See ChangeLog: Mon Jan 24 13:04:28 CET 2000 Werner Koch
[gnupg.git] / g10 / seckey-cert.c
index f30e5d0..10f7092 100644 (file)
@@ -1,14 +1,14 @@
-/* seckey-cert.c -  secret key certifucate packet handling
- *     Copyright (C) 1998 Free Software Foundation, Inc.
+/* seckey-cert.c -  secret key certificate packet handling
+ *     Copyright (C) 1998, 1999 Free Software Foundation, Inc.
  *
- * This file is part of GNUPG.
+ * This file is part of GnuPG.
  *
- * GNUPG is free software; you can redistribute it and/or modify
+ * GnuPG is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
- * GNUPG is distributed in the hope that it will be useful,
+ * GnuPG is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+
+#include <gcrypt.h>
 #include "util.h"
-#include "memory.h"
 #include "packet.h"
-#include "mpi.h"
 #include "keydb.h"
-#include "cipher.h"
 #include "main.h"
 #include "options.h"
 #include "i18n.h"
+#include "status.h"
 
 
 static int
-do_check( PKT_secret_cert *cert )
+do_check( PKT_secret_key *sk )
 {
     byte *buffer;
     u16 csum=0;
     int i, res;
     unsigned nbytes;
 
-    if( cert->is_protected ) { /* remove the protection */
+    if( sk->is_protected ) { /* remove the protection */
        DEK *dek = NULL;
-       u32 keyid[2];
-       CIPHER_HANDLE cipher_hd=NULL;
-       PKT_secret_cert *save_cert;
-       char save_iv[8];
+       u32 keyid[4]; /* 4! because we need two of them */
+       GCRY_CIPHER_HD cipher_hd=NULL;
+       PKT_secret_key *save_sk;
 
