netscape-revival
security/lib/util/secasn1e.c
/* -*- Mode: C; tab-width: 8 -*-
*
* Support for ENcoding ASN.1 data based on BER/DER (Basic/Distinguished
* Encoding Rules).
*
* Copyright © 1996 Netscape Communications Corporation, all rights reserved.
*
* $Id: secasn1e.c,v 1.7.2.2 1997/04/26 00:02:05 jwz Exp $
*/
#include "secasn1.h"
typedef enum {
beforeHeader,
duringContents,
duringGroup,
duringSequence,
afterContents,
afterImplicit,
afterInline,
afterPointer,
notInUse
} sec_asn1e_parse_place;
typedef enum {
allDone,
encodeError,
keepGoing,
needBytes
} sec_asn1e_parse_status;
typedef struct sec_asn1e_state_struct {
SEC_ASN1EncoderContext *top;
const SEC_ASN1Template *template;
void *src;
struct sec_asn1e_state_struct *parent; /* aka prev */
struct sec_asn1e_state_struct *child; /* aka next */
sec_asn1e_parse_place place; /* where we are in encoding process */
/*
* XXX explain the next fields as clearly as possible...
*/
unsigned char tag_modifiers;
unsigned char tag_number;
unsigned long underlying_kind;
int depth;
PRBool explicit, /* we are handling an explicit header */
indefinite, /* need end-of-contents */
is_string, /* encoding a simple string or an ANY */
may_stream, /* when streaming, do indefinite encoding */
optional; /* omit field if it has no contents */
} sec_asn1e_state;
/*
* An "outsider" will have an opaque pointer to this, created by calling
* SEC_ASN1EncoderStart(). It will be passed back in to all subsequent
* calls to SEC_ASN1EncoderUpdate() and related routines, and when done
* it is passed to SEC_ASN1EncoderFinish().
*/
struct sec_EncoderContext_struct {
PRArenaPool *our_pool; /* for our internal allocs */
sec_asn1e_state *current;
sec_asn1e_parse_status status;
PRBool streaming;
PRBool from_buf;
SEC_ASN1NotifyProc notify_proc; /* call before/after handling field */
void *notify_arg; /* argument to notify_proc */
PRBool during_notify; /* true during call to notify_proc */
SEC_ASN1WriteProc output_proc; /* pass encoded bytes to this */
void *output_arg; /* argument to that function */
};
static sec_asn1e_state *
sec_asn1e_push_state (SEC_ASN1EncoderContext *cx,
const SEC_ASN1Template *template,
void *src, PRBool new_depth)
{
sec_asn1e_state *state, *new_state;
state = cx->current;
new_state = PORT_ArenaZAlloc (cx->our_pool, sizeof(*new_state));
if (new_state == NULL) {
cx->status = encodeError;
return NULL;
}
new_state->top = cx;
new_state->parent = state;
new_state->template = template;
new_state->place = notInUse;
if (src != NULL)
new_state->src = (char *)src + template->offset;
if (state != NULL) {
new_state->depth = state->depth;
if (new_depth)
new_state->depth++;
state->child = new_state;
}
cx->current = new_state;
return new_state;
}
static void
sec_asn1e_scrub_state (sec_asn1e_state *state)
{
/*
* Some default "scrubbing".
* XXX right set of initializations?
