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0310c45fa3
RetroZilla/security/nss/lib/util/secasn1d.c
Roy Tam 0310c45fa3 cherry-picked mozilla NSS upstream changes (to rev 46bd290c): 
bug1061701, bug1210361, bug1210364, bug1210380, bug1210389, bug1009429, bug1211444, bug1180096, bug1210484, bug1211915, bug1211725, bug1213931, bug1214806, bug1214762, bug1214777, bug1214841, bug1214834, bug1213948, bug1213980, bug1192028, bug1202868, bug1214829, bug1026688, bug1214825, bug1216318
2020-01-07 20:22:09 +08:00

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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* Support for DEcoding ASN.1 data based on BER/DER (Basic/Distinguished
* Encoding Rules).
*/
/* #define DEBUG_ASN1D_STATES 1 */
#ifdef DEBUG_ASN1D_STATES
#include <stdio.h>
#define PR_Assert sec_asn1d_Assert
#endif
#include "secasn1.h"
#include "secerr.h"
typedef enum {
beforeIdentifier,
duringIdentifier,
afterIdentifier,
beforeLength,
duringLength,
afterLength,
beforeBitString,
duringBitString,
duringConstructedString,
duringGroup,
duringLeaf,
duringSaveEncoding,
duringSequence,
afterConstructedString,
afterGroup,
afterExplicit,
afterImplicit,
afterInline,
afterPointer,
afterSaveEncoding,
beforeEndOfContents,
duringEndOfContents,
afterEndOfContents,
beforeChoice,
duringChoice,
afterChoice,
notInUse
} sec_asn1d_parse_place;
#ifdef DEBUG_ASN1D_STATES
static const char * const place_names[] = {
"beforeIdentifier",
"duringIdentifier",
"afterIdentifier",
"beforeLength",
"duringLength",
"afterLength",
"beforeBitString",
"duringBitString",
"duringConstructedString",
"duringGroup",
"duringLeaf",
"duringSaveEncoding",
"duringSequence",
"afterConstructedString",
"afterGroup",
"afterExplicit",
"afterImplicit",
"afterInline",
"afterPointer",
"afterSaveEncoding",
"beforeEndOfContents",
"duringEndOfContents",
"afterEndOfContents",
"beforeChoice",
"duringChoice",
"afterChoice",
"notInUse"
};
static const char * const class_names[] = {
"UNIVERSAL",
"APPLICATION",
"CONTEXT_SPECIFIC",
"PRIVATE"
};
static const char * const method_names[] = { "PRIMITIVE", "CONSTRUCTED" };
static const char * const type_names[] = {
"END_OF_CONTENTS",
"BOOLEAN",
"INTEGER",
"BIT_STRING",
"OCTET_STRING",
"NULL",
"OBJECT_ID",
"OBJECT_DESCRIPTOR",
"(type 08)",
"REAL",
"ENUMERATED",
"EMBEDDED",
"UTF8_STRING",
"(type 0d)",
"(type 0e)",
"(type 0f)",
"SEQUENCE",
"SET",
"NUMERIC_STRING",
"PRINTABLE_STRING",
"T61_STRING",
"VIDEOTEXT_STRING",
"IA5_STRING",
"UTC_TIME",
"GENERALIZED_TIME",
"GRAPHIC_STRING",
"VISIBLE_STRING",
"GENERAL_STRING",
"UNIVERSAL_STRING",
"(type 1d)",
"BMP_STRING",
"HIGH_TAG_VALUE"
};
static const char * const flag_names[] = { /* flags, right to left */
"OPTIONAL",
"EXPLICIT",
"ANY",
"INLINE",
"POINTER",
"GROUP",
"DYNAMIC",
"SKIP",
"INNER",
"SAVE",
"", /* decoder ignores "MAY_STREAM", */
"SKIP_REST",
"CHOICE",
"NO_STREAM",
"DEBUG_BREAK",
"unknown 08",
"unknown 10",
"unknown 20",
"unknown 40",
"unknown 80"
};
static int /* bool */
formatKind(unsigned long kind, char * buf)
{
int i;
unsigned long k = kind & SEC_ASN1_TAGNUM_MASK;
unsigned long notag = kind & (SEC_ASN1_CHOICE | SEC_ASN1_POINTER |
SEC_ASN1_INLINE | SEC_ASN1_ANY | SEC_ASN1_SAVE);
buf[0] = 0;
if ((kind & SEC_ASN1_CLASS_MASK) != SEC_ASN1_UNIVERSAL) {
sprintf(buf, " %s", class_names[(kind & SEC_ASN1_CLASS_MASK) >> 6] );
buf += strlen(buf);
}
if (kind & SEC_ASN1_METHOD_MASK) {
sprintf(buf, " %s", method_names[1]);
buf += strlen(buf);
}
if ((kind & SEC_ASN1_CLASS_MASK) == SEC_ASN1_UNIVERSAL) {
if (k || !notag) {
sprintf(buf, " %s", type_names[k] );
if ((k == SEC_ASN1_SET || k == SEC_ASN1_SEQUENCE) &&
(kind & SEC_ASN1_GROUP)) {
buf += strlen(buf);
sprintf(buf, "_OF");
}
}
} else {
sprintf(buf, " [%d]", k);
}
buf += strlen(buf);
for (k = kind >> 8, i = 0; k; k >>= 1, ++i) {
if (k & 1) {
sprintf(buf, " %s", flag_names[i]);
buf += strlen(buf);
}
}
return notag != 0;
}
#endif /* DEBUG_ASN1D_STATES */
typedef enum {
allDone,
decodeError,
keepGoing,
needBytes
} sec_asn1d_parse_status;
struct subitem {
const void *data;
unsigned long len; /* only used for substrings */
struct subitem *next;
};
typedef struct sec_asn1d_state_struct {
SEC_ASN1DecoderContext *top;
const SEC_ASN1Template *theTemplate;
void *dest;
void *our_mark; /* free on completion */
struct sec_asn1d_state_struct *parent; /* aka prev */
struct sec_asn1d_state_struct *child; /* aka next */
sec_asn1d_parse_place place;
/*
* XXX explain the next fields as clearly as possible...
*/
unsigned char found_tag_modifiers;
unsigned char expect_tag_modifiers;
unsigned long check_tag_mask;
unsigned long found_tag_number;
unsigned long expect_tag_number;
unsigned long underlying_kind;
unsigned long contents_length;
unsigned long pending;
unsigned long consumed;
int depth;
/*
* Bit strings have their length adjusted -- the first octet of the
* contents contains a value between 0 and 7 which says how many bits
* at the end of the octets are not actually part of the bit string;
* when parsing bit strings we put that value here because we need it
* later, for adjustment of the length (when the whole string is done).
*/
unsigned int bit_string_unused_bits;
/*
* The following are used for indefinite-length constructed strings.
*/
struct subitem *subitems_head;
struct subitem *subitems_tail;
PRPackedBool
allocate, /* when true, need to allocate the destination */
endofcontents, /* this state ended up parsing end-of-contents octets */
explicit, /* we are handling an explicit header */
indefinite, /* the current item has indefinite-length encoding */
missing, /* an optional field that was not present */
optional, /* the template says this field may be omitted */
substring; /* this is a substring of a constructed string */
} sec_asn1d_state;
#define IS_HIGH_TAG_NUMBER(n) ((n) == SEC_ASN1_HIGH_TAG_NUMBER)
#define LAST_TAG_NUMBER_BYTE(b) (((b) & 0x80) == 0)
#define TAG_NUMBER_BITS 7
#define TAG_NUMBER_MASK 0x7f
#define LENGTH_IS_SHORT_FORM(b) (((b) & 0x80) == 0)
#define LONG_FORM_LENGTH(b) ((b) & 0x7f)
#define HIGH_BITS(field,cnt) ((field) >> ((sizeof(field) * 8) - (cnt)))
/*
* An "outsider" will have an opaque pointer to this, created by calling
* SEC_ASN1DecoderStart(). It will be passed back in to all subsequent
* calls to SEC_ASN1DecoderUpdate(), and when done it is passed to
* SEC_ASN1DecoderFinish().
*/
struct sec_DecoderContext_struct {
PLArenaPool *our_pool; /* for our internal allocs */
PLArenaPool *their_pool; /* for destination structure allocs */
#ifdef SEC_ASN1D_FREE_ON_ERROR /*
* XXX see comment below (by same
* ifdef) that explains why this
* does not work (need more smarts
* in order to free back to mark)
*/
/*
* XXX how to make their_mark work in the case where they do NOT
* give us a pool pointer?
*/
void *their_mark; /* free on error */
#endif
sec_asn1d_state *current;
sec_asn1d_parse_status status;
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 filter_proc; /* pass field bytes to this */
void *filter_arg; /* argument to that function */
PRBool filter_only; /* do not allocate/store fields */
};
/*
* XXX this is a fairly generic function that may belong elsewhere
*/
static void *
sec_asn1d_alloc (PLArenaPool *poolp, unsigned long len)
{
void *thing;
if (poolp != NULL) {
/*
* Allocate from the pool.
*/
thing = PORT_ArenaAlloc (poolp, len);
} else {
/*
* Allocate generically.
