Add more passphrase policy rules.

(--max-passphrase-days).

NEWS

@@ -7,8 +7,9 @@ Noteworthy changes in version 2.0.7
  * Made it work on Windows Vista.  Note that the entire Windows port
    is still considered Beta.
 
- * Add new options min-passphrase-nonalpha, check-passphrase-pattern
+ * Add new options min-passphrase-nonalpha, check-passphrase-pattern,
-   and enforce-passphrase-constraints to gpg-agent.
+   enforce-passphrase-constraints and max-passphrase-days to
+   gpg-agent.
 
 
 Noteworthy changes in version 2.0.6 (2007-08-16)

agent/ChangeLog

@@ -1,3 +1,21 @@
+2007-08-28  Werner Koch  <wk@g10code.com>
+
+	* gpg-agent.c (main): Add option --faked-system-time.
+
+	* protect-tool.c (read_and_unprotect): Print the protected-at date.
+
+	* agent.h (struct server_control_s): Add member IN_PASSWD.
+	* command.c (cmd_passwd): Set it.
+	* findkey.c (try_unprotect_cb): Use it.
+
+	* protect.c (do_encryption): Replace asprintf by xtryasprint.
+	(agent_protect): Create the protected-at item.
+	(agent_unprotect): Add optional arg PROTECTED_AT.
+	(merge_lists): Add args CUTOFF and CUTLEN.
+	(agent_unprotect): Use them.
+	* findkey.c (try_unprotect_cb): Add code to test for expired keys.
+	(unprotect): Allow changing the passphrase.
+
 2007-08-27  Werner Koch  <wk@g10code.com>
 
 	* gpg-agent.c: Add options --min-passphrase-nonalpha,

agent/agent.h

@@ -88,7 +88,12 @@ struct
   unsigned int min_passphrase_nonalpha;
   /* File name with a patternfile or NULL if not enabled.  */
   const char *check_passphrase_pattern;
-
+  /* If not 0 the user is asked to change his passphrase after these
+     number of days.  */
+  unsigned int max_passphrase_days;
+  /* If set, a passphrase history will be written and checked at each
+     passphrase change.  */
+  int enable_passhrase_history;
 
   int running_detached; /* We are running detached from the tty. */
 
@@ -153,6 +158,8 @@ struct server_control_s
 
   int use_auth_call; /* Hack to send the PKAUTH command instead of the
                         PKSIGN command to the scdaemon.  */
+  int in_passwd;     /* Hack to inhibit enforced passphrase change
+                        during an explicit passwd command.  */
 };
 
 
@@ -182,7 +189,7 @@ enum
 /* Values for the cache_mode arguments. */
 typedef enum 
   {
-    CACHE_MODE_IGNORE = 0, /* Special mode to by pass the cache. */
+    CACHE_MODE_IGNORE = 0, /* Special mode to bypass the cache. */
     CACHE_MODE_ANY,        /* Any mode except ignore matches. */
     CACHE_MODE_NORMAL,     /* Normal cache (gpg-agent). */
     CACHE_MODE_USER,       /* GET_PASSPHRASE related cache. */
@@ -271,6 +278,7 @@ int agent_protect_and_store (ctrl_t ctrl, gcry_sexp_t s_skey);
 int agent_protect (const unsigned char *plainkey, const char *passphrase,
                    unsigned char **result, size_t *resultlen);
 int agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
+                     gnupg_isotime_t protected_at, 
                      unsigned char **result, size_t *resultlen);
 int agent_private_key_type (const unsigned char *privatekey);
 unsigned char *make_shadow_info (const char *serialno, const char *idstring);

agent/command.c

@@ -1039,6 +1039,7 @@ cmd_passwd (assuan_context_t ctx, char *line)
   if (rc)
     goto leave;
 
+  ctrl->in_passwd++;
   rc = agent_key_from_file (ctrl, ctrl->server_local->keydesc,
                             grip, &shadow_info, CACHE_MODE_IGNORE, &s_skey);
   if (rc)
@@ -1050,6 +1051,7 @@ cmd_passwd (assuan_context_t ctx, char *line)
     }
   else
     rc = agent_protect_and_store (ctrl, s_skey);
+  ctrl->in_passwd--;
 
   xfree (ctrl->server_local->keydesc);
   ctrl->server_local->keydesc = NULL;

agent/findkey.c

@@ -1,5 +1,6 @@
-/* findkey.c - locate the secret key
+/* findkey.c - Locate the secret key
- * Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ * Copyright (C) 2001, 2002, 2003, 2004, 2005,
+ *               2007  Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.
  *
@@ -31,15 +32,20 @@
 #include <pth.h> /* (we use pth_sleep) */
 
 #include "agent.h"
+#include "i18n.h"
 
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif
 
 /* Helper to pass data to the check callback of the unprotect function. */
-struct try_unprotect_arg_s {
+struct try_unprotect_arg_s 
+{
+  ctrl_t ctrl;
   const unsigned char *protected_key;
   unsigned char *unprotected_key;
+  int change_required; /* Set by the callback to indicate that the
+                          user should chnage the passphrase.  */
 };
 
