* keydb.h, pkclist.c (select_algo_from_prefs): Allow passing a suggested

algorithm which will be used if available.

* encode.c (encode_crypt, encrypt_filter), sign.c (sign_file): Use new
select_algo_from_prefs feature to check if forcing an algorithm would
violate the recipient preferences.

* photoid.c (get_default_photo_command, show_photos): Use different
default viewers on different platforms.  Currently we have Win 9x, Win NT
(2k, xp), Mac OSX, RISC OS, and "everybody else".  These are #ifdefs as
much as possible to avoid clutter.

* g10.c (strusage, build_list), keyedit.c (show_prefs), main.h, misc.c
(compress_algo_to_string, check_compress_algo), pkclist.c
(algo_available), keygen.c (keygen_set_std_prefs): New algo_to_string and
check functions for compress algorithms.

11 files changed, 184 insertions, 76 deletions

diff --git a/g10/ChangeLog b/g10/ChangeLog
index ce2c0b410..0579504da 100644
--- a/g10/ChangeLog
+++ b/g10/ChangeLog
@@ -1,3 +1,22 @@
+2002-06-20  David Shaw  <[email protected]>
+
+	* keydb.h, pkclist.c (select_algo_from_prefs): Allow passing a
+	suggested algorithm which will be used if available.
+
+	* encode.c (encode_crypt, encrypt_filter), sign.c (sign_file): Use
+	new select_algo_from_prefs feature to check if forcing an
+	algorithm would violate the recipient preferences.
+
+	* photoid.c (get_default_photo_command, show_photos): Use
+	different default viewers on different platforms.  Currently we
+	have Win 9x, Win NT (2k, xp), Mac OSX, RISC OS, and "everybody
+	else".  These are #ifdefs as much as possible to avoid clutter.
+
+	* g10.c (strusage, build_list), keyedit.c (show_prefs), main.h,
+	misc.c (compress_algo_to_string, check_compress_algo), pkclist.c
+	(algo_available), keygen.c (keygen_set_std_prefs): New
+	algo_to_string and check functions for compress algorithms.
+
 2002-06-20  Werner Koch  <[email protected]>
 
 	* misc.c (setsysinfo): Removed a #warning for Alpha's uniligedn
diff --git a/g10/encode.c b/g10/encode.c
index 9c5075f74..80a9039ec 100644
--- a/g10/encode.c
+++ b/g10/encode.c
@@ -387,7 +387,7 @@ encode_crypt( const char *filename, STRLIST remusr )
     /* create a session key */
     cfx.dek = m_alloc_secure_clear (sizeof *cfx.dek);
     if( !opt.def_cipher_algo ) { /* try to get it from the prefs */
-	cfx.dek->algo = select_algo_from_prefs( pk_list, PREFTYPE_SYM, NULL );
+	cfx.dek->algo = select_algo_from_prefs(pk_list,PREFTYPE_SYM,-1,NULL);
 	/* The only way select_algo_from_prefs can fail here is when
            mixing v3 and v4 keys, as v4 keys have an implicit
            preference entry for 3DES, and the pk_list cannot be empty.
@@ -406,8 +406,17 @@ encode_crypt( const char *filename, STRLIST remusr )
 	    }
 	}
     }
-    else
-	cfx.dek->algo = opt.def_cipher_algo;
+    else {
+      if(!opt.expert &&
+	 select_algo_from_prefs(pk_list,PREFTYPE_SYM,
+				opt.def_cipher_algo,NULL)!=opt.def_cipher_algo)
+	log_info(_("forcing symmetric cipher %s (%d) "
+		   "violates recipient preferences\n"),
+		 cipher_algo_to_string(opt.def_cipher_algo),
+		 opt.def_cipher_algo);
+
+      cfx.dek->algo = opt.def_cipher_algo;
+    }
     cfx.dek->use_mdc = select_mdc_from_pklist (pk_list);
 
     make_session_key( cfx.dek );
@@ -467,9 +476,15 @@ encode_crypt( const char *filename, STRLIST remusr )
 	if(compr_algo==-1)
 	  {
 	    if((compr_algo=
-		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,NULL))==-1)
+		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,-1,NULL))==-1)
 	      compr_algo=DEFAULT_COMPRESS_ALGO;
 	  }
+	else if(!opt.expert &&
+		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,
+				       compr_algo,NULL)!=compr_algo)
+	  log_info(_("forcing compression algorithm %s (%d) "
+		     "violates recipient preferences\n"),
+		   compress_algo_to_string(compr_algo),compr_algo);
 