-       if( cert->protect.algo == CIPHER_ALGO_NONE )
+       if( sk->protect.algo == GCRY_CIPHER_NONE )
            BUG();
-       if( check_cipher_algo( cert->protect.algo ) )
-           return G10ERR_CIPHER_ALGO; /* unsupported protection algorithm */
-       keyid_from_skc( cert, keyid );
-       dek = passphrase_to_dek( keyid, cert->protect.algo,
-                                &cert->protect.s2k, 0 );
-       cipher_hd = cipher_open( cert->protect.algo,
-                                CIPHER_MODE_AUTO_CFB, 1);
-       cipher_setkey( cipher_hd, dek->key, dek->keylen );
-       cipher_setiv( cipher_hd, NULL );
-       m_free(dek);
-       save_cert = copy_secret_cert( NULL, cert );
-       memcpy(save_iv, cert->protect.iv, 8 );
-       cipher_decrypt( cipher_hd, cert->protect.iv, cert->protect.iv, 8 );
+       if( openpgp_cipher_test_algo( sk->protect.algo ) ) {
+           log_info(_("protection algorithm %d is not supported\n"),
+                       sk->protect.algo );
+           return G10ERR_CIPHER_ALGO;
+       }
+       keyid_from_sk( sk, keyid );
+       keyid[2] = keyid[3] = 0;
+       if( !sk->is_primary ) {
+           PKT_secret_key *sk2 = gcry_xcalloc( 1, sizeof *sk2 );
+           if( !get_primary_seckey( sk2, keyid ) )
+               keyid_from_sk( sk2, keyid+2 );
+           free_secret_key( sk2 );
+       }
+       dek = passphrase_to_dek( keyid, sk->pubkey_algo, sk->protect.algo,
+                                &sk->protect.s2k, 0 );
+       if( !(cipher_hd = gcry_cipher_open( sk->protect.algo,
+                                     GCRY_CIPHER_MODE_CFB,
+                                     GCRY_CIPHER_SECURE
+                                     | (sk->protect.algo >= 100 ?
+                                          0 : GCRY_CIPHER_ENABLE_SYNC) ) )
+                                   ) {
+           BUG();
+       }
+
+       if( gcry_cipher_setkey( cipher_hd, dek->key, dek->keylen ) )
+           log_fatal("set key failed: %s\n", gcry_strerror(-1) );
+       gcry_free(dek);
+       save_sk = copy_secret_key( NULL, sk );
+       if( gcry_cipher_setiv( cipher_hd, sk->protect.iv, sk->protect.ivlen ))
+           log_fatal("set IV failed: %s\n", gcry_strerror(-1) );
        csum = 0;
-       for(i=pubkey_get_npkey(cert->pubkey_algo);
-               i < pubkey_get_nskey(cert->pubkey_algo); i++ ) {
-           buffer = mpi_get_secure_buffer( cert->skey[i], &nbytes, NULL );
-           cipher_sync( cipher_hd );
-           cipher_decrypt( cipher_hd, buffer, buffer, nbytes );
-           mpi_set_buffer( cert->skey[i], buffer, nbytes, 0 );
-           csum += checksum_mpi( cert->skey[i] );
-           m_free( buffer );
+       if( sk->version >= 4 ) {
+           size_t ndata;
+           unsigned int ndatabits;
+           byte *p, *data;
+
+           i = pubkey_get_npkey(sk->pubkey_algo);
+           assert( gcry_mpi_get_flag( sk->skey[i], GCRYMPI_FLAG_OPAQUE ) );
+           p = gcry_mpi_get_opaque( sk->skey[i], &ndatabits );
+           ndata = (ndatabits+7)/8;
+           data = gcry_xmalloc_secure( ndata );
+           gcry_cipher_decrypt( cipher_hd, data, ndata, p, ndata );
+           mpi_release( sk->skey[i] ); sk->skey[i] = NULL ;
+           p = data;
+           if( ndata < 2 ) {
+               log_error("not enough bytes for checksum\n");
+               sk->csum = 0;
+               csum = 1;
+           }
+           else {
+               csum = checksum( data, ndata-2);
+               sk->csum = data[ndata-2] << 8 | data[ndata-1];
+           }
+           /* must check it here otherwise the mpi_read_xx would fail
+            * because the length may have an arbitrary value */
+           if( sk->csum == csum ) {
+               for( ; i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+                   nbytes = ndata;
+                   assert( gcry_is_secure( p ) );
+                   res = gcry_mpi_scan( &sk->skey[i], GCRYMPI_FMT_PGP,
+                                                            p, &nbytes);
+                   if( res )
+                       log_bug("gcry_mpi_scan failed in do_check: rc=%d\n", res);
+
+                   ndata -= nbytes;
+                   p += nbytes;
+               }
+           }
+           gcry_free(data);
        }
-       if( opt.emulate_bugs & 1 ) {
-          log_debug("secret key csum is=%04hx should=%04hx algos=%d/%d\n",
-                    csum, cert->csum, cert->pubkey_algo,cert->protect.algo );
-          csum = cert->csum;
+       else {
+           for(i=pubkey_get_npkey(sk->pubkey_algo);
+                   i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+               size_t ndata;
+               unsigned int ndatabits;
+               byte *p, *data;
+
+               assert( gcry_mpi_get_flag( sk->skey[i], GCRYMPI_FLAG_OPAQUE ) );
+               p = gcry_mpi_get_opaque( sk->skey[i], &ndatabits );
+               ndata = (ndatabits+7)/8;
+               data = gcry_xmalloc_secure( ndata );
+               gcry_cipher_sync( cipher_hd );
+               gcry_cipher_decrypt( cipher_hd, data, ndata, p, ndata );
+               mpi_release( sk->skey[i] ); sk->skey[i] = NULL ;
+
+               res = gcry_mpi_scan( &sk->skey[i], GCRYMPI_FMT_USG,
+                                    data, &ndata );
+               if( res )
+                   log_bug("gcry_mpi_scan failed in do_check: rc=%d\n", res);
+
+               csum += checksum_mpi( sk->skey[i] );
+               gcry_free( buffer );
+           }
        }
-       cipher_close( cipher_hd );
+       gcry_cipher_close( cipher_hd );
        /* now let's see whether we have used the right passphrase */
-       if( csum != cert->csum ) {
-           copy_secret_cert( cert, save_cert );
-           free_secret_cert( save_cert );
-           memcpy( cert->protect.iv, save_iv, 8 );
+       if( csum != sk->csum ) {
+           copy_secret_key( sk, save_sk );
+           free_secret_key( save_sk );
            return G10ERR_BAD_PASS;
        }
        /* the checksum may fail, so we also check the key itself */
-       res = pubkey_check_secret_key( cert->pubkey_algo, cert->skey );
+       res = pubkey_check_secret_key( sk->pubkey_algo, sk->skey );
        if( res ) {
-           copy_secret_cert( cert, save_cert );
-           free_secret_cert( save_cert );
-           memcpy( cert->protect.iv, save_iv, 8 );
+           copy_secret_key( sk, save_sk );
+           free_secret_key( save_sk );
            return G10ERR_BAD_PASS;
        }
-       free_secret_cert( save_cert );
-       cert->is_protected = 0;
+       free_secret_key( save_sk );
+       sk->is_protected = 0;
     }
     else { /* not protected, assume it is okay if the checksum is okay */
        csum = 0;
-       for(i=pubkey_get_npkey(cert->pubkey_algo);
-               i < pubkey_get_nskey(cert->pubkey_algo); i++ ) {
-           csum += checksum_mpi( cert->skey[i] );
+       for(i=pubkey_get_npkey(sk->pubkey_algo);
+               i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+           csum += checksum_mpi( sk->skey[i] );
        }
-       if( csum != cert->csum )
+       if( csum != sk->csum )
            return G10ERR_CHECKSUM;
     }
 
