diff -up gnupg-2.0.25/g10/gpg.c.file-is-digest gnupg-2.0.25/g10/gpg.c
--- gnupg-2.0.25/g10/gpg.c.file-is-digest	2014-08-05 16:46:28.865869320 +0200
+++ gnupg-2.0.25/g10/gpg.c	2014-08-05 16:49:27.520063937 +0200
@@ -345,6 +345,7 @@ enum cmd_and_opt_values
     oTTYtype,
     oLCctype,
     oLCmessages,
+    oFileIsDigest,
     oXauthority,
     oGroup,
     oUnGroup,
@@ -711,6 +712,7 @@ static ARGPARSE_OPTS opts[] = {
   ARGPARSE_s_s (oPersonalDigestPreferences, "personal-digest-preferences","@"),
   ARGPARSE_s_s (oPersonalCompressPreferences,
                                          "personal-compress-preferences", "@"),
+  ARGPARSE_s_n (oFileIsDigest, "file-is-digest", "@"),
 
   /* Aliases.  I constantly mistype these, and assume other people do
      as well. */
@@ -2003,6 +2005,7 @@ main (int argc, char **argv)
     set_homedir ( default_homedir () );
     opt.passphrase_repeat=1;
     opt.emit_version = 1; /* Limit to the major number.  */
+    opt.file_is_digest=0;
 
     opt.list_options   |= LIST_SHOW_UID_VALIDITY;
     opt.verify_options |= LIST_SHOW_UID_VALIDITY;
@@ -2493,6 +2496,7 @@ main (int argc, char **argv)
 	  case oPhotoViewer: opt.photo_viewer = pargs.r.ret_str; break;
 	  case oForceV3Sigs: opt.force_v3_sigs = 1; break;
 	  case oNoForceV3Sigs: opt.force_v3_sigs = 0; break;
+	  case oFileIsDigest: opt.file_is_digest = 1; break;
           case oForceV4Certs: opt.force_v4_certs = 1; break;
           case oNoForceV4Certs: opt.force_v4_certs = 0; break;
 	  case oForceMDC: opt.force_mdc = 1; break;
diff -up gnupg-2.0.25/g10/options.h.file-is-digest gnupg-2.0.25/g10/options.h
--- gnupg-2.0.25/g10/options.h.file-is-digest	2014-06-30 17:28:52.000000000 +0200
+++ gnupg-2.0.25/g10/options.h	2014-08-05 16:46:28.869869414 +0200
@@ -198,6 +198,7 @@ struct
   int no_auto_check_trustdb;
   int preserve_permissions;
   int no_homedir_creation;
+  int file_is_digest;
   struct groupitem *grouplist;
   int mangle_dos_filenames;
   int enable_progress_filter;
diff -up gnupg-2.0.25/g10/sign.c.file-is-digest gnupg-2.0.25/g10/sign.c
--- gnupg-2.0.25/g10/sign.c.file-is-digest	2014-06-30 17:28:52.000000000 +0200
+++ gnupg-2.0.25/g10/sign.c	2014-08-05 16:46:28.870869438 +0200
@@ -665,8 +665,12 @@ write_signature_packets (SK_LIST sk_list
             mk_notation_policy_etc (sig, NULL, sk);
           }
 
+	if (!opt.file_is_digest) {
         hash_sigversion_to_magic (md, sig);
 	gcry_md_final (md);
+	} else if (sig->version >= 4) {
+	    log_bug("file-is-digest doesn't work with v4 sigs\n");
+	}
 
 	rc = do_sign( sk, sig, md, hash_for (sk) );
 	gcry_md_close (md);
@@ -723,6 +727,8 @@ sign_file( strlist_t filenames, int deta
     SK_LIST sk_rover = NULL;
     int multifile = 0;
     u32 duration=0;
+    int sigclass = 0x00;
+    u32 timestamp = 0;
 
     pfx = new_progress_context ();
     afx = new_armor_context ();
@@ -739,7 +745,16 @@ sign_file( strlist_t filenames, int deta
 	fname = NULL;
 
