* cache.c: Add a few debug outputs.

* protect.c (agent_private_key_type): New.
* agent.h: Add PRIVATE_KEY_ enums.
* findkey.c (agent_key_from_file): Use it to decide whether we
have to unprotect a key.
(unprotect): Cache the passphrase.

* findkey.c (agent_key_from_file,agent_key_available): The key
files do now require a ".key" suffix to make a script's life
easier.
* genkey.c (store_key): Ditto.

agent/ChangeLog

@@ -1,3 +1,18 @@
+2002-02-01  Werner Koch  <wk@gnupg.org>
+
+	* cache.c: Add a few debug outputs.
+
+	* protect.c (agent_private_key_type): New.
+	* agent.h: Add PRIVATE_KEY_ enums.
+	* findkey.c (agent_key_from_file): Use it to decide whether we
+	have to unprotect a key.
+	(unprotect): Cache the passphrase.
+	
+	* findkey.c (agent_key_from_file,agent_key_available): The key
+	files do now require a ".key" suffix to make a script's life
+	easier. 
+	* genkey.c (store_key): Ditto.
+
 2002-01-31  Werner Koch  <wk@gnupg.org>
 
 	* genkey.c (store_key): Protect the key.

agent/agent.h

@@ -83,6 +83,13 @@ struct pin_entry_info_s {
 };
 
 
+enum {
+  PRIVATE_KEY_UNKNOWN = 0,
+  PRIVATE_KEY_CLEAR = 1,
+  PRIVATE_KEY_PROTECTED = 2,
+  PRIVATE_KEY_SHADOWED = 3
+};
+
 /*-- gpg-agent.c --*/
 void agent_exit (int rc); /* also implemented in other tools */
 
@@ -125,6 +132,7 @@ 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,
                      unsigned char **result, size_t *resultlen);
+int agent_private_key_type (const unsigned char *privatekey);
 
 
 /*-- trustlist.c --*/

agent/cache.c

@@ -89,6 +89,9 @@ housekeeping (void)
     {
       if (r->pw && r->accessed + r->ttl < current)
         {
+          if (DBG_CACHE)
+            log_debug ("  expired `%s' (%ds after last access)\n",
+                       r->key, r->ttl);
           release_data (r->pw);
           r->pw = NULL;
           r->accessed = current;
@@ -101,6 +104,8 @@ housekeeping (void)
     {
       if (r->pw && r->created + 60*60 < current)
         {
+          if (DBG_CACHE)
+            log_debug ("  expired `%s' (1h after creation)\n", r->key);
           release_data (r->pw);
           r->pw = NULL;
           r->accessed = current;
@@ -114,6 +119,8 @@ housekeeping (void)
       if (!r->pw && r->accessed + 60*30 < current)
         {
           ITEM r2 = r->next;
+          if (DBG_CACHE)
+            log_debug ("  removed `%s' (slot not used for 30m)\n", r->key);
           xfree (r);
           if (!rprev)
             thecache = r2;
@@ -140,6 +147,8 @@ agent_put_cache (const char *key, const char *data, int ttl)
 {
   ITEM r;
 
+  if (DBG_CACHE)
+    log_debug ("agent_put_cache `%s'\n", key);
   housekeeping ();
 
   if (ttl < 1)
@@ -198,6 +207,8 @@ agent_get_cache (const char *key)
   ITEM r;
   int count = 0;
 
+  if (DBG_CACHE)
+    log_debug ("agent_get_cache `%s'...\n", key);
   housekeeping ();
 
   /* FIXME: Returning pointers is not thread safe - add a referencense
@@ -209,9 +220,13 @@ agent_get_cache (const char *key)
           /* put_cache does only put strings into the cache, so we
              don't need the lengths */
           r->accessed = time (NULL);
+          if (DBG_CACHE)
+            log_debug ("... hit\n");
           return r->pw->data;
         }
     }
+  if (DBG_CACHE)
+    log_debug ("... miss\n");
 
   return NULL;
 }

agent/findkey.c

@@ -31,15 +31,35 @@
 #include "agent.h"
 
 static int
-unprotect (unsigned char **keybuf)
+unprotect (unsigned char **keybuf, const unsigned char *grip)
 {
   struct pin_entry_info_s *pi;
-  int rc;
+  int rc, i;
   unsigned char *result;
   size_t resultlen;
   int tries = 0;
+  char hexgrip[40+1];
   
