* asn1buf.h: New prototpyes for asn1buf_sync() and

	asn1buf_skiptail().

	* asn1buf.c (asn1buf_sync): Fix to deal with
	constructed-indefinite encodings with trailing fields.  As a
	result, this requires that the most recently read tag number be
	passed in.
	(asn1buf_skiptail): New helper function to skip trailing fields in
	a constructed-indefinite encoding.

	* krb5_decode.c (end_structure): Hack to deal with changed
	asn1buf_sync().

	* asn1_k_decode.c (end_structure, end_sequence_of): Hack to deal
	with changed asn1buf_sync().

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@11541 dc483132-0cff-0310-8789-dd5450dbe970

5 files changed, 71 insertions, 10 deletions

diff --git a/src/lib/krb5/asn.1/ChangeLog b/src/lib/krb5/asn.1/ChangeLog
index 33940ce20..4b4d31847 100644
--- a/src/lib/krb5/asn.1/ChangeLog
+++ b/src/lib/krb5/asn.1/ChangeLog
@@ -1,3 +1,21 @@
+1999-07-03  Tom Yu  <tlyu@mit.edu>
+
+	* asn1buf.h: New prototpyes for asn1buf_sync() and
+	asn1buf_skiptail().
+
+	* asn1buf.c (asn1buf_sync): Fix to deal with
+	constructed-indefinite encodings with trailing fields.  As a
+	result, this requires that the most recently read tag number be
+	passed in.
+	(asn1buf_skiptail): New helper function to skip trailing fields in
+	a constructed-indefinite encoding.
+
+	* krb5_decode.c (end_structure): Hack to deal with changed
+	asn1buf_sync().
+
+	* asn1_k_decode.c (end_structure, end_sequence_of): Hack to deal
+	with changed asn1buf_sync().
+
 1999-06-30  Tom Yu  <tlyu@mit.edu>
 
 	* asn1buf.c (asn1buf_sync): Interim fix for DCE compat problem
diff --git a/src/lib/krb5/asn.1/asn1_k_decode.c b/src/lib/krb5/asn.1/asn1_k_decode.c
index 090fcc3d9..875db9ade 100644
--- a/src/lib/krb5/asn.1/asn1_k_decode.c
+++ b/src/lib/krb5/asn.1/asn1_k_decode.c
@@ -56,7 +56,7 @@ if(class != APPLICATION || construction != CONSTRUCTED ||\
 #define get_field_body(var,decoder)\
 retval = decoder(&subbuf,&(var));\
 if(retval) return retval;\
-if(!taglen) next_tag();\
+if(!taglen) { next_tag(); }\
 next_tag()
 
 #define get_field(var,tagexpect,decoder)\
@@ -73,7 +73,7 @@ else var = optvalue
 #define get_lenfield_body(len,var,decoder)\
 retval = decoder(&subbuf,&(len),&(var));\
 if(retval) return retval;\
-if(!taglen) next_tag();\
+if(!taglen) { next_tag(); }\
 next_tag()
 
 #define get_lenfield(len,var,tagexpect,decoder)\
@@ -98,7 +98,8 @@ if(retval) return retval;\
 next_tag()
 
 #define end_structure()\
-asn1buf_sync(buf,&subbuf)
+retval = asn1buf_sync(buf,&subbuf,tagnum);\
+if(retval) return retval
 
 #define sequence_of(buf)\
 int size=0;\
@@ -110,7 +111,8 @@ retval = asn1buf_imbed(&seqbuf,buf,length);\
 if(retval) return retval
 
 #define end_sequence_of(buf)\
-asn1buf_sync(buf,&seqbuf)
+retval = asn1buf_sync(buf,&seqbuf,ASN1_TAGNUM_CEILING);\
+if(retval) return retval
 