@@ -114,38 +177,37 @@ do_check( PKT_secret_cert *cert )
 
 
 /****************
- * Check the secret key certificate
- * Ask up to 3 times for a correct passphrase
+ * Check the secret key
+ * Ask up to 3 (or n) times for a correct passphrase
  */
 int
-check_secret_key( PKT_secret_cert *cert )
+check_secret_key( PKT_secret_key *sk, int n )
 {
     int rc = G10ERR_BAD_PASS;
     int i;
 
-    for(i=0; i < 3 && rc == G10ERR_BAD_PASS; i++ ) {
+    if( n < 1 )
+       n = opt.batch? 1 : 3; /* use the default value */
+
+    for(i=0; i < n && rc == G10ERR_BAD_PASS; i++ ) {
        if( i )
-           log_error(_("Invalid passphrase; please try again ...\n"));
-       rc = do_check( cert );
-      #if 0 /* set to 1 to enable the workaround */
-       if( rc == G10ERR_BAD_PASS && cert->is_protected
-           && cert->protect.algo == CIPHER_ALGO_BLOWFISH
-           && cert->pubkey_algo != PUBKEY_ALGO_ELGAMAL ) {
-           /* Workaround for a bug in 0.2.16 which still used
-            * a 160 bit key for BLOWFISH. */
-           log_info("trying workaround for 0.2.16 passphrase bug ...\n");
-           log_info("If you don't need this, uncomment it in g10/seckey-cert.c\n\n");
-           cert->protect.algo = CIPHER_ALGO_BLOWFISH160;
-           rc = do_check( cert );
-           if( rc )
-               rc = G10ERR_BAD_PASS;
-           cert->protect.algo = CIPHER_ALGO_BLOWFISH;
+           log_info(_("Invalid passphrase; please try again ...\n"));
+       rc = do_check( sk );
+       if( rc == G10ERR_BAD_PASS && is_status_enabled() ) {
+           u32 kid[2];
+           char buf[50];
+
+           keyid_from_sk( sk, kid );
+           sprintf(buf, "%08lX%08lX", (ulong)kid[0], (ulong)kid[1]);
+           write_status_text( STATUS_BAD_PASSPHRASE, buf );
        }
-      #endif
-       if( get_passphrase_fd() != -1 )
+       if( have_static_passphrase() )
            break;
     }
 
