Stricter test of allowed signature packet compositions.
[gnupg.git] / g10 / export.c
index b91c044..626b7d0 100644 (file)
@@ -1,6 +1,6 @@
 /* export.c
- * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003,
- *               2004 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
+ *               2005 Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.
  *
@@ -16,7 +16,8 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
  */
 
 #include <config.h>
 #include "util.h"
 #include "main.h"
 #include "i18n.h"
+#include "trustdb.h"
+
+
+/* An object to keep track of subkeys. */
+struct subkey_list_s
+{
+  struct subkey_list_s *next;
+  u32 kid[2];
+};
+typedef struct subkey_list_s *subkey_list_t;
+
 
 static int do_export( STRLIST users, int secret, unsigned int options );
 static int do_export_stream( IOBUF out, STRLIST users, int secret,
@@ -45,22 +57,34 @@ parse_export_options(char *str,unsigned int *options,int noisy)
 {
   struct parse_options export_opts[]=
     {
-      {"export-local-sigs",EXPORT_LOCAL_SIGS,NULL},
-      {"export-attributes",EXPORT_ATTRIBUTES,NULL},
-      {"export-sensitive-revkeys",EXPORT_SENSITIVE_REVKEYS,NULL},
-      {"export-minimal",EXPORT_MINIMAL,NULL},
-      {"export-unusable-sigs",EXPORT_UNUSABLE_SIGS,NULL},
+      {"export-local-sigs",EXPORT_LOCAL_SIGS,NULL,
+       N_("export signatures that are marked as local-only")},
+      {"export-attributes",EXPORT_ATTRIBUTES,NULL,
+       N_("export attribute user IDs (generally photo IDs)")},
+      {"export-sensitive-revkeys",EXPORT_SENSITIVE_REVKEYS,NULL,
+       N_("export revocation keys marked as \"sensitive\"")},
+      {"export-reset-subkey-passwd",EXPORT_RESET_SUBKEY_PASSWD,NULL,
+       N_("remove the passphrase from exported subkeys")},
+      {"export-clean",EXPORT_CLEAN,NULL,
+       N_("remove unusable parts from key during export")},
+      {"export-minimal",EXPORT_MINIMAL|EXPORT_CLEAN,NULL,
+       N_("remove as much as possible from key during export")},
       /* Aliases for backward compatibility */
-      {"include-local-sigs",EXPORT_LOCAL_SIGS,NULL},
-      {"include-attributes",EXPORT_ATTRIBUTES,NULL},
-      {"include-sensitive-revkeys",EXPORT_SENSITIVE_REVKEYS,NULL},
-      {NULL,0,NULL}
+      {"include-local-sigs",EXPORT_LOCAL_SIGS,NULL,NULL},
+      {"include-attributes",EXPORT_ATTRIBUTES,NULL,NULL},
+      {"include-sensitive-revkeys",EXPORT_SENSITIVE_REVKEYS,NULL,NULL},
+      /* dummy */
+      {"export-unusable-sigs",0,NULL,NULL},
+      {"export-clean-sigs",0,NULL,NULL},
+      {"export-clean-uids",0,NULL,NULL},
+      {NULL,0,NULL,NULL}
       /* add tags for include revoked and disabled? */
     };
 
   return parse_options(str,options,export_opts,noisy);
 }
 
+
 /****************
  * Export the public keys (to standard out or --output).
  * Depending on opt.armor the output is armored.
@@ -131,6 +155,124 @@ do_export( STRLIST users, int secret, unsigned int options )
 }
 
