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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* Utility routines to complement the ASN.1 encoding and decoding functions.
*/
#include "secasn1.h"
/*
* We have a length that needs to be encoded; how many bytes will the
* encoding take?
*
* The rules are that 0 - 0x7f takes one byte (the length itself is the
* entire encoding); everything else takes one plus the number of bytes
* in the length.
*/
int
SEC_ASN1LengthLength(unsigned long len)
{
int lenlen = 1;
if (len > 0x7f) {
do {
lenlen++;
len >>= 8;
} while (len);
}
return lenlen;
}
/*
* XXX Move over (and rewrite as appropriate) the rest of the
* stuff in dersubr.c!
*/
/*
* Find the appropriate subtemplate for the given template.
* This may involve calling a "chooser" function, or it may just
* be right there. In either case, it is expected to *have* a
* subtemplate; this is asserted in debug builds (in non-debug
* builds, NULL will be returned).
*
* "thing" is a pointer to the structure being encoded/decoded
* "encoding", when true, means that we are in the process of encoding
* (as opposed to in the process of decoding)
*/
const SEC_ASN1Template *
SEC_ASN1GetSubtemplate(const SEC_ASN1Template *theTemplate, void *thing,
PRBool encoding)
{
const SEC_ASN1Template *subt = NULL;
PORT_Assert(theTemplate->sub != NULL);
if (theTemplate->sub != NULL) {
if (theTemplate->kind & SEC_ASN1_DYNAMIC) {
SEC_ASN1TemplateChooserPtr chooserp;
chooserp = *(SEC_ASN1TemplateChooserPtr *)theTemplate->sub;
if (chooserp) {
if (thing != NULL)
thing = (char *)thing - theTemplate->offset;
subt = (*chooserp)(thing, encoding);
}
} else {
subt = (SEC_ASN1Template *)theTemplate->sub;
}
}
return subt;
}
PRBool
SEC_ASN1IsTemplateSimple(const SEC_ASN1Template *theTemplate)
{
if (!theTemplate) {
return PR_TRUE; /* it doesn't get any simpler than NULL */
}
/* only templates made of one primitive type or a choice of primitive
types are considered simple */
if (!(theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK))) {
return PR_TRUE; /* primitive type */
}
if (!(theTemplate->kind & SEC_ASN1_CHOICE)) {
return PR_FALSE; /* no choice means not simple */
}
while (++theTemplate && theTemplate->kind) {
if (theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK)) {
return PR_FALSE; /* complex type */
}
}
return PR_TRUE; /* choice of primitive types */
}