* g10.c, options.h: Removed option --emulate-checksum-bug.

* misc.c (checksum_u16_nobug): Removed.
(checksum_u16): Removed the bug emulation.
(checksum_mpi): Ditto.
(checksum_mpi_counted_nbits): Removed and replaced all calls
with checksum_mpi.
* parse-packet.c (read_protected_v3_mpi): New.
(parse_key): Use it here to store it as an opaque MPI.
* seckey-cert.c (do_check): Changed the v3 unprotection to the new
why to store these keys.
(protect_secret_key): Likewise.
* build-packet.c (do_secret_key): And changed the writing.

10 files changed, 152 insertions, 126 deletions

diff --git a/g10/ChangeLog b/g10/ChangeLog
index 757df923c..a180dfc55 100644
--- a/g10/ChangeLog
+++ b/g10/ChangeLog
@@ -1,10 +1,30 @@
 2002-09-10  David Shaw  <dshaw@jabberwocky.com>
 
 	* exec.c (expand_args): Remove loop left over from earlier
-	implementation.  (exec_write): Missed one tick.
+	implementation.
+	(exec_write): Missed one tick.
 
 2002-09-10  Werner Koch  <wk@gnupg.org>
 
+	* g10.c, options.h: Removed option --emulate-checksum-bug.
+	* misc.c (checksum_u16_nobug): Removed.
+	(checksum_u16): Removed the bug emulation.
+	(checksum_mpi): Ditto.
+	(checksum_mpi_counted_nbits): Removed and replaced all calls
+	with checksum_mpi.
+
+	* parse-packet.c (read_protected_v3_mpi): New.
+	(parse_key): Use it here to store it as an opaque MPI.
+	* seckey-cert.c (do_check): Changed the v3 unprotection to the new
+	why to store these keys.
+	(protect_secret_key): Likewise.
+	* build-packet.c (do_secret_key): And changed the writing.
+
+	* tdbio.c (tdbio_set_dbname, open_db): Use new macro MY_O_BINARY
+	to avoid silly ifdefs.
+	(open_db): Fallback to RDONLY so that gpg may be used from a
+	RO-medium.
+
 	* encode.c (encode_simple): Make sure we don't use an ESK packet
 	when we don't have a salt in the S2K.
 
diff --git a/g10/build-packet.c b/g10/build-packet.c
index c4508116c..da1cbbe39 100644
--- a/g10/build-packet.c
+++ b/g10/build-packet.c
@@ -390,7 +390,7 @@ do_secret_key( IOBUF out, int ctb, PKT_secret_key *sk )
 	    iobuf_put(a, sk->protect.algo );
 	    if( sk->protect.s2k.mode >= 1000 ) {
                 /* These modes are not possible in OpenPGP, we use them
-                   to implement our extesnsions, 101 can ve views as a
+                   to implement our extensions, 101 can be seen as a
                    private/experimental extension (this is not
                    specified in rfc2440 but the same scheme is used
                    for all other algorithm identifiers) */
@@ -426,8 +426,20 @@ do_secret_key( IOBUF out, int ctb, PKT_secret_key *sk )
 	p = mpi_get_opaque( sk->skey[npkey], &i );
 	iobuf_write(a, p, i );
     }
+    else if( sk->is_protected ) {
+        /* The secret key is protected te old v4 way. */
+	for(   ; i < nskey; i++ ) {
+            byte *p;
+            int ndata;
+
+            assert (mpi_is_opaque (sk->skey[i]));
+            p = mpi_get_opaque (sk->skey[i], &ndata);
+            iobuf_write (a, p, ndata);
+        }
+	write_16(a, sk->csum );
+    }
     else {
-        /* v3 way - same code for protected and non- protected key */
+        /* non-protected key */
 	for(   ; i < nskey; i++ )
 	    mpi_write(a, sk->skey[i] );
 	write_16(a, sk->csum );
diff --git a/g10/g10.c b/g10/g10.c
index e0d2e9450..8206d641e 100644
--- a/g10/g10.c
+++ b/g10/g10.c
@@ -1432,7 +1432,6 @@ main( int argc, char **argv )
 	  case oNoPGP6: opt.pgp6 = 0; break;
 	  case oPGP7: opt.pgp7 = 1; break;
 	  case oNoPGP7: opt.pgp7 = 0; break;
-	  case oEmuChecksumBug: opt.emulate_bugs |= EMUBUG_GPGCHKSUM; break;
 	  case oEmuMDEncodeBug: opt.emulate_bugs |= EMUBUG_MDENCODE; break;
 	  case oCompressSigs: opt.compress_sigs = 1; break;
 	  case oRunAsShmCP:
diff --git a/g10/keygen.c b/g10/keygen.c
index b8398b88a..b45618e90 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -690,7 +690,7 @@ gen_elg(int algo, unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
     sk->is_protected = 0;
     sk->protect.algo = 0;
 