 
+
+/* Release an entire subkey list. */
+static void
+release_subkey_list (subkey_list_t list)
+{
+  while (list)
+    {
+      subkey_list_t tmp = list->next;;
+      xfree (list);
+      list = tmp;
+    }
+}
+
+
+/* Returns true if NODE is a subkey and contained in LIST. */
+static int
+subkey_in_list_p (subkey_list_t list, KBNODE node)
+{
+  if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY
+      || node->pkt->pkttype == PKT_SECRET_SUBKEY )
+    {
+      u32 kid[2];
+
+      if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
+        keyid_from_pk (node->pkt->pkt.public_key, kid);
+      else
+        keyid_from_sk (node->pkt->pkt.secret_key, kid);
+      
+      for (; list; list = list->next)
+        if (list->kid[0] == kid[0] && list->kid[1] == kid[1])
+          return 1;
+    }
+  return 0;
+}
+
+/* Allocate a new subkey list item from NODE. */
+static subkey_list_t
+new_subkey_list_item (KBNODE node)
+{
+  subkey_list_t list = xcalloc (1, sizeof *list);
+
+  if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
+    keyid_from_pk (node->pkt->pkt.public_key, list->kid);
+  else if (node->pkt->pkttype == PKT_SECRET_SUBKEY)
+    keyid_from_sk (node->pkt->pkt.secret_key, list->kid);
+
+  return list;
+}
+
+
+/* Helper function to check whether the subkey at NODE actually
+   matches the description at DESC.  The function returns true if the
+   key under question has been specified by an exact specification
+   (keyID or fingerprint) and does match the one at NODE.  It is
+   assumed that the packet at NODE is either a public or secret
+   subkey. */
+static int
+exact_subkey_match_p (KEYDB_SEARCH_DESC *desc, KBNODE node)
+{
+  u32 kid[2];
+  byte fpr[MAX_FINGERPRINT_LEN];
+  size_t fprlen;
+  int result = 0;
+
+  switch(desc->mode)
+    {
+    case KEYDB_SEARCH_MODE_SHORT_KID:
+    case KEYDB_SEARCH_MODE_LONG_KID:
+      if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
+        keyid_from_pk (node->pkt->pkt.public_key, kid);
+      else
+        keyid_from_sk (node->pkt->pkt.secret_key, kid);
+      break;
+      
+    case KEYDB_SEARCH_MODE_FPR16:
+    case KEYDB_SEARCH_MODE_FPR20:
+    case KEYDB_SEARCH_MODE_FPR:
+      if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
+        fingerprint_from_pk (node->pkt->pkt.public_key, fpr,&fprlen);
+      else
+        fingerprint_from_sk (node->pkt->pkt.secret_key, fpr,&fprlen);
+      break;
+      
+    default:
+      break;
+    }
+  
+  switch(desc->mode)
+    {
+    case KEYDB_SEARCH_MODE_SHORT_KID:
+      if (desc->u.kid[1] == kid[1])
+        result = 1;
+      break;
+
+    case KEYDB_SEARCH_MODE_LONG_KID:
+      if (desc->u.kid[0] == kid[0] && desc->u.kid[1] == kid[1])
+        result = 1;
+      break;
+
+    case KEYDB_SEARCH_MODE_FPR16:
+      if (!memcmp (desc->u.fpr, fpr, 16))
+        result = 1;
+      break;
+
+    case KEYDB_SEARCH_MODE_FPR20:
+    case KEYDB_SEARCH_MODE_FPR:
+      if (!memcmp (desc->u.fpr, fpr, 20))
+        result = 1;
+      break;
+
+    default:
+      break;
+    }
+
+  return result;
+}
+
+
 /* If keyblock_out is non-NULL, AND the exit code is zero, then it
    contains a pointer to the first keyblock found and exported.  No
    other keyblocks are exported.  The caller must free it. */
@@ -144,9 +286,9 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
     KBNODE kbctx, node;
     size_t ndesc, descindex;
     KEYDB_SEARCH_DESC *desc = NULL;
+    subkey_list_t subkey_list = NULL;  /* Track alreay processed subkeys. */
     KEYDB_HANDLE kdbhd;
     STRLIST sl;
-    u32 keyid[2];
 