*/
state->place = beforeHeader;
state->indefinite = PR_FALSE;
}
static void
sec_asn1e_notify_before (SEC_ASN1EncoderContext *cx, void *src, int depth)
{
if (cx->notify_proc == NULL)
return;
cx->during_notify = PR_TRUE;
(* cx->notify_proc) (cx->notify_arg, PR_TRUE, src, depth);
cx->during_notify = PR_FALSE;
}
static void
sec_asn1e_notify_after (SEC_ASN1EncoderContext *cx, void *src, int depth)
{
if (cx->notify_proc == NULL)
return;
cx->during_notify = PR_TRUE;
(* cx->notify_proc) (cx->notify_arg, PR_FALSE, src, depth);
cx->during_notify = PR_FALSE;
}
static sec_asn1e_state *
sec_asn1e_init_state_based_on_template (sec_asn1e_state *state)
{
PRBool explicit, is_string, may_stream, optional, universal;
unsigned char tag_modifiers;
unsigned long encode_kind, under_kind;
unsigned long tag_number;
encode_kind = state->template->kind;
universal = ((encode_kind & SEC_ASN1_CLASS_MASK) == SEC_ASN1_UNIVERSAL)
? PR_TRUE : PR_FALSE;
explicit = (encode_kind & SEC_ASN1_EXPLICIT) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_EXPLICIT;
optional = (encode_kind & SEC_ASN1_OPTIONAL) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_OPTIONAL;
PORT_Assert (!(explicit && universal)); /* bad templates */
may_stream = (encode_kind & SEC_ASN1_MAY_STREAM) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_MAY_STREAM;
/* Just clear this to get it out of the way; we do not need it here */
encode_kind &= ~SEC_ASN1_DYNAMIC;
if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) || (!universal
&& !explicit)) {
const SEC_ASN1Template *subt;
void *src;
PORT_Assert ((encode_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP)) == 0);
sec_asn1e_scrub_state (state);
subt = SEC_ASN1GetSubtemplate (state->template, state->src, PR_TRUE);
if (encode_kind & SEC_ASN1_POINTER) {
/* check that there are no extraneous bits */
PORT_Assert (encode_kind == SEC_ASN1_POINTER && !optional);
src = *(void **)state->src;
state->place = afterPointer;
} else {
src = state->src;
if (encode_kind & SEC_ASN1_INLINE) {
/* check that there are no extraneous bits */
PORT_Assert (encode_kind == SEC_ASN1_INLINE && !optional);
state->place = afterInline;
} else {
/* Save the tag modifiers and tag number here before move
on to the next state in case this is a member of a SEQUENCE OF
hl
*/
state->tag_modifiers = encode_kind & SEC_ASN1_TAG_MASK & ~SEC_ASN1_TAGNUM_MASK;
state->tag_number = encode_kind & SEC_ASN1_TAGNUM_MASK;
state->place = afterImplicit;
state->optional = optional;
}
}
state = sec_asn1e_push_state (state->top, subt, src, PR_FALSE);
if (state == NULL)
return NULL;
if (universal) {
/*
* This is a POINTER or INLINE; just init based on that
* and we are done.
*/
return sec_asn1e_init_state_based_on_template (state);
}
/*
* This is an implicit, non-universal (meaning, application-private
* or context-specific) field. This results in a "magic" tag but
* encoding based on the underlying type. We pushed a new state
* that is based on the subtemplate (the underlying type), but
* now we will sort of alias it to give it some of our properties
* (tag, optional status, etc.).
*/
under_kind = state->template->kind;
if (under_kind & SEC_ASN1_MAY_STREAM) {
may_stream = PR_TRUE;
under_kind &= ~SEC_ASN1_MAY_STREAM;
}
} else {
under_kind = encode_kind;
}
/*
* Sanity check that there are no unwanted bits marked in under_kind.
* These bits were either removed above (after we recorded them) or
* they simply should not be found (signalling a bad/broken template).
* XXX is this the right set of bits to test here? (i.e. need to add
* or remove any?)
*/
PORT_Assert ((under_kind & (SEC_ASN1_EXPLICIT | SEC_ASN1_OPTIONAL
| SEC_ASN1_SKIP | SEC_ASN1_INNER
| SEC_ASN1_DYNAMIC | SEC_ASN1_MAY_STREAM
| SEC_ASN1_INLINE | SEC_ASN1_POINTER)) == 0);
if (encode_kind & SEC_ASN1_ANY) {
PORT_Assert (encode_kind == under_kind);
tag_modifiers = 0;
tag_number = 0;
is_string = PR_TRUE;
} else {
tag_modifiers = encode_kind & SEC_ASN1_TAG_MASK & ~SEC_ASN1_TAGNUM_MASK;
/*
* XXX This assumes only single-octet identifiers. To handle
* the HIGH TAG form we would need to do some more work, especially
* in how to specify them in the template, because right now we
* do not provide a way to specify more *tag* bits in encode_kind.
*/
tag_number = encode_kind & SEC_ASN1_TAGNUM_MASK;
is_string = PR_FALSE;
switch (under_kind & SEC_ASN1_TAGNUM_MASK) {
case SEC_ASN1_SET:
/*
* XXX A plain old SET (as opposed to a SET OF) is not implemented.
* If it ever is, remove this assert...
