Rewrite tagnum-checking code to streamline normal path and push refined

error code selection into error path.

Don't expand asn1buf_insert_octet inline or define asn1buf_ensure_space
macro if CONFIG_SMALL.

Remove some null-before-free checks.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@20626 dc483132-0cff-0310-8789-dd5450dbe970

5 files changed, 40 insertions, 33 deletions

diff --git a/src/lib/krb5/asn.1/asn1_k_decode.c b/src/lib/krb5/asn.1/asn1_k_decode.c
index bad4b00..ad4539e 100644
--- a/src/lib/krb5/asn.1/asn1_k_decode.c
+++ b/src/lib/krb5/asn.1/asn1_k_decode.c
@@ -103,6 +103,15 @@
   next_tag()
 
 /*
+ * error_if_bad_tag
+ *
+ * Checks that the next tag is the expected one; returns with an error
+ * if not.
+ */
+#define error_if_bad_tag(tagexpect) \
+  if (tagnum != (tagexpect)) { return (tagnum < (tagexpect)) ? ASN1_MISPLACED_FIELD : ASN1_MISSING_FIELD; }
+
+/*
  * get_field
  *
  * Get field having an expected context specific tag.  This assumes
@@ -110,8 +119,7 @@
  * verification of tag numbers.
  */
 #define get_field(var, tagexpect, decoder)				\
-  if (tagnum > (tagexpect)) return ASN1_MISSING_FIELD;			\
-  if (tagnum < (tagexpect)) return ASN1_MISPLACED_FIELD;		\
+  error_if_bad_tag(tagexpect);						\
   if ((asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)	\
       && (tagnum || taglen || asn1class != UNIVERSAL))			\
     return ASN1_BAD_ID;							\
@@ -146,8 +154,7 @@
 
 /* similar to get_field_body */
 #define get_lenfield(len, var, tagexpect, decoder)			\
-  if (tagnum > (tagexpect)) return ASN1_MISSING_FIELD;			\
-  if (tagnum < (tagexpect)) return ASN1_MISPLACED_FIELD;		\
+  error_if_bad_tag(tagexpect);						\
   if ((asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)	\
       && (tagnum || taglen || asn1class != UNIVERSAL))			\
     return ASN1_BAD_ID;							\
diff --git a/src/lib/krb5/asn.1/asn1buf.c b/src/lib/krb5/asn.1/asn1buf.c
index 8baac24..c78f4b9 100644
--- a/src/lib/krb5/asn.1/asn1buf.c
+++ b/src/lib/krb5/asn.1/asn1buf.c
@@ -143,7 +143,7 @@ asn1_error_code asn1buf_skiptail(asn1buf *buf, const unsigned int length, const
 asn1_error_code asn1buf_destroy(asn1buf **buf)
 {
   if (*buf != NULL) {
-    if ((*buf)->base != NULL) free((*buf)->base);
+    free((*buf)->base);
     free(*buf);
     *buf = NULL;
   }
@@ -273,7 +273,7 @@ asn1_error_code asn12krb5_buf(const asn1buf *buf, krb5_data **code)
 
 asn1_error_code asn1buf_unparse(const asn1buf *buf, char **s)
 {
-  if(*s != NULL) free(*s);
+  free(*s);
   if(buf == NULL){
     *s = malloc(sizeof("<NULL>"));
     if(*s == NULL) return ENOMEM;
@@ -301,7 +301,7 @@ asn1_error_code asn1buf_hex_unparse(const asn1buf *buf, char **s)
 		    ((d)<=15 ? ('A'+(d)-10) :\
 		    'X'))
 
-  if(*s != NULL) free(*s);
+  free(*s);
 
   if(buf == NULL){
     *s = malloc(sizeof("<NULL>"));
diff --git a/src/lib/krb5/asn.1/asn1buf.h b/src/lib/krb5/asn.1/asn1buf.h
index c9c956a..4936ed6 100644
--- a/src/lib/krb5/asn.1/asn1buf.h
+++ b/src/lib/krb5/asn.1/asn1buf.h
@@ -39,10 +39,12 @@ asn1_error_code asn1buf_ensure_space
    effects  If buf has less than amount octets of free space, then it is
             expanded to have at least amount octets of free space.
             Returns ENOMEM memory is exhausted. */
+#ifndef CONFIG_SMALL
 #define asn1buf_ensure_space(buf,amount) \
   ((asn1buf_free(buf) < (amount)) \
    ? (asn1buf_expand((buf), (amount)-asn1buf_free(buf))) \
    : 0)
+#endif
 
 
 asn1_error_code asn1buf_expand
@@ -146,7 +148,7 @@ asn1_error_code asn1buf_insert_octet
 /* requires  *buf is allocated
    effects   Inserts o into the buffer *buf, expanding the buffer if
              necessary.  Returns ENOMEM memory is exhausted. */
-#if ((__GNUC__ >= 2) && !defined(ASN1BUF_OMIT_INLINE_FUNCS))
+#if ((__GNUC__ >= 2) && !defined(ASN1BUF_OMIT_INLINE_FUNCS)) && !defined(CONFIG_SMALL)
 extern __inline__ asn1_error_code asn1buf_insert_octet(asn1buf *buf, const int o)
 {
   asn1_error_code retval;
diff --git a/src/lib/krb5/asn.1/krb5_decode.c b/src/lib/krb5/asn.1/krb5_decode.c
index cbd6a12..ea21f7e4 100644
--- a/src/lib/krb5/asn.1/krb5_decode.c
+++ b/src/lib/krb5/asn.1/krb5_decode.c
@@ -1,7 +1,7 @@
 /*
  * src/lib/krb5/asn.1/krb5_decode.c
  * 
- * Copyright 1994 by the Massachusetts Institute of Technology.
+ * Copyright 1994, 2008 by the Massachusetts Institute of Technology.
  * All Rights Reserved.
  *
  * Export of this software from the United States of America may
@@ -130,13 +130,21 @@ if(retval) clean_return(retval);\
 if (indef) { get_eoc(); }\
 next_tag()
 