-    sk->csum = checksum_mpi_counted_nbits( sk->skey[3] );
+    sk->csum = checksum_mpi( sk->skey[3] );
     if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
 	*ret_sk = copy_secret_key( NULL, sk );
 
@@ -776,7 +776,7 @@ gen_dsa(unsigned int nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
     sk->is_protected = 0;
     sk->protect.algo = 0;
 
-    sk->csum = checksum_mpi_counted_nbits( sk->skey[4] );
+    sk->csum = checksum_mpi ( sk->skey[4] );
     if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
 	*ret_sk = copy_secret_key( NULL, sk );
 
@@ -866,10 +866,10 @@ gen_rsa(int algo, unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
     sk->is_protected = 0;
     sk->protect.algo = 0;
 
-    sk->csum  = checksum_mpi_counted_nbits( sk->skey[2] );
-    sk->csum += checksum_mpi_counted_nbits( sk->skey[3] );
-    sk->csum += checksum_mpi_counted_nbits( sk->skey[4] );
-    sk->csum += checksum_mpi_counted_nbits( sk->skey[5] );
+    sk->csum  = checksum_mpi (sk->skey[2] );
+    sk->csum += checksum_mpi (sk->skey[3] );
+    sk->csum += checksum_mpi (sk->skey[4] );
+    sk->csum += checksum_mpi (sk->skey[5] );
     if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
 	*ret_sk = copy_secret_key( NULL, sk );
 
diff --git a/g10/main.h b/g10/main.h
index efb528aed..0d04911d7 100644
--- a/g10/main.h
+++ b/g10/main.h
@@ -64,7 +64,6 @@ int disable_core_dumps(void);
 u16 checksum_u16( unsigned n );
 u16 checksum( byte *p, unsigned n );
 u16 checksum_mpi( MPI a );
-u16 checksum_mpi_counted_nbits( MPI a );
 u32 buffer_to_u32( const byte *buffer );
 const byte *get_session_marker( size_t *rlen );
 int openpgp_cipher_test_algo( int algo );
diff --git a/g10/misc.c b/g10/misc.c
index f4728eb5d..ae553eb47 100644
--- a/g10/misc.c
+++ b/g10/misc.c
@@ -109,25 +109,11 @@ checksum_u16( unsigned n )
     u16 a;
 
     a  = (n >> 8) & 0xff;
-    if( opt.emulate_bugs & EMUBUG_GPGCHKSUM ) {
-       a |= n & 0xff;
-       log_debug("csum_u16 emulated for n=%u\n", n);
-    }
-    else
-       a += n & 0xff;
-    return a;
-}
-
-static u16
-checksum_u16_nobug( unsigned n )
-{
-    u16 a;
-
-    a  = (n >> 8) & 0xff;
     a += n & 0xff;
     return a;
 }
 