 
@@ -132,10 +138,71 @@ try_unprotect_cb (struct pin_entry_info_s *pi)
 {
   struct try_unprotect_arg_s *arg = pi->check_cb_arg;
   size_t dummy;
+  gpg_error_t err;
+  gnupg_isotime_t now, protected_at, tmptime;
+  char *desc = NULL;
 
   assert (!arg->unprotected_key);
-  return agent_unprotect (arg->protected_key, pi->pin,
+
+  arg->change_required = 0;
+  err = agent_unprotect (arg->protected_key, pi->pin, protected_at,
                          &arg->unprotected_key, &dummy);
+  if (err)
+    return err;
+  if (!opt.max_passphrase_days || arg->ctrl->in_passwd)
+    return 0;  /* No regular passphrase change required.  */
+
+  if (!*protected_at)
+    {
+      /* No protection date known - must force passphrase change.  */
+      desc = xtrystrdup (_("Note: This passphrase has never been changed.%0A"
+                           "Please change it now."));
+      if (!desc)
+        return gpg_error_from_syserror ();
+    }
+  else
+    {
+      gnupg_get_isotime (now);
+      gnupg_copy_time (tmptime, protected_at);
+      err = add_days_to_isotime (tmptime, opt.max_passphrase_days);
+      if (err)
+        return err;
+      if (strcmp (now, tmptime) > 0 )
+        {
+          /* Passphrase "expired".  */
+          desc = xtryasprintf 
+            (_("This passphrase has not been changed%%0A"
+               "since %.4s-%.2s-%.2s.  Please change it now."),
+             protected_at, protected_at+4, protected_at+6);
+          if (!desc)
+            return gpg_error_from_syserror ();
+        }
+    }
+
+  if (desc)
+    {
+      /* Change required.  */
+      if (opt.enforce_passphrase_constraints)
+        {
+          err = agent_get_confirmation (arg->ctrl, desc,
+                                        _("Change passphrase"), NULL);
+          if (!err)
+            arg->change_required = 1;
+        }
+      else
+        {
+          err = agent_get_confirmation (arg->ctrl, desc,
+                                        _("Change passphrase"),
+                                        _("I'll change it later"));
+          if (!err)
+            arg->change_required = 1;
+          else if (gpg_err_code (err) == GPG_ERR_CANCELED)
+            err = 0;
+        }
+      xfree (desc);
+    }
+
+  return 0;
 }
 
 
@@ -260,7 +327,7 @@ unprotect (ctrl_t ctrl, const char *desc_text,
       pw = agent_get_cache (hexgrip, cache_mode, &cache_marker);
       if (pw)
         {
-          rc = agent_unprotect (*keybuf, pw, &result, &resultlen);
+          rc = agent_unprotect (*keybuf, pw, NULL, &result, &resultlen);
           agent_unlock_cache_entry (&cache_marker);
           if (!rc)
             {
@@ -272,7 +339,7 @@ unprotect (ctrl_t ctrl, const char *desc_text,
         }
 
       /* If the pinentry is currently in use, we wait up to 60 seconds
-         for it close and check the cache again.  This solves a common
+         for it to close and check the cache again.  This solves a common
          situation where several requests for unprotecting a key have
          been made but the user is still entering the passphrase for
          the first request.  Because all requests to agent_askpin are
@@ -303,14 +370,46 @@ unprotect (ctrl_t ctrl, const char *desc_text,
   pi->max_digits = 8;
   pi->max_tries = 3;
   pi->check_cb = try_unprotect_cb;
+  arg.ctrl = ctrl;
   arg.protected_key = *keybuf;
   arg.unprotected_key = NULL;
+  arg.change_required = 0;
   pi->check_cb_arg = &arg;
 
   rc = agent_askpin (ctrl, desc_text, NULL, NULL, pi);
   if (!rc)
     {
       assert (arg.unprotected_key);
+      if (arg.change_required)
+        {
+          size_t canlen, erroff;
+          gcry_sexp_t s_skey;
+          
+          assert (arg.unprotected_key);
+          canlen = gcry_sexp_canon_len (arg.unprotected_key, 0, NULL, NULL);
+          rc = gcry_sexp_sscan (&s_skey, &erroff,
+                                (char*)arg.unprotected_key, canlen);
+          if (rc)
+            {
+              log_error ("failed to build S-Exp (off=%u): %s\n",
+                         (unsigned int)erroff, gpg_strerror (rc));
+              wipememory (arg.unprotected_key, canlen);
+              xfree (arg.unprotected_key);
+              xfree (pi);
+              return rc;
+            }
+          rc = agent_protect_and_store (ctrl, s_skey);
+          gcry_sexp_release (s_skey);
+          if (rc)
+            {
+              log_error ("changing the passphrase failed: %s\n", 
+                         gpg_strerror (rc));
+              wipememory (arg.unprotected_key, canlen);
+              xfree (arg.unprotected_key);
+              xfree (pi);
+              return rc;
+            }
+        }
       agent_put_cache (hexgrip, cache_mode, pi->pin, 0);
       xfree (*keybuf);
       *keybuf = arg.unprotected_key;

agent/genkey.c

@@ -1,4 +1,4 @@
-/* pksign.c - Generate a keypair
+/* genkey.c - Generate a keypair
  *	Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
  *
  * This file is part of GnuPG.

