not supported either by the token or the slot", pMechanism->mechanism));
     return CKR_MECHANISM_INVALID;
   }
-
-  
-  
-  sign_info.active = CK_TRUE;
   memcpy(&sign_info.mechanism, pMechanism, sizeof(CK_MECHANISM));
-  sign_info.key = hKey;
-  // TODO: also allocate some space for the signature
 
+  //  Get key algorithm
+  /*if (get_key_algo(hKey, &sign_info.algo) != CKR_OK) {
+    DBG(("Unable to retrieve type for key %lu", hKey));
+    return CKR_FUNCTION_FAILED;
+    }*/ // TODO: use get attribute instead?
+  sign_info.algo = YKPIV_ALGO_RSA2048; // TODO: fix
+
+  sign_info.key = piv_2_ykpiv(hKey);
+  if (sign_info.key == 0) {
+    DBG(("Incorrect key %lu", hKey));
+    return CKR_KEY_HANDLE_INVALID;
+  }
+
+  // Make sure that both mechanism and key have the same algorithm
+  if ((is_RSA_mechanism(pMechanism->mechanism) && sign_info.algo == YKPIV_ALGO_ECCP256) ||
+      (!is_RSA_mechanism(pMechanism->mechanism) && (sign_info.algo != YKPIV_ALGO_ECCP256))) {
+    DBG(("Key and mechanism algorithm do not match"));
+    return CKR_ARGUMENTS_BAD;
+  }
+
+  // TODO: also allocate some space for the signature in case of multipart
+
+  sign_info.active = CK_TRUE;
 
   DOUT;
   return CKR_OK;
 }
-/* TOTOD: DELETE */
-CK_BYTE  sig_buf[1024];
-CK_ULONG sig_len = 1024;
-void dump_hex(const unsigned char *buf, unsigned int len, FILE *output, CK_BBOOL space) {
-  unsigned int i;
-  for (i = 0; i < len; i++) {
-    fprintf(output, "%02x%s", buf[i], space == CK_TRUE ? " " : "");
-  }
-  fprintf(output, "\n");
-}
-/* TODO: DELETE END*/
+
 CK_DEFINE_FUNCTION(CK_RV, C_Sign)(
   CK_SESSION_HANDLE hSession,
   CK_BYTE_PTR pData,
@@ -1164,39 +1227,35 @@ CK_DEFINE_FUNCTION(CK_RV, C_Sign)(
 )
 {
   DIN;
+  CK_BYTE  buf[YKCS11_MAX_SIG_BUF_LEN];
+  CK_ULONG buf_len = sizeof(buf);
 
   if (sign_info.active == CK_FALSE)
     return CKR_OPERATION_NOT_INITIALIZED;
 
   // TODO: check conditions
-  char test_buf[] = "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04\x20\xa7\x47\x16\x1b\x15\x5f\xd0\x05\xbc\xbe\x84\x4a\x28\xa9\x6c\x74\xfe\xf6\x6a\x42\x84\xa0\x4e\x05\x7a\x0c\x88\xe2\xc8\x83\xc0\x00";
-  CK_ULONG sig_len_in = sizeof(test_buf) - 1;
-  CK_ULONG sig_len_out = 1024;
   ykpiv_rc r;
-  CK_CHAR key;
+  CK_CHAR algo;
 
-  DBG(("Sending %lu bytes to sign", ulDataLen/*sig_len_in*/));
+  DBG(("Sending %lu bytes to sign", ulDataLen));
   dump_hex(pData, ulDataLen, stderr, CK_TRUE);
 
-  if (sign_info.key == PIV_DATA_OBJ_X509_PIV_AUTH) {
-    key = YKPIV_KEY_AUTHENTICATION;
-    DBG(("Using key 9a"));
-  }
-  else { // TODO: test what happens if there is no key on the card
-    key = YKPIV_KEY_SIGNATURE;
-    DBG(("Using key 9c"));
-  }
-
-  // TODO: check that mechanism makes sense for the key that we have (check in signinit).
-
-  if ((r = ykpiv_sign_data(piv_state, /*pData*/test_buf, /*ulDataLen*/sig_len_in, sig_buf, &sig_len_out, YKPIV_ALGO_RSA2048, key)) != YKPIV_OK) {
-      DBG(("Sign error %s", ykpiv_strerror(r)));
+/*  if (do_sign_padding(&sign_info.mechanism, pData, ulDataLen, buf, buf_len, 2048 / 8) != CKR_OK) {
+    DBG(("Unable to apply padding scheme"));
+    return CKR_FUNCTION_FAILED;
+    }*/
+  memcpy(buf, pData, ulDataLen); // ykpiv does padding already
+  //dump_hex(buf, 256, stderr, CK_TRUE);
+  //*pulSignatureLen = 256;
+  DBG(("Using key %lx", sign_info.key)); // TODO: test what happens if there is no key on the card
+  if ((r = ykpiv_sign_data(piv_state, buf, ulDataLen, pSignature, pulSignatureLen, YKPIV_ALGO_RSA2048, sign_info.key)) != YKPIV_OK) {
+      DBG(("Sign error, %s", ykpiv_strerror(r)));
     return CKR_FUNCTION_FAILED;
   }
-  DBG(("Got %lu bytes back", sig_len_out));
-  dump_hex(sig_buf, sig_len_out, stderr, CK_TRUE);
-  memcpy(pSignature, sig_buf, sig_len_out);
-  *pulSignatureLen = sig_len_out;
+  DBG(("Got %lu bytes back", *pulSignatureLen));
+  dump_hex(pSignature, *pulSignatureLen, stderr, CK_TRUE);
+/*  memcpy(pSignature, sig_buf, sig_len_out);
+ *pulSignatureLen = sig_len_out;*/
   DOUT;
   return CKR_OK;
 }
diff --git a/ykcs11/ykcs11.h b/ykcs11/ykcs11.h
index 2c9f644..cfa22da 100644
--- a/ykcs11/ykcs11.h
+++ b/ykcs11/ykcs11.h
@@ -8,8 +8,9 @@
 typedef struct {
   vendor_id_t   vid;
   CK_TOKEN_INFO info;
-  piv_obj_id_t  *objects;
-  CK_ULONG      n_objects;
+  piv_obj_id_t  *objects;  // List of objects in the token
+  CK_ULONG      n_objects; // TOTAL number of objects in the token
+  CK_ULONG      n_certs;   // Number of certificate objects in the token (portion of n_objects)
 } ykcs11_token_t;
 