+
 u16
 checksum( byte *p, unsigned n )
 {
@@ -147,45 +133,13 @@ checksum_mpi( MPI a )
     unsigned nbits;
 
     buffer = mpi_get_buffer( a, &nbytes, NULL );
-    /* some versions of gpg encode wrong values for the length of an mpi
-     * so that mpi_get_nbits() which counts the mpi yields another (shorter)
-     * value than the one store with the mpi.  mpi_get_nbit_info() returns
-     * this stored value if it is still available.
-     */
-
-    if( opt.emulate_bugs & EMUBUG_GPGCHKSUM )
-	nbits = 0;
-    else
-	nbits = mpi_get_nbit_info(a);
-    if( !nbits )
-       nbits = mpi_get_nbits(a);
-    csum = checksum_u16( nbits );
-    csum += checksum( buffer, nbytes );
-    m_free( buffer );
-    return csum;
-}
-
-/****************
- * This is the correct function
- */
-u16
-checksum_mpi_counted_nbits( MPI a )
-{
-    u16 csum;
-    byte *buffer;
-    unsigned nbytes;
-    unsigned nbits;
-
-    buffer = mpi_get_buffer( a, &nbytes, NULL );
     nbits = mpi_get_nbits(a);
-    mpi_set_nbit_info(a,nbits);
-    csum = checksum_u16_nobug( nbits );
+    csum = checksum_u16( nbits );
     csum += checksum( buffer, nbytes );
     m_free( buffer );
     return csum;
 }
 
-
 u32
 buffer_to_u32( const byte *buffer )
 {
diff --git a/g10/options.h b/g10/options.h
index 9ab1042f6..f9301fdd3 100644
--- a/g10/options.h
+++ b/g10/options.h
@@ -180,7 +180,6 @@ struct {
 } opt;
 
 
-#define EMUBUG_GPGCHKSUM  1
 #define EMUBUG_MDENCODE   4
 
 #define DBG_PACKET_VALUE  1	/* debug packet reading/writing */
diff --git a/g10/parse-packet.c b/g10/parse-packet.c
index 18f860e7a..5ed75e490 100644
--- a/g10/parse-packet.c
+++ b/g10/parse-packet.c
@@ -1386,6 +1386,51 @@ parse_onepass_sig( IOBUF inp, int pkttype, unsigned long pktlen,
 }
 
 
+static MPI
+read_protected_v3_mpi (IOBUF inp, unsigned long *length)
+{
+  int c;
+  unsigned int nbits, nbytes;
+  unsigned char *buf, *p;
+  MPI val;
+
+  if (*length < 2)
+    {
+      log_error ("mpi too small\n");
+      return NULL;
+    }
+
+  if ((c=iobuf_get (inp)) == -1)
+    return NULL;
+  --*length;
+  nbits = c << 8;
+  if ((c=iobuf_get(inp)) == -1)
+    return NULL;
+  --*length;
+  nbits |= c;
+
+  if (nbits > 16384)
+    {
+      log_error ("mpi too large (%u bits)\n", nbits);
+      return NULL;
+    }
+  nbytes = (nbits+7) / 8;
+  buf = p = m_alloc (2 + nbytes);
+  *p++ = nbits >> 8;
+  *p++ = nbits;
+  for (; nbytes && length; nbytes--, --*length)
+    *p++ = iobuf_get (inp);
+  if (nbytes)
+    {
+      log_error ("packet shorter tham mpi\n");
+      m_free (buf);
+      return NULL;
+    }
+
+  /* convert buffer into an opaque MPI */
+  val = mpi_set_opaque (NULL, buf, p-buf); 
+  return val;
+}
 