 	/* algo 0 means no compression */
 	if( compr_algo )
@@ -537,15 +552,25 @@ encrypt_filter( void *opaque, int control,
 
 	    if( !opt.def_cipher_algo  ) { /* try to get it from the prefs */
 		efx->cfx.dek->algo =
-		  select_algo_from_prefs( efx->pk_list, PREFTYPE_SYM, NULL );
+		  select_algo_from_prefs(efx->pk_list,PREFTYPE_SYM,-1,NULL);
 		if( efx->cfx.dek->algo == -1 ) {
                     /* because 3DES is implicitly in the prefs, this can only
                      * happen if we do not have any public keys in the list */
 		    efx->cfx.dek->algo = DEFAULT_CIPHER_ALGO;
                 }
 	    }
-	    else
-		efx->cfx.dek->algo = opt.def_cipher_algo;
+	    else {
+	      if(!opt.expert &&
+		 select_algo_from_prefs(efx->pk_list,PREFTYPE_SYM,
+					opt.def_cipher_algo,
+					NULL)!=opt.def_cipher_algo)
+		log_info(_("forcing symmetric cipher %s (%d) "
+			   "violates recipient preferences\n"),
+			 cipher_algo_to_string(opt.def_cipher_algo),
+			 opt.def_cipher_algo);
+
+	      efx->cfx.dek->algo = opt.def_cipher_algo;
+	    }
 
             efx->cfx.dek->use_mdc = select_mdc_from_pklist (efx->pk_list);
 
diff --git a/g10/g10.c b/g10/g10.c
index 6a897bceb..33aa164af 100644
--- a/g10/g10.c
+++ b/g10/g10.c
@@ -607,7 +607,7 @@ const char *__dynamic_da_name = "GnuPG Heap";
 const char *
 strusage( int level )
 {
-  static char *digests, *pubkeys, *ciphers;
+  static char *digests, *pubkeys, *ciphers, *zips;
     const char *p;
     switch( level ) {
       case 11: p = "gpg (GnuPG)";
@@ -653,13 +653,12 @@ strusage( int level )
 	p = digests;
 	break;
       case 37:
-	if(opt.verbose)
-	  p = "Compress: Uncompressed (Z0), ZIP (Z1), ZLIB (Z2)\n";
-	else
-	  p = "Compress: Uncompressed, ZIP, ZLIB\n";
+	if( !zips )
+	    zips = build_list("Compress: ",'Z',compress_algo_to_string,
+			                                check_compress_algo);
+	p = zips;
 	break;
 
-
       default:	p = default_strusage(level);
     }
     return p;
@@ -678,11 +677,11 @@ build_list( const char *text, char letter,
     if( maybe_setuid )
 	secmem_init( 0 );    /* drop setuid */
 
-    for(i=1; i <= 110; i++ )
+    for(i=0; i <= 110; i++ )
 	if( !chkf(i) && (s=mapf(i)) )
 	    n += strlen(s) + 7 + 2;
     list = m_alloc( 21 + n ); *list = 0;
-    for(p=NULL, i=1; i <= 110; i++ ) {
+    for(p=NULL, i=0; i <= 110; i++ ) {
 	if( !chkf(i) && (s=mapf(i)) ) {
 	    if( !p ) {
 		p = stpcpy( list, text );
diff --git a/g10/keydb.h b/g10/keydb.h
index 13106955d..34d02d702 100644
--- a/g10/keydb.h
+++ b/g10/keydb.h
@@ -166,7 +166,8 @@ void show_revocation_reason( PKT_public_key *pk, int mode );
 int  check_signatures_trust( PKT_signature *sig );
 void release_pk_list( PK_LIST pk_list );
 int  build_pk_list( STRLIST rcpts, PK_LIST *ret_pk_list, unsigned use );
-int  select_algo_from_prefs( PK_LIST pk_list, int preftype, void *hint );
+int select_algo_from_prefs( PK_LIST pk_list, int preftype,
+			    int request, void *hint );
 int  select_mdc_from_pklist (PK_LIST pk_list);
 
