Imported Upstream version 2.0.19upstream/2.0.19

1 files changed, 473 insertions, 0 deletions

diff --git a/g10/seckey-cert.c b/g10/seckey-cert.c
new file mode 100644
index 0000000..9995aa4
--- /dev/null
+++ b/g10/seckey-cert.c
@@ -0,0 +1,473 @@
+/* seckey-cert.c -  secret key certificate packet handling
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002,
+ *               2006, 2009 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "gpg.h"
+#include "util.h"
+#include "packet.h"
+#include "keydb.h"
+#include "cipher.h"
+#include "main.h"
+#include "options.h"
+#include "i18n.h"
+#include "status.h"
+#include "pkglue.h"
+
+static int
+do_check( PKT_secret_key *sk, const char *tryagain_text, int mode,
+          int *canceled )
+{
+    gpg_error_t err;
+    byte *buffer;
+    u16 csum=0;
+    int i, res;
+    size_t nbytes;
+
+    if( sk->is_protected ) { /* remove the protection */
+	DEK *dek = NULL;
+	u32 keyid[4]; /* 4! because we need two of them */
+	gcry_cipher_hd_t cipher_hd=NULL;
+	PKT_secret_key *save_sk;
+
+	if( sk->protect.s2k.mode == 1001 ) {
+	    log_info(_("secret key parts are not available\n"));
+	    return G10ERR_UNU_SECKEY;
+	}
+	if( sk->protect.algo == CIPHER_ALGO_NONE )
+	    BUG();
+	if( openpgp_cipher_test_algo( sk->protect.algo ) ) {
+	    log_info(_("protection algorithm %d%s is not supported\n"),
+			sk->protect.algo,sk->protect.algo==1?" (IDEA)":"" );
+	    if (sk->protect.algo==CIPHER_ALGO_IDEA)
+              {
+                write_status (STATUS_RSA_OR_IDEA);
+                idea_cipher_warn (0);
+              }
+	    return G10ERR_CIPHER_ALGO;
+	}
+	if(gcry_md_test_algo (sk->protect.s2k.hash_algo))
+	  {
+	    log_info(_("protection digest %d is not supported\n"),
+		     sk->protect.s2k.hash_algo);
+	    return G10ERR_DIGEST_ALGO;
+	  }
+	keyid_from_sk( sk, keyid );
+	keyid[2] = keyid[3] = 0;
+	if( !sk->is_primary ) {
+            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, mode,
+                                 tryagain_text, canceled );
+        if (!dek && canceled && *canceled)
+	    return GPG_ERR_CANCELED;
+
+
+	err = openpgp_cipher_open (&cipher_hd, sk->protect.algo,
+				   GCRY_CIPHER_MODE_CFB,
+				   (GCRY_CIPHER_SECURE
+				    | (sk->protect.algo >= 100 ?
+				       0 : GCRY_CIPHER_ENABLE_SYNC)));
+        if (err)
+          log_fatal ("cipher open failed: %s\n", gpg_strerror (err) );
+
+	err = gcry_cipher_setkey (cipher_hd, dek->key, dek->keylen);
+        if (err)
+          log_fatal ("set key failed: %s\n", gpg_strerror (err) );
+
+	xfree(dek);
+	save_sk = copy_secret_key( NULL, sk );
+
+	gcry_cipher_setiv ( cipher_hd, sk->protect.iv, sk->protect.ivlen );
+
+	csum = 0;
+	if( sk->version >= 4 ) {
+            int ndata;
+	    unsigned int ndatabits;
+	    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;
+
+            if ( ndata > 1 )
+                csumc = p[ndata-2] << 8 | p[ndata-1];
+	    data = xmalloc_secure ( ndata );
+	    gcry_cipher_decrypt ( cipher_hd, data, ndata, p, ndata );
+	    gcry_mpi_release (sk->skey[i]); sk->skey[i] = NULL ;
+
+	    p = 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 {
+                    gcry_md_hd_t h;
+
+                    if ( gcry_md_open (&h, DIGEST_ALGO_SHA1, 1))
+                        BUG(); /* Algo not available. */
+                    gcry_md_write (h, data, ndata - 20);
+                    gcry_md_final (h);
+                    if (!memcmp (gcry_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);
+                      } 
+                    gcry_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++ ) {
+                    if ( gcry_mpi_scan( &sk->skey[i], GCRYMPI_FMT_PGP,
+                                        p, ndata, &nbytes))
+                      {
+                        /* Checksum was okay, but not correctly
+                           decrypted.  */