*/
PORT_Assert ((under_kind & SEC_ASN1_GROUP) != 0);
/* fallthru */
case SEC_ASN1_SEQUENCE:
tag_modifiers |= SEC_ASN1_CONSTRUCTED;
break;
case SEC_ASN1_BIT_STRING:
case SEC_ASN1_OCTET_STRING:
case SEC_ASN1_PRINTABLE_STRING:
case SEC_ASN1_T61_STRING:
case SEC_ASN1_IA5_STRING:
case SEC_ASN1_UTC_TIME:
case SEC_ASN1_BMP_STRING:
/*
* We do not yet know if we will be constructing the string,
* so we have to wait to do this final tag modification.
*/
is_string = PR_TRUE;
break;
}
}
state->tag_modifiers = tag_modifiers;
state->tag_number = tag_number;
state->underlying_kind = under_kind;
state->explicit = explicit;
state->may_stream = may_stream;
state->is_string = is_string;
state->optional = optional;
sec_asn1e_scrub_state (state);
return state;
}
static void
sec_asn1e_write_part (sec_asn1e_state *state,
const char *buf, unsigned long len,
SEC_ASN1EncodingPart part)
{
SEC_ASN1EncoderContext *cx;
cx = state->top;
(* cx->output_proc) (cx->output_arg, buf, len, state->depth, part);
}
/*
* XXX This assumes only single-octet identifiers. To handle
* the HIGH TAG form we would need to modify this interface and
* teach it to properly encode the special form.
*/
static void
sec_asn1e_write_identifier_bytes (sec_asn1e_state *state, unsigned char value)
{
char byte;
byte = (char) value;
sec_asn1e_write_part (state, &byte, 1, SEC_ASN1_Identifier);
}
static void
sec_asn1e_write_length_bytes (sec_asn1e_state *state, unsigned long value,
PRBool indefinite)
{
int lenlen;
unsigned char buf[sizeof(unsigned long) + 1];
if (indefinite) {
PORT_Assert (value == 0);
buf[0] = 0x80;
lenlen = 1;
} else {
lenlen = SEC_ASN1LengthLength (value);
if (lenlen == 1) {
buf[0] = value;
} else {
int i;
i = lenlen - 1;
buf[0] = 0x80 | i;
while (i) {
buf[i--] = value;
value >>= 8;
}
PORT_Assert (value == 0);
}
}
sec_asn1e_write_part (state, (char *) buf, lenlen, SEC_ASN1_Length);
}
static void
sec_asn1e_write_contents_bytes (sec_asn1e_state *state,
const char *buf, unsigned long len)
{
sec_asn1e_write_part (state, buf, len, SEC_ASN1_Contents);
}
static void
sec_asn1e_write_end_of_contents_bytes (sec_asn1e_state *state)
{
const char eoc[2] = {0, 0};
sec_asn1e_write_part (state, eoc, 2, SEC_ASN1_EndOfContents);
}
static unsigned long
sec_asn1e_contents_length (const SEC_ASN1Template *template, void *src,
PRBool *noheaderp)
{
unsigned long encode_kind, underlying_kind;
PRBool explicit, optional, universal;
unsigned long len;
encode_kind = template->kind;
universal = ((encode_kind & SEC_ASN1_CLASS_MASK) == SEC_ASN1_UNIVERSAL)
? PR_TRUE : PR_FALSE;
explicit = (encode_kind & SEC_ASN1_EXPLICIT) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_EXPLICIT;
optional = (encode_kind & SEC_ASN1_OPTIONAL) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_OPTIONAL;
PORT_Assert (!(explicit && universal)); /* bad templates */
/* We have already decided we are not streaming. */
encode_kind &= ~SEC_ASN1_MAY_STREAM;
/* Just clear this to get it out of the way; we do not need it here */
encode_kind &= ~SEC_ASN1_DYNAMIC;
if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) || !universal) {
/* XXX any bits we want to disallow (PORT_Assert against) here? */
template = SEC_ASN1GetSubtemplate (template, src, PR_TRUE);
if (encode_kind & SEC_ASN1_POINTER) {
/* check that there are no extraneous bits */
PORT_Assert (encode_kind == SEC_ASN1_POINTER && !optional);
src = *(void **)src;
if (src == NULL) {
if (optional)
*noheaderp = PR_TRUE;
else
*noheaderp = PR_FALSE;
return 0;
}
} else if (encode_kind & SEC_ASN1_INLINE) {
/* check that there are no extraneous bits */
PORT_Assert (encode_kind == SEC_ASN1_INLINE && !optional);
}
src = (char *)src + template->offset;
if (explicit) {
len = sec_asn1e_contents_length (template, src, noheaderp);
if (len == 0 && optional) {
*noheaderp = PR_TRUE;
} else if (*noheaderp) {
/*
* Okay, *we* do not want to add in a header, but our
* caller still does.