     *any = 0;
     init_packet( &pkt );
@@ -154,13 +296,13 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
 
     if (!users) {
         ndesc = 1;
-        desc = m_alloc_clear ( ndesc * sizeof *desc);
+        desc = xcalloc ( ndesc, sizeof *desc );
         desc[0].mode = KEYDB_SEARCH_MODE_FIRST;
     }
     else {
         for (ndesc=0, sl=users; sl; sl = sl->next, ndesc++) 
             ;
-        desc = m_alloc ( ndesc * sizeof *desc);
+        desc = xmalloc ( ndesc * sizeof *desc);
         
         for (ndesc=0, sl=users; sl; sl = sl->next) {
            if (classify_user_id (sl->d, desc+ndesc))
@@ -170,7 +312,7 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
                            sl->d, g10_errstr (G10ERR_INV_USER_ID));
         }
 
-        /* it would be nice to see which of the given users did
+        /* It would be nice to see which of the given users did
            actually match one in the keyring.  To implement this we
            need to have a found flag for each entry in desc and to set
            this we must check all those entries after a match to mark
@@ -193,7 +335,7 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
        if (!users) 
             desc[0].mode = KEYDB_SEARCH_MODE_NEXT;
 
-        /* read the keyblock */
+        /* Read the keyblock. */
         rc = keydb_get_keyblock (kdbhd, &keyblock );
        if( rc ) {
             log_error (_("error reading keyblock: %s\n"), g10_errstr(rc) );
@@ -206,7 +348,7 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
 
            keyid_from_sk(sk,sk_keyid);
 
-           /* we can't apply GNU mode 1001 on an unprotected key */
+           /* We can't apply GNU mode 1001 on an unprotected key. */
            if( secret == 2 && !sk->is_protected )
              {
                log_info(_("key %s: not protected - skipped\n"),
@@ -214,7 +356,7 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
                continue;
              }
 
-           /* no v3 keys with GNU mode 1001 */
+           /* No v3 keys with GNU mode 1001. */
            if( secret == 2 && sk->version == 3 )
              {
                log_info(_("key %s: PGP 2.x style key - skipped\n"),
@@ -222,14 +364,30 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
                continue;
              }
 
-           if(options&EXPORT_MINIMAL)
-             keyid_from_sk(sk,keyid);
+            /* It does not make sense to export a key with a primary
+               key on card using a non-key stub.  We simply skip those
+               keys when used with --export-secret-subkeys. */
+            if (secret == 2 && sk->is_protected
+                && sk->protect.s2k.mode == 1002 ) 
+              {
+               log_info(_("key %s: key material on-card - skipped\n"),
+                        keystr(sk_keyid));
+               continue;
+              }
+         }
+       else
+         {
+           /* It's a public key export, so do the cleaning if
+              requested.  Note that both export-clean and
+              export-minimal only apply to UID sigs (0x10, 0x11,
+              0x12, and 0x13).  A designated revocation is never
+              stripped, even with export-minimal set. */
+
+           if(options&EXPORT_CLEAN)
+             clean_key(keyblock,opt.verbose,options&EXPORT_MINIMAL,NULL,NULL);
          }
-       else if((options&EXPORT_MINIMAL)
-               && (node=find_kbnode(keyblock,PKT_PUBLIC_KEY)))
-         keyid_from_pk(node->pkt->pkt.public_key,keyid);
 
-       /* and write it */
+       /* And write it. */
        for( kbctx=NULL; (node = walk_kbnode( keyblock, &kbctx, 0 )); ) {
            if( skip_until_subkey )
              {
@@ -246,96 +404,60 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
            if( node->pkt->pkttype == PKT_COMMENT )
              continue;
 
-            /* make sure that ring_trust packets never get exported */
+            /* Make sure that ring_trust packets never get exported. */
             if (node->pkt->pkttype == PKT_RING_TRUST)
               continue;
 