     if( fname && filenames->next && (!detached || encryptflag) )
-	log_bug("multiple files can only be detached signed");
+	log_bug("multiple files can only be detached signed\n");
+
+    if (opt.file_is_digest && (multifile || !fname))
+	log_bug("file-is-digest only works with one file\n");
+    if (opt.file_is_digest && !detached)
+	log_bug("file-is-digest can only write detached signatures\n");
+    if (opt.file_is_digest && !opt.def_digest_algo)
+	log_bug("file-is-digest needs --digest-algo\n");
+    if (opt.file_is_digest && opt.textmode)
+	log_bug("file-is-digest doesn't work with --textmode\n");
 
     if(encryptflag==2
        && (rc=setup_symkey(&efx.symkey_s2k,&efx.symkey_dek)))
@@ -767,7 +782,7 @@ sign_file( strlist_t filenames, int deta
       goto leave;
 
     /* prepare iobufs */
-    if( multifile )  /* have list of filenames */
+    if( multifile || opt.file_is_digest)  /* have list of filenames */
 	inp = NULL; /* we do it later */
     else {
       inp = iobuf_open(fname);
@@ -900,7 +915,7 @@ sign_file( strlist_t filenames, int deta
 	gcry_md_enable (mfx.md, hash_for(sk));
     }
 
-    if( !multifile )
+    if( !multifile && !opt.file_is_digest )
 	iobuf_push_filter( inp, md_filter, &mfx );
 
     if( detached && !encryptflag && !RFC1991 )
@@ -955,6 +970,8 @@ sign_file( strlist_t filenames, int deta
 
     write_status_begin_signing (mfx.md);
 
+    sigclass = opt.textmode && !outfile? 0x01 : 0x00;
+
     /* Setup the inner packet. */
     if( detached ) {
 	if( multifile ) {
@@ -995,6 +1012,45 @@ sign_file( strlist_t filenames, int deta
 	    if( opt.verbose )
 		putc( '\n', stderr );
 	}
+	else if (opt.file_is_digest) {
+	    byte *mdb, ts[5];
+	    size_t mdlen;
+	    const char *fp;
+	    int c, d;
+
+	    gcry_md_final(mfx.md);
+	    /* this assumes gcry_md_read returns the same buffer */
+	    mdb = gcry_md_read(mfx.md, opt.def_digest_algo);
+		mdlen = gcry_md_get_algo_dlen(opt.def_digest_algo);
+	    if (strlen(fname) != mdlen * 2 + 11)
+	        log_bug("digests must be %zu + @ + 5 bytes\n", mdlen);
+	    d = -1;
+	    for (fp = fname ; *fp; ) {
+		c = *fp++;
+		if (c >= '0' && c <= '9')
+		    c -= '0';
+		else if (c >= 'a' && c <= 'f')
+		    c -= 'a' - 10;
+		else if (c >= 'A' && c <= 'F')
+		    c -= 'A' - 10;
+		else
+		    log_bug("filename is not hex\n");
+		if (d >= 0) {
+		    *mdb++ = d << 4 | c;
+		    c = -1;
+		    if (--mdlen == 0) {
+			mdb = ts;
+			if (*fp++ != '@')
+			    log_bug("missing time separator\n");
+		    }
+		}
+		d = c;
+	    }
+	    sigclass = ts[0];
+	    if (sigclass != 0x00 && sigclass != 0x01)
+		log_bug("bad cipher class\n");
+	    timestamp = buffer_to_u32(ts + 1);
+	}
 	else {
 	    /* read, so that the filter can calculate the digest */
 	    while( iobuf_get(inp) != -1 )
@@ -1012,8 +1068,8 @@ sign_file( strlist_t filenames, int deta
 
     /* write the signatures */
     rc = write_signature_packets (sk_list, out, mfx.md,
-                                  opt.textmode && !outfile? 0x01 : 0x00,
-				  0, duration, detached ? 'D':'S');
+                                  sigclass,
+				  timestamp, duration, detached ? 'D':'S');
     if( rc )
         goto leave;