*/
*noheaderp = PR_FALSE;
} else {
/*
* XXX The 1 below is the presumed length of the identifier;
* to support a high-tag-number this would need to be smarter.
*/
len += 1 + SEC_ASN1LengthLength (len);
}
return len;
}
underlying_kind = template->kind;
underlying_kind &= ~SEC_ASN1_MAY_STREAM;
/* XXX Should we recurse here? */
} else {
underlying_kind = encode_kind;
}
/* This is only used in decoding; it plays no part in encoding. */
if (underlying_kind & SEC_ASN1_SAVE) {
/* check that there are no extraneous bits */
PORT_Assert (underlying_kind == SEC_ASN1_SAVE);
*noheaderp = PR_TRUE;
return 0;
}
/* Having any of these bits is not expected here... */
PORT_Assert ((underlying_kind & (SEC_ASN1_EXPLICIT | SEC_ASN1_OPTIONAL
| SEC_ASN1_INLINE | SEC_ASN1_POINTER
| SEC_ASN1_DYNAMIC | SEC_ASN1_MAY_STREAM
| SEC_ASN1_SAVE | SEC_ASN1_SKIP)) == 0);
switch (underlying_kind) {
case SEC_ASN1_SEQUENCE_OF:
case SEC_ASN1_SET_OF:
{
const SEC_ASN1Template *tmpt;
void *sub_src;
unsigned long sub_len;
void **group;
len = 0;
group = *(void ***)src;
if (group == NULL)
break;
tmpt = SEC_ASN1GetSubtemplate (template, src, PR_TRUE);
for (; *group != NULL; group++) {
sub_src = (char *)(*group) + tmpt->offset;
sub_len = sec_asn1e_contents_length (tmpt, sub_src, noheaderp);
len += sub_len;
/*
* XXX The 1 below is the presumed length of the identifier;
* to support a high-tag-number this would need to be smarter.
*/
if (!*noheaderp)
len += 1 + SEC_ASN1LengthLength (sub_len);
}
}
break;
case SEC_ASN1_SEQUENCE:
case SEC_ASN1_SET:
{
const SEC_ASN1Template *tmpt;
void *sub_src;
unsigned long sub_len;
len = 0;
for (tmpt = template + 1; tmpt->kind; tmpt++) {
sub_src = (char *)src + tmpt->offset;
sub_len = sec_asn1e_contents_length (tmpt, sub_src, noheaderp);
len += sub_len;
/*
* XXX The 1 below is the presumed length of the identifier;
* to support a high-tag-number this would need to be smarter.
*/
if (!*noheaderp)
len += 1 + SEC_ASN1LengthLength (sub_len);
}
}
break;
case SEC_ASN1_BIT_STRING:
/* convert bit length to byte */
len = (((SECItem *)src)->len + 7) >> 3;
/* bit string contents involve an extra octet */
if (len)
len++;
break;
default:
len = ((SECItem *)src)->len;
break;
}
if ((len == 0 && optional) || underlying_kind == SEC_ASN1_ANY)
*noheaderp = PR_TRUE;
else
*noheaderp = PR_FALSE;
return len;
}
static void
sec_asn1e_write_header (sec_asn1e_state *state)
{
unsigned long contents_length;
unsigned char tag_number, tag_modifiers;
PORT_Assert (state->place == beforeHeader);
tag_number = state->tag_number;
tag_modifiers = state->tag_modifiers;
if (state->underlying_kind == SEC_ASN1_ANY) {
state->place = duringContents;
return;
}
if (state->top->streaming && state->may_stream
&& (state->top->from_buf || !state->is_string)) {
/*
* We need to put out an indefinite-length encoding.
*/
state->indefinite = PR_TRUE;
/*
* The only universal types that can be constructed are SETs,
* SEQUENCEs, and strings; so check that it is one of those,
* or that it is not universal (e.g. context-specific).
*/
PORT_Assert ((tag_number == SEC_ASN1_SET)
|| (tag_number == SEC_ASN1_SEQUENCE)
|| ((tag_modifiers & SEC_ASN1_CLASS_MASK) != 0)
|| state->is_string);
tag_modifiers |= SEC_ASN1_CONSTRUCTED;
contents_length = 0;
} else {
PRBool noheader;
/*
* We are doing a definite-length encoding. First we have to
* walk the data structure to calculate the entire contents length.
