Update head to match stable 1.0
[gnupg.git] / g10 / seckey-cert.c
index 88ec693..01f4c7b 100644 (file)
@@ -1,5 +1,5 @@
 /* seckey-cert.c -  secret key certificate packet handling
- *     Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.
  *
 #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"
 
-/****************
- * Emulate our old PK interface here - sometime in the future we might
- * change the internal design to directly fit to libgcrypt.
- */
-static int
-pk_check_secret_key( int algo, MPI *skey )
-{
-    GCRY_SEXP s_skey;
-    int rc;
-
-    /* make a sexp from skey */
-    if( algo == GCRY_PK_DSA ) {
-       s_skey = SEXP_CONS( SEXP_NEW( "private-key", 0 ),
-                         gcry_sexp_vlist( SEXP_NEW( "dsa", 0 ),
-                         gcry_sexp_new_name_mpi( "p", skey[0] ),
-                         gcry_sexp_new_name_mpi( "q", skey[1] ),
-                         gcry_sexp_new_name_mpi( "g", skey[2] ),
-                         gcry_sexp_new_name_mpi( "y", skey[3] ),
-                         gcry_sexp_new_name_mpi( "x", skey[4] ),
-                         NULL ));
-    }
-    else if( algo == GCRY_PK_ELG || algo == GCRY_PK_ELG_E ) {
-       s_skey = SEXP_CONS( SEXP_NEW( "private-key", 0 ),
-                         gcry_sexp_vlist( SEXP_NEW( "elg", 0 ),
-                         gcry_sexp_new_name_mpi( "p", skey[0] ),
-                         gcry_sexp_new_name_mpi( "g", skey[1] ),
-                         gcry_sexp_new_name_mpi( "y", skey[2] ),
-                         gcry_sexp_new_name_mpi( "x", skey[3] ),
-                         NULL ));
-    }
-    else if( algo == GCRY_PK_RSA ) {
-       s_skey = SEXP_CONS( SEXP_NEW( "private-key", 0 ),
-                         gcry_sexp_vlist( SEXP_NEW( "rsa", 0 ),
-                         gcry_sexp_new_name_mpi( "n", skey[0] ),
-                         gcry_sexp_new_name_mpi( "e", skey[1] ),
-                         gcry_sexp_new_name_mpi( "d", skey[2] ),
-                         gcry_sexp_new_name_mpi( "p", skey[3] ),
-                         gcry_sexp_new_name_mpi( "q", skey[4] ),
-                         gcry_sexp_new_name_mpi( "u", skey[5] ),
-                         NULL ));
-    }
-    else
-       return G10ERR_PUBKEY_ALGO;
-
-    rc = gcry_pk_testkey( s_skey );
-    gcry_sexp_release( s_skey );
-    return rc;
-}
 
 static int
-do_check( PKT_secret_key *sk )
+do_check( PKT_secret_key *sk, const char *tryagain_text )
 {
+    byte *buffer;
     u16 csum=0;
     int i, res;
     unsigned nbytes;
@@ -92,116 +46,135 @@ do_check( PKT_secret_key *sk )
     if( sk->is_protected ) { /* remove the protection */
        DEK *dek = NULL;
        u32 keyid[4]; /* 4! because we need two of them */
-       GCRY_CIPHER_HD cipher_hd=NULL;
+       CIPHER_HANDLE cipher_hd=NULL;
        PKT_secret_key *save_sk;
 
-       if( sk->protect.algo == GCRY_CIPHER_NONE )
+       if( sk->protect.s2k.mode == 1001 ) {
+           log_info(_("secret key parts are not available\n"));
+           return G10ERR_GENERAL;
+       }
+       if( sk->protect.algo == CIPHER_ALGO_NONE )
            BUG();
-       if( openpgp_cipher_test_algo( sk->protect.algo ) ) {
-           log_info(_("protection algorithm %d is not supported\n"),
-                       sk->protect.algo );
+       if( check_cipher_algo( sk->protect.algo ) ) {
+           log_info(_("protection algorithm %d%s is not supported\n"),
+                       sk->protect.algo,sk->protect.algo==1?" (IDEA)":"" );
+           idea_cipher_warn(0);
            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 );
+            keyid[2] = sk->main_keyid[0];
+            keyid[3] = sk->main_keyid[1];
        }
        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);
+                                &sk->protect.s2k, 0, tryagain_text );
+       cipher_hd = cipher_open( sk->protect.algo,
+                                CIPHER_MODE_AUTO_CFB, 1);
+       cipher_setkey( cipher_hd, dek->key, dek->keylen );
+       m_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) );
+       cipher_setiv( cipher_hd, sk->protect.iv, sk->protect.ivlen );
        csum = 0;
        if( sk->version >= 4 ) {
-           size_t ndata;
-           unsigned int ndatabits;
+           int ndata;
            byte *p, *data;
+            u16 csumc = 0;
 
