scd: PC/SC reader selection by partial string match.

* scd/apdu.c (open_pcsc_reader_direct): Partial string match.

--

The card reader name by PC/SC service might include USB bus,
which varies (on some platform like GNU/Linux).  Thus, it's
better to match partial string.

Original patch was submitted by anstein.  I changed it to fallback to
the first reader if no match found.

Note that we need to change pcsc-wrapper.c in 2.0 backport.

GnuPG-bug-id: 1618, 1930

1 files changed, 8 insertions, 4 deletions

diff --git a/scd/apdu.c b/scd/apdu.c
index f6cca8c7b..189fd4afa 100644
--- a/scd/apdu.c
+++ b/scd/apdu.c
@@ -1911,6 +1911,7 @@ open_pcsc_reader_direct (const char *portstr)
   long err;
   int slot;
   char *list = NULL;
+  char *rdrname = NULL;
   pcsc_dword_t nreader;
   char *p;
 
@@ -1963,18 +1964,22 @@ open_pcsc_reader_direct (const char *portstr)
     {
       if (!*p && !p[1])
         break;
-      if (*p)
-        log_info ("detected reader '%s'\n", p);
+      log_info ("detected reader '%s'\n", p);
       if (nreader < (strlen (p)+1))
         {
           log_error ("invalid response from pcsc_list_readers\n");
           break;
         }
+      if (!rdrname && portstr && !strncmp (p, portstr, strlen (portstr)))
+        rdrname = p;
       nreader -= strlen (p)+1;
       p += strlen (p) + 1;
     }
 
-  reader_table[slot].rdrname = xtrymalloc (strlen (portstr? portstr : list)+1);
+  if (!rdrname)
+    rdrname = list;
+
+  reader_table[slot].rdrname = xtrystrdup (rdrname);
   if (!reader_table[slot].rdrname)
     {
       log_error ("error allocating memory for reader name\n");
@@ -1983,7 +1988,6 @@ open_pcsc_reader_direct (const char *portstr)
       unlock_slot (slot);
       return -1;
     }
-  strcpy (reader_table[slot].rdrname, portstr? portstr : list);
   xfree (list);
   list = NULL;