sexp: Extend gcry_sexp_extract_param with new format specifiers.

* src/sexp.c (_gcry_sexp_vextract_param): Add new conversion methods.
* tests/t-sexp.c (check_extract_param): Add corresponding tests.

Signed-off-by: Werner Koch <wk@gnupg.org>

4 files changed, 268 insertions, 26 deletions

diff --git a/NEWS b/NEWS
index aa58fda8..264f34f1 100644
--- a/NEWS
+++ b/NEWS
@@ -41,10 +41,18 @@ Noteworthy changes in version 1.9.0 (unreleased)  [C22/A3/R0]
    - Fix fatal out of secure memory status in the s-expression parser
      on heavy loaded systems.  [also in 1.8.2]
 
+ * Extended interfaces:
+
+   - gcry_sexp_extract_param understands new format specifiers to
+     directly store to integers and strings.
+
+
  * Interface changes relative to the 1.8.0 release:
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    gcry_mpi_get_ui                 NEW function.
    GCRYCTL_AUTO_EXPAND_SECMEM      NEW control code.
+   gcry_sexp_extract_param         EXTENDED.
+
 
  * Release dates of 1.8.x versions:
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/doc/gcrypt.texi b/doc/gcrypt.texi
index d3142d07..fad1dfea 100644
--- a/doc/gcrypt.texi
+++ b/doc/gcrypt.texi
@@ -4513,7 +4513,7 @@ likely want to use @code{GCRYMPI_FMT_USG}.
 Extract parameters from an S-expression using a list of parameter
 names.  The names of these parameters are specified in LIST.  White
 space between the parameter names are ignored. Some special characters
-may be given to control the conversion:
+and character sequences may be given to control the conversion:
 
 @table @samp
 @item +
@@ -4526,6 +4526,25 @@ Switch to opaque MPI format.  The resulting MPIs may not be used for
 computations; see @code{gcry_mpi_get_opaque} for details.
 @item &
 Switch to buffer descriptor mode.  See below for details.
+@item %s
+Switch to string mode.  The expected argument is the address of a
+@code{char *} variable; the caller must release that value.  If the
+parameter was marked optional and is not found, NULL is stored.
+@item %u
+Switch to unsigned integer mode. The expected argument is address of
+a @code{unsigned int} variable.
+@item %lu
+Switch to unsigned long integer mode. The expected argument is address of
+a @code{unsigned long} variable.
+@item %d
+Switch to signed integer mode. The expected argument is address of
+a @code{int} variable.
+@item %ld
+Switch to signed long integer mode. The expected argument is address of
+a @code{long} variable.
+@item %zu
+Switch to size_t mode. The expected argument is address of
+a @code{size_t} variable.
 @item ?
 If immediately following a parameter letter (no white space allowed),
 that parameter is considered optional.
diff --git a/src/sexp.c b/src/sexp.c
index 17341ba5..4697f77e 100644
--- a/src/sexp.c
+++ b/src/sexp.c
@@ -2246,11 +2246,17 @@ _gcry_sexp_canon_len (const unsigned char *buffer, size_t length,
  * names of these parameters are given by the string LIST.  Some
  * special characters may be given to control the conversion:
  *
- *    + :: Switch to unsigned integer format (default).
- *    - :: Switch to standard signed format.
- *    / :: Switch to opaque format.
- *    & :: Switch to buffer descriptor mode - see below.
- *    ? :: The previous parameter is optional.
+ *   +   :: Switch to unsigned integer format (default).
+ *   -   :: Switch to standard signed format.
+ *   /   :: Switch to opaque format
+ *   &   :: Switch to buffer descriptor mode - see below.
+ *   %s  :: Switch to allocated string arguments.
+ *   %u  :: Switch to unsigned integer arguments.
+ *   %lu :: Switch to unsigned long integer arguments.
+ *   %zu :: Switch to size_t arguments.
+ *   %d  :: Switch to signed integer arguments.
+ *   %ld :: Switch to signed long integer arguments.
+ *   ?   :: The previous parameter is optional.
  *
  * In general parameter names are single letters.  To use a string for
  * a parameter name, enclose the name in single quotes.
@@ -2293,13 +2299,22 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
 {
   gpg_err_code_t rc;
   const char *s, *s2;
-  gcry_mpi_t *array[20];
+  void **array[20];
   char arrayisdesc[20];
   int idx;
   gcry_sexp_t l1 = NULL;
   int mode = '+'; /* Default to GCRYMPI_FMT_USG.  */
+  int submode = 0;
   gcry_sexp_t freethis = NULL;
-
+  char *tmpstr = NULL;
+
+  /* Values in ARRAYISDESC describing what the ARRAY holds.
+   *  0  - MPI
+   *  1  - gcry_buffer_t provided by caller.
+   *  2  - gcry_buffer_t allocated by us.
+   * 's' - String allocated by us.
+   * 'x' - Ignore
+   */
   memset (arrayisdesc, 0, sizeof arrayisdesc);
 