 
 static int
@@ -1666,18 +1711,22 @@ parse_key( IOBUF inp, int pkttype, unsigned long pktlen,
 	}
 	else { /* v3 method: the mpi length is not encrypted */
 	    for(i=npkey; i < nskey; i++ ) {
-		n = pktlen; sk->skey[i] = mpi_read(inp, &n, 0 ); pktlen -=n;
-		if( sk->is_protected && sk->skey[i] )
-		    mpi_set_protect_flag(sk->skey[i]);
-		if( list_mode ) {
-		    printf(  "\tskey[%d]: ", i);
-		    if( sk->is_protected )
-			printf(  "[encrypted]\n");
-		    else {
-			mpi_print(stdout, sk->skey[i], mpi_print_mode  );
-			putchar('\n');
-		    }
-		}
+                if ( sk->is_protected ) {
+                    sk->skey[i] = read_protected_v3_mpi (inp, &pktlen);
+                    if( list_mode ) 
+                        printf(  "\tskey[%d]: [encrypted]\n", i);
+                }
+                else {
+                    n = pktlen;
+                    sk->skey[i] = mpi_read(inp, &n, 0 );
+                    pktlen -=n;
+                    if( list_mode ) {
+                        printf(  "\tskey[%d]: ", i);
+                        mpi_print(stdout, sk->skey[i], mpi_print_mode  );
+                        putchar('\n');
+                    }
+                }
+
                 if (!sk->skey[i])
                     rc = G10ERR_INVALID_PACKET;
 	    }
diff --git a/g10/seckey-cert.c b/g10/seckey-cert.c
index 2eadc9dd3..d2d39dacf 100644
--- a/g10/seckey-cert.c
+++ b/g10/seckey-cert.c
@@ -149,43 +149,26 @@ do_check( PKT_secret_key *sk, const char *tryagain_text )
 	else {
 	    for(i=pubkey_get_npkey(sk->pubkey_algo);
 		    i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
-		buffer = mpi_get_secure_buffer( sk->skey[i], &nbytes, NULL );
-		cipher_sync( cipher_hd );
-		assert( mpi_is_protected(sk->skey[i]) );
-		cipher_decrypt( cipher_hd, buffer, buffer, nbytes );
-		mpi_set_buffer( sk->skey[i], buffer, nbytes, 0 );
-		mpi_clear_protect_flag( sk->skey[i] );
-		csum += checksum_mpi( sk->skey[i] );
-		m_free( buffer );
-	    }
-            if( csum != sk->csum ) {
-              /* Due to a fix of a bug in mpi_get_secure_buffer we
-                 might encounter seceret keys which are not correctly
-                 encrypted.  We fix this by a second try, this time
-                 with a reversed bug fix (the memmove below). */
                 byte *p;
-              
-                copy_secret_key( sk, save_sk );
-                cipher_setiv( cipher_hd, sk->protect.iv, sk->protect.ivlen );
-                csum = 0;
-                for(i=pubkey_get_npkey (sk->pubkey_algo);
-		    i < pubkey_get_nskey (sk->pubkey_algo); i++ ) {
-                    buffer = mpi_get_secure_buffer (sk->skey[i], &nbytes,NULL);
-                    for (p=buffer; !*p && nbytes; p++, --nbytes )
-                      ;
-                    if (p != buffer)
-                      memmove (buffer, p, nbytes);
-                    cipher_sync (cipher_hd);
-                    assert (mpi_is_protected(sk->skey[i]));
-                    cipher_decrypt (cipher_hd, buffer, buffer, nbytes);
-                    mpi_set_buffer (sk->skey[i], buffer, nbytes, 0);
-                    mpi_clear_protect_flag (sk->skey[i]);
-                    csum += checksum_mpi (sk->skey[i]);
-                    m_free (buffer);
-                }
-            }
-	    if( opt.emulate_bugs & EMUBUG_GPGCHKSUM ) {
-	       csum = sk->csum;
+                int ndata;
+                unsigned int dummy;
+
+                assert (mpi_is_opaque (sk->skey[i]));
+                p = mpi_get_opaque (sk->skey[i], &ndata);
+                assert (ndata >= 2);
+                assert (ndata == ((p[0] << 8 | p[1]) + 7)/8 + 2);
+                buffer = m_alloc_secure (ndata);
+		cipher_sync (cipher_hd);
+                buffer[0] = p[0];
+                buffer[1] = p[1];
+                cipher_decrypt (cipher_hd, buffer+2, p+2, ndata-2);
+                csum += checksum (buffer, ndata);
+                mpi_free (sk->skey[i]);
+                dummy = ndata;
+                sk->skey[i] = mpi_read_from_buffer (buffer, &dummy, 1);
+                assert (sk->skey[i]);
+		m_free (buffer);
+/*  		csum += checksum_mpi (sk->skey[i]); */
 	    }
 	}
 	cipher_close( cipher_hd );
@@ -366,19 +349,26 @@ protect_secret_key( PKT_secret_key *sk, DEK *dek )
 		sk->skey[i] = mpi_set_opaque(NULL, data, ndata );
 	    }
 	    else {
-		/* NOTE: we always recalculate the checksum because there
-		 * are some test releases which calculated it wrong */
 		csum = 0;
 		for(i=pubkey_get_npkey(sk->pubkey_algo);
 			i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
-		    csum += checksum_mpi_counted_nbits( sk->skey[i] );
+                    byte *data;
+		    unsigned int nbits;
+
+		    csum += checksum_mpi (sk->skey[i]);
 		    buffer = mpi_get_buffer( sk->skey[i], &nbytes, NULL );
-		    cipher_sync( cipher_hd );
-		    assert( !mpi_is_protected(sk->skey[i]) );
-		    cipher_encrypt( cipher_hd, buffer, buffer, nbytes );
-		    mpi_set_buffer( sk->skey[i], buffer, nbytes, 0 );
-		    mpi_set_protect_flag( sk->skey[i] );
+		    cipher_sync (cipher_hd);
+		    assert ( !mpi_is_opaque (sk->skey[i]) );
+                    data = m_alloc (nbytes+2);
+                    nbits  = mpi_get_nbits (sk->skey[i]);
+                    assert (nbytes == (nbits + 7)/8);
+                    data[0] = nbits >> 8;
+                    data[1] = nbits;
+		    cipher_encrypt (cipher_hd, data+2, buffer, nbytes);
 		    m_free( buffer );
+                    
+                    mpi_free (sk->skey[i]);
+                    sk->skey[i] = mpi_set_opaque (NULL, data, nbytes+2);
 		}
 		sk->csum = csum;
 	    }
diff --git a/g10/tdbio.c b/g10/tdbio.c
index cdeba46cf..62ff26774 100644
--- a/g10/tdbio.c
+++ b/g10/tdbio.c
@@ -43,6 +43,13 @@
 #define ftruncate chsize
 #endif
 