agent/gpg-agent.c

@@ -92,8 +92,11 @@ enum cmd_and_opt_values
   oMinPassphraseLen,
   oMinPassphraseNonalpha,
   oCheckPassphrasePattern,
+  oMaxPassphraseDays,
+  oEnablePassphraseHistory,
   oUseStandardSocket,
   oNoUseStandardSocket,
+  oFakedSystemTime,
 
   oIgnoreCacheForSigning,
   oAllowMarkTrusted,
@@ -137,6 +140,7 @@ static ARGPARSE_OPTS opts[] = {
   { oScdaemonProgram, "scdaemon-program", 2 ,
                                N_("|PGM|use PGM as the SCdaemon program") },
   { oDisableScdaemon, "disable-scdaemon", 0, N_("do not use the SCdaemon") },
+  { oFakedSystemTime, "faked-system-time", 2, "@" }, /* (epoch time) */
 
   { oDisplay,    "display",     2, "@" },
   { oTTYname,    "ttyname",     2, "@" },
@@ -157,6 +161,8 @@ static ARGPARSE_OPTS opts[] = {
   { oMinPassphraseLen, "min-passphrase-len", 4, "@" },
   { oMinPassphraseNonalpha, "min-passphrase-nonalpha", 4, "@" },
   { oCheckPassphrasePattern, "check-passphrase-pattern", 2, "@" },
+  { oMaxPassphraseDays, "max-passphrase-days", 4, "@" },
+  { oEnablePassphraseHistory, "enable-passphrase-history", 0, "@" },
 
   { oIgnoreCacheForSigning, "ignore-cache-for-signing", 0,
                                N_("do not use the PIN cache when signing")},
@@ -177,6 +183,7 @@ static ARGPARSE_OPTS opts[] = {
 #define MAX_CACHE_TTL_SSH     (120*60) /* 2 hours */
 #define MIN_PASSPHRASE_LEN    (8)      
 #define MIN_PASSPHRASE_NONALPHA (1)      
+#define MAX_PASSPHRASE_DAYS   (0)
 
 /* The timer tick used for housekeeping stuff.  For Windows we use a
    longer period as the SetWaitableTimer seems to signal earlier than
@@ -375,6 +382,8 @@ parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
       opt.min_passphrase_len = MIN_PASSPHRASE_LEN;
       opt.min_passphrase_nonalpha = MIN_PASSPHRASE_NONALPHA;
       opt.check_passphrase_pattern = NULL;
+      opt.max_passphrase_days = MAX_PASSPHRASE_DAYS;
+      opt.enable_passhrase_history = 0;
       opt.ignore_cache_for_signing = 0;
       opt.allow_mark_trusted = 0;
       opt.disable_scdaemon = 0;
@@ -424,6 +433,12 @@ parse_rereadable_options (ARGPARSE_ARGS *pargs, int reread)
     case oCheckPassphrasePattern:
       opt.check_passphrase_pattern = pargs->r.ret_str;
       break;
+    case oMaxPassphraseDays:
+      opt.max_passphrase_days = pargs->r.ret_ulong; 
+      break;
+    case oEnablePassphraseHistory:
+      opt.enable_passhrase_history = 1;
+      break;
 
     case oIgnoreCacheForSigning: opt.ignore_cache_for_signing = 1; break;
 
@@ -646,6 +661,15 @@ main (int argc, char **argv )
         case oUseStandardSocket: standard_socket = 1; break;
         case oNoUseStandardSocket: standard_socket = 0; break;
 
+        case oFakedSystemTime:
+          {
+            time_t faked_time = isotime2epoch (pargs.r.ret_str); 
+            if (faked_time == (time_t)(-1))
+              faked_time = (time_t)strtoul (pargs.r.ret_str, NULL, 10);
+            gnupg_set_time (faked_time, 0);
+          }
+          break;
+
         case oKeepTTY: opt.keep_tty = 1; break;
         case oKeepDISPLAY: opt.keep_display = 1; break;
 
