added patch to enable GnuTLS 2.4.x to read gnu-dummy S2K extensions, along with build...

diff --git a/patches/gnutls/22_functional_s2k_with_GNU_dummy.diff b/patches/gnutls/22_functional_s2k_with_GNU_dummy.diff
new file mode 100644 (file)
index 0000000..2d7e35d
--- /dev/null
+++ b/patches/gnutls/22_functional_s2k_with_GNU_dummy.diff
@@ -0,0 +1,146 @@
+diff -ruN gnutls26-2.4.1.orig/lib/opencdk/opencdk.h gnutls26-2.4.1/lib/opencdk/opencdk.h
+--- gnutls26-2.4.1.orig/lib/opencdk/opencdk.h  2008-06-30 16:45:51.000000000 -0400
++++ gnutls26-2.4.1/lib/opencdk/opencdk.h       2008-08-21 19:23:44.000000000 -0400
+@@ -214,7 +214,11 @@
+ enum cdk_s2k_type_t {
+     CDK_S2K_SIMPLE     = 0,
+     CDK_S2K_SALTED     = 1,
+-    CDK_S2K_ITERSALTED = 3
++    CDK_S2K_ITERSALTED = 3,
++    CDK_S2K_GNU_EXT = 101 
++ /* GNU S2K extensions: refer to DETAILS from GnuPG: 
++  http://cvs.gnupg.org/cgi-bin/viewcvs.cgi/trunk/doc/DETAILS?root=GnuPG
++ */
+ };
+ 
+ 
+diff -ruN gnutls26-2.4.1.orig/lib/opencdk/read-packet.c gnutls26-2.4.1/lib/opencdk/read-packet.c
+--- gnutls26-2.4.1.orig/lib/opencdk/read-packet.c      2008-06-30 16:45:51.000000000 -0400
++++ gnutls26-2.4.1/lib/opencdk/read-packet.c   2008-08-21 19:30:09.000000000 -0400
+@@ -78,10 +78,35 @@
+ }
+ 
+ 
+-static int
++/* read about S2K at http://tools.ietf.org/html/rfc4880#section-3.7.1 */
++static cdk_error_t
+ read_s2k (cdk_stream_t inp, cdk_s2k_t s2k)
+ {
+-  return CDK_Not_Implemented;
++  size_t nread;
++
++  s2k->mode = cdk_stream_getc (inp);
++  s2k->hash_algo = cdk_stream_getc (inp);
++  if (s2k->mode == CDK_S2K_SIMPLE) 
++      return 0;
++  else if (s2k->mode == CDK_S2K_SALTED || s2k->mode == CDK_S2K_ITERSALTED)
++    {
++      if (stream_read (inp, s2k->salt, DIM (s2k->salt), &nread))
++      return CDK_Inv_Packet;
++      if (nread != DIM (s2k->salt))
++      return CDK_Inv_Packet;
++      
++      if (s2k->mode == CDK_S2K_ITERSALTED)
++      s2k->count = cdk_stream_getc (inp);
++    }
++  else if (s2k->mode == CDK_S2K_GNU_EXT)
++    {
++      /* GNU extensions to the S2K : read DETAILS from gnupg */
++      return 0;
++    }
++  else
++    return CDK_Not_Implemented;
++
++  return 0;
+ }
+ 
+ 
+@@ -194,6 +219,7 @@
+ static cdk_error_t
+ read_symkey_enc (cdk_stream_t inp, size_t pktlen, cdk_pkt_symkey_enc_t ske)
+ {
++  cdk_error_t ret;
+   cdk_s2k_t s2k;
+   size_t minlen;
+   size_t nread, nleft;
+@@ -213,7 +239,9 @@
+     return CDK_Out_Of_Core;
+   
+   ske->cipher_algo = cdk_stream_getc (inp);
+-  s2k->mode = cdk_stream_getc (inp);
++  ret = read_s2k(inp, s2k);
++  if (ret != 0)
++    return ret;
+   switch (s2k->mode)
+     {
+     case CDK_S2K_SIMPLE    : minlen = 0; break;
+@@ -225,18 +253,6 @@
+       return CDK_Inv_Packet;
+     }
+   
+-  s2k->hash_algo = cdk_stream_getc (inp);
+-  if (s2k->mode == CDK_S2K_SALTED || s2k->mode == CDK_S2K_ITERSALTED)
+-    {
+-      if (stream_read (inp, s2k->salt, DIM (s2k->salt), &nread))
+-      return CDK_Inv_Packet;
+-      if (nread != DIM (s2k->salt))
+-      return CDK_Inv_Packet;
+-      
+-      if (s2k->mode == CDK_S2K_ITERSALTED)
+-      s2k->count = cdk_stream_getc (inp);