+/*
+ * error_if_bad_tag
+ *
+ * Checks that the next tag is the expected one; returns with an error
+ * if not.
+ */
+#define error_if_bad_tag(tagexpect) \
+  if (tagnum != (tagexpect)) { clean_return ((tagnum < (tagexpect)) ? ASN1_MISPLACED_FIELD : ASN1_MISSING_FIELD); }
+
 /* decode a field (<[UNIVERSAL id]> <length> <contents>)
     check that the id number == tagexpect then
     decode into var
     get the next tag */
 #define get_field(var,tagexpect,decoder)\
-if(tagnum > (tagexpect)) clean_return(ASN1_MISSING_FIELD);\
-if(tagnum < (tagexpect)) clean_return(ASN1_MISPLACED_FIELD);\
+error_if_bad_tag(tagexpect);\
 if(asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)\
   clean_return(ASN1_BAD_ID);\
 get_field_body(var,decoder)
@@ -160,8 +168,7 @@ next_tag()
 
 /* decode a field w/ its length (for string types) */
 #define get_lenfield(len,var,tagexpect,decoder)\
-if(tagnum > (tagexpect)) clean_return(ASN1_MISSING_FIELD);\
-if(tagnum < (tagexpect)) clean_return(ASN1_MISPLACED_FIELD);\
+error_if_bad_tag(tagexpect);\
 if(asn1class != CONTEXT_SPECIFIC || construction != CONSTRUCTED)\
   clean_return(ASN1_BAD_ID);\
 get_lenfield_body(len,var,decoder)
@@ -197,7 +204,7 @@ error_out: \
 #define cleanup_manual()\
    return 0;
 
-#define free_field(rep,f) if ((rep)->f) free((rep)->f)
+#define free_field(rep,f) free((rep)->f)
 #define clear_field(rep,f) (*(rep))->f = 0
 
 krb5_error_code decode_krb5_authenticator(const krb5_data *code, krb5_authenticator **rep)
@@ -1034,10 +1041,8 @@ krb5_error_code decode_krb5_reply_key_pack(const krb5_data *code, krb5_reply_key
   cleanup_manual();
 error_out:
   if (rep && *rep) {
-    if ((*rep)->replyKey.contents)
-	free((*rep)->replyKey.contents);
-    if ((*rep)->asChecksum.contents)
-      free((*rep)->asChecksum.contents);
+    free((*rep)->replyKey.contents);
+    free((*rep)->asChecksum.contents);
     free(*rep);
     *rep = NULL;
   }
diff --git a/src/lib/krb5/asn.1/ldap_key_seq.c b/src/lib/krb5/asn.1/ldap_key_seq.c
index b910e72..6d0ef1a 100644
--- a/src/lib/krb5/asn.1/ldap_key_seq.c
+++ b/src/lib/krb5/asn.1/ldap_key_seq.c
@@ -206,8 +206,7 @@ last:
     asn1buf_destroy (&buf);
 
     if (ret != 0 && *code != NULL) {
-        if ((*code)->data != NULL)
-            free ((*code)->data);
+	free ((*code)->data);
         free (*code);
     }
 
@@ -301,7 +300,7 @@ decode_tagged_octetstring (asn1buf *buf, asn1_tagnum expectedtag, int *len,
     *buf = tmp;
 
 last:
-    if (ret != 0 && *val != NULL)
+    if (ret != 0)
 	free (*val);
     return ret;
 }
@@ -379,14 +378,10 @@ static asn1_error_code asn1_decode_key(asn1buf *buf, krb5_key_data *key)
 
 last:
     if (ret != 0) {
-	if (key->key_data_contents[0] != NULL) {
-	    free (key->key_data_contents[0]);
-	    key->key_data_contents[0] = NULL;
-	}
-	if (key->key_data_contents[1] != NULL) {
-	    free (key->key_data_contents[1]);
-	    key->key_data_contents[1] = NULL;
-	}
+	free (key->key_data_contents[0]);
+	key->key_data_contents[0] = NULL;
+	free (key->key_data_contents[1]);
+	key->key_data_contents[1] = NULL;
     }
     return ret;
 }
@@ -467,10 +462,8 @@ last:
     if (ret != 0) {
 	int i;
 	for (i = 0; i < *n_key_data; i++) {
-	    if ((*out)[i].key_data_contents[0] != NULL)
-		free ((*out)[i].key_data_contents[0]);
-	    if ((*out)[i].key_data_contents[1] != NULL)
-		free ((*out)[i].key_data_contents[1]);
+	    free ((*out)[i].key_data_contents[0]);
+	    free ((*out)[i].key_data_contents[1]);
 	}
 	free (*out);
 	*out = NULL;