*/
thing = PORT_Alloc (len);
}
return thing;
}
/*
* XXX this is a fairly generic function that may belong elsewhere
*/
static void *
sec_asn1d_zalloc (PLArenaPool *poolp, unsigned long len)
{
void *thing;
thing = sec_asn1d_alloc (poolp, len);
if (thing != NULL)
PORT_Memset (thing, 0, len);
return thing;
}
static sec_asn1d_state *
sec_asn1d_push_state (SEC_ASN1DecoderContext *cx,
const SEC_ASN1Template *theTemplate,
void *dest, PRBool new_depth)
{
sec_asn1d_state *state, *new_state;
state = cx->current;
PORT_Assert (state == NULL || state->child == NULL);
if (state != NULL) {
PORT_Assert (state->our_mark == NULL);
state->our_mark = PORT_ArenaMark (cx->our_pool);
}
new_state = (sec_asn1d_state*)sec_asn1d_zalloc (cx->our_pool,
sizeof(*new_state));
if (new_state == NULL) {
goto loser;
}
new_state->top = cx;
new_state->parent = state;
new_state->theTemplate = theTemplate;
new_state->place = notInUse;
if (dest != NULL)
new_state->dest = (char *)dest + theTemplate->offset;
if (state != NULL) {
new_state->depth = state->depth;
if (new_depth) {
if (++new_state->depth > SEC_ASN1D_MAX_DEPTH) {
PORT_SetError (SEC_ERROR_BAD_DER);
goto loser;
}
}
state->child = new_state;
}
cx->current = new_state;
return new_state;
loser:
cx->status = decodeError;
if (state != NULL) {
PORT_ArenaRelease(cx->our_pool, state->our_mark);
state->our_mark = NULL;
}
return NULL;
}
static void
sec_asn1d_scrub_state (sec_asn1d_state *state)
{
/*
* Some default "scrubbing".
* XXX right set of initializations?
*/
state->place = beforeIdentifier;
state->endofcontents = PR_FALSE;
state->indefinite = PR_FALSE;
state->missing = PR_FALSE;
PORT_Assert (state->consumed == 0);
}
static void
sec_asn1d_notify_before (SEC_ASN1DecoderContext *cx, void *dest, int depth)
{
if (cx->notify_proc == NULL)
return;
cx->during_notify = PR_TRUE;
(* cx->notify_proc) (cx->notify_arg, PR_TRUE, dest, depth);
cx->during_notify = PR_FALSE;
}
static void
sec_asn1d_notify_after (SEC_ASN1DecoderContext *cx, void *dest, int depth)
{
if (cx->notify_proc == NULL)
return;
cx->during_notify = PR_TRUE;
(* cx->notify_proc) (cx->notify_arg, PR_FALSE, dest, depth);
cx->during_notify = PR_FALSE;
}
static sec_asn1d_state *
sec_asn1d_init_state_based_on_template (sec_asn1d_state *state)
{
PRBool explicit, optional, universal;
unsigned char expect_tag_modifiers;
unsigned long encode_kind, under_kind;
unsigned long check_tag_mask, expect_tag_number;
/* XXX Check that both of these tests are really needed/appropriate. */
if (state == NULL || state->top->status == decodeError)
return state;
encode_kind = state->theTemplate->kind;
if (encode_kind & SEC_ASN1_SAVE) {
/*
* This is a "magic" field that saves away all bytes, allowing
* the immediately following field to still be decoded from this
* same spot -- sort of a fork.
*/
/* check that there are no extraneous bits */
PORT_Assert (encode_kind == SEC_ASN1_SAVE);
if (state->top->filter_only) {
/*
* If we are not storing, then we do not do the SAVE field
* at all. Just move ahead to the "real" field instead,
* doing the appropriate notify calls before and after.
*/
sec_asn1d_notify_after (state->top, state->dest, state->depth);
/*
* Since we are not storing, allow for our current dest value
* to be NULL. (This might not actually occur, but right now I
* cannot convince myself one way or the other.) If it is NULL,
* assume that our parent dest can help us out.
*/
if (state->dest == NULL)
state->dest = state->parent->dest;
else
state->dest = (char *)state->dest - state->theTemplate->offset;
state->theTemplate++;
if (state->dest != NULL)
state->dest = (char *)state->dest + state->theTemplate->offset;
sec_asn1d_notify_before (state->top, state->dest, state->depth);
encode_kind = state->theTemplate->kind;
PORT_Assert ((encode_kind & SEC_ASN1_SAVE) == 0);
} else {
sec_asn1d_scrub_state (state);
state->place = duringSaveEncoding;
state = sec_asn1d_push_state (state->top, SEC_AnyTemplate,
state->dest, PR_FALSE);
if (state != NULL)
state = sec_asn1d_init_state_based_on_template (state);
return state;
}
}
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 */
encode_kind &= ~SEC_ASN1_DYNAMIC;
encode_kind &= ~SEC_ASN1_MAY_STREAM;
if (encode_kind & SEC_ASN1_CHOICE) {
#if 0 /* XXX remove? */
sec_asn1d_state *child = sec_asn1d_push_state(state->top, state->theTemplate, state->dest, PR_FALSE);
if ((sec_asn1d_state *)NULL == child) {
return (sec_asn1d_state *)NULL;
}
child->allocate = state->allocate;
child->place = beforeChoice;
return child;
#else
state->place = beforeChoice;
return state;
#endif
}
if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) || (!universal
&& !explicit)) {
const SEC_ASN1Template *subt;
void *dest;
PRBool child_allocate;
PORT_Assert ((encode_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP)) == 0);
sec_asn1d_scrub_state (state);
child_allocate = PR_FALSE;
if (encode_kind & SEC_ASN1_POINTER) {
/*
* A POINTER means we need to allocate the destination for
* this field. But, since it may also be an optional field,
* we defer the allocation until later; we just record that
* it needs to be done.
*
* There are two possible scenarios here -- one is just a
* plain POINTER (kind of like INLINE, except with allocation)
* and the other is an implicitly-tagged POINTER. We don't
* need to do anything special here for the two cases, but
* since the template definition can be tricky, we do check
* that there are no extraneous bits set in encode_kind.
*
* XXX The same conditions which assert should set an error.
*/
if (universal) {
/*
* "universal" means this entry is a standalone POINTER;
* there should be no other bits set in encode_kind.
*/
PORT_Assert (encode_kind == SEC_ASN1_POINTER);
} else {
/*
* If we get here we have an implicitly-tagged field
* that needs to be put into a POINTER. The subtemplate
* will determine how to decode the field, but encode_kind
* describes the (implicit) tag we are looking for.
* The non-tag bits of encode_kind will be ignored by
* the code below; none of them should be set, however,
* except for the POINTER bit itself -- so check that.
*/
PORT_Assert ((encode_kind & ~SEC_ASN1_TAG_MASK)
== SEC_ASN1_POINTER);
}
if (!state->top->filter_only)
child_allocate = PR_TRUE;
dest = NULL;
state->place = afterPointer;
} else {
dest = state->dest;
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 {
state->place = afterImplicit;
}
}
state->optional = optional;
subt = SEC_ASN1GetSubtemplate (state->theTemplate, state->dest, PR_FALSE);
state = sec_asn1d_push_state (state->top, subt, dest, PR_FALSE);
if (state == NULL)
return NULL;
state->allocate = child_allocate;
if (universal) {
state = sec_asn1d_init_state_based_on_template (state);
if (state != NULL) {
/*
* If this field is optional, we need to record that on
* the pushed child so it won't fail if the field isn't
* found. I can't think of a way that this new state
* could already have optional set (which we would wipe
* out below if our local optional is not set) -- but
* just to be sure, assert that it isn't set.
*/
PORT_Assert (!state->optional);
state->optional = optional;
}
return state;
}
under_kind = state->theTemplate->kind;
under_kind &= ~SEC_ASN1_MAY_STREAM;
} else if (explicit) {
/*
* For explicit, we only need to match the encoding tag next,
* then we will push another state to handle the entire inner
* part. In this case, there is no underlying kind which plays
* any part in the determination of the outer, explicit tag.
* So we just set under_kind to 0, which is not a valid tag,
* and the rest of the tag matching stuff should be okay.
*/
under_kind = 0;
} else {
/*
* Nothing special; the underlying kind and the given encoding
* information are the same.
*/
under_kind = encode_kind;
}
/* XXX is this the right set of bits to test here? */
PORT_Assert ((under_kind & (SEC_ASN1_EXPLICIT | SEC_ASN1_OPTIONAL
| SEC_ASN1_MAY_STREAM
| SEC_ASN1_INLINE | SEC_ASN1_POINTER)) == 0);
if (encode_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP)) {
PORT_Assert (encode_kind == under_kind);
if (encode_kind & SEC_ASN1_SKIP) {
PORT_Assert (!optional);
PORT_Assert (encode_kind == SEC_ASN1_SKIP);
state->dest = NULL;
}
check_tag_mask = 0;
expect_tag_modifiers = 0;
expect_tag_number = 0;
} else {
check_tag_mask = SEC_ASN1_TAG_MASK;
expect_tag_modifiers = (unsigned char)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.