@@ -753,6 +777,11 @@ main (int argc, char **argv )
               MIN_PASSPHRASE_NONALPHA);
       printf ("check-passphrase-pattern:%lu:\n",
               GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME);
+      printf ("max-passphrase-days:%lu:%d:\n",
+              GC_OPT_FLAG_DEFAULT|GC_OPT_FLAG_RUNTIME, 
+              MAX_PASSPHRASE_DAYS);
+      printf ("enable-passphrase-history:%lu:\n", 
+              GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
       printf ("no-grab:%lu:\n", 
               GC_OPT_FLAG_NONE|GC_OPT_FLAG_RUNTIME);
       printf ("ignore-cache-for-signing:%lu:\n",

agent/keyformat.txt

@@ -69,6 +69,7 @@ A protected key is like this:
     (n #00e0ce9..[some bytes not shown]..51#)
     (e #010001#)
     (protected mode (parms) encrypted_octet_string)
+    (protected-at <isotimestamp>)
    )
    (uri http://foo.bar x-foo:whatever_you_want)
    (comment whatever)
@@ -79,7 +80,8 @@ In this scheme the encrypted_octet_string is encrypted according to
 the algorithm described after the keyword protected; most protection
 algorithms need some parameters, which are given in a list before the
 encrypted_octet_string.  The result of the decryption process is a
-list of the secret key parameters.
+list of the secret key parameters.  The protected-at expression is
+optional; the isotimestamp is 15 bytes long (e.g. "19610711T172000").
 
 The only available protection mode for now is
 
@@ -115,7 +117,8 @@ easily be stripped by looking for the end of the list.
 The hash is calculated on the concatenation of the public key and
 secret key parameter lists: i.e it is required to hash the
 concatenation of these 6 canonical encoded lists for RSA, including
-the parenthesis and the algorithm keyword.
+the parenthesis, the algorithm keyword and (if used) the protected-at
+list.
 
 (rsa
  (n #00e0ce9..[some bytes not shown]..51#)
@@ -124,6 +127,7 @@ the parenthesis and the algorithm keyword.
  (p #00e861b..[some bytes not shown]..f1#)
  (q #00f7a7c..[some bytes not shown]..61#)
  (u #304559a..[some bytes not shown]..9b#)
+ (protected-at "18950523T000000")
 )
 
 After decryption the hash must be recalculated and compared against

agent/protect-tool.c

@@ -366,12 +366,14 @@ read_and_unprotect (const char *fname)
   unsigned char *result;
   size_t resultlen;
   char *pw;
+  gnupg_isotime_t protected_at;
 
   key = read_key (fname);
   if (!key)
     return;
 
-  rc = agent_unprotect (key, (pw=get_passphrase (1, 0)), &result, &resultlen);
+  rc = agent_unprotect (key, (pw=get_passphrase (1, 0)), 
+                        protected_at, &result, &resultlen);
   release_passphrase (pw);
   xfree (key);
   if (rc)
@@ -381,6 +383,11 @@ read_and_unprotect (const char *fname)
       log_error ("unprotecting the key failed: %s\n", gpg_strerror (rc));
       return;
     }
+  if (opt.verbose)
+    log_info ("key protection done at %.4s-%.2s-%.2s %.2s:%.2s:%s\n",
+              protected_at, protected_at+4, protected_at+6,
+              protected_at+9, protected_at+11, protected_at+13);
+
 
   if (opt_armor)
     {
@@ -883,7 +890,8 @@ export_p12_file (const char *fname)
       unsigned char *tmpkey;
       size_t tmplen;
 
-      rc = agent_unprotect (key, (pw=get_passphrase (1, 0)), &tmpkey, &tmplen);
+      rc = agent_unprotect (key, (pw=get_passphrase (1, 0)),
+                            NULL, &tmpkey, &tmplen);
       release_passphrase (pw);
       if (rc)
         {

agent/protect.c

@@ -163,7 +163,7 @@ do_encryption (const unsigned char *protbegin, size_t protlen,
      ((<parameter_list>)(4:hash4:sha120:<hashvalue>)) + padding
 
      We always append a full block of random bytes as padding but
-     encrypt only what is needed for a full blocksize */
+     encrypt only what is needed for a full blocksize.  */
   blklen = gcry_cipher_get_algo_blklen (PROT_CIPHER);
   outlen = 2 + protlen + 2 + 6 + 6 + 23 + 2 + blklen;
   enclen = outlen/blklen * blklen;
@@ -229,21 +229,13 @@ do_encryption (const unsigned char *protbegin, size_t protlen,
        encrypted_octet_string)
        
      in canoncical format of course.  We use asprintf and %n modifier
-     and spaces as palceholders.  */
+     and dummy values as placeholders.  */
-  asprintf (&p,
+  p = xtryasprintf
-            "(9:protected%d:%s((4:sha18:%n_8bytes_2:96)%d:%n%*s)%d:%n%*s)",
+    ("(9:protected%d:%s((4:sha18:%n_8bytes_2:96)%d:%n%*s)%d:%n%*s)",
      (int)strlen (modestr), modestr,
      &saltpos, 
      blklen, &ivpos, blklen, "",
      enclen, &encpos, enclen, "");
-  if (p)
-    { /* asprintf does not use our malloc system */
-      char *psave = p;
-      p = xtrymalloc (strlen (psave)+1);
-      if (p)
-        strcpy (p, psave);
-      free (psave);
-    }
   if (!p)
     {
       gpg_error_t tmperr = out_of_core ();
@@ -276,11 +268,19 @@ agent_protect (const unsigned char *plainkey, const char *passphrase,
   size_t n;
   int c, infidx, i;
   unsigned char hashvalue[20];
+  char timestamp_exp[35];
   unsigned char *protected;
   size_t protectedlen;
   int depth = 0;
   unsigned char *p;
+  gcry_md_hd_t md;
 