 /*-- skclist.c --*/
diff --git a/g10/keyedit.c b/g10/keyedit.c
index 6462b1d13..db811ac0c 100644
--- a/g10/keyedit.c
+++ b/g10/keyedit.c
@@ -1503,21 +1503,7 @@ show_prefs (PKT_user_id *uid, int verbose)
         tty_printf ("\n     Compression: ");
         for(i=any=0; prefs[i].type; i++ ) {
             if( prefs[i].type == PREFTYPE_ZIP ) {
-                const char *s=NULL;
-		switch(prefs[i].value)
-		  {
-		  case 0:
-		    s="Uncompressed";
-		    break;
-
-		  case 1:
-		    s="ZIP";
-		    break;
-
-		  case 2:
-		    s="ZLIB";
-		    break;
-		  }
+                const char *s=compress_algo_to_string(prefs[i].value);
                 
                 if (any)
                     tty_printf (", ");
@@ -1534,9 +1520,11 @@ show_prefs (PKT_user_id *uid, int verbose)
         if (!uncomp_seen) {
             if (any)
                 tty_printf (", ");
-	    else
-	        tty_printf ("ZIP, ");
-	    tty_printf ("Uncompressed");
+	    else {
+	      tty_printf ("%s",compress_algo_to_string(1));
+	      tty_printf (", ");
+	    }
+	    tty_printf ("%s",compress_algo_to_string(0));
         }
         tty_printf ("\n     Features: ");
 	if(uid->mdc_feature)
diff --git a/g10/keygen.c b/g10/keygen.c
index 4f9becbfe..b8398b88a 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -198,11 +198,6 @@ set_one_pref (ulong val, int type, int (*cf)(int), byte *buf, int *nbuf)
     return 0;
 }
 
-static int 
-check_zip_algo (int algo)
-{
-    return algo < 0 || algo > 2;
-}
 
 /*
  * Parse the supplied string and use it to set the standard preferences.
@@ -252,7 +247,7 @@ keygen_set_std_prefs (const char *string,int personal)
         }
         else if ((*s=='z' || *s == 'Z') && isdigit(s[1]) ) {
             val = strtoul (++s, (char**)&s2, 10);
-            if (set_one_pref (val, 'Z', check_zip_algo, zip, &nzip))
+            if (set_one_pref (val, 'Z', check_compress_algo, zip, &nzip))
                 rc = -1;
         }
 	else if (ascii_strcasecmp(s,"mdc")==0) {
diff --git a/g10/main.h b/g10/main.h
index 6946362f4..e7153bd55 100644
--- a/g10/main.h
+++ b/g10/main.h
@@ -85,6 +85,8 @@ char *pct_expando(const char *string,struct expando_args *args);
 int hextobyte( const char *s );
 void deprecated_warning(const char *configname,unsigned int configlineno,
 			const char *option,const char *repl1,const char *repl2);
+const char *compress_algo_to_string(int algo);
+int check_compress_algo(int algo);
 
 /*-- helptext.c --*/
 void display_online_help( const char *keyword );
diff --git a/g10/misc.c b/g10/misc.c
index 1fb635d83..c2330d959 100644
--- a/g10/misc.c
+++ b/g10/misc.c
@@ -657,3 +657,35 @@ deprecated_warning(const char *configname,unsigned int configlineno,
 