*/
expect_tag_number = encode_kind & SEC_ASN1_TAGNUM_MASK;
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:
expect_tag_modifiers |= SEC_ASN1_CONSTRUCTED;
break;
case SEC_ASN1_BIT_STRING:
case SEC_ASN1_BMP_STRING:
case SEC_ASN1_GENERALIZED_TIME:
case SEC_ASN1_IA5_STRING:
case SEC_ASN1_OCTET_STRING:
case SEC_ASN1_PRINTABLE_STRING:
case SEC_ASN1_T61_STRING:
case SEC_ASN1_UNIVERSAL_STRING:
case SEC_ASN1_UTC_TIME:
case SEC_ASN1_UTF8_STRING:
case SEC_ASN1_VISIBLE_STRING:
check_tag_mask &= ~SEC_ASN1_CONSTRUCTED;
break;
}
}
state->check_tag_mask = check_tag_mask;
state->expect_tag_modifiers = expect_tag_modifiers;
state->expect_tag_number = expect_tag_number;
state->underlying_kind = under_kind;
state->explicit = explicit;
state->optional = optional;
sec_asn1d_scrub_state (state);
return state;
}
static sec_asn1d_state *
sec_asn1d_get_enclosing_construct(sec_asn1d_state *state)
{
for (state = state->parent; state; state = state->parent) {
sec_asn1d_parse_place place = state->place;
if (place != afterImplicit &&
place != afterPointer &&
place != afterInline &&
place != afterSaveEncoding &&
place != duringSaveEncoding &&
place != duringChoice) {
/* we've walked up the stack to a state that represents
** the enclosing construct.
*/
break;
}
}
return state;
}
static PRBool
sec_asn1d_parent_allows_EOC(sec_asn1d_state *state)
{
/* get state of enclosing construct. */
state = sec_asn1d_get_enclosing_construct(state);
if (state) {
sec_asn1d_parse_place place = state->place;
/* Is it one of the types that permits an unexpected EOC? */
int eoc_permitted =
(place == duringGroup ||
place == duringConstructedString ||
state->child->optional);
return (state->indefinite && eoc_permitted) ? PR_TRUE : PR_FALSE;
}
return PR_FALSE;
}
static unsigned long
sec_asn1d_parse_identifier (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
unsigned char byte;
unsigned char tag_number;
PORT_Assert (state->place == beforeIdentifier);
if (len == 0) {
state->top->status = needBytes;
return 0;
}
byte = (unsigned char) *buf;
#ifdef DEBUG_ASN1D_STATES
{
char kindBuf[256];
formatKind(byte, kindBuf);
printf("Found tag %02x %s\n", byte, kindBuf);
}
#endif
tag_number = byte & SEC_ASN1_TAGNUM_MASK;
if (IS_HIGH_TAG_NUMBER (tag_number)) {
state->place = duringIdentifier;
state->found_tag_number = 0;
/*
* Actually, we have no idea how many bytes are pending, but we
* do know that it is at least 1. That is all we know; we have
* to look at each byte to know if there is another, etc.
*/
state->pending = 1;
} else {
if (byte == 0 && sec_asn1d_parent_allows_EOC(state)) {
/*
* Our parent has indefinite-length encoding, and the
* entire tag found is 0, so it seems that we have hit the
* end-of-contents octets. To handle this, we just change
* our state to that which expects to get the bytes of the
* end-of-contents octets and let that code re-read this byte
* so that our categorization of field types is correct.
* After that, our parent will then deal with everything else.
*/
state->place = duringEndOfContents;
state->pending = 2;
state->found_tag_number = 0;
state->found_tag_modifiers = 0;
/*
* We might be an optional field that is, as we now find out,
* missing. Give our parent a clue that this happened.
*/
if (state->optional)
state->missing = PR_TRUE;
return 0;
}
state->place = afterIdentifier;
state->found_tag_number = tag_number;
}
state->found_tag_modifiers = byte & ~SEC_ASN1_TAGNUM_MASK;
return 1;
}
static unsigned long
sec_asn1d_parse_more_identifier (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
unsigned char byte;
int count;
PORT_Assert (state->pending == 1);
PORT_Assert (state->place == duringIdentifier);
if (len == 0) {
state->top->status = needBytes;
return 0;
}
count = 0;
while (len && state->pending) {
if (HIGH_BITS (state->found_tag_number, TAG_NUMBER_BITS) != 0) {
/*
* The given high tag number overflows our container;
* just give up. This is not likely to *ever* happen.
*/
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return 0;
}
state->found_tag_number <<= TAG_NUMBER_BITS;
byte = (unsigned char) buf[count++];
state->found_tag_number |= (byte & TAG_NUMBER_MASK);
len--;
if (LAST_TAG_NUMBER_BYTE (byte))
state->pending = 0;
}
if (state->pending == 0)
state->place = afterIdentifier;
return count;
}
static void
sec_asn1d_confirm_identifier (sec_asn1d_state *state)
{
PRBool match;
PORT_Assert (state->place == afterIdentifier);
match = (PRBool)(((state->found_tag_modifiers & state->check_tag_mask)
== state->expect_tag_modifiers)
&& ((state->found_tag_number & state->check_tag_mask)
== state->expect_tag_number));
if (match) {
state->place = beforeLength;
} else {
if (state->optional) {
state->missing = PR_TRUE;
state->place = afterEndOfContents;
} else {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
}
}
}
static unsigned long
sec_asn1d_parse_length (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
unsigned char byte;
PORT_Assert (state->place == beforeLength);
if (len == 0) {
state->top->status = needBytes;
return 0;
}
/*
* The default/likely outcome. It may get adjusted below.
*/
state->place = afterLength;
byte = (unsigned char) *buf;
if (LENGTH_IS_SHORT_FORM (byte)) {
state->contents_length = byte;
} else {
state->contents_length = 0;
state->pending = LONG_FORM_LENGTH (byte);
if (state->pending == 0) {
state->indefinite = PR_TRUE;
} else {
state->place = duringLength;
}
}
/* If we're parsing an ANY, SKIP, or SAVE template, and
** the object being saved is definite length encoded and constructed,
** there's no point in decoding that construct's members.
** So, just forget it's constructed and treat it as primitive.
** (SAVE appears as an ANY at this point)
*/
if (!state->indefinite &&
(state->underlying_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP))) {
state->found_tag_modifiers &= ~SEC_ASN1_CONSTRUCTED;
}
return 1;
}
static unsigned long
sec_asn1d_parse_more_length (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
int count;
PORT_Assert (state->pending > 0);
PORT_Assert (state->place == duringLength);
if (len == 0) {
state->top->status = needBytes;
return 0;
}
count = 0;
while (len && state->pending) {
if (HIGH_BITS (state->contents_length, 9) != 0) {
/*
* The given full content length overflows our container;
* just give up.
*/
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return 0;
}
state->contents_length <<= 8;
state->contents_length |= (unsigned char) buf[count++];
len--;
state->pending--;
}
if (state->pending == 0)
state->place = afterLength;
return count;
}
/*
* Helper function for sec_asn1d_prepare_for_contents.
* Checks that a value representing a number of bytes consumed can be
* subtracted from a remaining length. If so, returns PR_TRUE.
* Otherwise, sets the error SEC_ERROR_BAD_DER, indicates that there was a
* decoding error in the given SEC_ASN1DecoderContext, and returns PR_FALSE.
*/
static PRBool
sec_asn1d_check_and_subtract_length (unsigned long *remaining,
unsigned long consumed,
SEC_ASN1DecoderContext *cx)
{
PORT_Assert(remaining);
PORT_Assert(cx);
if (!remaining || !cx) {
PORT_SetError (SEC_ERROR_INVALID_ARGS);
cx->status = decodeError;
return PR_FALSE;
}
if (*remaining < consumed) {
PORT_SetError (SEC_ERROR_BAD_DER);
cx->status = decodeError;
return PR_FALSE;
}
*remaining -= consumed;
return PR_TRUE;
}
static void
sec_asn1d_prepare_for_contents (sec_asn1d_state *state)
{
SECItem *item;
PLArenaPool *poolp;
unsigned long alloc_len;
sec_asn1d_state *parent;
#ifdef DEBUG_ASN1D_STATES
{
printf("Found Length %d %s\n", state->contents_length,
state->indefinite ? "indefinite" : "");
}
#endif
/**
* The maximum length for a child element should be constrained to the
* length remaining in the first definite length element in the ancestor
* stack. If there is no definite length element in the ancestor stack,
* there's nothing to constrain the length of the child, so there's no
* further processing necessary.
*
* It's necessary to walk the ancestor stack, because it's possible to have
* definite length children that are part of an indefinite length element,
* which is itself part of an indefinite length element, and which is
* ultimately part of a definite length element. A simple example of this
* would be the handling of constructed OCTET STRINGs in BER encoding.
*
* This algorithm finds the first definite length element in the ancestor
* stack, if any, and if so, ensures that the length of the child element
* is consistent with the number of bytes remaining in the constraining
* ancestor element (that is, after accounting for any other sibling
* elements that may have been read).
*
* It's slightly complicated by the need to account both for integer
* underflow and overflow, as well as ensure that for indefinite length
* encodings, there's also enough space for the End-of-Contents (EOC)
* octets (Tag = 0x00, Length = 0x00, or two bytes).
*/
/* Determine the maximum length available for this element by finding the
* first definite length ancestor, if any. */
parent = sec_asn1d_get_enclosing_construct(state);
while (parent && parent->indefinite) {
parent = sec_asn1d_get_enclosing_construct(parent);
}
/* If parent is null, state is either the outermost state / at the top of
* the stack, or the outermost state uses indefinite length encoding. In
* these cases, there's nothing external to constrain this element, so
* there's nothing to check. */
if (parent) {
unsigned long remaining = parent->pending;
parent = state;
do {
if (!sec_asn1d_check_and_subtract_length(
&remaining, parent->consumed, state->top) ||
/* If parent->indefinite is true, parent->contents_length is
* zero and this is a no-op. */
!sec_asn1d_check_and_subtract_length(
&remaining, parent->contents_length, state->top) ||
/* If parent->indefinite is true, then ensure there is enough
* space for an EOC tag of 2 bytes. */
(parent->indefinite && !sec_asn1d_check_and_subtract_length(
&remaining, 2, state->top))) {
/* This element is larger than its enclosing element, which is
* invalid. */
return;
}
} while ((parent = sec_asn1d_get_enclosing_construct(parent)) &&
parent->indefinite);
}
/*
* XXX I cannot decide if this allocation should exclude the case
* where state->endofcontents is true -- figure it out!
*/
if (state->allocate) {
void *dest;
PORT_Assert (state->dest == NULL);
/*
* We are handling a POINTER or a member of a GROUP, and need to
* allocate for the data structure.
*/
dest = sec_asn1d_zalloc (state->top->their_pool,
state->theTemplate->size);
if (dest == NULL) {
state->top->status = decodeError;
return;
}
state->dest = (char *)dest + state->theTemplate->offset;
/*
* For a member of a GROUP, our parent will later put the
* pointer wherever it belongs. But for a POINTER, we need
* to record the destination now, in case notify or filter
* procs need access to it -- they cannot find it otherwise,
* until it is too late (for one-pass processing).