+#ifdef HAVE_DOSISH_SYSTEM
+#define MY_O_BINARY  O_BINARY
+#else
+#define MY_O_BINARY  0
+#endif
+
+
 /****************
  * Yes, this is a very simple implementation. We should really
  * use a page aligned buffer and read complete pages.
@@ -484,11 +491,7 @@ tdbio_set_dbname( const char *new_dbname, int create )
 	    if( !fp )
 		log_fatal( _("%s: can't create: %s\n"), fname, strerror(errno) );
 	    fclose(fp);
-	  #ifdef HAVE_DOSISH_SYSTEM
-	    db_fd = open( db_name, O_RDWR | O_BINARY );
-	  #else
-	    db_fd = open( db_name, O_RDWR );
-	  #endif
+	    db_fd = open( db_name, O_RDWR | MY_O_BINARY );
 	    if( db_fd == -1 )
 		log_fatal( _("%s: can't open: %s\n"), db_name, strerror(errno) );
 
@@ -544,11 +547,12 @@ open_db()
   if (make_dotlock( lockhandle, -1 ) )
     log_fatal( _("%s: can't make lock\n"), db_name );
 #endif /* __riscos__ */
-#ifdef HAVE_DOSISH_SYSTEM
-  db_fd = open (db_name, O_RDWR | O_BINARY );
-#else
-  db_fd = open (db_name, O_RDWR );
-#endif
+  db_fd = open (db_name, O_RDWR | MY_O_BINARY );
+  if (db_fd == -1 && errno == EACCES) {
+      db_fd = open (db_name, O_RDONLY | MY_O_BINARY );
+      if (db_fd != -1)
+          log_info (_("NOTE: trustdb not writable\n"));
+  }
   if ( db_fd == -1 )
     log_fatal( _("%s: can't open: %s\n"), db_name, strerror(errno) );