            /* If exact is set, then we only export what was requested
               (plus the primary key, if the user didn't specifically
-              request it) */
+              request it). */
            if(desc[descindex].exact
               && (node->pkt->pkttype==PKT_PUBLIC_SUBKEY
                   || node->pkt->pkttype==PKT_SECRET_SUBKEY))
              {
-               u32 kid[2];
-               byte fpr[MAX_FINGERPRINT_LEN];
-               size_t fprlen;
-
-               switch(desc[descindex].mode)
-                 {
-                 case KEYDB_SEARCH_MODE_SHORT_KID:
-                 case KEYDB_SEARCH_MODE_LONG_KID:
-                   if(node->pkt->pkttype==PKT_PUBLIC_SUBKEY)
-                     keyid_from_pk(node->pkt->pkt.public_key,kid);
-                   else
-                     keyid_from_sk(node->pkt->pkt.secret_key,kid);
-                   break;
-
-                 case KEYDB_SEARCH_MODE_FPR16:
-                 case KEYDB_SEARCH_MODE_FPR20:
-                 case KEYDB_SEARCH_MODE_FPR:
-                   if(node->pkt->pkttype==PKT_PUBLIC_SUBKEY)
-                     fingerprint_from_pk(node->pkt->pkt.public_key,
-                                         fpr,&fprlen);
-                   else
-                     fingerprint_from_sk(node->pkt->pkt.secret_key,
-                                         fpr,&fprlen);
-                   break;
-
-                 default:
-                   break;
-                 }
-
-               switch(desc[descindex].mode)
-                 {
-                 case KEYDB_SEARCH_MODE_SHORT_KID:
-                   if (desc[descindex].u.kid[1] != kid[1])
-                     skip_until_subkey=1;
-                   break;
-                 case KEYDB_SEARCH_MODE_LONG_KID:
-                   if (desc[descindex].u.kid[0] != kid[0]
-                       || desc[descindex].u.kid[1] != kid[1])
-                     skip_until_subkey=1;
-                   break;
-                 case KEYDB_SEARCH_MODE_FPR16:
-                   if (memcmp (desc[descindex].u.fpr, fpr, 16))
-                     skip_until_subkey=1;
-                   break;
-                 case KEYDB_SEARCH_MODE_FPR20:
-                 case KEYDB_SEARCH_MODE_FPR:
-                   if (memcmp (desc[descindex].u.fpr, fpr, 20))
-                     skip_until_subkey=1;
-                   break;
-                 default:
-                   break;
-                 }
+                if (!exact_subkey_match_p (desc+descindex, node))
+                  {
+                    /* Before skipping this subkey, check whether any
+                       other description wants an exact match on a
+                       subkey and include that subkey into the output
+                       too.  Need to add this subkey to a list so that
+                       it won't get processed a second time.
+                   
+                       So the first step here is to check that list and
+                       skip in any case if the key is in that list.
+
+                       We need this whole mess because the import
+                       function is not able to merge secret keys and
+                       thus it is useless to output them as two
+                       separate keys and have import merge them.  */
+                    if (subkey_in_list_p (subkey_list, node))  
+                      skip_until_subkey = 1; /* Already processed this one. */
+                    else
+                      {
+                        size_t j;
+
+                        for (j=0; j < ndesc; j++)
+                          if (j != descindex && desc[j].exact
+                              && exact_subkey_match_p (desc+j, node))
+                            break;
+                        if (!(j < ndesc))
+                          skip_until_subkey = 1; /* No other one matching. */ 
+                      }
+                  }
 
                if(skip_until_subkey)
                  continue;
+
+                /* Mark this one as processed. */
+                {
+                  subkey_list_t tmp = new_subkey_list_item (node);
+                  tmp->next = subkey_list;
+                  subkey_list = tmp;
+                }
              }
 