            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 ;
+           assert( mpi_is_opaque( sk->skey[i] ) );
+           p = mpi_get_opaque( sk->skey[i], &ndata );
+            if ( ndata > 1 )
+                csumc = p[ndata-2] << 8 | p[ndata-1];
+           data = m_alloc_secure( ndata );
+           cipher_decrypt( cipher_hd, data, p, ndata );
+           mpi_free( 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 (sk->protect.sha1chk) {
+                /* This is the new SHA1 checksum method to detect
+                   tampering with the key as used by the Klima/Rosa
+                   attack */
+                sk->csum = 0;
+                csum = 1;
+                if( ndata < 20 ) 
+                    log_error("not enough bytes for SHA-1 checksum\n");
+                else {
+                    MD_HANDLE h = md_open (DIGEST_ALGO_SHA1, 1);
+                    if (!h)
+                        BUG(); /* algo not available */
+                    md_write (h, data, ndata - 20);
+                    md_final (h);
+                    if (!memcmp (md_read (h, DIGEST_ALGO_SHA1),
+                                 data + ndata - 20, 20) ) {
+                        /* digest does match.  We have to keep the old
+                           style checksum in sk->csum, so that the
+                           test used for unprotected keys does work.
+                           This test gets used when we are adding new
+                           keys. */
+                        sk->csum = csum = checksum (data, ndata-20);
+                    }
+                    md_close (h);
+                }
+            }
+            else {
+                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];
+                    if ( sk->csum != csum ) {
+                        /* This is a PGP 7.0.0 workaround */
+                        sk->csum = csumc; /* take the encrypted one */
+                    }
+                }
+            }
+                
+            /* 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;
+                    sk->skey[i] = mpi_read_from_buffer(p, &nbytes, 1 );
+                    ndata -= nbytes;
+                    p += nbytes;
+                }
+                /* Note: at this point ndata should be 2 for a simple
+                   checksum or 20 for the sha1 digest */
+            }
+           m_free(data);
        }
        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);
-
+               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] );
-               gcry_free( data );
+               m_free( buffer );
+           }
+           if( opt.emulate_bugs & EMUBUG_GPGCHKSUM ) {
+              csum = sk->csum;
            }
        }
-       gcry_cipher_close( cipher_hd );
+       cipher_close( cipher_hd );
        /* now let's see whether we have used the right passphrase */
        if( csum != sk->csum ) {
            copy_secret_key( sk, save_sk );
+            passphrase_clear_cache ( keyid, sk->pubkey_algo );
            free_secret_key( save_sk );
            return G10ERR_BAD_PASS;
        }
        /* the checksum may fail, so we also check the key itself */
-       res = pk_check_secret_key( sk->pubkey_algo, sk->skey );
+       res = pubkey_check_secret_key( sk->pubkey_algo, sk->skey );
        if( res ) {
            copy_secret_key( sk, save_sk );
+            passphrase_clear_cache ( keyid, sk->pubkey_algo );
            free_secret_key( save_sk );
            return G10ERR_BAD_PASS;
        }
@@ -212,7 +185,6 @@ do_check( PKT_secret_key *sk )
        csum = 0;
        for(i=pubkey_get_npkey(sk->pubkey_algo);
                i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
-           assert( !gcry_mpi_get_flag( sk->skey[i], GCRYMPI_FLAG_OPAQUE ) );
            csum += checksum_mpi( sk->skey[i] );
        }
        if( csum != sk->csum )
@@ -235,12 +207,15 @@ check_secret_key( PKT_secret_key *sk, int n )
     int i;
 
     if( n < 1 )
-       n = opt.batch? 1 : 3; /* use the default value */
+       n = (opt.batch && !opt.use_agent)? 1 : 3; /* use the default value */
 
