1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/nss/lib/util/secasn1u.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,97 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +/*
1.9 + * Utility routines to complement the ASN.1 encoding and decoding functions.
1.10 + */
1.11 +
1.12 +#include "secasn1.h"
1.13 +
1.14 +
1.15 +/*
1.16 + * We have a length that needs to be encoded; how many bytes will the
1.17 + * encoding take?
1.18 + *
1.19 + * The rules are that 0 - 0x7f takes one byte (the length itself is the
1.20 + * entire encoding); everything else takes one plus the number of bytes
1.21 + * in the length.
1.22 + */
1.23 +int
1.24 +SEC_ASN1LengthLength (unsigned long len)
1.25 +{
1.26 + int lenlen = 1;
1.27 +
1.28 + if (len > 0x7f) {
1.29 + do {
1.30 + lenlen++;
1.31 + len >>= 8;
1.32 + } while (len);
1.33 + }
1.34 +
1.35 + return lenlen;
1.36 +}
1.37 +
1.38 +
1.39 +/*
1.40 + * XXX Move over (and rewrite as appropriate) the rest of the
1.41 + * stuff in dersubr.c!
1.42 + */
1.43 +
1.44 +
1.45 +/*
1.46 + * Find the appropriate subtemplate for the given template.
1.47 + * This may involve calling a "chooser" function, or it may just
1.48 + * be right there. In either case, it is expected to *have* a
1.49 + * subtemplate; this is asserted in debug builds (in non-debug
1.50 + * builds, NULL will be returned).
1.51 + *
1.52 + * "thing" is a pointer to the structure being encoded/decoded
1.53 + * "encoding", when true, means that we are in the process of encoding
1.54 + * (as opposed to in the process of decoding)
1.55 + */
1.56 +const SEC_ASN1Template *
1.57 +SEC_ASN1GetSubtemplate (const SEC_ASN1Template *theTemplate, void *thing,
1.58 + PRBool encoding)
1.59 +{
1.60 + const SEC_ASN1Template *subt = NULL;
1.61 +
1.62 + PORT_Assert (theTemplate->sub != NULL);
1.63 + if (theTemplate->sub != NULL) {
1.64 + if (theTemplate->kind & SEC_ASN1_DYNAMIC) {
1.65 + SEC_ASN1TemplateChooserPtr chooserp;
1.66 +
1.67 + chooserp = *(SEC_ASN1TemplateChooserPtr *) theTemplate->sub;
1.68 + if (chooserp) {
1.69 + if (thing != NULL)
1.70 + thing = (char *)thing - theTemplate->offset;
1.71 + subt = (* chooserp)(thing, encoding);
1.72 + }
1.73 + } else {
1.74 + subt = (SEC_ASN1Template*)theTemplate->sub;
1.75 + }
1.76 + }
1.77 + return subt;
1.78 +}
1.79 +
1.80 +PRBool SEC_ASN1IsTemplateSimple(const SEC_ASN1Template *theTemplate)
1.81 +{
1.82 + if (!theTemplate) {
1.83 + return PR_TRUE; /* it doesn't get any simpler than NULL */
1.84 + }
1.85 + /* only templates made of one primitive type or a choice of primitive
1.86 + types are considered simple */
1.87 + if (! (theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK))) {
1.88 + return PR_TRUE; /* primitive type */
1.89 + }
1.90 + if (!(theTemplate->kind & SEC_ASN1_CHOICE)) {
1.91 + return PR_FALSE; /* no choice means not simple */
1.92 + }
1.93 + while (++theTemplate && theTemplate->kind) {
1.94 + if (theTemplate->kind & (~SEC_ASN1_TAGNUM_MASK)) {
1.95 + return PR_FALSE; /* complex type */
1.96 + }
1.97 + }
1.98 + return PR_TRUE; /* choice of primitive types */
1.99 +}
1.100 +