*/
contents_length = sec_asn1e_contents_length (state->template,
state->src, &noheader);
/*
* We might be told explicitly not to put out a header.
* But it can also be the case, via a pushed subtemplate, that
* sec_asn1e_contents_length could not know that this field is
* really optional. So check for that explicitly, too.
*/
if (noheader || (contents_length == 0 && state->optional)) {
state->place = afterContents;
return;
}
}
sec_asn1e_write_identifier_bytes (state, tag_number | tag_modifiers);
sec_asn1e_write_length_bytes (state, contents_length, state->indefinite);
if (contents_length == 0 && !state->indefinite) {
/*
* If no real contents to encode, then we are done with this field.
*/
state->place = afterContents;
return;
}
/*
* An EXPLICIT is nothing but an outer header, which we have already
* written. Now we need to do the inner header and contents.
*/
if (state->explicit) {
state->place = afterContents;
state = sec_asn1e_push_state (state->top,
SEC_ASN1GetSubtemplate(state->template,
state->src,
PR_TRUE),
state->src, PR_TRUE);
if (state != NULL)
state = sec_asn1e_init_state_based_on_template (state);
return;
}
switch (state->underlying_kind) {
case SEC_ASN1_SET_OF:
case SEC_ASN1_SEQUENCE_OF:
/*
* We need to push a child to handle each member.
*/
{
void **group;
const SEC_ASN1Template *subt;
group = *(void ***)state->src;
if (group == NULL || *group == NULL) {
/*
* Group is empty; we are done.
*/
state->place = afterContents;
return;
}
state->place = duringGroup;
subt = SEC_ASN1GetSubtemplate (state->template, state->src,
PR_TRUE);
state = sec_asn1e_push_state (state->top, subt, *group, PR_TRUE);
if (state != NULL)
state = sec_asn1e_init_state_based_on_template (state);
}
break;
case SEC_ASN1_SEQUENCE:
case SEC_ASN1_SET:
/*
* We need to push a child to handle the individual fields.
*/
state->place = duringSequence;
state = sec_asn1e_push_state (state->top, state->template + 1,
state->src, PR_TRUE);
if (state != NULL) {
/*
* Do the "before" field notification.
*/
sec_asn1e_notify_before (state->top, state->src, state->depth);
state = sec_asn1e_init_state_based_on_template (state);
}
break;
default:
/*
* I think we do not need to do anything else.
* XXX Correct?
*/
state->place = duringContents;
break;
}
}
static void
sec_asn1e_write_contents (sec_asn1e_state *state,
const char *buf, unsigned long len)
{
PORT_Assert (state->place == duringContents);
if (state->top->from_buf) {
/*
* Probably they just turned on "take from buf", but have not
* yet given us any bytes. If there is nothing in the buffer
* then we have nothing to do but return and wait.
*/
if (buf == NULL || len == 0) {
state->top->status = needBytes;
return;
}
/*
* We are streaming, reading from a passed-in buffer.
* This means we are encoding a simple string or an ANY.
* For the former, we need to put out a substring, with its
* own identifier and length. For an ANY, we just write it
* out as is (our caller is required to ensure that it
* is a properly encoded entity).
*/
PORT_Assert (state->is_string); /* includes ANY */
if (state->underlying_kind != SEC_ASN1_ANY) {
unsigned char identifier;
/*
* Create the identifier based on underlying_kind. We cannot
* use tag_number and tag_modifiers because this can be an
* implicitly encoded field. In that case, the underlying
* substrings *are* encoded with their real tag.
*/
identifier = state->underlying_kind & SEC_ASN1_TAG_MASK;
/*
* The underlying kind should just be a simple string; there
* should be no bits like CONTEXT_SPECIFIC or CONSTRUCTED set.
*/
PORT_Assert ((identifier & SEC_ASN1_TAGNUM_MASK) == identifier);
/*
* Write out the tag and length for the substring.
*/
sec_asn1e_write_identifier_bytes (state, identifier);
if (state->underlying_kind == SEC_ASN1_BIT_STRING) {
char byte;
/*
* Assume we have a length in bytes but we need to output
* a proper bit string. This interface only works for bit
* strings that are full multiples of 8. If support for
* real, variable length bit strings is needed then the
* caller will have to know to pass in a bit length instead
* of a byte length and then this code will have to
* perform the encoding necessary (length written is length
* in bytes plus 1, and the first octet of string is the
* number of bits remaining between the end of the bit
* string and the next byte boundary).