   /* First copy all the args into an array.  This is required so that
@@ -2309,6 +2324,15 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
     {
       if (*s == '&' || *s == '+' || *s == '-' || *s == '/' || *s == '?')
         ;
+      else if (*s == '%')
+        {
+          s++;
+          if (*s == 'l' && (s[1] == 'u' || s[1] == 'd'))
+            s++;
+          else if (*s == 'z' && s[1] == 'u')
+            s++;
+          continue;
+        }
       else if (whitespacep (s))
         ;
       else
@@ -2324,7 +2348,7 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
                 }
               s = s2;
             }
-          array[idx] = va_arg (arg_ptr, gcry_mpi_t *);
+          array[idx] = va_arg (arg_ptr, void *);
           if (!array[idx])
             return GPG_ERR_MISSING_VALUE; /* NULL pointer given.  */
           idx++;
@@ -2368,6 +2392,30 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
     {
       if (*s == '&' || *s == '+' || *s == '-' || *s == '/')
         mode = *s;
+      else if (*s == '%')
+        {
+          s++;
+          if (!*s)
+            continue;  /* Ignore at end of format.  */
+          if (*s == 's' || *s == 'd' || *s == 'u')
+            {
+              mode = *s;
+              submode = 0;
+            }
+          else if (*s == 'l' && (s[1] == 'u' || s[1] == 'd'))
+            {
+              mode = s[1];
+              submode = 'l';
+              s++;
+            }
+          else if (*s == 'z' && s[1] == 'u')
+            {
+              mode = s[1];
+              submode = 'z';
+              s++;
+            }
+          continue;
+        }
       else if (whitespacep (s))
         ;
       else if (*s == '?')
@@ -2404,6 +2452,29 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
                     }
                   spec->len = 0;
                 }
+              else if (mode == 's')
+                {
+                  *array[idx] = NULL;
+                  arrayisdesc[idx] = 's';
+                }
+              else if (mode == 'd')
+                {
+                  if (submode == 'l')
+                    *(long *)array[idx] = 0;
+                  else
+                    *(int *)array[idx] = 0;
+                  arrayisdesc[idx] = 'x';
+                }
+              else if (mode == 'u')
+                {
+                  if (submode == 'l')
+                    *(unsigned long *)array[idx] = 0;
+                  else if (submode == 'z')
+                    *(size_t *)array[idx] = 0;
+                  else
+                    *(unsigned int *)array[idx] = 0;
+                  arrayisdesc[idx] = 'x';
+                }
               else
                 *array[idx] = NULL;
             }
@@ -2451,27 +2522,79 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
                       arrayisdesc[idx] = 2;
                     }
                 }
-              else if (mode == '/')
-                *array[idx] = _gcry_sexp_nth_mpi (l1, 1, GCRYMPI_FMT_OPAQUE);
-              else if (mode == '-')
-                *array[idx] = _gcry_sexp_nth_mpi (l1, 1, GCRYMPI_FMT_STD);
+              else if (mode == 's')
+                {
+                  *array[idx] = _gcry_sexp_nth_string (l1, 1);
+                  if (!*array[idx])
+                    {
+                      rc = gpg_err_code_from_syserror ();
+                      goto cleanup;
+                    }
+                  arrayisdesc[idx] = 's';
+                }
+              else if (mode == 'd')
+                {
+                  long along;
+
+                  xfree (tmpstr);
+                  tmpstr = _gcry_sexp_nth_string (l1, 1);
+                  if (!tmpstr)
+                    {
+                      rc = gpg_err_code_from_syserror ();
+                      goto cleanup;
+                    }
+                  along = strtol (tmpstr, NULL, 10);
+                  if (submode == 'l')
+                    *(long *)array[idx] = along;
+                  else
+                    *(int *)array[idx] = along;
+                  arrayisdesc[idx] = 'x';
+                }
+              else if (mode == 'u')
+                {
+                  long aulong;
+
+                  xfree (tmpstr);
+                  tmpstr = _gcry_sexp_nth_string (l1, 1);
+                  if (!tmpstr)
+                    {
+                      rc = gpg_err_code_from_syserror ();
+                      goto cleanup;
+                    }
+                  aulong = strtoul (tmpstr, NULL, 10);
+                  if (submode == 'l')
+                    *(unsigned long *)array[idx] = aulong;
+                  else if (submode == 'z')
+                    *(size_t *)array[idx] = aulong;
+                  else
+                    *(unsigned int *)array[idx] = aulong;
+                  arrayisdesc[idx] = 'x';
+                }
               else
-                *array[idx] = _gcry_sexp_nth_mpi (l1, 1, GCRYMPI_FMT_USG);
-              sexp_release (l1); l1 = NULL;
-              if (!*array[idx])
                 {
-                  rc = GPG_ERR_INV_OBJ;  /* Conversion failed.  */
-                  goto cleanup;
+                  if (mode == '/')
+                    *array[idx] = _gcry_sexp_nth_mpi (l1,1,GCRYMPI_FMT_OPAQUE);                  else if (mode == '-')
+                    *array[idx] = _gcry_sexp_nth_mpi (l1,1,GCRYMPI_FMT_STD);
+                  else
+                    *array[idx] = _gcry_sexp_nth_mpi (l1,1,GCRYMPI_FMT_USG);
+                  if (!*array[idx])
+                    {
+                      rc = GPG_ERR_INV_OBJ;  /* Conversion failed.  */
+                      goto cleanup;
+                    }
                 }
+              sexp_release (l1); l1 = NULL;
             }
           idx++;
         }
     }
 