+    if( !rc )
+       write_status( STATUS_GOOD_PASSPHRASE );
+
     return rc;
 }
 
@@ -154,20 +216,20 @@ check_secret_key( PKT_secret_cert *cert )
  * Returns: 0 not protected, -1 on error or the protection algorithm
  */
 int
-is_secret_key_protected( PKT_secret_cert *cert )
+is_secret_key_protected( PKT_secret_key *sk )
 {
-    return cert->is_protected? cert->protect.algo : 0;
+    return sk->is_protected? sk->protect.algo : 0;
 }
 
 
 
 /****************
- * Protect the secret key certificate with the passphrase from DEK
+ * Protect the secret key with the passphrase from DEK
  */
 int
-protect_secret_key( PKT_secret_cert *cert, DEK *dek )
+protect_secret_key( PKT_secret_key *sk, DEK *dek )
 {
-    int i, rc = 0;
+    int i,j, rc = 0;
     byte *buffer;
     unsigned nbytes;
     u16 csum;
@@ -175,33 +237,119 @@ protect_secret_key( PKT_secret_cert *cert, DEK *dek )
     if( !dek )
        return 0;
 
-    if( !cert->is_protected ) { /* okay, apply the protection */
-       CIPHER_HANDLE cipher_hd=NULL;
+    if( !sk->is_protected ) { /* okay, apply the protection */
+       GCRY_CIPHER_HD cipher_hd=NULL;
 