*/
sec_asn1e_write_length_bytes (state, len + 1, PR_FALSE);
byte = 0;
sec_asn1e_write_contents_bytes (state, &byte, 1);
} else {
sec_asn1e_write_length_bytes (state, len, PR_FALSE);
}
}
sec_asn1e_write_contents_bytes (state, buf, len);
state->top->status = needBytes;
} else {
switch (state->underlying_kind) {
case SEC_ASN1_SET:
case SEC_ASN1_SEQUENCE:
PORT_Assert (0);
break;
case SEC_ASN1_BIT_STRING:
{
SECItem *item;
char rem;
item = (SECItem *)state->src;
len = (item->len + 7) >> 3;
rem = (len << 3) - item->len; /* remaining bits */
sec_asn1e_write_contents_bytes (state, &rem, 1);
sec_asn1e_write_contents_bytes (state, (char *) item->data,
len);
}
break;
case SEC_ASN1_BMP_STRING:
/* The number of bytes must be divisable by 2 */
if ((((SECItem *)state->src)->len) % 2) {
SEC_ASN1EncoderContext *cx;
cx = state->top;
cx->status = encodeError;
break;
}
/* otherwise, fall through to write the content */
default:
{
SECItem *item;
item = (SECItem *)state->src;
sec_asn1e_write_contents_bytes (state, (char *) item->data,
item->len);
}
break;
}
state->place = afterContents;
}
}
/*
* We are doing a SET OF or SEQUENCE OF, and have just finished an item.
*/
static void
sec_asn1e_next_in_group (sec_asn1e_state *state)
{
sec_asn1e_state *child;
void **group;
void *member;
PORT_Assert (state->place == duringGroup);
PORT_Assert (state->child != NULL);
child = state->child;
group = *(void ***)state->src;
/*
* Find placement of current item.
*/
member = (char *)(state->child->src) - child->template->offset;
while (*group != member)
group++;
/*
* Move forward to next item.
*/
group++;
if (*group == NULL) {
/*
* That was our last one; we are done now.
*/
child->place = notInUse;
state->place = afterContents;
return;
}
child->src = (char *)(*group) + child->template->offset;
/*
* Re-"push" child.
*/
sec_asn1e_scrub_state (child);
state->top->current = child;
}
/*
* We are moving along through a sequence; move forward by one,
* (detecting end-of-sequence when it happens).
*/
static void
sec_asn1e_next_in_sequence (sec_asn1e_state *state)
{
sec_asn1e_state *child;
PORT_Assert (state->place == duringSequence);
PORT_Assert (state->child != NULL);
child = state->child;
/*
* Do the "after" field notification.
*/
sec_asn1e_notify_after (state->top, child->src, child->depth);
/*
* Move forward.
*/
child->template++;
if (child->template->kind == 0) {
/*
* We are done with this sequence.
*/
child->place = notInUse;
state->place = afterContents;
return;
}
/*
* Reset state and push.
*/
child->src = (char *)state->src + child->template->offset;
/*
* Do the "before" field notification.
*/
sec_asn1e_notify_before (state->top, child->src, child->depth);
state->top->current = child;
(void) sec_asn1e_init_state_based_on_template (child);
}
static void
sec_asn1e_after_contents (sec_asn1e_state *state)
{
PORT_Assert (state->place == afterContents);
if (state->indefinite)
sec_asn1e_write_end_of_contents_bytes (state);
/*
* Just make my parent be the current state. It will then clean
* up after me and free me (or reuse me).
*/
state->top->current = state->parent;
}
/*
* This function is called whether or not we are streaming; if we
* *are* streaming, our caller can also instruct us to take bytes
* from the passed-in buffer (at buf, for length len, which is likely
* bytes but could even mean bits if the current field is a bit string).
* If we have been so instructed, we will gobble up bytes from there
* (rather than from our src structure) and output them, and then
* we will just return, expecting to be called again -- either with
* more bytes or after our caller has instructed us that we are done
* (for now) with the buffer.
*/
SECStatus
SEC_ASN1EncoderUpdate (SEC_ASN1EncoderContext *cx,
const char *buf, unsigned long len)
{
sec_asn1e_state *state;
if (cx->status == needBytes) {
PORT_Assert (buf != NULL && len != 0);
cx->status = keepGoing;
}
while (cx->status == keepGoing) {
state = cx->current;
switch (state->place) {
case beforeHeader:
sec_asn1e_write_header (state);
break;
case duringContents:
sec_asn1e_write_contents (state, buf, len);
break;
case duringGroup:
sec_asn1e_next_in_group (state);
break;
case duringSequence:
sec_asn1e_next_in_sequence (state);
break;
case afterContents:
sec_asn1e_after_contents (state);
break;
case afterImplicit:
case afterInline:
case afterPointer:
/*
* These states are more documentation than anything.