+                        sk->csum = 0;
+                        csum = 1;
+                        break;
+                      }
+                    ndata -= nbytes;
+                    p += nbytes;
+                }
+                /* Note: at this point ndata should be 2 for a simple
+                   checksum or 20 for the sha1 digest */
+            }
+	    xfree(data);
+	}
+	else {
+	    for(i=pubkey_get_npkey(sk->pubkey_algo);
+		    i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+                byte *p;
+                size_t ndata;
+                unsigned int ndatabits;
+
+                assert (gcry_mpi_get_flag (sk->skey[i], GCRYMPI_FLAG_OPAQUE));
+                p = gcry_mpi_get_opaque (sk->skey[i], &ndatabits);
+                ndata = (ndatabits+7)/8;
+                assert (ndata >= 2);
+                assert (ndata == ((p[0] << 8 | p[1]) + 7)/8 + 2);
+                buffer = xmalloc_secure (ndata);
+		gcry_cipher_sync (cipher_hd);
+                buffer[0] = p[0];
+                buffer[1] = p[1];
+                gcry_cipher_decrypt (cipher_hd, buffer+2, ndata-2,
+                                     p+2, ndata-2);
+                csum += checksum (buffer, ndata);
+                gcry_mpi_release (sk->skey[i]);
+
+		err = gcry_mpi_scan( &sk->skey[i], GCRYMPI_FMT_PGP,
+				     buffer, ndata, &ndata );
+		xfree (buffer);
+                if (err)
+                  {
+                    /* Checksum was okay, but not correctly
+                       decrypted.  */
+                    sk->csum = 0;
+                    csum = 1;
+                    break;
+                  }
+/*  		csum += checksum_mpi (sk->skey[i]); */
+	    }
+	}
+	gcry_cipher_close ( cipher_hd );
+
+	/* Now let's see whether we have used the correct passphrase. */
+	if( csum != sk->csum ) {
+	    copy_secret_key( sk, save_sk );
+            passphrase_clear_cache ( keyid, NULL, sk->pubkey_algo );
+	    free_secret_key( save_sk );
+	    return gpg_error (GPG_ERR_BAD_PASSPHRASE);
+	}
+
+	/* The checksum may fail, so we also check the key itself. */
+	res = pk_check_secret_key ( sk->pubkey_algo, sk->skey );
+	if( res ) {
+	    copy_secret_key( sk, save_sk );
+            passphrase_clear_cache ( keyid, NULL, sk->pubkey_algo );
+	    free_secret_key( save_sk );
+	    return gpg_error (GPG_ERR_BAD_PASSPHRASE);
+	}
+	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(sk->pubkey_algo);
+		i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+	    csum += checksum_mpi( sk->skey[i] );
+	}
+	if( csum != sk->csum )
+	    return G10ERR_CHECKSUM;
+    }
+
+    return 0;
+}
+
+
+
+/****************
+ * Check the secret key
+ * Ask up to 3 (or n) times for a correct passphrase
+ * If n is negative, disable the key info prompt and make n=abs(n)
+ */
+int
+check_secret_key( PKT_secret_key *sk, int n )
+{
+    int rc = gpg_error (GPG_ERR_BAD_PASSPHRASE);
+    int i,mode;
+
+    if (sk && sk->is_protected && sk->protect.s2k.mode == 1002)
+      return 0; /* Let the scdaemon handle this. */
+
+    if(n<0)
+      {
+	n=abs(n);
+	mode=1;
+      }
+    else
+      mode=0;
+
+    if( n < 1 )
+	n = 3; /* Use the default value */
+
+    for(i=0; i < n && gpg_err_code (rc) == GPG_ERR_BAD_PASSPHRASE; i++ ) {
+        int canceled = 0;
+        const char *tryagain = NULL;
+	if (i) {
+            tryagain = N_("Invalid passphrase; please try again");
+            log_info (_("%s ...\n"), _(tryagain));
+        }
+	rc = do_check( sk, tryagain, mode, &canceled );
+	if ( gpg_err_code (rc) == GPG_ERR_BAD_PASSPHRASE
+             && 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 );
+	}
+	if( have_static_passphrase() || canceled)
+	    break;
+    }
+
+    if( !rc )
+	write_status( STATUS_GOOD_PASSPHRASE );
+
+    return rc;
+}
+
+/****************
+ * check whether the secret key is protected.