   log_info(_("please use \"%s%s\" instead\n"),repl1,repl2);
 }
+
+const char *
+compress_algo_to_string(int algo)
+{
+  const char *s="?";
+
+  switch(algo)
+    {
+    case 0:
+      s="Uncompressed";
+      break;
+
+    case 1:
+      s="ZIP";
+      break;
+
+    case 2:
+      s="ZLIB";
+      break;
+    }
+
+  return s;
+}
+
+int
+check_compress_algo(int algo)
+{
+  if(algo>=0 && algo<=2)
+    return 0;
+
+  return G10ERR_COMPR_ALGO;
+}
diff --git a/g10/photoid.c b/g10/photoid.c
index 13e4cd1c7..66240ecc2 100644
--- a/g10/photoid.c
+++ b/g10/photoid.c
@@ -22,7 +22,9 @@
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
-
+#ifdef HAVE_DOSISH_SYSTEM
+#include <windows.h>
+#endif
 #include "packet.h"
 #include "status.h"
 #include "exec.h"
@@ -35,12 +37,6 @@
 #include "main.h"
 #include "photoid.h"
 
-#ifdef HAVE_DOSISH_SYSTEM
-#define DEFAULT_PHOTO_COMMAND "start /w %i"
-#else
-#define DEFAULT_PHOTO_COMMAND "xloadimage -fork -quiet -title 'KeyID 0x%k' stdin"
-#endif
-
 /* Generate a new photo id packet, or return NULL if canceled */
 PKT_user_id *generate_photo_id(PKT_public_key *pk)
 {
@@ -219,6 +215,29 @@ char *image_type_to_string(byte type,int style)
   return string;
 }
 
+static const char *get_default_photo_command(void)
+{
+#if defined(HAVE_DOSISH_SYSTEM)
+  OSVERSIONINFO osvi;
+
+  memset(&osvi,0,sizeof(osvi));
+  osvi.dwOSVersionInfoSize=sizeof(osvi);
+  GetVersionEx(&osvi);
+
+  if(osvi.dwPlatformId==VER_PLATFORM_WIN32_WINDOWS)
+    return "start /w %i";
+  else
+    return "cmd /c start /w %i";
+#elif defined(__APPLE__)
+  /* OS X.  This really needs more than just __APPLE__. */
+  return "open %I";
+#elif defined(__riscos__)
+  return "Filer_Run %I";
+#else
+  return "xloadimage -fork -quiet -title 'KeyID 0x%k' stdin";
+#endif
+}
+
 void show_photos(const struct user_attribute *attrs,
 		 int count,PKT_public_key *pk,PKT_secret_key *sk)
 {
@@ -244,9 +263,11 @@ void show_photos(const struct user_attribute *attrs,
 	struct exec_info *spawn;
 	int offset=attrs[i].len-len;
 
+	if(!opt.photo_viewer)
+	  opt.photo_viewer=get_default_photo_command();
+
 	/* make command grow */
-	command=pct_expando(opt.photo_viewer?
-			    opt.photo_viewer:DEFAULT_PHOTO_COMMAND,&args);
+	command=pct_expando(opt.photo_viewer,&args);
 	if(!command)
 	  goto fail;
 
diff --git a/g10/pkclist.c b/g10/pkclist.c
index 70e551fad..671b56879 100644
--- a/g10/pkclist.c
+++ b/g10/pkclist.c
@@ -1058,7 +1058,7 @@ algo_available( int preftype, int algo, void *hint )
         if ( ( opt.pgp6 || opt.pgp7 ) && ( algo !=0 && algo != 1) )
 	  return 0;
 
-	return !algo || algo == 1 || algo == 2;
+	return !check_compress_algo( algo );
     }
     else
 	return 0;
@@ -1070,7 +1070,7 @@ algo_available( int preftype, int algo, void *hint )
  * Return -1 if we could not find an algorithm.
  */
 int
-select_algo_from_prefs( PK_LIST pk_list, int preftype, void *hint )
+select_algo_from_prefs(PK_LIST pk_list, int preftype, int request, void *hint)
 {
     PK_LIST pkr;
     u32 bits[8];
@@ -1189,6 +1189,11 @@ select_algo_from_prefs( PK_LIST pk_list, int preftype, void *hint )
 		}
 	    }
     }
+
+    /* Can we use the requested algorithm? */
+    if(request>-1 && request==i)
+      return i;
+
   #if 0
     log_debug("prefs of type %d: selected %d\n", preftype, i );
   #endif
diff --git a/g10/sign.c b/g10/sign.c
index cfab80066..6a8ce2991 100644
--- a/g10/sign.c
+++ b/g10/sign.c
@@ -679,24 +679,39 @@ sign_file( STRLIST filenames, int detached, STRLIST locusr,
 