*/
if (state->parent->place == afterPointer) {
void **placep;
placep = state->parent->dest;
*placep = dest;
}
}
/*
* Remember, length may be indefinite here! In that case,
* both contents_length and pending will be zero.
*/
state->pending = state->contents_length;
/*
* An EXPLICIT is nothing but an outer header, which we have
* already parsed and accepted. Now we need to do the inner
* header and its contents.
*/
if (state->explicit) {
state->place = afterExplicit;
state = sec_asn1d_push_state (state->top,
SEC_ASN1GetSubtemplate(state->theTemplate,
state->dest,
PR_FALSE),
state->dest, PR_TRUE);
if (state != NULL)
state = sec_asn1d_init_state_based_on_template (state);
return;
}
/*
* For GROUP (SET OF, SEQUENCE OF), even if we know the length here
* we cannot tell how many items we will end up with ... so push a
* state that can keep track of "children" (the individual members
* of the group; we will allocate as we go and put them all together
* at the end.
*/
if (state->underlying_kind & SEC_ASN1_GROUP) {
/* XXX If this assertion holds (should be able to confirm it via
* inspection, too) then move this code into the switch statement
* below under cases SET_OF and SEQUENCE_OF; it will be cleaner.
*/
PORT_Assert (state->underlying_kind == SEC_ASN1_SET_OF
|| state->underlying_kind == SEC_ASN1_SEQUENCE_OF
|| state->underlying_kind == (SEC_ASN1_SEQUENCE_OF|SEC_ASN1_DYNAMIC)
|| state->underlying_kind == (SEC_ASN1_SEQUENCE_OF|SEC_ASN1_DYNAMIC)
);
if (state->contents_length != 0 || state->indefinite) {
const SEC_ASN1Template *subt;
state->place = duringGroup;
subt = SEC_ASN1GetSubtemplate (state->theTemplate, state->dest,
PR_FALSE);
state = sec_asn1d_push_state (state->top, subt, NULL, PR_TRUE);
if (state != NULL) {
if (!state->top->filter_only)
state->allocate = PR_TRUE; /* XXX propogate this? */
/*
* Do the "before" field notification for next in group.
*/
sec_asn1d_notify_before (state->top, state->dest, state->depth);
state = sec_asn1d_init_state_based_on_template (state);
}
} else {
/*
* A group of zero; we are done.
* Set state to afterGroup and let that code plant the NULL.
*/
state->place = afterGroup;
}
return;
}
switch (state->underlying_kind) {
case SEC_ASN1_SEQUENCE:
/*
* We need to push a child to handle the individual fields.
*/
state->place = duringSequence;
state = sec_asn1d_push_state (state->top, state->theTemplate + 1,
state->dest, PR_TRUE);
if (state != NULL) {
/*
* Do the "before" field notification.
*/
sec_asn1d_notify_before (state->top, state->dest, state->depth);
state = sec_asn1d_init_state_based_on_template (state);
}
break;
case SEC_ASN1_SET: /* XXX SET is not really implemented */
/*
* XXX A plain SET requires special handling; scanning of a
* template to see where a field should go (because by definition,
* they are not in any particular order, and you have to look at
* each tag to disambiguate what the field is). We may never
* implement this because in practice, it seems to be unused.
*/
PORT_Assert(0);
PORT_SetError (SEC_ERROR_BAD_DER); /* XXX */
state->top->status = decodeError;
break;
case SEC_ASN1_NULL:
/*
* The NULL type, by definition, is "nothing", content length of zero.
* An indefinite-length encoding is not alloweed.
*/
if (state->contents_length || state->indefinite) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
break;
}
if (state->dest != NULL) {
item = (SECItem *)(state->dest);
item->data = NULL;
item->len = 0;
}
state->place = afterEndOfContents;
break;
case SEC_ASN1_BMP_STRING:
/* Error if length is not divisable by 2 */
if (state->contents_length % 2) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
break;
}
/* otherwise, handle as other string types */
goto regular_string_type;
case SEC_ASN1_UNIVERSAL_STRING:
/* Error if length is not divisable by 4 */
if (state->contents_length % 4) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
break;
}
/* otherwise, handle as other string types */
goto regular_string_type;
case SEC_ASN1_SKIP:
case SEC_ASN1_ANY:
case SEC_ASN1_ANY_CONTENTS:
/*
* These are not (necessarily) strings, but they need nearly
* identical handling (especially when we need to deal with
* constructed sub-pieces), so we pretend they are.
*/
/* fallthru */
regular_string_type:
case SEC_ASN1_BIT_STRING:
case SEC_ASN1_IA5_STRING:
case SEC_ASN1_OCTET_STRING:
case SEC_ASN1_PRINTABLE_STRING:
case SEC_ASN1_T61_STRING:
case SEC_ASN1_UTC_TIME:
case SEC_ASN1_UTF8_STRING:
case SEC_ASN1_VISIBLE_STRING:
/*
* We are allocating for a primitive or a constructed string.
* If it is a constructed string, it may also be indefinite-length.
* If it is primitive, the length can (legally) be zero.
* Our first order of business is to allocate the memory for
* the string, if we can (if we know the length).
*/
item = (SECItem *)(state->dest);
/*
* If the item is a definite-length constructed string, then
* the contents_length is actually larger than what we need
* (because it also counts each intermediate header which we
* will be throwing away as we go), but it is a perfectly good
* upper bound that we just allocate anyway, and then concat
* as we go; we end up wasting a few extra bytes but save a
* whole other copy.
*/
alloc_len = state->contents_length;
poolp = NULL; /* quiet compiler warnings about unused... */
if (item == NULL || state->top->filter_only) {
if (item != NULL) {
item->data = NULL;
item->len = 0;
}
alloc_len = 0;
} else if (state->substring) {
/*
* If we are a substring of a constructed string, then we may
* not have to allocate anything (because our parent, the
* actual constructed string, did it for us). If we are a
* substring and we *do* have to allocate, that means our
* parent is an indefinite-length, so we allocate from our pool;
* later our parent will copy our string into the aggregated
* whole and free our pool allocation.
*/
if (item->data == NULL) {
PORT_Assert (item->len == 0);
poolp = state->top->our_pool;
} else {
alloc_len = 0;
}
} else {
item->len = 0;
item->data = NULL;
poolp = state->top->their_pool;
}
if (alloc_len || ((! state->indefinite)
&& (state->subitems_head != NULL))) {
struct subitem *subitem;
int len;
PORT_Assert (item);
if (!item) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
PORT_Assert (item->len == 0 && item->data == NULL);
/*
* Check for and handle an ANY which has stashed aside the
* header (identifier and length) bytes for us to include
* in the saved contents.
*/
if (state->subitems_head != NULL) {
PORT_Assert (state->underlying_kind == SEC_ASN1_ANY);
for (subitem = state->subitems_head;
subitem != NULL; subitem = subitem->next)
alloc_len += subitem->len;
}
item->data = (unsigned char*)sec_asn1d_zalloc (poolp, alloc_len);
if (item->data == NULL) {
state->top->status = decodeError;
break;
}
len = 0;
for (subitem = state->subitems_head;
subitem != NULL; subitem = subitem->next) {
PORT_Memcpy (item->data + len, subitem->data, subitem->len);
len += subitem->len;
}
item->len = len;
/*
* Because we use arenas and have a mark set, we later free
* everything we have allocated, so this does *not* present
* a memory leak (it is just temporarily left dangling).
*/
state->subitems_head = state->subitems_tail = NULL;
}
if (state->contents_length == 0 && (! state->indefinite)) {
/*
* A zero-length simple or constructed string; we are done.
*/
state->place = afterEndOfContents;
} else if (state->found_tag_modifiers & SEC_ASN1_CONSTRUCTED) {
const SEC_ASN1Template *sub;
switch (state->underlying_kind) {
case SEC_ASN1_ANY:
case SEC_ASN1_ANY_CONTENTS:
sub = SEC_AnyTemplate;
break;
case SEC_ASN1_BIT_STRING:
sub = SEC_BitStringTemplate;
break;
case SEC_ASN1_BMP_STRING:
sub = SEC_BMPStringTemplate;
break;
case SEC_ASN1_GENERALIZED_TIME:
sub = SEC_GeneralizedTimeTemplate;
break;
case SEC_ASN1_IA5_STRING:
sub = SEC_IA5StringTemplate;
break;
case SEC_ASN1_OCTET_STRING:
sub = SEC_OctetStringTemplate;
break;
case SEC_ASN1_PRINTABLE_STRING:
sub = SEC_PrintableStringTemplate;
break;
case SEC_ASN1_T61_STRING:
sub = SEC_T61StringTemplate;
break;
case SEC_ASN1_UNIVERSAL_STRING:
sub = SEC_UniversalStringTemplate;
break;
case SEC_ASN1_UTC_TIME:
sub = SEC_UTCTimeTemplate;
break;
case SEC_ASN1_UTF8_STRING:
sub = SEC_UTF8StringTemplate;
break;
case SEC_ASN1_VISIBLE_STRING:
sub = SEC_VisibleStringTemplate;
break;
case SEC_ASN1_SKIP:
sub = SEC_SkipTemplate;
break;
default: /* redundant given outer switch cases, but */
PORT_Assert(0); /* the compiler does not seem to know that, */
sub = NULL; /* so just do enough to quiet it. */
break;
}
state->place = duringConstructedString;
state = sec_asn1d_push_state (state->top, sub, item, PR_TRUE);
if (state != NULL) {
state->substring = PR_TRUE; /* XXX propogate? */
state = sec_asn1d_init_state_based_on_template (state);
}
} else if (state->indefinite) {
/*
* An indefinite-length string *must* be constructed!
*/
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
} else {
/*
* A non-zero-length simple string.