+  /* Create an S-expression with the procted-at timestamp.  */
+  memcpy (timestamp_exp, "(12:protected-at15:", 19);
+  gnupg_get_isotime (timestamp_exp+19);
+  timestamp_exp[19+15] = ')';
+
+  /* Parse original key.  */
   s = plainkey;
   if (*s != '(')
     return gpg_error (GPG_ERR_INV_SEXP);
@@ -345,8 +345,18 @@ agent_protect (const unsigned char *plainkey, const char *passphrase,
   assert (!depth);
   real_end = s-1;
 
-  gcry_md_hash_buffer (GCRY_MD_SHA1, hashvalue,
+  
-                       hash_begin, hash_end - hash_begin + 1);
+  /* Hash the stuff.  Because the timestamp_exp won't get protected,
+     we can't simply hash a continuous buffer but need to use several
+     md_writes.  */ 
+  rc = gcry_md_open (&md, GCRY_MD_SHA1, 0 );
+  if (rc)
+    return rc;
+  gcry_md_write (md, hash_begin, hash_end - hash_begin);
+  gcry_md_write (md, timestamp_exp, 35);
+  gcry_md_write (md, ")", 1);
+  memcpy (hashvalue, gcry_md_read (md, GCRY_MD_SHA1), 20);
+  gcry_md_close (md);
 
   rc = do_encryption (prot_begin, prot_end - prot_begin + 1,
                       passphrase,  hashvalue,
@@ -356,10 +366,12 @@ agent_protect (const unsigned char *plainkey, const char *passphrase,
 
   /* Now create the protected version of the key.  Note that the 10
      extra bytes are for for the inserted "protected-" string (the
-     beginning of the plaintext reads: "((11:private-key(" ). */
+     beginning of the plaintext reads: "((11:private-key(" ).  The 35
+     term is the space for (12:protected-at15:<timestamp>).  */
   *resultlen = (10
                 + (prot_begin-plainkey)
                 + protectedlen
+                + 35
                 + (real_end-prot_end));
   *result = p = xtrymalloc (*resultlen);
   if (!p)
@@ -374,10 +386,15 @@ agent_protect (const unsigned char *plainkey, const char *passphrase,
   p += prot_begin - plainkey - 4;
   memcpy (p, protected, protectedlen);
   p += protectedlen;
+
+  memcpy (p, timestamp_exp, 35);
+  p += 35;
+
   memcpy (p, prot_end+1, real_end - prot_end);
   p += real_end - prot_end;
   assert ( p - *result == *resultlen);
   xfree (protected);
+
   return 0;
 }
 
@@ -457,13 +474,16 @@ do_decryption (const unsigned char *protected, size_t protectedlen,
 /* Merge the parameter list contained in CLEARTEXT with the original
    protect lists PROTECTEDKEY by replacing the list at REPLACEPOS.
    Return the new list in RESULT and the MIC value in the 20 byte
-   buffer SHA1HASH. */
+   buffer SHA1HASH.  CUTOFF and CUTLEN will receive the offset and the
+   length of the resulting list which should go into the MIC
+   calculation but then be removed.  */
 static int
 merge_lists (const unsigned char *protectedkey,
              size_t replacepos, 
              const unsigned char *cleartext,
              unsigned char *sha1hash,
-             unsigned char **result, size_t *resultlen)
+             unsigned char **result, size_t *resultlen,
+             size_t *cutoff, size_t *cutlen)
 {
   size_t n, newlistlen;
   unsigned char *newlist, *p;
@@ -473,6 +493,8 @@ merge_lists (const unsigned char *protectedkey,
   
   *result = NULL;
   *resultlen = 0;
+  *cutoff = 0;
+  *cutlen = 0;
 
   if (replacepos < 26)
     return gpg_error (GPG_ERR_BUG);
@@ -522,7 +544,7 @@ merge_lists (const unsigned char *protectedkey,
     goto invalid_sexp;
   endpos = s;
   s++;
-  /* short intermezzo: Get the MIC */
+  /* Intermezzo: Get the MIC */
   if (*s != '(')
     goto invalid_sexp;
   s++;
@@ -539,13 +561,13 @@ merge_lists (const unsigned char *protectedkey,
   s += n;
   if (*s != ')')
     goto invalid_sexp;
-  /* end intermezzo */
+  /* End intermezzo */
 
   /* append the parameter list */
   memcpy (p, startpos, endpos - startpos);
   p += endpos - startpos;
   
