Add ASN.1 ADB callback.

Add support for application supplied any defined by callback. An
application can change the selector value if it wishes. This is
mainly intended for values which are only known at runtime, for
example dynamically created OIDs.
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/asn1/tasn_utl.c

@@ -243,6 +243,12 @@ const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,
     else
         selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);
 
+    /* Let application callback translate value */
+    if (adb->adb_cb != NULL && adb->adb_cb(&selector) == 0) {
+        ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);
+        return NULL;
+    }
+
     /*
      * Try to find matching entry in table Maybe should check application
      * types first to allow application override? Might also be useful to

include/openssl/asn1t.h

@@ -463,12 +463,12 @@ extern "C" {
 
 # ifndef OPENSSL_EXPORT_VAR_AS_FUNCTION
 
-#  define ASN1_ADB_END(name, flags, field, app_table, def, none) \
+#  define ASN1_ADB_END(name, flags, field, adb_cb, def, none) \
         ;\
         static const ASN1_ADB name##_adb = {\
                 flags,\
                 offsetof(name, field),\
-                app_table,\
+                adb_cb,\
                 name##_adbtbl,\
                 sizeof(name##_adbtbl) / sizeof(ASN1_ADB_TABLE),\
                 def,\
@@ -477,7 +477,7 @@ extern "C" {
 
 # else
 
-#  define ASN1_ADB_END(name, flags, field, app_table, def, none) \
+#  define ASN1_ADB_END(name, flags, field, adb_cb, def, none) \
         ;\
         static const ASN1_ITEM *name##_adb(void) \
         { \
@@ -485,7 +485,7 @@ extern "C" {
                 {\
                 flags,\
                 offsetof(name, field),\
-                app_table,\
+                adb_cb,\
                 name##_adbtbl,\
                 sizeof(name##_adbtbl) / sizeof(ASN1_ADB_TABLE),\
                 def,\
@@ -529,7 +529,7 @@ typedef struct ASN1_ADB_st ASN1_ADB;
 struct ASN1_ADB_st {
     unsigned long flags;        /* Various flags */
     unsigned long offset;       /* Offset of selector field */
-    STACK_OF(ASN1_ADB_TABLE) **app_items; /* Application defined items */
+    int (*adb_cb)(long *psel);  /* Application callback */
     const ASN1_ADB_TABLE *tbl;  /* Table of possible types */
     long tblcount;              /* Number of entries in tbl */
     const ASN1_TEMPLATE *default_tt; /* Type to use if no match */