    /* If we're encrypting and signing, it is reasonable to pick the
        hash algorithm to use out of the recepient key prefs. */
-    if(pk_list && !opt.def_digest_algo)
+    if(pk_list)
       {
-	int hashlen=0,algo;
-
-	/* Of course, if the recipient asks for something unreasonable
-	   (like a non-160-bit hash for DSA, for example), then don't
-	   do it.  Check all sk's - if any are DSA, then the hash must
-	   be 160-bit.  In the future this can be more complex with
-	   different hashes for each sk, but so long as there is only
-	   one signing algorithm with hash restrictions, this is
-	   ok. -dms */
-
-	for( sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next )
-	  if(sk_rover->sk->pubkey_algo==PUBKEY_ALGO_DSA)
-	    hashlen=20;
-
-	if((algo=select_algo_from_prefs(pk_list,PREFTYPE_HASH,&hashlen))>0)
-	  recipient_digest_algo=algo;
+	if(opt.def_digest_algo)
+	  {
+	    if(!opt.expert &&
+	       select_algo_from_prefs(pk_list,PREFTYPE_HASH,
+				      opt.def_digest_algo,
+				      NULL)!=opt.def_digest_algo)
+	  log_info(_("forcing digest algorithm %s (%d) "
+		     "violates recipient preferences\n"),
+		   digest_algo_to_string(opt.def_digest_algo),
+		   opt.def_digest_algo);
+	  }
+	else
+	  {
+	    int hashlen=0,algo;
+
+	    /* Of course, if the recipient asks for something
+	       unreasonable (like a non-160-bit hash for DSA, for
+	       example), then don't do it.  Check all sk's - if any
+	       are DSA, then the hash must be 160-bit.  In the future
+	       this can be more complex with different hashes for each
+	       sk, but so long as there is only one signing algorithm
+	       with hash restrictions, this is ok. -dms */
+
+	    for( sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next )
+	      if(sk_rover->sk->pubkey_algo==PUBKEY_ALGO_DSA)
+		hashlen=20;
+
+	    if((algo=
+		select_algo_from_prefs(pk_list,PREFTYPE_HASH,-1,&hashlen))>0)
+	      recipient_digest_algo=algo;
+	  }
       }
 
     for( sk_rover = sk_list; sk_rover; sk_rover = sk_rover->next ) {
@@ -724,19 +739,25 @@ sign_file( STRLIST filenames, int detached, STRLIST locusr,
         int compr_algo=opt.def_compress_algo;
 
 	/* If not forced by user */
-        if(compr_algo==-1)
+	if(compr_algo==-1)
 	  {
 	    /* If we're not encrypting, then select_algo_from_prefs
-               will fail and we'll end up with the default.  If we are
-               encrypting, select_algo_from_prefs cannot fail since
-               there is an assumed preference for uncompressed data.
-               Still, if it did fail, we'll also end up with the
-               default. */
-
+	       will fail and we'll end up with the default.  If we are
+	       encrypting, select_algo_from_prefs cannot fail since
+	       there is an assumed preference for uncompressed data.
+	       Still, if it did fail, we'll also end up with the
+	       default. */
+ 
 	    if((compr_algo=
-		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,NULL))==-1)
+		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,-1,NULL))==-1)
 	      compr_algo=DEFAULT_COMPRESS_ALGO;
 	  }
+ 	else if(!opt.expert &&
+ 		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,
+ 				       compr_algo,NULL)!=compr_algo)
+ 	  log_info(_("forcing compression algorithm %s (%d) "
+ 		     "violates recipient preferences\n"),
+ 		   compress_algo_to_string(compr_algo),compr_algo);
 
 	/* algo 0 means no compression */
 	if( compr_algo )