Rewrite asn1_get_tag interface to use a structure pointer rather than several

pointer variables for the returned data.  Use the structure in the caller when
straightforward; in cases where macros use different but overlapping sets of
automatic scalar variables in one file, copy the values out of the structures
for now, until they can be analyzed more carefully.

* asn1_get.c (asn1_get_tag): Deleted.
(asn1_get_tag_2): Renamed from asn1_get_tag_indef, now uses a pointer to
taginfo rather than a bunch of pointer args.
(asn1_get_id, asn1_get_length): Folded into asn1_get_tag_2.
(asn1_get_sequence): Call asn1_get_tag_2.
* asn1_get.h (taginfo): New structure.
(asn1_get_tag_indef, asn1_get_tag, asn1_get_id, asn1_get_length): Declarations
deleted.
(asn1_get_tag_2): Declare.
* asn1_decode.c (setup): Declare only a taginfo variable.
(asn1class, construction, tagnum, length): New macros.
(tag): Call asn1_get_tag_2.
* asn1_k_decode.c (next_tag, get_eoc, apptag, end_sequence_of,
end_sequence_of_no_tagvars, asn1_decode_krb5_flags): Call asn1_get_tag_2; if no
error, copy out values into scalar variables.
(asn1_decode_ticket): Call asn1_get_tag_2.
* asn1buf.c (asn1buf_skiptail): Call asn1_get_tag_2.
* krb5_decode.c (check_apptag, next_tag, get_eoc): Call asn1_get_tag_2; if no
error, copy out values into scalar variables.
(decode_krb5_enc_kdc_rep_part): Call asn1_get_tag_2.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@15274 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 79 insertions, 36 deletions

diff --git a/src/lib/krb5/asn.1/asn1_k_decode.c b/src/lib/krb5/asn.1/asn1_k_decode.c
index 0917d71..c64ebb8 100644
--- a/src/lib/krb5/asn.1/asn1_k_decode.c
+++ b/src/lib/krb5/asn.1/asn1_k_decode.c
@@ -40,29 +40,52 @@
 #define unused_var(x) if (0) { x = 0; x = x - x; }
 
 /* This is used for prefetch of next tag in sequence. */
-#define next_tag()							\
-  retval = asn1_get_tag_indef(&subbuf, &asn1class, &construction,	\
-			      &tagnum, &taglen, &indef);		\
-  if (retval) return retval;
+#define next_tag()								\
+{ taginfo t2;									\
+  retval = asn1_get_tag_2(&subbuf, &t2);					\
+  if (retval) return retval;							\
+  /* Copy out to match previous functionality, until better integrated.  */	\
+  asn1class = t2.asn1class;							\
+  construction = t2.construction;						\
+  tagnum = t2.tagnum;								\
+  taglen = t2.length;								\
+  indef = t2.indef;								\
+}
 
 /* Force check for EOC tag. */
-#define get_eoc()							\
-  retval = asn1_get_tag_indef(&subbuf, &asn1class, &construction,	\
-			      &tagnum, &taglen, &indef);		\
-  if (retval) return retval;						\
-  if (asn1class != UNIVERSAL || tagnum || indef)			\
-    return ASN1_MISSING_EOC
+#define get_eoc()									\
+    {											\
+	taginfo t3;									\
+	retval = asn1_get_tag_2(&subbuf, &t3);						\
+	if(retval) return retval;							\
+        if (t3.asn1class != UNIVERSAL || t3.tagnum || t3.indef)				\
+	    return ASN1_MISSING_EOC;							\
+        /* Copy out to match previous functionality, until better integrated.  */	\
+	asn1class = t3.asn1class;							\
+	construction = t3.construction;							\
+	tagnum = t3.tagnum;								\
+	taglen = t3.length;								\
+	indef = t3.indef;								\
+    }
 
 #define alloc_field(var, type)			\
   var = (type*)calloc(1, sizeof(type));		\
   if ((var) == NULL) return ENOMEM
 
 /* Fetch an expected APPLICATION class tag and verify. */
-#define apptag(tagexpect)						   \
-  retval = asn1_get_tag(buf, &asn1class, &construction, &tagnum, &applen); \
-  if (retval) return retval;						   \
-  if (asn1class != APPLICATION || construction != CONSTRUCTED ||	   \
-      tagnum != (tagexpect)) return ASN1_BAD_ID
+#define apptag(tagexpect)								\
+  {											\
+      taginfo t1;									\
+      retval = asn1_get_tag_2(buf, &t1);						\
+      if (retval) return retval;						   	\
+      if (t1.asn1class != APPLICATION || t1.construction != CONSTRUCTED ||	   	\
+	  t1.tagnum != (tagexpect)) return ASN1_BAD_ID;					\
+      /* Copy out to match previous functionality, until better integrated.  */		\
+      asn1class = t1.asn1class;								\
+      construction = t1.construction;							\
+      tagnum = t1.tagnum;								\
+      applen = t1.length;								\
+  }
 