     for(i=0; i < n && rc == G10ERR_BAD_PASS; i++ ) {
-       if( i )
-           log_info(_("Invalid passphrase; please try again ...\n"));
-       rc = do_check( sk );
+        const char *tryagain = NULL;
+       if (i) {
+            tryagain = _("Invalid passphrase; please try again");
+            log_info (_("%s ...\n"), tryagain);
+        }
+       rc = do_check( sk, tryagain );
        if( rc == G10ERR_BAD_PASS && is_status_enabled() ) {
            u32 kid[2];
            char buf[50];
@@ -286,118 +261,103 @@ protect_secret_key( PKT_secret_key *sk, DEK *dek )
        return 0;
 
     if( !sk->is_protected ) { /* okay, apply the protection */
-       GCRY_CIPHER_HD cipher_hd=NULL;
+       CIPHER_HANDLE cipher_hd=NULL;
 
-       if( openpgp_cipher_test_algo( sk->protect.algo ) )
+       if( check_cipher_algo( sk->protect.algo ) )
            rc = G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
        else {
            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 ) {
+           cipher_hd = cipher_open( sk->protect.algo,
+                                    CIPHER_MODE_AUTO_CFB, 1 );
+           if( cipher_setkey( cipher_hd, dek->key, dek->keylen ) )
                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;
-           }
-
+           sk->protect.ivlen = cipher_get_blocksize( sk->protect.algo );
            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->protect.ivlen != 8 && sk->protect.ivlen != 16 )
+               BUG(); /* yes, we are very careful */
+           randomize_buffer(sk->protect.iv, sk->protect.ivlen, 1);
+           cipher_setiv( cipher_hd, sk->protect.iv, sk->protect.ivlen );
            if( sk->version >= 4 ) {
-             #define NMPIS (GNUPG_MAX_NSKEY - GNUPG_MAX_NPKEY)
-               byte *bufarr[NMPIS];
-               unsigned narr[NMPIS];
-               unsigned nbits[NMPIS];
+                byte *bufarr[PUBKEY_MAX_NSKEY];
+               unsigned narr[PUBKEY_MAX_NSKEY];
+               unsigned nbits[PUBKEY_MAX_NSKEY];
                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] );
+                   assert( !mpi_is_opaque( sk->skey[i] ) );
+                   bufarr[j] = mpi_get_buffer( sk->skey[i], &narr[j], NULL );
+                   nbits[j]  = mpi_get_nbits( sk->skey[i] );
                    ndata += narr[j] + 2;
                }
-               for( ; j < NMPIS; j++ )
+               for( ; j < PUBKEY_MAX_NSKEY; j++ )
                    bufarr[j] = NULL;
-               ndata += 2; /* for checksum */
+               ndata += opt.simple_sk_checksum? 2 : 20; /* for checksum */
 
-               data = gcry_xmalloc_secure( ndata );
+               data = m_alloc_secure( ndata );
                p = data;
-               for(j=0; j < NMPIS && bufarr[j]; j++ ) {
+               for(j=0; j < PUBKEY_MAX_NSKEY && 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]);
+                   m_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 );
+                
+                if (opt.simple_sk_checksum) {
+                    log_info (_("generating the deprecated 16-bit checksum"
+                              " for secret key protection\n")); 
+                    csum = checksum( data, ndata-2);
+                    sk->csum = csum;
+                    *p++ =     csum >> 8;
+                    *p++ =     csum;
+                    sk->protect.sha1chk = 0;
+                }
+                else {
+                    MD_HANDLE h = md_open (DIGEST_ALGO_SHA1, 1);
+                    if (!h)
+                        BUG(); /* algo not available */
+                    md_write (h, data, ndata - 20);
+                    md_final (h);
+                    memcpy (p, md_read (h, DIGEST_ALGO_SHA1), 20);
+                    p += 20;
+                    md_close (h);
+                    sk->csum = csum = 0;
+                    sk->protect.sha1chk = 1;
+                }
+                assert( p == data+ndata );
+
+               cipher_encrypt( cipher_hd, data, data, ndata );
                for(i = pubkey_get_npkey(sk->pubkey_algo);
                        i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
-                   mpi_release( sk->skey[i] );
+                   mpi_free( 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 );
+               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 */
-              #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 );
+                   csum += checksum_mpi_counted_nbits( 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] );
+                   m_free( buffer );
                }
                sk->csum = csum;
            }
            sk->is_protected = 1;
-           gcry_cipher_close( cipher_hd );
+           cipher_close( cipher_hd );
        }
     }
     return rc;