+-    }
+-  
+   ske->seskeylen = pktlen - 4 - minlen;
+   /* We check if there is an encrypted session key and if it fits into
+      the buffer. The maximal key length is 256-bit. */
+@@ -421,14 +437,19 @@
+       rc = read_s2k (inp, sk->protect.s2k);
+       if (rc) 
+       return rc;
+-      sk->protect.ivlen = gcry_cipher_get_algo_blklen (sk->protect.algo);
+-      if (!sk->protect.ivlen)
+-      return CDK_Inv_Packet;
+-      rc = stream_read (inp, sk->protect.iv, sk->protect.ivlen, &nread);
+-      if (rc)
+-      return rc;
+-      if (nread != sk->protect.ivlen)
+-      return CDK_Inv_Packet;
++      /* refer to --export-secret-subkeys in gpg(1) */
++      if (sk->protect.s2k->mode == CDK_S2K_GNU_EXT) 
++      sk->protect.ivlen = 0;
++      else {
++      sk->protect.ivlen = gcry_cipher_get_algo_blklen (sk->protect.algo);
++      if (!sk->protect.ivlen)
++        return CDK_Inv_Packet;
++      rc = stream_read (inp, sk->protect.iv, sk->protect.ivlen, &nread);
++      if (rc)
++        return rc;
++      if (nread != sk->protect.ivlen)
++        return CDK_Inv_Packet;
++      }
+     }
+   else
+     sk->protect.algo = sk->s2k_usage;
+@@ -476,6 +497,22 @@
+       return CDK_Out_Of_Core;
+       if (stream_read (inp, sk->encdata, sk->enclen, &nread))
+       return CDK_Inv_Packet;
++      /* Handle the GNU S2K extensions we know (just gnu-dummy right now): */
++      if (sk->protect.s2k->mode == CDK_S2K_GNU_EXT) {
++      unsigned char gnumode;
++      if ((sk->enclen < strlen("GNU") + 1) ||
++          (0 != memcmp("GNU", sk->encdata, strlen("GNU"))))
++        return CDK_Inv_Packet;
++      gnumode = sk->encdata[strlen("GNU")];
++      /* we only handle gnu-dummy (mode 1).
++         mode 2 should refer to external smart cards.
++      */
++      if (gnumode != 1)
++        return CDK_Inv_Packet;
++      /* gnu-dummy should have no more data */
++      if (sk->enclen != strlen("GNU") + 1)
++        return CDK_Inv_Packet;
++      }
+       nskey = cdk_pk_get_nskey (sk->pk->pubkey_algo);
+       if (!nskey)
+       return CDK_Inv_Algo;

diff --git a/patches/gnutls/build b/patches/gnutls/build
new file mode 100755 (executable)
index 0000000..0037431
--- /dev/null
+++ b/patches/gnutls/build
@@ -0,0 +1,26 @@
+#!/bin/sh -e
+
+# build a patched version of GnuTLS version 2.4.x, including the
+# ability to parse and accept the GNU S2K extension known as
+# "gnu-dummy" (which doesn't have any secret key data at all)
+
+# Note: you probably want 
+
+# Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+# Date: 2008-08-22 00:11:05-0400
+
+# Note: please run this from the current directory, so it can find and
+# transfer the patch it needs.
+
+workingdir=$(mktemp -d)
+
+(cd "$workingdir" && apt-get source libgnutls26)
+
+cp ./*.diff "$workingdir/gnutls26-2.4".*/debian/patches/
+
+(cd "$workingdir/gnutls26-2.4".* && \
+    dch --local .s2kext1 --distribution experimental 'added patch to handle GNU extensions to S2K' && \
+    debuild -uc -us -sa)
+
+echo now you should:
+echo reprepro -C gnutls include experimental "$workingdir/"*.changes