 /**** normal fields ****/
 
@@ -211,12 +234,20 @@
  * Attempts to fetch an EOC tag, if any, and to sync over trailing
  * garbage, if any.
  */
-#define end_sequence_of(buf)						\
-  retval = asn1_get_tag_indef(&seqbuf, &asn1class, &construction,	\
-			      &tagnum, &taglen, &indef);		\
-  if (retval) return retval;						\
-  retval = asn1buf_sync(buf, &seqbuf, asn1class, tagnum,		\
-			length, indef, seqofindef);			\
+#define end_sequence_of(buf)							\
+  {										\
+      taginfo t4;								\
+      retval = asn1_get_tag_2(&seqbuf, &t4);					\
+      if (retval) return retval;						\
+      /* Copy out to match previous functionality, until better integrated.  */	\
+      asn1class = t4.asn1class;							\
+      construction = t4.construction;						\
+      tagnum = t4.tagnum;							\
+      taglen = t4.length;							\
+      indef = t4.indef;								\
+  }										\
+  retval = asn1buf_sync(buf, &seqbuf, asn1class, tagnum,			\
+			length, indef, seqofindef);				\
   if (retval) return retval;
 
 /*
@@ -225,12 +256,20 @@
  * Like end_sequence_of(), but uses the different (non-shadowing)
  * variable names.
  */
-#define end_sequence_of_no_tagvars(buf)				\
-  retval = asn1_get_tag_indef(&seqbuf, &eseqclass, &eseqconstr,	\
-			      &eseqnum, &eseqlen, &eseqindef);	\
-  if (retval) return retval;					\
-  retval = asn1buf_sync(buf, &seqbuf, eseqclass, eseqnum,	\
-			eseqlen, eseqindef, seqofindef);	\
+#define end_sequence_of_no_tagvars(buf)						\
+  {										\
+      taginfo t5;								\
+      retval = asn1_get_tag_2(&seqbuf, &t5);					\
+      if (retval) return retval;						\
+      /* Copy out to match previous functionality, until better integrated.  */	\
+      eseqclass = t5.asn1class;							\
+      eseqconstr = t5.construction;						\
+      eseqnum = t5.tagnum;							\
+      eseqlen = t5.length;							\
+      eseqindef = t5.indef;							\
+  }										\
+  retval = asn1buf_sync(buf, &seqbuf, eseqclass, eseqnum,			\
+			eseqlen, eseqindef, seqofindef);			\
   if (retval) return retval;
 
 #define cleanup()				\
@@ -374,16 +413,19 @@ asn1_error_code asn1_decode_encrypted_data(asn1buf *buf, krb5_enc_data *val)
 
 asn1_error_code asn1_decode_krb5_flags(asn1buf *buf, krb5_flags *val)
 {
-  setup();
+  asn1_error_code retval;
   asn1_octet unused, o;
+  taginfo t;
   int i;
   krb5_flags f=0;
-  unused_var(taglen);
+  unsigned int length;
 
-  retval = asn1_get_tag(buf,&asn1class,&construction,&tagnum,&length);
-  if(retval) return retval;
-  if(asn1class != UNIVERSAL || construction != PRIMITIVE ||
-     tagnum != ASN1_BITSTRING) return ASN1_BAD_ID;
+  retval = asn1_get_tag_2(buf, &t);
+  if (retval) return retval;
+  if (t.asn1class != UNIVERSAL || t.construction != PRIMITIVE ||
+      t.tagnum != ASN1_BITSTRING)
+      return ASN1_BAD_ID;
+  length = t.length;
 
   retval = asn1buf_remove_octet(buf,&unused); /* # of padding bits */
   if(retval) return retval;
@@ -472,9 +514,10 @@ asn1_error_code asn1_decode_ticket(asn1buf *buf, krb5_ticket *val)
     end_structure();
     val->magic = KV5M_TICKET;
   }
-  if(!applen) {
-    retval = asn1_get_tag(buf,&asn1class,&construction,&tagnum,NULL);
-    if (retval) return retval;
+  if (!applen) {
+      taginfo t;
+      retval = asn1_get_tag_2(buf, &t);
+      if (retval) return retval;
   }
   cleanup();
 }