-       if( check_cipher_algo( cert->protect.algo ) )
+       if( openpgp_cipher_test_algo( sk->protect.algo ) )
            rc = G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
        else {
-           cipher_hd = cipher_open( cert->protect.algo,
-                                    CIPHER_MODE_AUTO_CFB, 1 );
-           cipher_setkey( cipher_hd, dek->key, dek->keylen );
-           cipher_setiv( cipher_hd, NULL );
-           cipher_encrypt( cipher_hd, cert->protect.iv, cert->protect.iv, 8 );
-           /* NOTE: we always recalculate the checksum because there are some
-            * test releases which calculated it wrong */
-           csum = 0;
-           for(i=pubkey_get_npkey(cert->pubkey_algo);
-                   i < pubkey_get_nskey(cert->pubkey_algo); i++ ) {
-               csum += checksum_mpi_counted_nbits( cert->skey[i] );
-               buffer = mpi_get_buffer( cert->skey[i], &nbytes, NULL );
-          log_debug("protecing i=%d csum=%04hx nbytes=%u\n", i, csum, nbytes );
-               cipher_sync( cipher_hd );
-               cipher_encrypt( cipher_hd, buffer, buffer, nbytes );
-               mpi_set_buffer( cert->skey[i], buffer, nbytes, 0 );
-               m_free( buffer );
+           print_cipher_algo_note( sk->protect.algo );
+           if( !(cipher_hd = gcry_cipher_open( sk->protect.algo,
+                                         GCRY_CIPHER_MODE_CFB,
+                                         GCRY_CIPHER_SECURE
+                                         | (sk->protect.algo >= 100 ?
+                                             0 : GCRY_CIPHER_ENABLE_SYNC) ))
+                                        ) {
+               BUG();
+           }
+
+
+           rc = gcry_cipher_setkey( cipher_hd, dek->key, dek->keylen );
+           if( rc == GCRYERR_WEAK_KEY ) {
+               log_info(_("WARNING: Weak key detected"
+                          " - please change passphrase again.\n"));
+               rc = 0;
+           }
+           else if( rc )
+               BUG();
+
+           /* set the IV length */
+           {   int blocksize = gcry_cipher_get_algo_blklen( sk->protect.algo );
+               if( blocksize != 8 && blocksize != 16 )
+                   log_fatal("unsupported blocksize %d\n", blocksize );
+               sk->protect.ivlen = blocksize;
+           }
+
+           assert( sk->protect.ivlen <= DIM(sk->protect.iv) );
+           gcry_randomize(sk->protect.iv, sk->protect.ivlen,
+                                                       GCRY_STRONG_RANDOM);
+           gcry_cipher_setiv( cipher_hd, sk->protect.iv, sk->protect.ivlen );
+           #warning FIXME: replace set/get buffer
+           if( sk->version >= 4 ) {
+             #define NMPIS (GNUPG_MAX_NSKEY - GNUPG_MAX_NPKEY)
+               byte *bufarr[NMPIS];
+               unsigned narr[NMPIS];
+               unsigned nbits[NMPIS];
+               int ndata=0;
+               byte *p, *data;
+
+               for(j=0, i = pubkey_get_npkey(sk->pubkey_algo);
+                       i < pubkey_get_nskey(sk->pubkey_algo); i++, j++ ) {
+                   assert( !gcry_mpi_get_flag( sk->skey[i], GCRYMPI_FLAG_OPAQUE ) );
+
+                   if( gcry_mpi_aprint( GCRYMPI_FMT_USG, (char*)bufarr+j,
+                                                         narr+j, sk->skey[i]))
+                       BUG();
+
+                   nbits[j]  = gcry_mpi_get_nbits( sk->skey[i] );
+                   ndata += narr[j] + 2;
+               }
+               for( ; j < NMPIS; j++ )
+                   bufarr[j] = NULL;
+               ndata += 2; /* for checksum */
+
+               data = gcry_xmalloc_secure( ndata );
+               p = data;
+               for(j=0; j < NMPIS && bufarr[j]; j++ ) {
+                   p[0] = nbits[j] >> 8 ;
+                   p[1] = nbits[j];
+                   p += 2;
+                   memcpy(p, bufarr[j], narr[j] );
+                   p += narr[j];
+                   gcry_free(bufarr[j]);
+               }
+             #undef NMPIS
+               csum = checksum( data, ndata-2);
+               sk->csum = csum;
+               *p++ =  csum >> 8;
+               *p++ =  csum;
+               assert( p == data+ndata );
+               gcry_cipher_encrypt( cipher_hd, data, ndata, NULL, 0 );
+               for(i = pubkey_get_npkey(sk->pubkey_algo);
+                       i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+                   mpi_release( sk->skey[i] );
+                   sk->skey[i] = NULL;
+               }
+               i = pubkey_get_npkey(sk->pubkey_algo);
+               sk->skey[i] = gcry_mpi_set_opaque(NULL, data, ndata*8 );
+           }
+           else {
+               /* NOTE: we always recalculate the checksum because there
+                * are some test releases which calculated it wrong */
+              #warning FIXME:  Replace this code
+               csum = 0;
+               for(i=pubkey_get_npkey(sk->pubkey_algo);
+                       i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+                   csum += checksum_mpi( sk->skey[i] );
+
+                   if( gcry_mpi_aprint( GCRYMPI_FMT_USG,
+                                        &buffer, &nbytes, sk->skey[i] ) )
+                       BUG();
+
+                   gcry_cipher_sync( cipher_hd );
+                   assert( !gcry_mpi_get_flag( sk->skey[i], GCRYMPI_FLAG_OPAQUE ) );
+                   gcry_cipher_encrypt( cipher_hd, buffer, nbytes, NULL, 0 );
+                   gcry_mpi_release( sk->skey[i] );
+                   if( gcry_mpi_scan( &sk->skey[i], GCRYMPI_FMT_USG,
+                                      buffer,&nbytes ) )
+                       BUG();
+
+                   gcry_free( buffer );
+               }
+               sk->csum = csum;
            }
-           cert->csum = csum;
-           cert->is_protected = 1;
-           cipher_close( cipher_hd );
+           sk->is_protected = 1;
+           gcry_cipher_close( cipher_hd );
        }
     }
     return rc;