*/
if (state->underlying_kind == SEC_ASN1_BIT_STRING)
state->place = beforeBitString;
else
state->place = duringLeaf;
}
break;
default:
/*
* We are allocating for a simple leaf item.
*/
if (state->contents_length) {
if (state->dest != NULL) {
item = (SECItem *)(state->dest);
item->len = 0;
if (state->top->filter_only) {
item->data = NULL;
} else {
item->data = (unsigned char*)
sec_asn1d_zalloc (state->top->their_pool,
state->contents_length);
if (item->data == NULL) {
state->top->status = decodeError;
return;
}
}
}
state->place = duringLeaf;
} else {
/*
* An indefinite-length or zero-length item is not allowed.
* (All legal cases of such were handled above.)
*/
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
}
}
}
static void
sec_asn1d_free_child (sec_asn1d_state *state, PRBool error)
{
if (state->child != NULL) {
PORT_Assert (error || state->child->consumed == 0);
PORT_Assert (state->our_mark != NULL);
PORT_ArenaZRelease (state->top->our_pool, state->our_mark);
if (error && state->top->their_pool == NULL) {
/*
* XXX We need to free anything allocated.
* At this point, we failed in the middle of decoding. But we
* can't free the data we previously allocated with PR_Malloc
* unless we keep track of every pointer. So instead we have a
* memory leak when decoding fails half-way, unless an arena is
* used. See bug 95311 .
*/
}
state->child = NULL;
state->our_mark = NULL;
} else {
/*
* It is important that we do not leave a mark unreleased/unmarked.
* But I do not think we should ever have one set in this case, only
* if we had a child (handled above). So check for that. If this
* assertion should ever get hit, then we probably need to add code
* here to release back to our_mark (and then set our_mark to NULL).
*/
PORT_Assert (state->our_mark == NULL);
}
state->place = beforeEndOfContents;
}
/* We have just saved an entire encoded ASN.1 object (type) for a SAVE
** template, and now in the next template, we are going to decode that
** saved data by calling SEC_ASN1DecoderUpdate recursively.
** If that recursive call fails with needBytes, it is a fatal error,
** because the encoded object should have been complete.
** If that recursive call fails with decodeError, it will have already
** cleaned up the state stack, so we must bail out quickly.
**
** These checks of the status returned by the recursive call are now
** done in the caller of this function, immediately after it returns.
*/
static void
sec_asn1d_reuse_encoding (sec_asn1d_state *state)
{
sec_asn1d_state *child;
unsigned long consumed;
SECItem *item;
void *dest;
child = state->child;
PORT_Assert (child != NULL);
consumed = child->consumed;
child->consumed = 0;
item = (SECItem *)(state->dest);
PORT_Assert (item != NULL);
PORT_Assert (item->len == consumed);
/*
* Free any grandchild.
*/
sec_asn1d_free_child (child, PR_FALSE);
/*
* Notify after the SAVE field.
*/
sec_asn1d_notify_after (state->top, state->dest, state->depth);
/*
* Adjust to get new dest and move forward.
*/
dest = (char *)state->dest - state->theTemplate->offset;
state->theTemplate++;
child->dest = (char *)dest + state->theTemplate->offset;
child->theTemplate = state->theTemplate;
/*
* Notify before the "real" field.
*/
PORT_Assert (state->depth == child->depth);
sec_asn1d_notify_before (state->top, child->dest, child->depth);
/*
* This will tell DecoderUpdate to return when it is done.
*/
state->place = afterSaveEncoding;
/*
* We already have a child; "push" it by making it current.
*/
state->top->current = child;
/*
* And initialize it so it is ready to parse.
*/
(void) sec_asn1d_init_state_based_on_template(child);
/*
* Now parse that out of our data.
*/
if (SEC_ASN1DecoderUpdate (state->top,
(char *) item->data, item->len) != SECSuccess)
return;
if (state->top->status == needBytes) {
return;
}
PORT_Assert (state->top->current == state);
PORT_Assert (state->child == child);
/*
* That should have consumed what we consumed before.
*/
PORT_Assert (consumed == child->consumed);
child->consumed = 0;
/*
* Done.
*/
state->consumed += consumed;
child->place = notInUse;
state->place = afterEndOfContents;
}
static unsigned long
sec_asn1d_parse_leaf (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
SECItem *item;
unsigned long bufLen;
if (len == 0) {
state->top->status = needBytes;
return 0;
}
if (state->pending < len)
len = state->pending;
bufLen = len;
item = (SECItem *)(state->dest);
if (item != NULL && item->data != NULL) {
/* Strip leading zeroes when target is unsigned integer */
if (state->underlying_kind == SEC_ASN1_INTEGER && /* INTEGER */
item->len == 0 && /* MSB */
item->type == siUnsignedInteger) /* unsigned */
{
while (len > 1 && buf[0] == 0) { /* leading 0 */
buf++;
len--;
}
}
PORT_Memcpy (item->data + item->len, buf, len);
item->len += len;
}
state->pending -= bufLen;
if (state->pending == 0)
state->place = beforeEndOfContents;
return bufLen;
}
static unsigned long
sec_asn1d_parse_bit_string (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
unsigned char byte;
/*PORT_Assert (state->pending > 0); */
PORT_Assert (state->place == beforeBitString);
if (state->pending == 0) {
if (state->dest != NULL) {
SECItem *item = (SECItem *)(state->dest);
item->data = NULL;
item->len = 0;
state->place = beforeEndOfContents;
return 0;
}
}
if (len == 0) {
state->top->status = needBytes;
return 0;
}
byte = (unsigned char) *buf;
if (byte > 7) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return 0;
}
state->bit_string_unused_bits = byte;
state->place = duringBitString;
state->pending -= 1;
return 1;
}
static unsigned long
sec_asn1d_parse_more_bit_string (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
PORT_Assert (state->place == duringBitString);
if (state->pending == 0) {
/* An empty bit string with some unused bits is invalid. */
if (state->bit_string_unused_bits) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
} else {
/* An empty bit string with no unused bits is OK. */
state->place = beforeEndOfContents;
}
return 0;
}
len = sec_asn1d_parse_leaf (state, buf, len);
if (state->place == beforeEndOfContents && state->dest != NULL) {
SECItem *item;
item = (SECItem *)(state->dest);
if (item->len)
item->len = (item->len << 3) - state->bit_string_unused_bits;
}
return len;
}
/*
* XXX All callers should be looking at return value to detect
* out-of-memory errors (and stop!).
*/
static struct subitem *
sec_asn1d_add_to_subitems (sec_asn1d_state *state,
const void *data, unsigned long len,
PRBool copy_data)
{
struct subitem *thing;
thing = (struct subitem*)sec_asn1d_zalloc (state->top->our_pool,
sizeof (struct subitem));
if (thing == NULL) {
state->top->status = decodeError;
return NULL;
}
if (copy_data) {
void *copy;
copy = sec_asn1d_alloc (state->top->our_pool, len);
if (copy == NULL) {
state->top->status = decodeError;
if (!state->top->our_pool)
PORT_Free(thing);
return NULL;
}
PORT_Memcpy (copy, data, len);
thing->data = copy;
} else {
thing->data = data;
}
thing->len = len;
thing->next = NULL;
if (state->subitems_head == NULL) {
PORT_Assert (state->subitems_tail == NULL);
state->subitems_head = state->subitems_tail = thing;
} else {
state->subitems_tail->next = thing;
state->subitems_tail = thing;
}
return thing;
}
static void
sec_asn1d_record_any_header (sec_asn1d_state *state,
const char *buf,
unsigned long len)
{
SECItem *item;
item = (SECItem *)(state->dest);
if (item != NULL && item->data != NULL) {
PORT_Assert (state->substring);
PORT_Memcpy (item->data + item->len, buf, len);
item->len += len;
} else {
sec_asn1d_add_to_subitems (state, buf, len, PR_TRUE);
}
}
/*
* We are moving along through the substrings of a constructed string,
* and have just finished parsing one -- we need to save our child data
* (if the child was not already writing directly into the destination)
* and then move forward by one.
*
* We also have to detect when we are done:
* - a definite-length encoding stops when our pending value hits 0
* - an indefinite-length encoding stops when our child is empty
* (which means it was the end-of-contents octets)
*/
static void
sec_asn1d_next_substring (sec_asn1d_state *state)
{
sec_asn1d_state *child;
SECItem *item;
unsigned long child_consumed;
PRBool done;
PORT_Assert (state->place == duringConstructedString);
PORT_Assert (state->child != NULL);
child = state->child;
child_consumed = child->consumed;
child->consumed = 0;
state->consumed += child_consumed;
done = PR_FALSE;
if (state->pending) {
PORT_Assert (!state->indefinite);
if (child_consumed > state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
state->pending -= child_consumed;
if (state->pending == 0)
done = PR_TRUE;
} else {
PRBool preallocatedString;
sec_asn1d_state *temp_state;
PORT_Assert (state->indefinite);
item = (SECItem *)(child->dest);
/**
* At this point, there's three states at play:
* child: The element that was just parsed
* state: The currently processed element
* 'parent' (aka state->parent): The enclosing construct
* of state, or NULL if this is the top-most element.
*
* This state handles both substrings of a constructed string AND
* child elements of items whose template type was that of
* SEC_ASN1_ANY, SEC_ASN1_SAVE, SEC_ASN1_ANY_CONTENTS, SEC_ASN1_SKIP
* template, as described in sec_asn1d_prepare_for_contents. For
* brevity, these will be referred to as 'string' and 'any' types.
*
* This leads to the following possibilities:
* 1: This element is an indefinite length string, part of a
* definite length string.
* 2: This element is an indefinite length string, part of an
* indefinite length string.
* 3: This element is an indefinite length any, part of a
* definite length any.
* 4: This element is an indefinite length any, part of an
* indefinite length any.