-  /* fixme: check whether the key needs unprotection */
+  for (i=0; i < 20; i++)
+    sprintf (hexgrip+2*i, "%02X", grip[i]);
+  hexgrip[40] = 0;
+
+  /* first try to get it from the cache - if there is none or we can't
+     unprotect it, we fall back to ask the user */
+  {
+    const char *pw = agent_get_cache (hexgrip);
+    if (pw)
+      {
+        rc = agent_unprotect (*keybuf, pw, &result, &resultlen);
+        if (!rc)
+          {
+            xfree (*keybuf);
+            *keybuf = result;
+            return 0;
+          }
+        rc  = 0;
+      }
+  }
   
   pi = gcry_calloc_secure (1, sizeof (*pi) + 100);
   pi->max_length = 100;
@@ -55,6 +75,7 @@ unprotect (unsigned char **keybuf)
           rc = agent_unprotect (*keybuf, pi->pin, &result, &resultlen);
           if (!rc)
             {
+              agent_put_cache (hexgrip, pi->pin, 0);
               xfree (*keybuf);
               *keybuf = result;
               xfree (pi);
@@ -82,13 +103,13 @@ agent_key_from_file (const unsigned char *grip)
   unsigned char *buf;
   size_t len, buflen, erroff;
   GCRY_SEXP s_skey;
-  char hexgrip[41];
+  char hexgrip[40+4+1];
   
   for (i=0; i < 20; i++)
     sprintf (hexgrip+2*i, "%02X", grip[i]);
-  hexgrip[40] = 0;
+  strcpy (hexgrip+40, ".key");
 
-  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL );
+  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL);
   fp = fopen (fname, "rb");
   if (!fp)
     {
@@ -138,16 +159,32 @@ agent_key_from_file (const unsigned char *grip)
   assert (len);
   gcry_sexp_release (s_skey);
 
-  rc = unprotect (&buf);
+  switch (agent_private_key_type (buf))
+    {
+    case PRIVATE_KEY_CLEAR:
+      break; /* no unprotection needed */
+    case PRIVATE_KEY_PROTECTED:
+      rc = unprotect (&buf, grip);
+      if (rc)
+        log_error ("failed to unprotect the secret key: %s\n",
+                   gnupg_strerror (rc));
+      break;
+    case PRIVATE_KEY_SHADOWED:
+      log_error ("shadowed private keys are not yet supported\n");
+      rc = GNUPG_Not_Implemented;
+      break;
+    default:
+      log_error ("invalid private key format\n");
+      rc = GNUPG_Bad_Secret_Key;
+      break;
+    }
   if (rc)
     {
-      log_error ("failed to unprotect the secret key: %s\n",
-                 gcry_strerror (rc));
       xfree (buf);
       return NULL;
     }
 
-  /* arggg FIXME: does scna support secure memory? */
+  /* arggg FIXME: does scan support secure memory? */
   rc = gcry_sexp_sscan (&s_skey, &erroff,
                         buf, gcry_sexp_canon_len (buf, 0, NULL, NULL));
   xfree (buf);
@@ -168,13 +205,13 @@ agent_key_available (const unsigned char *grip)
 {
   int i;
   char *fname;
-  char hexgrip[41];
+  char hexgrip[40+4+1];
   
   for (i=0; i < 20; i++)
     sprintf (hexgrip+2*i, "%02X", grip[i]);
-  hexgrip[40] = 0;
+  strcpy (hexgrip+40, ".key");
 
-  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL );
+  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL);
   i = !access (fname, R_OK)? 0 : -1;
   xfree (fname);
   return i;

agent/genkey.c

@@ -40,7 +40,7 @@ store_key (GCRY_SEXP private, const char *passphrase)
   char *buf;
   size_t len;
   unsigned char grip[20];
-  char hexgrip[41];
+  char hexgrip[40+4+1];
   
   if ( !gcry_pk_get_keygrip (private, grip) )
     {
@@ -49,7 +49,7 @@ store_key (GCRY_SEXP private, const char *passphrase)
     }
   for (i=0; i < 20; i++)
     sprintf (hexgrip+2*i, "%02X", grip[i]);
-  hexgrip[40] = 0;
+  strcpy (hexgrip+40, ".key");
 
   fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL);
   if (!access (fname, F_OK))

agent/protect.c

@@ -776,6 +776,33 @@ agent_unprotect (const unsigned char *protectedkey, const char *passphrase,
   return 0;
 }
 
+/* Check the type of the private key, this is one of the constants:
+   PRIVATE_KEY_UNKNOWN if we can't figure out the type (this is the
+   value 0), PRIVATE_KEY_CLEAR for an unprotected private key.
+   PRIVATE_KEY_PROTECTED for an protected private key or
+   PRIVATE_KEY_SHADOWED for a sub key where the secret parts are store
+   elsewhere. */
+int
+agent_private_key_type (const unsigned char *privatekey)
+{
+  const unsigned char *s;
+  size_t n;
+
+  s = privatekey;
+  if (*s != '(')
+    return PRIVATE_KEY_UNKNOWN;
+  s++;
+  n = snext (&s);
+  if (!n)
+    return PRIVATE_KEY_UNKNOWN;
+  if (smatch (&s, n, "protected-private-key"))
+    return PRIVATE_KEY_PROTECTED;
+  if (smatch (&s, n, "shadowed-private-key"))
+    return PRIVATE_KEY_SHADOWED;
+  if (smatch (&s, n, "private-key"))
+    return PRIVATE_KEY_CLEAR;
+  return PRIVATE_KEY_UNKNOWN;
+}