(sexp_iterator_get_uint32): New function.

Rev: src/nettle/sexp.c:1.12
Rev: src/nettle/sexp.h:1.9

diff --git a/sexp.c b/sexp.c
index b35f9cb1b8f597addd1de7e213c0293b19829800..1e0934855f0c43da6f607ef18851c9d955e03dfa 100644 (file)
--- a/sexp.c
+++ b/sexp.c
@@ -25,6 +25,8 @@
 
 #include "sexp.h"
 
+#include "macros.h"
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -222,6 +224,48 @@ sexp_iterator_subexpr(struct sexp_iterator *iterator,
   return iterator->buffer + start;
 }
 
+int
+sexp_iterator_get_uint32(struct sexp_iterator *iterator,
+                        uint32_t *x)
+{
+  if (iterator->type == SEXP_ATOM
+      && !iterator->display
+      && iterator->atom_length
+      && iterator->atom[0] < 0x80)
+    {
+      unsigned length = iterator->atom_length;
+      const uint8_t *p = iterator->atom;
+
+      /* Skip leading zeros. */
+      while(length && !*p)
+       {
+         length--; p++;
+       }
+
+      switch(length)
+       {
+       case 0:
+         *x = 0;
+         break;
+       case 1:
+         *x = p[0];
+         break;
+       case 2:
+         *x = READ_UINT16(p);
+         break;
+       case 3:
+         *x = READ_UINT24(p);
+         break;
+       case 4:
+         *x = READ_UINT32(p);
+         break;
+       default:
+         return 0;
+       }
+      return sexp_iterator_next(iterator);
+    }
+  return 0;
+}
 
 int
 sexp_iterator_check_type(struct sexp_iterator *iterator,

diff --git a/sexp.h b/sexp.h
index 72bbae9c7d59f43e5704d68ddedb4d40ae2d6053..074c7c8f242473aacdb445a88618130e010168a9 100644 (file)
--- a/sexp.h
+++ b/sexp.h
@@ -83,6 +83,10 @@ const uint8_t *
 sexp_iterator_subexpr(struct sexp_iterator *iterator,
                      unsigned *length);
 
+int
+sexp_iterator_get_uint32(struct sexp_iterator *iterator,
+                        uint32_t *x);
+
 \f
 /* Checks the type of the current expression, which should be a list
  *