* 5: This element is an indefinite length any and does not
* meet any of the above criteria. Note that this would include
* an indefinite length string type matching an indefinite
* length any template.
*
* In Cases #1 and #3, the definite length 'parent' element will
* have allocated state->dest based on the parent elements definite
* size. During the processing of 'child', sec_asn1d_parse_leaf will
* have copied the (string, any) data directly into the offset of
* dest, as appropriate, so there's no need for this class to still
* store the child - it's already been processed.
*
* In Cases #2 and #4, dest will be set to the parent element's dest,
* but dest->data will not have been allocated yet, due to the
* indefinite length encoding. In this situation, it's necessary to
* hold onto child (and all other children) until the EOC, at which
* point, it becomes possible to compute 'state's overall length. Once
* 'state' has a computed length, this can then be fed to 'parent' (via
* this state), and then 'parent' can similarly compute the length of
* all of its children up to the EOC, which will ultimately transit to
* sec_asn1d_concat_substrings, determine the overall size needed,
* allocate, and copy the contents (of all of parent's children, which
* would include 'state', just as 'state' will have copied all of its
* children via sec_asn1d_concat_substrings)
*
* The final case, Case #5, will manifest in that item->data and
* item->len will be NULL/0, respectively, since this element was
* indefinite-length encoded. In that case, both the tag and length will
* already exist in state's subitems, via sec_asn1d_record_any_header,
* and so the contents (aka 'child') should be added to that list of
* items to concatenate in sec_asn1d_concat_substrings once the EOC
* is encountered.
*
* To distinguish #2/#4 from #1/#3, it's sufficient to walk the ancestor
* tree. If the current type is a string type, then the enclosing
* construct will be that same type (#1/#2). If the current type is an
* any type, then the enclosing construct is either an any type (#3/#4)
* or some other type (#5). Since this is BER, this nesting relationship
* between 'state' and 'parent' may go through several levels of
* constructed encoding, so continue walking the ancestor chain until a
* clear determination can be made.
*
* The variable preallocatedString is used to indicate Case #1/#3,
* indicating an in-place copy has already occurred, and Cases #2, #4,
* and #5 all have the same behaviour of adding a new substring.
*/
preallocatedString = PR_FALSE;
temp_state = state;
while (temp_state && item == temp_state->dest && temp_state->indefinite) {
sec_asn1d_state *parent = sec_asn1d_get_enclosing_construct(temp_state);
if (!parent || parent->underlying_kind != temp_state->underlying_kind) {
/* Case #5 - Either this is a top-level construct or it is part
* of some other element (e.g. a SEQUENCE), in which case, a
* new item should be allocated. */
break;
}
if (!parent->indefinite) {
/* Cases #1 / #3 - A definite length ancestor exists, for which
* this is a substring that has already copied into dest. */
preallocatedString = PR_TRUE;
break;
}
if (!parent->substring) {
/* Cases #2 / #4 - If the parent is not a substring, but is
* indefinite, then there's nothing further up that may have
* preallocated dest, thus child will not have already
* been copied in place, therefore it's necessary to save child
* as a subitem. */
break;
}
temp_state = parent;
}
if (item != NULL && item->data != NULL && !preallocatedString) {
/*
* Save the string away for later concatenation.
*/
PORT_Assert (item->data != NULL);
sec_asn1d_add_to_subitems (state, item->data, item->len, PR_FALSE);
/*
* Clear the child item for the next round.
*/
item->data = NULL;
item->len = 0;
}
/*
* If our child was just our end-of-contents octets, we are done.
*/
if (child->endofcontents)
done = PR_TRUE;
}
/*
* Stop or do the next one.
*/
if (done) {
child->place = notInUse;
state->place = afterConstructedString;
} else {
sec_asn1d_scrub_state (child);
state->top->current = child;
}
}
/*
* We are doing a SET OF or SEQUENCE OF, and have just finished an item.
*/
static void
sec_asn1d_next_in_group (sec_asn1d_state *state)
{
sec_asn1d_state *child;
unsigned long child_consumed;
PORT_Assert (state->place == duringGroup);
PORT_Assert (state->child != NULL);
child = state->child;
child_consumed = child->consumed;
child->consumed = 0;
state->consumed += child_consumed;
/*
* If our child was just our end-of-contents octets, we are done.
*/
if (child->endofcontents) {
/* XXX I removed the PORT_Assert (child->dest == NULL) because there
* was a bug in that a template that was a sequence of which also had
* a child of a sequence of, in an indefinite group was not working
* properly. This fix seems to work, (added the if statement below),
* and nothing appears broken, but I am putting this note here just
* in case. */
/*
* XXX No matter how many times I read that comment,
* I cannot figure out what case he was fixing. I believe what he
* did was deliberate, so I am loathe to touch it. I need to
* understand how it could ever be that child->dest != NULL but
* child->endofcontents is true, and why it is important to check
* that state->subitems_head is NULL. This really needs to be
* figured out, as I am not sure if the following code should be
* compensating for "offset", as is done a little farther below
* in the more normal case.
*/
PORT_Assert (state->indefinite);
PORT_Assert (state->pending == 0);
if(child->dest && !state->subitems_head) {
sec_asn1d_add_to_subitems (state, child->dest, 0, PR_FALSE);
child->dest = NULL;
}
child->place = notInUse;
state->place = afterGroup;
return;
}
/*
* Do the "after" field notification for next in group.
*/
sec_asn1d_notify_after (state->top, child->dest, child->depth);
/*
* Save it away (unless we are not storing).
*/
if (child->dest != NULL) {
void *dest;
dest = child->dest;
dest = (char *)dest - child->theTemplate->offset;
sec_asn1d_add_to_subitems (state, dest, 0, PR_FALSE);
child->dest = NULL;
}
/*
* Account for those bytes; see if we are done.
*/
if (state->pending) {
PORT_Assert (!state->indefinite);
if (child_consumed > state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
state->pending -= child_consumed;
if (state->pending == 0) {
child->place = notInUse;
state->place = afterGroup;
return;
}
}
/*
* Do the "before" field notification for next item in group.
*/
sec_asn1d_notify_before (state->top, child->dest, child->depth);
/*
* Now we do the next one.
*/
sec_asn1d_scrub_state (child);
/* Initialize child state from the template */
sec_asn1d_init_state_based_on_template(child);
state->top->current = child;
}
/*
* We are moving along through a sequence; move forward by one,
* (detecting end-of-sequence when it happens).
* XXX The handling of "missing" is ugly. Fix it.
*/
static void
sec_asn1d_next_in_sequence (sec_asn1d_state *state)
{
sec_asn1d_state *child;
unsigned long child_consumed;
PRBool child_missing;
PORT_Assert (state->place == duringSequence);
PORT_Assert (state->child != NULL);
child = state->child;
/*
* Do the "after" field notification.
*/
sec_asn1d_notify_after (state->top, child->dest, child->depth);
child_missing = (PRBool) child->missing;
child_consumed = child->consumed;
child->consumed = 0;
/*
* Take care of accounting.
*/
if (child_missing) {
PORT_Assert (child->optional);
} else {
state->consumed += child_consumed;
/*
* Free any grandchild.
*/
sec_asn1d_free_child (child, PR_FALSE);
if (state->pending) {
PORT_Assert (!state->indefinite);
if (child_consumed > state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
state->pending -= child_consumed;
if (state->pending == 0) {
child->theTemplate++;
while (child->theTemplate->kind != 0) {
if ((child->theTemplate->kind & SEC_ASN1_OPTIONAL) == 0) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
child->theTemplate++;
}
child->place = notInUse;
state->place = afterEndOfContents;
return;
}
}
}
/*
* Move forward.
*/
child->theTemplate++;
if (child->theTemplate->kind == 0) {
/*
* We are done with this sequence.
*/
child->place = notInUse;
if (state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
} else if (child_missing) {
/*
* We got to the end, but have a child that started parsing
* and ended up "missing". The only legitimate reason for
* this is that we had one or more optional fields at the
* end of our sequence, and we were encoded indefinite-length,
* so when we went looking for those optional fields we
* found our end-of-contents octets instead.
* (Yes, this is ugly; dunno a better way to handle it.)
* So, first confirm the situation, and then mark that we
* are done.
*/
if (state->indefinite && child->endofcontents) {
PORT_Assert (child_consumed == 2);
if (child_consumed != 2) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
} else {
state->consumed += child_consumed;
state->place = afterEndOfContents;
}
} else {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
}
} else {
/*
* We have to finish out, maybe reading end-of-contents octets;
* let the normal logic do the right thing.
*/
state->place = beforeEndOfContents;
}
} else {
unsigned char child_found_tag_modifiers = 0;
unsigned long child_found_tag_number = 0;
/*
* Reset state and push.
*/
if (state->dest != NULL)
child->dest = (char *)state->dest + child->theTemplate->offset;
/*
* Do the "before" field notification.
*/
sec_asn1d_notify_before (state->top, child->dest, child->depth);
if (child_missing) { /* if previous child was missing, copy the tag data we already have */
child_found_tag_modifiers = child->found_tag_modifiers;
child_found_tag_number = child->found_tag_number;
}
state->top->current = child;
child = sec_asn1d_init_state_based_on_template (child);
if (child_missing && child) {
child->place = afterIdentifier;
child->found_tag_modifiers = child_found_tag_modifiers;
child->found_tag_number = child_found_tag_number;
child->consumed = child_consumed;
if (child->underlying_kind == SEC_ASN1_ANY
&& !child->top->filter_only) {
/*
* If the new field is an ANY, and we are storing, then
* we need to save the tag out. We would have done this
* already in the normal case, but since we were looking
* for an optional field, and we did not find it, we only
* now realize we need to save the tag.
*/
unsigned char identifier;
/*
* Check that we did not end up with a high tag; for that
* we need to re-encode the tag into multiple bytes in order
* to store it back to look like what we parsed originally.