* They just need to force a pop.
*/
PORT_Assert (!state->indefinite);
state->place = afterContents;
break;
case notInUse:
default:
/* This is not an error, but rather a plain old BUG! */
PORT_Assert (0);
cx->status = encodeError;
break;
}
if (cx->status == encodeError)
break;
/* It might have changed, so we have to update our local copy. */
state = cx->current;
/* If it is NULL, we have popped all the way to the top. */
if (state == NULL) {
cx->status = allDone;
break;
}
}
if (cx->status == encodeError) {
return SECFailure;
}
return SECSuccess;
}
void
SEC_ASN1EncoderFinish (SEC_ASN1EncoderContext *cx)
{
/*
* XXX anything else that needs to be finished?
*/
PORT_FreeArena (cx->our_pool, PR_FALSE);
}
SEC_ASN1EncoderContext *
SEC_ASN1EncoderStart (void *src, const SEC_ASN1Template *template,
SEC_ASN1WriteProc output_proc, void *output_arg)
{
PRArenaPool *our_pool;
SEC_ASN1EncoderContext *cx;
our_pool = PORT_NewArena (SEC_ASN1_DEFAULT_ARENA_SIZE);
if (our_pool == NULL)
return NULL;
cx = PORT_ArenaZAlloc (our_pool, sizeof(*cx));
if (cx == NULL) {
PORT_FreeArena (our_pool, PR_FALSE);
return NULL;
}
cx->our_pool = our_pool;
cx->output_proc = output_proc;
cx->output_arg = output_arg;
cx->status = keepGoing;
if (sec_asn1e_push_state(cx, template, src, PR_FALSE) == NULL
|| sec_asn1e_init_state_based_on_template (cx->current) == NULL) {
/*
* Trouble initializing (probably due to failed allocations)
* requires that we just give up.
*/
PORT_FreeArena (our_pool, PR_FALSE);
return NULL;
}
return cx;
}
/*
* XXX Do we need a FilterProc, too?
*/
void
SEC_ASN1EncoderSetNotifyProc (SEC_ASN1EncoderContext *cx,
SEC_ASN1NotifyProc fn, void *arg)
{
cx->notify_proc = fn;
cx->notify_arg = arg;
}
void
SEC_ASN1EncoderClearNotifyProc (SEC_ASN1EncoderContext *cx)
{
cx->notify_proc = NULL;
cx->notify_arg = NULL; /* not necessary; just being clean */
}
void
SEC_ASN1EncoderSetStreaming (SEC_ASN1EncoderContext *cx)
{
/* XXX is there a way to check that we are "between" fields here? */
cx->streaming = PR_TRUE;
}
void
SEC_ASN1EncoderClearStreaming (SEC_ASN1EncoderContext *cx)
{
/* XXX is there a way to check that we are "between" fields here? */
cx->streaming = PR_FALSE;
}
void
SEC_ASN1EncoderSetTakeFromBuf (SEC_ASN1EncoderContext *cx)
{
/* check that we are "between" fields here, and streaming */
PORT_Assert (cx->during_notify && cx->streaming);
cx->from_buf = PR_TRUE;
}
void
SEC_ASN1EncoderClearTakeFromBuf (SEC_ASN1EncoderContext *cx)
{
/* we should actually be taking from buf *now* */
PORT_Assert (cx->from_buf);
if (! cx->from_buf) /* if not, just do nothing */
return;
cx->from_buf = PR_FALSE;
if (cx->status == needBytes) {
cx->status = keepGoing;
cx->current->place = afterContents;
}
}
SECStatus
SEC_ASN1Encode (void *src, const SEC_ASN1Template *template,
SEC_ASN1WriteProc output_proc, void *output_arg)
{
SEC_ASN1EncoderContext *ecx;
SECStatus rv;
ecx = SEC_ASN1EncoderStart (src, template, output_proc, output_arg);
if (ecx == NULL)
return SECFailure;
rv = SEC_ASN1EncoderUpdate (ecx, NULL, 0);
SEC_ASN1EncoderFinish (ecx);
return rv;
}
/*
* XXX depth and data_kind are unused; is there a PC way to silence warnings?
