Editorial changes and allow building with old libgcrypts.

Changed order of some conditional to make to put the special case into
the true branch.  Indentation changes.  Minor other changes to make the
ECC code more similar to the rest of our code.

It builds but many sefltests still fail.  Need to fix that before
using it with an ECDH enabled libgcrypt.

[/]
2011-01-21  Werner Koch  <[email protected]>

	* configure.ac: Need Libgcrypt 1.4.6 due to AESWRAP.
	(HAVE_GCRY_PK_ECDH): Add new test.

[agent/]
2011-01-21  Werner Koch  <[email protected]>

	* cvt-openpgp.c (GCRY_PK_ECDH) [!HAVE_GCRY_PK_ECDH]: New.

[include/]
2011-01-21  Werner Koch  <[email protected]>

	* cipher.h (GCRY_PK_USAGE_CERT): Remove compatibility macros
	because we now require libgcrypt 1.4.6.
	(GCRY_PK_ECDH): Add replacement.

1 files changed, 50 insertions, 37 deletions

diff --git a/g10/build-packet.c b/g10/build-packet.c
index 3a2c206c8..d138e0614 100644
--- a/g10/build-packet.c
+++ b/g10/build-packet.c
@@ -178,21 +178,20 @@ mpi_write (iobuf_t out, gcry_mpi_t a)
   return rc;
 }
 
-/*
- * Write the name OID, encoded as an mpi, to OUT. The format of the content of the MPI is
- * one byte LEN, following by LEN bytes that are DER representation of an ASN.1 OID. 
- * This is true for each of the 3 following functions.
- */
+/* Write the name OID, encoded as an mpi, to OUT. The format of the
+ * content of the MPI is one byte LEN, following by LEN bytes that are
+ * DER representation of an ASN.1 OID.  This is true for each of the 3
+ * following functions.   */
 #define iobuf_name_oid_write iobuf_write_size_body_mpi
+
 /* Write the value of KEK fields for ECDH.  */
 #define ecdh_kek_params_write iobuf_write_size_body_mpi
-/* Write the value of encrypted filed for ECDH. */
+
+/* Write the value of encrypted filed for ECDH.  */
 #define ecdh_esk_write iobuf_write_size_body_mpi
 
 
-/****************
- * calculate the length of a packet described by PKT
- */
+/* Calculate the length of a packet described by PKT.  */
 u32
 calc_packet_length( PACKET *pkt )
 {
@@ -300,24 +299,35 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk)
     }
   assert (npkey < nskey);
 
-  if( pk->pubkey_algo != PUBKEY_ALGO_ECDSA && pk->pubkey_algo != PUBKEY_ALGO_ECDH )  {
-    /* Writing the public parameters is easy, */
-    for (i=0; i < npkey; i++ )
-      if ((err = mpi_write (a, pk->pkey[i])))
-        goto leave;
-  }
-  else  {
-     /* ... except we do an adjustment for ECC OID and possibly KEK params for ECDH */
-    if( (err=iobuf_name_oid_write(a, pk->pkey[0])) || /* DER of OID with preceeding length byte */
-        (err = mpi_write (a, pk->pkey[1])) )    /* point Q, the public key */
+  /* Writing the public parameters is easy.  Except if we do an
+     adjustment for ECC OID and possibly KEK params for ECDH.  */
+  if (pk->pubkey_algo == PUBKEY_ALGO_ECDSA
+      || pk->pubkey_algo == PUBKEY_ALGO_ECDH)
     {
-       goto leave;
+      /* Write DER of OID with preceeding length byte.  */
+      err = iobuf_name_oid_write (a, pk->pkey[0]);
+      if (err)
+        goto leave;
+      /* Write point Q, the public key.  */
+      err = mpi_write (a, pk->pkey[1]);
+      if (err)
+        goto leave;
+
+      /* Write one more public field for ECDH.  */
+      if (pk->pubkey_algo == PUBKEY_ALGO_ECDH)
+        {
+          err = ecdh_kek_params_write(a,pk->pkey[2]);
+          if (err)
+            goto leave;
+        }
     }
-    if( pk->pubkey_algo == PUBKEY_ALGO_ECDH && (err=ecdh_kek_params_write(a,pk->pkey[2])))  {	/* one more public field for ECDH */
-       goto leave;
+  else
+    {
+      for (i=0; i < npkey; i++ )
+        if ((err = mpi_write (a, pk->pkey[i])))
+          goto leave;
     }
-    /* followed by possibly protected private scalar */
-  }
+
   
   if (pk->seckey_info)
     {
@@ -483,22 +493,25 @@ do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc )
   if ( !n )
     write_fake_data( a, enc->data[0] );
 
-  if( enc->pubkey_algo != PUBKEY_ALGO_ECDH )  {
-    for (i=0; i < n && !rc ; i++ )
-      rc = mpi_write(a, enc->data[i] );
-  }
-  else  {
-    /* the second field persists as a LEN+field structure, even though it is 
-     * stored for uniformity as an MPI internally */
-    assert( n==2 );
-    rc = mpi_write(a, enc->data[0] );
-    if( !rc ) rc = ecdh_esk_write(a, enc->data[1] ); 
-  }
+  if (enc->pubkey_algo == PUBKEY_ALGO_ECDH )
+    {
+      /* The second field persists as a LEN+field structure, even
+       * though it is stored for uniformity as an MPI internally.  */
+      assert (n == 2);
+      rc = mpi_write (a, enc->data[0]);
+      if (!rc)
+        rc = ecdh_esk_write (a, enc->data[1]); 
+    }
+  else
+    {
+      for (i=0; i < n && !rc ; i++ )
+        rc = mpi_write(a, enc->data[i] );
+    }
 
   if (!rc)
     {
-      write_header(out, ctb, iobuf_get_temp_length(a) );
-      rc = iobuf_write_temp( out, a );
+      write_header (out, ctb, iobuf_get_temp_length(a) );
+      rc = iobuf_write_temp (out, a);
     }
   iobuf_close(a);
   return rc;