-           if( node->pkt->pkttype == PKT_SIGNATURE )
+           if(node->pkt->pkttype==PKT_SIGNATURE)
              {
-               /* If we have export-minimal turned on, do not include
-                  any signature that isn't a selfsig.  Note that this
-                  only applies to uid sigs (0x10, 0x11, 0x12, and
-                  0x13).  A designated revocation is not stripped. */
-               if((options&EXPORT_MINIMAL)
-                  && IS_UID_SIG(node->pkt->pkt.signature)
-                  && (node->pkt->pkt.signature->keyid[0]!=keyid[0]
-                      || node->pkt->pkt.signature->keyid[1]!=keyid[1]))
-                 continue;
-
-               /* We do basically the same thing for
-                  export-unusable-sigs.  It only applies to expired
-                  uid sigs that aren't selfsigs. */
-               if(!(options&EXPORT_UNUSABLE_SIGS)
-                  && IS_UID_SIG(node->pkt->pkt.signature)
-                  && node->pkt->pkt.signature->flags.expired
-                  && (node->pkt->pkt.signature->keyid[0]!=keyid[0]
-                      || node->pkt->pkt.signature->keyid[1]!=keyid[1]))
-                 continue;
-
                /* do not export packets which are marked as not
                   exportable */
                if(!(options&EXPORT_LOCAL_SIGS)
@@ -375,7 +497,7 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
 
            if( secret == 2 && node->pkt->pkttype == PKT_SECRET_KEY )
              {
-               /* we don't want to export the secret parts of the
+               /* We don't want to export the secret parts of the
                 * primary key, this is done by using GNU protection mode 1001
                 */
                int save_mode = node->pkt->pkt.secret_key->protect.s2k.mode;
@@ -383,6 +505,52 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
                rc = build_packet( out, node->pkt );
                node->pkt->pkt.secret_key->protect.s2k.mode = save_mode;
              }
+           else if (secret == 2 && node->pkt->pkttype == PKT_SECRET_SUBKEY
+                     && (opt.export_options&EXPORT_RESET_SUBKEY_PASSWD))
+              {
+                /* If the subkey is protected reset the passphrase to
+                   export an unprotected subkey.  This feature is
+                   useful in cases of a subkey copied to an unattended
+                   machine where a passphrase is not required. */
+                PKT_secret_key *sk_save, *sk;
+
+                sk_save = node->pkt->pkt.secret_key;
+                sk = copy_secret_key (NULL, sk_save);
+                node->pkt->pkt.secret_key = sk;
+
+                log_info (_("about to export an unprotected subkey\n"));
+                switch (is_secret_key_protected (sk))
+                  {
+                  case -1:
+                    rc = G10ERR_PUBKEY_ALGO;
+                    break;
+                  case 0:
+                    break;
+                  default:
+                    if (sk->protect.s2k.mode == 1001)
+                      ; /* No secret parts. */
+                    else if( sk->protect.s2k.mode == 1002 ) 
+                      ; /* Card key stub. */
+                    else 
+                      {
+                        rc = check_secret_key( sk, 0 );
+                      }
+                    break;
+                  }
+                if (rc)
+                  {
+                    node->pkt->pkt.secret_key = sk_save;
+                    free_secret_key (sk);
+                    log_error (_("failed to unprotect the subkey: %s\n"),
+                               g10_errstr (rc));
+                    goto leave;
+                  }
+
+               rc = build_packet (out, node->pkt);
+
+                node->pkt->pkt.secret_key = sk_save;
+                free_secret_key (sk);
+              }
            else
              {
                /* Warn the user if the secret key or any of the secret
@@ -421,7 +589,8 @@ do_export_stream( IOBUF out, STRLIST users, int secret,
        rc = 0;
 
   leave:
-    m_free(desc);
+    release_subkey_list (subkey_list);
+    xfree(desc);
     keydb_release (kdbhd);
     if(rc || keyblock_out==NULL)
       release_kbnode( keyblock );