* In practice this does not happen, but for completeness
* sake it should probably be made to work at some point.
*/
PORT_Assert (child_found_tag_number < SEC_ASN1_HIGH_TAG_NUMBER);
identifier = (unsigned char)(child_found_tag_modifiers | child_found_tag_number);
sec_asn1d_record_any_header (child, (char *) &identifier, 1);
}
}
}
}
static void
sec_asn1d_concat_substrings (sec_asn1d_state *state)
{
PORT_Assert (state->place == afterConstructedString);
if (state->subitems_head != NULL) {
struct subitem *substring;
unsigned long alloc_len, item_len;
unsigned char *where;
SECItem *item;
PRBool is_bit_string;
item_len = 0;
is_bit_string = (state->underlying_kind == SEC_ASN1_BIT_STRING)
? PR_TRUE : PR_FALSE;
substring = state->subitems_head;
while (substring != NULL) {
/*
* All bit-string substrings except the last one should be
* a clean multiple of 8 bits.
*/
if (is_bit_string && (substring->next == NULL)
&& (substring->len & 0x7)) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
item_len += substring->len;
substring = substring->next;
}
if (is_bit_string) {
alloc_len = ((item_len + 7) >> 3);
} else {
/*
* Add 2 for the end-of-contents octets of an indefinite-length
* ANY that is *not* also an INNER. Because we zero-allocate
* below, all we need to do is increase the length here.
*/
if (state->underlying_kind == SEC_ASN1_ANY && state->indefinite)
item_len += 2;
alloc_len = item_len;
}
item = (SECItem *)(state->dest);
PORT_Assert (item != NULL);
PORT_Assert (item->data == NULL);
item->data = (unsigned char*)sec_asn1d_zalloc (state->top->their_pool,
alloc_len);
if (item->data == NULL) {
state->top->status = decodeError;
return;
}
item->len = item_len;
where = item->data;
substring = state->subitems_head;
while (substring != NULL) {
if (is_bit_string)
item_len = (substring->len + 7) >> 3;
else
item_len = substring->len;
PORT_Memcpy (where, substring->data, item_len);
where += item_len;
substring = substring->next;
}
/*
* Because we use arenas and have a mark set, we later free
* everything we have allocated, so this does *not* present
* a memory leak (it is just temporarily left dangling).
*/
state->subitems_head = state->subitems_tail = NULL;
}
state->place = afterEndOfContents;
}
static void
sec_asn1d_concat_group (sec_asn1d_state *state)
{
const void ***placep;
PORT_Assert (state->place == afterGroup);
placep = (const void***)state->dest;
PORT_Assert(state->subitems_head == NULL || placep != NULL);
if (placep != NULL) {
struct subitem *item;
const void **group;
int count;
count = 0;
item = state->subitems_head;
while (item != NULL) {
PORT_Assert (item->next != NULL || item == state->subitems_tail);
count++;
item = item->next;
}
group = (const void**)sec_asn1d_zalloc (state->top->their_pool,
(count + 1) * (sizeof(void *)));
if (group == NULL) {
state->top->status = decodeError;
return;
}
*placep = group;
item = state->subitems_head;
while (item != NULL) {
*group++ = item->data;
item = item->next;
}
*group = NULL;
/*
* Because we use arenas and have a mark set, we later free
* everything we have allocated, so this does *not* present
* a memory leak (it is just temporarily left dangling).
*/
state->subitems_head = state->subitems_tail = NULL;
}
state->place = afterEndOfContents;
}
/*
* For those states that push a child to handle a subtemplate,
* "absorb" that child (transfer necessary information).
*/
static void
sec_asn1d_absorb_child (sec_asn1d_state *state)
{
/*
* There is absolutely supposed to be a child there.
*/
PORT_Assert (state->child != NULL);
/*
* Inherit the missing status of our child, and do the ugly
* backing-up if necessary.
*/
state->missing = state->child->missing;
if (state->missing) {
state->found_tag_number = state->child->found_tag_number;
state->found_tag_modifiers = state->child->found_tag_modifiers;
state->endofcontents = state->child->endofcontents;
}
/*
* Add in number of bytes consumed by child.
* (Only EXPLICIT should have already consumed bytes itself.)
*/
PORT_Assert (state->place == afterExplicit || state->consumed == 0);
state->consumed += state->child->consumed;
/*
* Subtract from bytes pending; this only applies to a definite-length
* EXPLICIT field.
*/
if (state->pending) {
PORT_Assert (!state->indefinite);
PORT_Assert (state->place == afterExplicit);
/*
* If we had a definite-length explicit, then what the child
* consumed should be what was left pending.
*/
if (state->pending != state->child->consumed) {
if (state->pending < state->child->consumed) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return;
}
/*
* Okay, this is a hack. It *should* be an error whether
* pending is too big or too small, but it turns out that
* we had a bug in our *old* DER encoder that ended up
* counting an explicit header twice in the case where
* the underlying type was an ANY. So, because we cannot
* prevent receiving these (our own certificate server can
* send them to us), we need to be lenient and accept them.
* To do so, we need to pretend as if we read all of the
* bytes that the header said we would find, even though
* we actually came up short.
*/
state->consumed += (state->pending - state->child->consumed);
}
state->pending = 0;
}
/*
* Indicate that we are done with child.
*/
state->child->consumed = 0;
/*
* And move on to final state.
* (Technically everybody could move to afterEndOfContents except
* for an indefinite-length EXPLICIT; for simplicity though we assert
* that but let the end-of-contents code do the real determination.)
*/
PORT_Assert (state->place == afterExplicit || (! state->indefinite));
state->place = beforeEndOfContents;
}
static void
sec_asn1d_prepare_for_end_of_contents (sec_asn1d_state *state)
{
PORT_Assert (state->place == beforeEndOfContents);
if (state->indefinite) {
state->place = duringEndOfContents;
state->pending = 2;
} else {
state->place = afterEndOfContents;
}
}
static unsigned long
sec_asn1d_parse_end_of_contents (sec_asn1d_state *state,
const char *buf, unsigned long len)
{
unsigned int i;
PORT_Assert (state->pending <= 2);
PORT_Assert (state->place == duringEndOfContents);
if (len == 0) {
state->top->status = needBytes;
return 0;
}
if (state->pending < len)
len = state->pending;
for (i = 0; i < len; i++) {
if (buf[i] != 0) {
/*
* We expect to find only zeros; if not, just give up.
*/
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return 0;
}
}
state->pending -= len;
if (state->pending == 0) {
state->place = afterEndOfContents;
state->endofcontents = PR_TRUE;
}
return len;
}
static void
sec_asn1d_pop_state (sec_asn1d_state *state)
{
#if 0 /* XXX I think this should always be handled explicitly by parent? */
/*
* Account for our child.
*/
if (state->child != NULL) {
state->consumed += state->child->consumed;
if (state->pending) {
PORT_Assert (!state->indefinite);
if (state->child->consumed > state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
} else {
state->pending -= state->child->consumed;
}
}
state->child->consumed = 0;
}
#endif /* XXX */
/*
* Free our child.
*/
sec_asn1d_free_child (state, PR_FALSE);
/*
* 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;
}
static sec_asn1d_state *
sec_asn1d_before_choice (sec_asn1d_state *state)
{
sec_asn1d_state *child;
if (state->allocate) {
void *dest;
dest = sec_asn1d_zalloc(state->top->their_pool, state->theTemplate->size);
if ((void *)NULL == dest) {
state->top->status = decodeError;
return (sec_asn1d_state *)NULL;
}
state->dest = (char *)dest + state->theTemplate->offset;
}
child = sec_asn1d_push_state(state->top, state->theTemplate + 1,
(char *)state->dest - state->theTemplate->offset,
PR_FALSE);
if ((sec_asn1d_state *)NULL == child) {
return (sec_asn1d_state *)NULL;
}
sec_asn1d_scrub_state(child);
child = sec_asn1d_init_state_based_on_template(child);
if ((sec_asn1d_state *)NULL == child) {
return (sec_asn1d_state *)NULL;
}
child->optional = PR_TRUE;
state->place = duringChoice;
return child;
}
static sec_asn1d_state *
sec_asn1d_during_choice (sec_asn1d_state *state)
{
sec_asn1d_state *child = state->child;
PORT_Assert((sec_asn1d_state *)NULL != child);
if (child->missing) {
unsigned char child_found_tag_modifiers = 0;
unsigned long child_found_tag_number = 0;
void * dest;
state->consumed += child->consumed;