-  /* skip overt the protected list element in the original list */
+  /* Skip over the protected list element in the original list.  */
   s = protectedkey + replacepos;
   assert (*s == '(');
   s++;
@@ -553,6 +575,22 @@ merge_lists (const unsigned char *protectedkey,
   rc = sskip (&s, &i);
   if (rc)
     goto failure;
+  /* Record the position of the optional protected-at expression.  */
+  if (*s == '(')
+    {
+      const unsigned char *save_s = s;
+      s++;
+      n = snext (&s);
+      if (smatch (&s, n, "protected-at"))
+        {
+          i = 1;
+          rc = sskip (&s, &i);
+          if (rc)
+            goto failure;
+          *cutlen = s - save_s;
+        }
+      s = save_s;
+    }
   startpos = s;
   i = 2; /* we are inside this level */
   rc = sskip (&s, &i);
@@ -561,10 +599,13 @@ merge_lists (const unsigned char *protectedkey,
   assert (s[-1] == ')');
   endpos = s; /* one behind the end of the list */
 
-  /* append the rest */
+  /* Append the rest. */
+  if (*cutlen)
+    *cutoff = p - newlist;
   memcpy (p, startpos, endpos - startpos);
   p += endpos - startpos;
   
+
   /* ready */
   *result = newlist;
   *resultlen = newlistlen;
@@ -584,13 +625,16 @@ merge_lists (const unsigned char *protectedkey,
 
 
 /* Unprotect the key encoded in canonical format.  We assume a valid
-   S-Exp here. */
+   S-Exp here.  If a protected-at item is available, its value will
+   be stored at protocted_at unless this is NULL.  */
 int 
 agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
+                 gnupg_isotime_t protected_at, 
                  unsigned char **result, size_t *resultlen)
 {
   int rc;
   const unsigned char *s;
+  const unsigned char *protect_list; 
   size_t n;
   int infidx, i;
   unsigned char sha1hash[20], sha1hash2[20];
@@ -601,6 +645,10 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
   unsigned char *cleartext;
   unsigned char *final;
   size_t finallen;
+  size_t cutoff, cutlen;
+
+  if (protected_at)
+    *protected_at = 0;
 
   s = protectedkey;
   if (*s != '(')
@@ -624,12 +672,44 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
   if (!protect_info[infidx].algo)
     return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM); 
 
+
+  /* See wether we have a protected-at timestamp.  */
+  protect_list = s;  /* Save for later.  */
+  if (protected_at)
+    {
+      while (*s == '(')
+        {
+          prot_begin = s;
+          s++;
+          n = snext (&s);
+          if (!n)
+            return gpg_error (GPG_ERR_INV_SEXP);
+          if (smatch (&s, n, "protected-at"))
+            {
+              n = snext (&s);
+              if (!n)
+                return gpg_error (GPG_ERR_INV_SEXP);
+              if (n != 15)
+                return gpg_error (GPG_ERR_UNKNOWN_SEXP);
+              memcpy (protected_at, s, 15);
+              protected_at[15] = 0;
+              break;
+            }
+          s += n;
+          i = 1;
+          rc = sskip (&s, &i);
+          if (rc)
+            return rc;
+        }
+    }
+
   /* Now find the list with the protected information.  Here is an
      example for such a list:
      (protected openpgp-s2k3-sha1-aes-cbc 
         ((sha1 <salt> <count>) <Initialization_Vector>)
         <encrypted_data>)
    */
+  s = protect_list;
   for (;;)
     {
       if (*s != '(')
@@ -700,7 +780,7 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
     return rc;
 
   rc = merge_lists (protectedkey, prot_begin-protectedkey, cleartext,
-                    sha1hash, &final, &finallen);
+                    sha1hash, &final, &finallen, &cutoff, &cutlen);
   /* Albeit cleartext has been allocated in secure memory and thus
      xfree will wipe it out, we do an extra wipe just in case
      somethings goes badly wrong. */
@@ -718,6 +798,13 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
       xfree (final);
       return rc;
     }
+  /* Now remove tha part which is included in the MIC but should not
+     go into the final thing.  */
+  if (cutlen)
+    {
+      memmove (final+cutoff, final+cutoff+cutlen, finallen-cutoff-cutlen);
+      finallen -= cutlen;
+    }
 
   *result = final;
   *resultlen = gcry_sexp_canon_len (final, 0, NULL, NULL);

common/ChangeLog

@@ -1,3 +1,11 @@
+2007-08-28  Werner Koch  <wk@g10code.com>
+
+	* gettime.c (check_isotime, add_isotime): New.  Orginally written
+	for DirMngr by me.
+	(add_days_to_isotime): New.
+	(date2jd, jd2date, days_per_month, days_per_year): New. Taken from
+	my ancient (1988) code used in Wedit (time2.c).
+
 2007-08-27  Werner Koch  <wk@g10code.com>
 
 	* util.h (GNUPG_MODULE_NAME_CHECK_PATTERN): New.