 #define cleanup()\
 return 0
diff --git a/src/lib/krb5/asn.1/asn1buf.c b/src/lib/krb5/asn.1/asn1buf.c
index 785b14091..648626ee5 100644
--- a/src/lib/krb5/asn.1/asn1buf.c
+++ b/src/lib/krb5/asn.1/asn1buf.c
@@ -52,6 +52,7 @@
 #include "asn1buf.h"
 #undef ASN1BUF_OMIT_INLINE_FUNCS
 #include <stdio.h>
+#include "asn1_get.h"
 
 asn1_error_code asn1buf_create(buf)
      asn1buf ** buf;
@@ -89,19 +90,51 @@ asn1_error_code asn1buf_imbed(subbuf, buf, length)
   return 0;
 }
 
-void asn1buf_sync(buf, subbuf)
+asn1_error_code asn1buf_sync(buf, subbuf, lasttag)
      asn1buf * buf;
      asn1buf * subbuf;
+     asn1_tagnum lasttag;
 {
+  asn1_error_code retval;
+
   if (subbuf->bound != buf->bound) {
     buf->next = subbuf->bound + 1;
   } else {
     /*
-     * indefinite length; this will suck
-     * XXX - need to skip fields somehow
+     * indefinite length:
+     *
+     * Note that asn1_get_tag() returns ASN1_TAGNUM_CEILING
+     * for an EOC encoding.
      */
+    if (lasttag != ASN1_TAGNUM_CEILING) {
+      retval = asn1buf_skiptail(subbuf);
+      if (retval) return retval;
+    }
     buf->next = subbuf->next;
   }
+  return 0;
+}
+
+asn1_error_code asn1buf_skiptail(buf)
+     asn1buf *buf;
+{
+  asn1_error_code retval;
+  asn1_class class;
+  asn1_construction construction;
+  asn1_tagnum tagnum;
+  int taglen;
+  int nestlevel;
+
+  nestlevel = 1;
+  while (nestlevel > 0) {
+    retval = asn1_get_tag(buf, &class, &construction, &tagnum, &taglen);
+    if (retval) return retval;
+    if (construction == CONSTRUCTED && taglen == 0)
+      nestlevel++;
+    if (tagnum == ASN1_TAGNUM_CEILING)
+      nestlevel--;
+  }
+  return 0;
 }
 
 asn1_error_code asn1buf_destroy(buf)
diff --git a/src/lib/krb5/asn.1/asn1buf.h b/src/lib/krb5/asn.1/asn1buf.h
index 8103b9e03..1d7373ed0 100644
--- a/src/lib/krb5/asn.1/asn1buf.h
+++ b/src/lib/krb5/asn.1/asn1buf.h
@@ -119,11 +119,18 @@ asn1_error_code asn1buf_imbed
 	      that case, ASN1_OVERRUN is returned)  *subbuf's current
 	      position starts at the beginning of *subbuf. */
 
-void asn1buf_sync
-	PROTOTYPE((asn1buf *buf, asn1buf *subbuf));
+asn1_error_code asn1buf_sync
+	PROTOTYPE((asn1buf *buf, asn1buf *subbuf, asn1_tagnum lasttag));
 /* requires  *subbuf is a sub-buffer of *buf, as created by asn1buf_imbed.
+             lasttag is a pointer to the last tagnumber read.
    effects   Synchronizes *buf's current position to match that of *subbuf. */
 
+asn1_error_code asn1buf_skiptail
+	PROTOTYPE((asn1buf *buf));
+/* requires  *buf is a subbuffer used in a decoding of a
+             constructed indefinite sequence.
+   effects   skips trailing fields. */
+
 asn1_error_code asn1buf_destroy
 	PROTOTYPE((asn1buf **buf));
 /* effects   Deallocates **buf, sets *buf to NULL. */
diff --git a/src/lib/krb5/asn.1/krb5_decode.c b/src/lib/krb5/asn.1/krb5_decode.c
index 8896bea05..b0fe3160d 100644
--- a/src/lib/krb5/asn.1/krb5_decode.c
+++ b/src/lib/krb5/asn.1/krb5_decode.c
@@ -91,7 +91,8 @@ if(retval) clean_return(retval);\
 next_tag()
 
 #define end_structure()\
-asn1buf_sync(&buf,&subbuf)
+retval = asn1buf_sync(&buf,&subbuf,tagnum);\
+if (retval) clean_return(retval)
 
 /* process fields *******************************************/
 /* normal fields ************************/