+  xfree (tmpstr);
   sexp_release (freethis);
   return 0;
 
  cleanup:
+  xfree (tmpstr);
   sexp_release (freethis);
   sexp_release (l1);
   while (idx--)
@@ -2487,7 +2610,7 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
           gcry_buffer_t *spec = (gcry_buffer_t*)array[idx];
           spec->len = 0;
         }
-      else
+      else if (arrayisdesc[idx] == 2)
         {
           /* We might have allocated a buffer.  */
           gcry_buffer_t *spec = (gcry_buffer_t*)array[idx];
@@ -2495,6 +2618,12 @@ _gcry_sexp_vextract_param (gcry_sexp_t sexp, const char *path,
           spec->data = NULL;
           spec->size = spec->off = spec->len = 0;
         }
+      else if (arrayisdesc[idx] == 's')
+        {
+          /* We might have allocated a buffer.  */
+          xfree (*array[idx]);
+          *array[idx] = NULL;
+        }
      }
   return rc;
 }
diff --git a/tests/t-sexp.c b/tests/t-sexp.c
index 93a8d43d..94a97e17 100644
--- a/tests/t-sexp.c
+++ b/tests/t-sexp.c
@@ -608,7 +608,7 @@ static void
 check_extract_param (void)
 {
   /* This sample data is a real key but with some parameters of the
-     public key modified.  */
+     public key modified.  u,i,I are used for direct extraction tests. */
   static char sample1[] =
     "(key-data"
     " (public-key"
@@ -624,6 +624,10 @@ check_extract_param (void)
     "   (q #20B37806015CA06B3AEB9423EE84A41D7F31AA65F4148553755206D679F8BF62#)"
     "))"
     " (private-key"
+    "  (u +65537)"
+    "  (i +65537)"
+    "  (I -65535)"
+    "  (i0 1:0)"
     "  (ecc"
     "   (curve Ed25519)"
     "   (p #7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED#)"
@@ -820,6 +824,12 @@ check_extract_param (void)
   gcry_mpi_t mpis[7];
   gcry_buffer_t ioarray[7];
   char iobuffer[200];
+  char *string1, *string2;
+  int aint0, aint1, aint2;
+  unsigned int auint;
+  long along1, along2;
+  unsigned long aulong;
+  size_t asize;
 
   info ("checking gcry_sexp_extract_param\n");
   for (idx=0; tests[idx].sexp_str; idx++)
@@ -1070,8 +1080,70 @@ check_extract_param (void)
       gcry_sexp_release (sxp1);
     }
 