+ * Returns: 0 not protected, -1 on error or the protection algorithm
+ *                           -2 indicates a card stub.
+ *                           -3 indicates a not-online stub.
+ */
+int
+is_secret_key_protected( PKT_secret_key *sk )
+{
+    return sk->is_protected?
+               sk->protect.s2k.mode == 1002? -2 :
+               sk->protect.s2k.mode == 1001? -3 : sk->protect.algo : 0;
+}
+
+
+
+/****************
+ * Protect the secret key with the passphrase from DEK
+ */
+int
+protect_secret_key( PKT_secret_key *sk, DEK *dek )
+{
+    int i,j, rc = 0;
+    byte *buffer;
+    size_t nbytes;
+    u16 csum;
+
+    if( !dek )
+	return 0;
+
+    if( !sk->is_protected ) { /* okay, apply the protection */
+	gcry_cipher_hd_t cipher_hd=NULL;
+
+	if ( openpgp_cipher_test_algo ( sk->protect.algo ) ) {
+            /* Unsupport protection algorithm. */
+            rc = gpg_error (GPG_ERR_CIPHER_ALGO); 
+        }
+	else {
+	    print_cipher_algo_note( sk->protect.algo );
+	    
+	    if ( openpgp_cipher_open (&cipher_hd, 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_info(_("WARNING: Weak key detected"
+			   " - please change passphrase again.\n"));
+	    sk->protect.ivlen = openpgp_cipher_get_algo_blklen (sk->protect.algo);
+	    assert( sk->protect.ivlen <= DIM(sk->protect.iv) );
+	    if( sk->protect.ivlen != 8 && sk->protect.ivlen != 16 )
+		BUG(); /* yes, we are very careful */
+	    gcry_create_nonce (sk->protect.iv, sk->protect.ivlen);
+	    gcry_cipher_setiv (cipher_hd, sk->protect.iv, sk->protect.ivlen);
+	    if( sk->version >= 4 ) {
+                byte *bufarr[PUBKEY_MAX_NSKEY];
+		size_t narr[PUBKEY_MAX_NSKEY];
+		unsigned int 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, bufarr+j,
+                                         narr+j, sk->skey[i]))
+                      BUG();
+		    nbits[j] = gcry_mpi_get_nbits (sk->skey[i]);
+		    ndata += narr[j] + 2;
+                  }
+		for ( ; j < PUBKEY_MAX_NSKEY; j++ )
+                  bufarr[j] = NULL;
+
+		ndata += opt.simple_sk_checksum? 2 : 20; /* for checksum */
+
+		data = xmalloc_secure( ndata );
+		p = data;
+		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];
+		    xfree(bufarr[j]);
+		}
+                
+                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 {
+                    gcry_md_hd_t h;
+
+                    if (gcry_md_open (&h, GCRY_MD_SHA1, 1))
+                      BUG(); /* Algo not available. */
+                    gcry_md_write (h, data, ndata - 20);
+                    gcry_md_final (h);
+                    memcpy (p, gcry_md_read (h, DIGEST_ALGO_SHA1), 20);
+                    p += 20;
+                    gcry_md_close (h);
+                    sk->csum = csum = 0;
+                    sk->protect.sha1chk = 1;
+                }
+                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++ )
+                  {
+		    gcry_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 {
+		csum = 0;
+		for(i=pubkey_get_npkey(sk->pubkey_algo);
+			i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
+                    byte *data;
+		    unsigned int nbits;
+
+		    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));
+
+                    data = xmalloc (nbytes+2);  /* fixme: need xtrymalloc. */
+                    nbits = gcry_mpi_get_nbits (sk->skey[i]);
+                    assert (nbytes == (nbits + 7)/8);
+                    data[0] = nbits >> 8;
+                    data[1] = nbits;
+		    gcry_cipher_encrypt (cipher_hd, data+2, nbytes,
+                                         buffer, nbytes);
+		    xfree( buffer );
+                    
+                    gcry_mpi_release (sk->skey[i]);
+                    sk->skey[i] = gcry_mpi_set_opaque (NULL,
+                                                       data, (nbytes+2)*8 );
+		}
+		sk->csum = csum;
+	    }
+	    sk->is_protected = 1;
+	    gcry_cipher_close (cipher_hd);
+	}
+    }
+    return rc;
+}