 typedef struct {
diff --git a/ykcs11/yubico_token.c b/ykcs11/yubico_token.c
index 3f0be65..a70dab8 100644
--- a/ykcs11/yubico_token.c
+++ b/ykcs11/yubico_token.c
@@ -210,11 +210,12 @@ CK_RV YUBICO_get_token_mechanism_info(CK_MECHANISM_TYPE mec, CK_MECHANISM_INFO_P
 
 }
 #include <stdio.h> // TODO: delete
-static CK_RV get_objects(ykpiv_state *state, CK_BBOOL num_only, piv_obj_id_t *obj, CK_ULONG_PTR len) {
+static CK_RV get_objects(ykpiv_state *state, CK_BBOOL num_only,
+                         piv_obj_id_t *obj, CK_ULONG_PTR len, CK_ULONG_PTR num_certs) {
   CK_BYTE buf[2048];
   CK_ULONG buf_len;
 
-  piv_obj_id_t certs[4];
+  piv_obj_id_t certs[4]; // TODO: this can be > 4 if there are retired keys
   piv_obj_id_t pvtkeys[4];
   piv_obj_id_t pubkeys[4];
   CK_ULONG n_cert = 0;
@@ -267,6 +268,8 @@ static CK_RV get_objects(ykpiv_state *state, CK_BBOOL num_only, piv_obj_id_t *ob
     // We just want the number of objects
     // Each cert object counts for 3: cert, pub key, pvt key
     *len = (n_cert * 3) + token_objects_num;
+    if (num_certs != NULL)
+      *num_certs = n_cert;
     return CKR_OK;
   }
 
@@ -286,10 +289,18 @@ static CK_RV get_objects(ykpiv_state *state, CK_BBOOL num_only, piv_obj_id_t *ob
   return CKR_OK;
 }
 
-CK_RV YUBICO_get_token_objects_num(ykpiv_state *state, CK_ULONG_PTR num) {
-  return get_objects(state, CK_TRUE, NULL, num);
+CK_RV YUBICO_get_token_objects_num(ykpiv_state *state, CK_ULONG_PTR num, CK_ULONG_PTR num_certs) {
+  return get_objects(state, CK_TRUE, NULL, num, num_certs);
 }
 
 CK_RV YUBICO_get_token_object_list(ykpiv_state *state, piv_obj_id_t *obj, CK_ULONG num) {
-  return get_objects(state, CK_FALSE, obj, &num);
+  return get_objects(state, CK_FALSE, obj, &num, NULL);
+}
+
+CK_RV YUBICO_get_token_raw_certificate(ykpiv_state *state, piv_obj_id_t obj, CK_BYTE_PTR data, CK_ULONG len) {
+
+  if (ykpiv_fetch_object(state, piv_2_ykpiv(obj), data, &len) != YKPIV_OK)
+    return CKR_FUNCTION_FAILED;
+
+  return CKR_OK;
 }
diff --git a/ykcs11/yubico_token.h b/ykcs11/yubico_token.h
index d0c9f7a..c39a7d3 100644
--- a/ykcs11/yubico_token.h
+++ b/ykcs11/yubico_token.h
@@ -14,7 +14,8 @@ CK_RV YUBICO_get_token_version(CK_UTF8CHAR_PTR v_str, CK_ULONG v_str_len, CK_VER
 CK_RV YUBICO_get_token_mechanisms_num(CK_ULONG_PTR num);
 CK_RV YUBICO_get_token_mechanism_list(CK_MECHANISM_TYPE_PTR mec, CK_ULONG num);
 CK_RV YUBICO_get_token_mechanism_info(CK_MECHANISM_TYPE mec, CK_MECHANISM_INFO_PTR info);
-CK_RV YUBICO_get_token_objects_num(ykpiv_state *state, CK_ULONG_PTR num);
-CK_RV YUBICO_get_token_object_list(ykpiv_state *state, piv_obj_id_t * obj, CK_ULONG num);
+CK_RV YUBICO_get_token_objects_num(ykpiv_state *state, CK_ULONG_PTR num, CK_ULONG_PTR num_certs);
+CK_RV YUBICO_get_token_object_list(ykpiv_state *state, piv_obj_id_t *obj, CK_ULONG num);
+CK_RV YUBICO_get_token_raw_certificate(ykpiv_state *state, piv_obj_id_t obj, CK_BYTE_PTR data, CK_ULONG len);
 
 #endif