agent:kem:ecc: Support a key on smartcard.

* agent/agent.h (agent_card_ecc_kem): New.
* agent/divert-scd.c (agent_card_ecc_kem): New.
* agent/pkdecrypt.c (ecc_extract_pk_from_key): New.
(ecc_extract_sk_from_key): New.
(ecc_raw_kem, get_cardkey, ecc_get_curve): New.
(ecc_pgp_kem_decrypt): Support a key on smartcard for ECC.
(composite_pgp_kem_decrypt): Handle a case of a key on smartcard.
* common/sexputil.c (get_ecc_curve_from_key): New.
* common/util.h (get_ecc_curve_from_key): New.

--

GnuPG-bug-id: 7097
Signed-off-by: NIIBE Yutaka <[email protected]>

1 files changed, 28 insertions, 0 deletions

diff --git a/agent/divert-scd.c b/agent/divert-scd.c
index d7454d968..d8c2bcca7 100644
--- a/agent/divert-scd.c
+++ b/agent/divert-scd.c
@@ -486,6 +486,34 @@ divert_pkdecrypt (ctrl_t ctrl,
   return rc;
 }
 
+gpg_error_t
+agent_card_ecc_kem (ctrl_t ctrl, const unsigned char *ecc_ct,
+                    size_t ecc_point_len, unsigned char *ecc_ecdh)
+{
+  gpg_error_t err = 0;
+  char *ecdh = NULL;
+  size_t len;
+  int rc;
+
+  rc = agent_card_pkdecrypt (ctrl, ctrl->keygrip, getpin_cb, ctrl, NULL,
+                             ecc_ct, ecc_point_len, &ecdh, &len, NULL);
+  if (rc)
+    return rc;
+
+  if (len != ecc_point_len)
+    {
+      if (opt.verbose)
+        log_info ("%s: ECC result length invalid (%zu != %zu)\n",
+                  __func__, len, ecc_point_len);
+      return gpg_error (GPG_ERR_INV_DATA);
+    }
+  else
+    memcpy (ecc_ecdh, ecdh, len);
+
+  xfree (ecdh);
+  return err;
+}
+
 
 gpg_error_t
 divert_writekey (ctrl_t ctrl, int force, const char *serialno,