+  info ("checking gcry_sexp_extract_param new modes\n");
+
+  memset (mpis, 0, sizeof mpis);
+
   gcry_sexp_release (sxp);
+  err = gcry_sexp_new (&sxp, sample1, 0, 1);
+  if (err)
+    die ("converting string to sexp failed: %s", gpg_strerror (err));
+
+  err = gcry_sexp_extract_param (sxp, "key-data!private-key",
+                                 "%s'curve'+p%s'comment'"
+                                 "%uu%di%dI%d'i0'"
+                                 "%luu%ldi %ldI"
+                                 "%zui",
+                                 &string1, mpis+0, &string2,
+                                 &auint, &aint1, &aint2, &aint0,
+                                 &aulong, &along1, &along2,
+                                 &asize,
+                                 NULL);
+  if (err)
+    fail ("gcry_sexp_extract_param new modes failed: %s", gpg_strerror (err));
+
+  if (!string1)
+    fail ("gcry_sexp_extract_param new modes: no curve");
+  else if (strcmp (string1, "Ed25519"))
+    {
+      fail ("gcry_sexp_extract_param new modes failed: curve mismatch");
+      gcry_log_debug ("expected: %s\n", "Ed25519");
+      gcry_log_debug ("     got: %s\n", string1);
+    }
 
+  if (!mpis[0])
+    fail ("gcry_sexp_extract_param new modes failed: p not returned");
+  else if (cmp_mpihex (mpis[0], sample1_p))
+    {
+      fail ("gcry_sexp_extract_param new modes failed: p mismatch");
+      gcry_log_debug    ("expected: %s\n", sample1_p);
+      gcry_log_debugmpi ("     got", mpis[0]);
+    }
+
+  if (auint != 65537)
+    fail ("gcry_sexp_extract_param new modes failed: auint mismatch");
+  if (aint1 != 65537)
+    fail ("gcry_sexp_extract_param new modes failed: aint1 mismatch");
+  if (aint2 != -65535)
+    fail ("gcry_sexp_extract_param new modes failed: aint2 mismatch");
+  if (aint0)
+    fail ("gcry_sexp_extract_param new modes failed: aint0 mismatch");
+  if (aulong != 65537)
+    fail ("gcry_sexp_extract_param new modes failed: aulong mismatch");
+  if (along1 != 65537)
+    fail ("gcry_sexp_extract_param new modes failed: along1 mismatch");
+  if (along2 != -65535)
+    fail ("gcry_sexp_extract_param new modes failed: along2 mismatch");
+  if (asize != 65537)
+    fail ("gcry_sexp_extract_param new modes failed: asize mismatch");
+
+
+  gcry_free (string1);
+  gcry_free (string2);
+  gcry_mpi_release (mpis[0]);
+
+
+  gcry_sexp_release (sxp);
 }
 
 
@@ -1151,6 +1223,7 @@ int
 main (int argc, char **argv)
 {
   int last_argc = -1;
+  int loop = 0;
 
   if (argc)
     {
@@ -1185,6 +1258,15 @@ main (int argc, char **argv)
           verbose = debug = 1;
           argc--; argv++;
         }
+      else if (!strcmp (*argv, "--loop"))
+        {
+          argc--; argv++;
+          if (argc)
+            {
+              loop = atoi (*argv);
+              argc--; argv++;
+            }
+        }
       else if (!strncmp (*argv, "--", 2))
         die ("unknown option '%s'", *argv);
     }
@@ -1202,12 +1284,16 @@ main (int argc, char **argv)
   xgcry_control ((GCRYCTL_ENABLE_QUICK_RANDOM, 0));
   xgcry_control ((GCRYCTL_INITIALIZATION_FINISHED, 0));
 
-  basic ();
-  canon_len ();
-  back_and_forth ();
-  check_sscan ();
-  check_extract_param ();
-  bug_1594 ();
+  do
+    {
+      basic ();
+      canon_len ();
+      back_and_forth ();
+      check_sscan ();
+      check_extract_param ();
+      bug_1594 ();
+    }
+  while (!error_count && loop--);
 
   return error_count? 1:0;
 }