* (I mean "politically correct", not anything to do with intel/win platform)
*/
static void
sec_asn1e_encode_item_count (void *arg, const char *buf, unsigned long len,
int depth, SEC_ASN1EncodingPart data_kind)
{
unsigned long *count;
count = arg;
PORT_Assert (count != NULL);
*count += len;
}
/* XXX depth and data_kind are unused; is there a PC way to silence warnings? */
static void
sec_asn1e_encode_item_store (void *arg, const char *buf, unsigned long len,
int depth, SEC_ASN1EncodingPart data_kind)
{
SECItem *dest;
dest = arg;
PORT_Assert (dest != NULL);
PORT_Memcpy (dest->data + dest->len, buf, len);
dest->len += len;
}
/*
* Allocate an entire SECItem, or just the data part of it, to hold
* "len" bytes of stuff. Allocate from the given pool, if specified,
* otherwise just do a vanilla PORT_Alloc.
*
* XXX This seems like a reasonable general-purpose function (for SECITEM_)?
*/
static SECItem *
sec_asn1e_allocate_item (PRArenaPool *poolp, SECItem *dest, unsigned long len)
{
if (poolp != NULL) {
void *release;
release = PORT_ArenaMark (poolp);
if (dest == NULL)
dest = PORT_ArenaAlloc (poolp, sizeof(SECItem));
if (dest != NULL) {
dest->data = PORT_ArenaAlloc (poolp, len);
if (dest->data == NULL) {
PORT_ArenaRelease (poolp, release);
dest = NULL;
}
}
} else {
SECItem *indest;
indest = dest;
if (dest == NULL)
dest = PORT_Alloc (sizeof(SECItem));
if (dest != NULL) {
dest->data = PORT_Alloc (len);
if (dest->data == NULL) {
if (indest == NULL)
PORT_Free (dest);
dest = NULL;
}
}
}
return dest;
}
SECItem *
SEC_ASN1EncodeItem (PRArenaPool *poolp, SECItem *dest, void *src,
const SEC_ASN1Template *template)
{
unsigned long encoding_length;
SECStatus rv;
PORT_Assert (dest == NULL || dest->data == NULL);
encoding_length = 0;
rv = SEC_ASN1Encode (src, template,
sec_asn1e_encode_item_count, &encoding_length);
if (rv != SECSuccess)
return NULL;
dest = sec_asn1e_allocate_item (poolp, dest, encoding_length);
if (dest == NULL)
return NULL;
/* XXX necessary? This really just checks for a bug in the allocate fn */
PORT_Assert (dest->data != NULL);
if (dest->data == NULL)
return NULL;
dest->len = 0;
(void) SEC_ASN1Encode (src, template, sec_asn1e_encode_item_store, dest);
PORT_Assert (encoding_length == dest->len);
return dest;
}
static SECItem *
sec_asn1e_integer(PRArenaPool *poolp, SECItem *dest, unsigned long value,
PRBool make_unsigned)
{
unsigned long copy;
unsigned char sign;
int len = 0;
/*
* Determine the length of the encoded value (minimum of 1).
*/
copy = value;
do {
len++;
sign = copy & 0x80;
copy >>= 8;
} while (copy);
/*
* If this is an unsigned encoding, and the high bit of the last
* byte we counted was set, we need to add one to the length so
* we put a high-order zero byte in the encoding.
*/
if (sign && make_unsigned)
len++;
/*
* Allocate the item (if necessary) and the data pointer within.
*/
dest = sec_asn1e_allocate_item (poolp, dest, len);
if (dest == NULL)
return NULL;
/*
* Store the value, byte by byte, in the item.
*/
dest->len = len;
while (len) {
dest->data[--len] = value;
value >>= 8;
}
PORT_Assert (value == 0);
return dest;
}
SECItem *
SEC_ASN1EncodeInteger(PRArenaPool *poolp, SECItem *dest, long value)
{
return sec_asn1e_integer (poolp, dest, (unsigned long) value, PR_FALSE);
}
SECItem *
SEC_ASN1EncodeEnumerated(PRArenaPool *poolp, SECItem *dest, long value)
{
return sec_asn1e_integer (poolp, dest, (unsigned long) value, PR_FALSE);
}
extern SECItem *
SEC_ASN1EncodeUnsignedInteger(PRArenaPool *poolp,
SECItem *dest, unsigned long value)
{
return sec_asn1e_integer (poolp, dest, value, PR_TRUE);
}