Now uses generated ASN1-code.

kinit should be able to get a initial message from FOO.SE.


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@844 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/asn1/der_get.c

@@ -0,0 +1,239 @@
+/* $Id$ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdlib.h>
+#include <time.h>
+#include "der.h"
+
+/*
+ * All decoding functions take a pointer `p' to first position in
+ * which to read, from the left, `len' which means the maximum
+ * number of characters we are able to read and return an int
+ * indicating how many actually got read, or <0 in case of errors.
+ */
+
+int
+der_get_int (unsigned char *p, int len, int *ret)
+{
+  int val = 0;
+  int oldlen = len;
+
+  while (len--)
+    val = val * 256 + *p++;
+  *ret = val;
+  return oldlen;
+}
+
+int
+der_get_length (unsigned char *p, int len, int *ret)
+{
+  int val;
+
+  if (--len < 0)
+    return -1;
+  val = *p++;
+  if (val < 128) {
+    *ret = val;
+    return 1;
+  } else {
+    int l;
+
+    val &= 0x7F;
+    if (len < val)
+      return -1;
+    l = der_get_int (p, val, ret);
+    if (l < 0)
+      return l;
+    else
+      return l+1;
+  }
+}
+
+int
+der_get_general_string (unsigned char *p, int len, char **str)
+{
+  int l, slen;
+  char *s;
+
+  l = der_get_length (p, len, &slen);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  if (len < slen)
+    return -1;
+  s = malloc (slen + 1);
+  if (s == NULL)
+    return -1;
+  memcpy (s, p, slen);
+  s[slen] = '\0';
+  *str = s;
+  return slen + l;
+}
+
+int
+der_get_octet_string (unsigned char *p, int len, krb5_data *data)
+{
+  int l, slen;
+
+  l = der_get_length (p, len, &slen);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  if (len < slen)
+    return -1;
+  data->len = slen;
+  data->data = malloc(slen);
+  if (data->data == NULL)
+    return -1;
+  memcpy (data->data, p, slen);
+  return slen + l;
+}
+
+int
+der_get_tag (unsigned char *p, int len, Der_class *class, Der_type *type,
+	     int *tag)
+{
+  if (len < 1)
+    return -1;
+  *class = ((*p) >> 6) & 0x03;
+  *type = ((*p) >> 5) & 0x01;
+  *tag = (*p) & 0x1F;
+  return 1;
+}
+
+int
+der_match_tag (unsigned char *p, int len, Der_class class, Der_type type,
+	       int tag)
+{
+  int l;
+  Der_class thisclass;
+  Der_type thistype;
+  int thistag;
+
+  l = der_get_tag (p, len, &thisclass, &thistype, &thistag);
+  if (l < 0)
+    return l;
+  if (class == thisclass && type == thistype && tag == thistag)
+    return l;
+  else
+    return -1;
+}
+
+int
+decode_integer (unsigned char *p, int len, void *data)
+{
+  int *num = (int *)data;
+  int ret = 0;
+  int l, reallen;
+
+  l = der_match_tag (p, len, UNIV, PRIM, UT_Integer);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  l = der_get_length (p, len, &reallen);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  l = der_get_int (p, reallen, num);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  return ret;
+}
+
+int
+decode_general_string (unsigned char *p, int len, void *data)
+{
+  char **str = (char **)data;
+  int ret = 0;
+  int l;
+
+  l = der_match_tag (p, len, UNIV, PRIM, UT_GeneralString);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  l = der_get_general_string (p, len, str);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  return ret;
+}
+
+int
+decode_octet_string (unsigned char *p, int len, void *data)
+{
+  krb5_data *k = (krb5_data *)data;
+  int ret = 0;
+  int l;
+
+  l = der_match_tag (p, len, UNIV, PRIM, UT_OctetString);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  l = der_get_octet_string (p, len, k);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  return ret;
+}
+
+static void
+generalizedtime2time (char *s, time_t *t)
+{
+  struct tm tm;
+
+  sscanf (s, "%04d%02d%02d%02d%02d%02dZ",
+	  &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
+	  &tm.tm_min, &tm.tm_sec);
+  tm.tm_year -= 1900;
+  tm.tm_mon -= 1;
+  tm.tm_isdst = 0;
+
+  *t = mktime(&tm);
+#if 0 /* XXX */
+  *t -= timezone;
+#endif
+}
+
+int
+decode_generalized_time (unsigned char *p, int len, void *data)
+{
+  time_t *t = (time_t *)data;
+  krb5_data k;
+  int ret = 0;
+  int l;
+
+  l = der_match_tag (p, len, UNIV, PRIM, UT_GeneralizedTime);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  l = der_get_octet_string (p, len, &k);
+  if (l < 0)
+    return l;
+  p += l;
+  len -= l;
+  ret += l;
+  generalizedtime2time (k.data, t);
+  free (k.data);
+  return ret;
+}