common/gettime.c

@@ -30,6 +30,10 @@
 static unsigned long timewarp;
 static enum { NORMAL = 0, FROZEN, FUTURE, PAST } timemode;
 
+/* Correction used to map to real Julian days. */
+#define JD_DIFF 1721060L
+
+
 /* Wrapper for the time(3).  We use this here so we can fake the time
    for tests */
 time_t 
@@ -363,14 +367,215 @@ asctimestamp( u32 stamp )
 
 
 
+static int
+days_per_year (int y)
+{
+  int s ;
+
+  s = !(y % 4);
+  if ( !(y % 100))
+    if ((y%400))
+      s = 0;
+  return s ? 366 : 365;
+}
+
+static int
+days_per_month (int y, int m)
+{
+  int s;
+    
+  switch(m)
+    {
+    case 1: case 3: case 5: case 7: case 8: case 10: case 12:
+      return 31 ;
+    case 2:
+      s = !(y % 4);
+      if (!(y % 100))
+        if ((y % 400))
+          s = 0;
+      return s? 29 : 28 ;
+    case 4: case 6: case 9: case 11:
+      return 30;
+    }
+  BUG();
+}
+
+
+/* Convert YEAR, MONTH and DAY into the Julian date.  We assume that
+   it is already noon; we dont; support dates before 1582-10-15. */
+static unsigned long
+date2jd (int year, int month, int day)
+{
+  unsigned long jd;
+
+  jd = 365L * year + 31 * (month-1) + day + JD_DIFF;
+  if (month < 3)
+    year-- ;
+  else
+    jd -= (4 * month + 23) / 10;
+
+  jd += year / 4 - ((year / 100 + 1) *3) / 4;
+
+  return jd ;
+}
+
+/* Convert a Julian date back to YEAR, MONTH and DAY.  Return day of
+   the year or 0 on error.  This function uses some more or less
+   arbitrary limits, most important is that days before 1582 are not
+   supported. */
+static int
+jd2date (unsigned long jd, int *year, int *month, int *day)
+{
+  int y, m, d;
+  long delta;
+
+  if (!jd)
+    return 0 ;
+  if (jd < 1721425 || jd > 2843085)
+    return 0;
+
+  y = (jd - JD_DIFF) / 366;
+  d = m = 1;
+
+  while ((delta = jd - date2jd (y, m, d)) > days_per_year (y))
+    y++;
+
+  m = (delta / 31) + 1;
+  while( (delta = jd - date2jd (y, m, d)) > days_per_month (y,m))
+    if (++m > 12)
+      { 
+        m = 1;
+        y++;
+      }
+
+  d = delta + 1 ;
+  if (d > days_per_month (y, m))
+    { 
+      d = 1;
+      m++;
+    }
+  if (m > 12)
+    { 
+      m = 1;
+      y++;
+    }
+
+  if (year)
+    *year = y;
+  if (month)
+    *month = m;
+  if (day)
+    *day = d ;
+
+  return (jd - date2jd (y, 1, 1)) + 1;
+}
+
+
+/* Check that the 15 bytes in ATIME represent a valid ISO time.  Note
+   that this function does not expect a string but a plain 15 byte
+   isotime buffer. */
+gpg_error_t
+check_isotime (const gnupg_isotime_t atime)
+{
+  int i;
+  const char *s;
+
+  if (!*atime)
+    return gpg_error (GPG_ERR_NO_VALUE);
+  
+  for (s=atime, i=0; i < 8; i++, s++)
+    if (!digitp (s))
+      return gpg_error (GPG_ERR_INV_TIME);
+  if (*s != 'T')
+      return gpg_error (GPG_ERR_INV_TIME);
+  for (s++, i=9; i < 15; i++, s++)
+    if (!digitp (s))
+      return gpg_error (GPG_ERR_INV_TIME);
+  return 0;
+}
 
 
 
+/* Add SECONDS to ATIME.  SECONDS may not be negative and is limited
+   to about the equivalent of 62 years which should be more then
+   enough for our purposes. */
+gpg_error_t
+add_seconds_to_isotime (gnupg_isotime_t atime, int nseconds)
+{
+  gpg_error_t err;
+  int year, month, day, hour, minute, sec, ndays;
+  unsigned long jd;
+
+  err = check_isotime (atime);
+  if (err)
+    return err;
+
+  if (nseconds < 0 || nseconds >= (0x7fffffff - 61) )
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  year  = atoi_4 (atime+0);
+  month = atoi_2 (atime+4);
+  day   = atoi_2 (atime+6);
+  hour  = atoi_2 (atime+9);
+  minute= atoi_2 (atime+11);
+  sec   = atoi_2 (atime+13);
+
+  if (year <= 1582) /* The julian date functions don't support this. */
+    return gpg_error (GPG_ERR_INV_VALUE); 
+
+  sec    += nseconds;
+  minute += sec/60;
+  sec    %= 60;
+  hour   += minute/60;
+  minute %= 60;
+  ndays  = hour/24;
+  hour   %= 24;
+  
+  jd = date2jd (year, month, day) + ndays;
+  jd2date (jd, &year, &month, &day);
+
+  if (year > 9999 || month > 12 || day > 31
+      || year < 0 || month < 1 || day < 1)
+    return gpg_error (GPG_ERR_INV_VALUE); 
+    
+  snprintf (atime, 16, "%04d%02d%02dT%02d%02d%02d",
+            year, month, day, hour, minute, sec);
+  return 0;
+}
 
 
+gpg_error_t
+add_days_to_isotime (gnupg_isotime_t atime, int ndays)
+{
+  gpg_error_t err;
+  int year, month, day, hour, minute, sec;
+  unsigned long jd;
 
+  err = check_isotime (atime);
+  if (err)
+    return err;
 
+  if (ndays < 0 || ndays >= 9999*366 )
+    return gpg_error (GPG_ERR_INV_VALUE);
 
+  year  = atoi_4 (atime+0);
+  month = atoi_2 (atime+4);
+  day   = atoi_2 (atime+6);
+  hour  = atoi_2 (atime+9);
+  minute= atoi_2 (atime+11);
+  sec   = atoi_2 (atime+13);
 
+  if (year <= 1582) /* The julian date functions don't support this. */
+    return gpg_error (GPG_ERR_INV_VALUE); 
 
+  jd = date2jd (year, month, day) + ndays;
+  jd2date (jd, &year, &month, &day);
 
+  if (year > 9999 || month > 12 || day > 31
+      || year < 0 || month < 1 || day < 1)
+    return gpg_error (GPG_ERR_INV_VALUE); 
+    
+  snprintf (atime, 16, "%04d%02d%02dT%02d%02d%02d",
+            year, month, day, hour, minute, sec);
+  return 0;
+}

common/util.h

@@ -110,7 +110,9 @@ const char *strtimevalue (u32 stamp);
 const char *strtimestamp (u32 stamp); /* GMT */
 const char *isotimestamp (u32 stamp); /* GMT */
 const char *asctimestamp (u32 stamp); /* localized */
-
+gpg_error_t add_seconds_to_isotime (gnupg_isotime_t atime, int nseconds);
+gpg_error_t add_days_to_isotime (gnupg_isotime_t atime, int ndays);
+gpg_error_t check_isotime (const gnupg_isotime_t atime);
 
 /* Copy one ISO date to another, this is inline so that we can do a
    sanity check. */

doc/gpg-agent.texi

@@ -365,6 +365,15 @@ a policy.  A better policy is to educate users on good security
 behavior and optional to run a passphrase cracker regularly on all
 users passphrases t catch the very simple ones.
 
+@item --max-passphrase-days @var{n}
+@opindex max-passphrase-days 
+Ask the user to change the passphrase if @var{n} days have passed since
+the last change.  With @option{--enforce-passphrase-constraints} set the
+user may not bypass this check.
+
+@item --enable-passphrase-history
+@opindex enable-passphrase-history
+This option does nothing yet.
 
 @item --pinentry-program @var{filename}
 @opindex pinentry-program

po/ChangeLog

@@ -1,3 +1,7 @@
+2007-08-28  Werner Koch  <wk@g10code.com>
+
+	* de.po: Updated.
+
 2007-08-16  Werner Koch  <wk@g10code.com>
 
 	* pt_BR.po, es.po: Remove the "GNU" from the project ID.  That

po/POTFILES.in

@@ -8,6 +8,7 @@ agent/gpg-agent.c
 agent/preset-passphrase.c
 agent/protect-tool.c
 agent/trustlist.c
+agent/findkey.c
 
 common/exechelp.c
 common/http.c

tools/ChangeLog

@@ -1,3 +1,8 @@
+2007-08-28  Werner Koch  <wk@g10code.com>
+
+	* gpgconf-comp.c <gpg-agent>: Add options --max-passphrase-days
+	and --enable-passphrase-history.
+
 2007-08-27  Werner Koch  <wk@g10code.com>
 
 	* gpg-check-pattern.c: New

tools/gpgconf-comp.c

@@ -528,6 +528,14 @@ static gc_option_t gc_options_gpg_agent[] =
      GC_LEVEL_EXPERT,
      "gnupg", N_("|FILE|check new passphrases against pattern in FILE"),
      GC_ARG_TYPE_PATHNAME, GC_BACKEND_SCDAEMON },
+   { "max-passphrase-days", GC_OPT_FLAG_RUNTIME,
+     GC_LEVEL_EXPERT, "gnupg", 
+     N_("|N|expire the passphrase after N days"),
+     GC_ARG_TYPE_UINT32, GC_BACKEND_GPG_AGENT },
+   { "enable-passphrases-history", GC_OPT_FLAG_RUNTIME, 
+     GC_LEVEL_EXPERT, "gnupg", 
+     N_("do not allow the reuse of old passphrases"),
+     GC_ARG_TYPE_NONE, GC_BACKEND_GPG_AGENT },
 
    GC_OPTION_NULL
  };