if (child->endofcontents) {
/* This choice is probably the first item in a GROUP
** (e.g. SET_OF) that was indefinite-length encoded.
** We're actually at the end of that GROUP.
** We look up the stack to be sure that we find
** a state with indefinite length encoding before we
** find a state (like a SEQUENCE) that is definite.
*/
child->place = notInUse;
state->place = afterChoice;
state->endofcontents = PR_TRUE; /* propagate this up */
if (sec_asn1d_parent_allows_EOC(state))
return state;
PORT_SetError(SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return NULL;
}
dest = (char *)child->dest - child->theTemplate->offset;
child->theTemplate++;
if (0 == child->theTemplate->kind) {
/* Ran out of choices */
PORT_SetError(SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return (sec_asn1d_state *)NULL;
}
child->dest = (char *)dest + child->theTemplate->offset;
/* cargo'd from next_in_sequence innards */
if (state->pending) {
PORT_Assert(!state->indefinite);
if (child->consumed > state->pending) {
PORT_SetError (SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return NULL;
}
state->pending -= child->consumed;
if (0 == state->pending) {
/* XXX uh.. not sure if I should have stopped this
* from happening before. */
PORT_Assert(0);
PORT_SetError(SEC_ERROR_BAD_DER);
state->top->status = decodeError;
return (sec_asn1d_state *)NULL;
}
}
child->consumed = 0;
sec_asn1d_scrub_state(child);
/* move it on top again */
state->top->current = child;
child_found_tag_modifiers = child->found_tag_modifiers;
child_found_tag_number = child->found_tag_number;
child = sec_asn1d_init_state_based_on_template(child);
if ((sec_asn1d_state *)NULL == child) {
return (sec_asn1d_state *)NULL;
}
/* copy our findings to the new top */
child->found_tag_modifiers = child_found_tag_modifiers;
child->found_tag_number = child_found_tag_number;
child->optional = PR_TRUE;
child->place = afterIdentifier;
return child;
}
if ((void *)NULL != state->dest) {
/* Store the enum */
int *which = (int *)state->dest;
*which = (int)child->theTemplate->size;
}
child->place = notInUse;
state->place = afterChoice;
return state;
}
static void
sec_asn1d_after_choice (sec_asn1d_state *state)
{
state->consumed += state->child->consumed;
state->child->consumed = 0;
state->place = afterEndOfContents;
sec_asn1d_pop_state(state);
}
unsigned long
sec_asn1d_uinteger(SECItem *src)
{
unsigned long value;
int len;
if (src->len > 5 || (src->len > 4 && src->data[0] == 0))
return 0;
value = 0;
len = src->len;
while (len) {
value <<= 8;
value |= src->data[--len];
}
return value;
}
SECStatus
SEC_ASN1DecodeInteger(SECItem *src, unsigned long *value)
{
unsigned long v;
unsigned int i;
if (src == NULL) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (src->len > sizeof(unsigned long)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (src->data == NULL) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
if (src->data[0] & 0x80)
v = -1; /* signed and negative - start with all 1's */
else
v = 0;
for (i= 0; i < src->len; i++) {
/* shift in next byte */
v <<= 8;
v |= src->data[i];
}
*value = v;
return SECSuccess;
}
#ifdef DEBUG_ASN1D_STATES
static void
dump_states(SEC_ASN1DecoderContext *cx)
{
sec_asn1d_state *state;
char kindBuf[256];
for (state = cx->current; state->parent; state = state->parent) {
;
}
for (; state; state = state->child) {
int i;
for (i = 0; i < state->depth; i++) {
printf(" ");
}
i = formatKind(state->theTemplate->kind, kindBuf);
printf("%s: tmpl %08x, kind%s",
(state == cx->current) ? "STATE" : "State",
state->theTemplate,
kindBuf);
printf(" %s", (state->place >= 0 && state->place <= notInUse)
? place_names[ state->place ]
: "(undefined)");
if (!i)
printf(", expect 0x%02x",
state->expect_tag_number | state->expect_tag_modifiers);
printf("%s%s%s %d\n",
state->indefinite ? ", indef" : "",
state->missing ? ", miss" : "",
state->endofcontents ? ", EOC" : "",
state->pending
);
}
return;
}
#endif /* DEBUG_ASN1D_STATES */
SECStatus
SEC_ASN1DecoderUpdate (SEC_ASN1DecoderContext *cx,
const char *buf, unsigned long len)
{
sec_asn1d_state *state = NULL;
unsigned long consumed;
SEC_ASN1EncodingPart what;
sec_asn1d_state *stateEnd = cx->current;
if (cx->status == needBytes)
cx->status = keepGoing;
while (cx->status == keepGoing) {
state = cx->current;
what = SEC_ASN1_Contents;
consumed = 0;
#ifdef DEBUG_ASN1D_STATES
printf("\nPLACE = %s, next byte = 0x%02x, %08x[%d]\n",
(state->place >= 0 && state->place <= notInUse) ?
place_names[ state->place ] : "(undefined)",
(unsigned int)((unsigned char *)buf)[ consumed ],
buf, consumed);
dump_states(cx);
#endif /* DEBUG_ASN1D_STATES */
switch (state->place) {
case beforeIdentifier:
consumed = sec_asn1d_parse_identifier (state, buf, len);
what = SEC_ASN1_Identifier;
break;
case duringIdentifier:
consumed = sec_asn1d_parse_more_identifier (state, buf, len);
what = SEC_ASN1_Identifier;
break;
case afterIdentifier:
sec_asn1d_confirm_identifier (state);
break;
case beforeLength:
consumed = sec_asn1d_parse_length (state, buf, len);
what = SEC_ASN1_Length;
break;
case duringLength:
consumed = sec_asn1d_parse_more_length (state, buf, len);
what = SEC_ASN1_Length;
break;
case afterLength:
sec_asn1d_prepare_for_contents (state);
break;
case beforeBitString:
consumed = sec_asn1d_parse_bit_string (state, buf, len);
break;
case duringBitString:
consumed = sec_asn1d_parse_more_bit_string (state, buf, len);
break;
case duringConstructedString:
sec_asn1d_next_substring (state);
break;
case duringGroup:
sec_asn1d_next_in_group (state);
break;
case duringLeaf:
consumed = sec_asn1d_parse_leaf (state, buf, len);
break;
case duringSaveEncoding:
sec_asn1d_reuse_encoding (state);
if (cx->status == decodeError) {
/* recursive call has already popped all states from stack.
** Bail out quickly.
*/
return SECFailure;
}
if (cx->status == needBytes) {
/* recursive call wanted more data. Fatal. Clean up below. */
PORT_SetError (SEC_ERROR_BAD_DER);
cx->status = decodeError;
}
break;
case duringSequence:
sec_asn1d_next_in_sequence (state);
break;
case afterConstructedString:
sec_asn1d_concat_substrings (state);
break;
case afterExplicit:
case afterImplicit:
case afterInline:
case afterPointer:
sec_asn1d_absorb_child (state);
break;
case afterGroup:
sec_asn1d_concat_group (state);
break;
case afterSaveEncoding:
/* SEC_ASN1DecoderUpdate has called itself recursively to
** decode SAVEd encoded data, and now is done decoding that.
** Return to the calling copy of SEC_ASN1DecoderUpdate.
*/
return SECSuccess;
case beforeEndOfContents:
sec_asn1d_prepare_for_end_of_contents (state);
break;
case duringEndOfContents:
consumed = sec_asn1d_parse_end_of_contents (state, buf, len);
what = SEC_ASN1_EndOfContents;
break;
case afterEndOfContents:
sec_asn1d_pop_state (state);
break;
case beforeChoice:
state = sec_asn1d_before_choice(state);
break;
case duringChoice:
state = sec_asn1d_during_choice(state);
break;
case afterChoice:
sec_asn1d_after_choice(state);
break;
case notInUse:
default:
/* This is not an error, but rather a plain old BUG! */
PORT_Assert (0);
PORT_SetError (SEC_ERROR_BAD_DER);
cx->status = decodeError;
break;
}
if (cx->status == decodeError)
break;
/* We should not consume more than we have. */
PORT_Assert (consumed <= len);
if (consumed > len) {
PORT_SetError (SEC_ERROR_BAD_DER);
cx->status = decodeError;
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) {
PORT_Assert (consumed == 0);
#if 0 /* XXX I want this here, but it seems that we have situations (like
* downloading a pkcs7 cert chain from some issuers) that give us a
* length which is greater than the entire encoding. So, we cannot
* have this be an error.
*/
if (len > 0) {
PORT_SetError (SEC_ERROR_BAD_DER);
cx->status = decodeError;
} else
#endif
cx->status = allDone;
break;
}
else if (state->theTemplate->kind == SEC_ASN1_SKIP_REST) {
cx->status = allDone;
break;
}
if (consumed == 0)
continue;
/*
* The following check is specifically looking for an ANY
* that is *not* also an INNER, because we need to save aside
* all bytes in that case -- the contents parts will get
* handled like all other contents, and the end-of-contents
* bytes are added by the concat code, but the outer header
* bytes need to get saved too, so we do them explicitly here.
*/
if (state->underlying_kind == SEC_ASN1_ANY
&& !cx->filter_only && (what == SEC_ASN1_Identifier
|| what == SEC_ASN1_Length)) {
sec_asn1d_record_any_header (state, buf, consumed);
}
/*
* We had some number of good, accepted bytes. If the caller
* has registered to see them, pass them along.
*/
if (state->top->filter_proc != NULL) {
int depth;
depth = state->depth;
if (what == SEC_ASN1_EndOfContents && !state->indefinite) {
PORT_Assert (state->parent != NULL
&& state->parent->indefinite);
depth--;
PORT_Assert (depth == state->parent->depth);
}
(* state->top->filter_proc) (state->top->filter_arg,
buf, consumed, depth, what);
}
state->consumed += consumed;
buf += consumed;
len -= consumed;
}
if (cx->status == decodeError) {
while (state != NULL && stateEnd->parent!=state) {
sec_asn1d_free_child (state, PR_TRUE);
state = state->parent;
}
#ifdef SEC_ASN1D_FREE_ON_ERROR /*
* XXX This does not work because we can
* end up leaving behind dangling pointers
* to stuff that was allocated. In order
* to make this really work (which would
* be a good thing, I think), we need to
* keep track of every place/pointer that
* was allocated and make sure to NULL it
* out before we then free back to the mark.
*/
if (cx->their_pool != NULL) {
PORT_Assert (cx->their_mark != NULL);
PORT_ArenaRelease (cx->their_pool, cx->their_mark);
cx->their_mark = NULL;
}
#endif
return SECFailure;
}
#if 0 /* XXX This is what I want, but cannot have because it seems we
* have situations (like when downloading a pkcs7 cert chain from
* some issuers) that give us a total length which is greater than
* the entire encoding. So, we have to allow allDone to have a
* remaining length greater than zero. I wanted to catch internal
* bugs with this, noticing when we do not have the right length.
* Oh well.
*/
PORT_Assert (len == 0
&& (cx->status == needBytes || cx->status == allDone));
#else
PORT_Assert ((len == 0 && cx->status == needBytes)
|| cx->status == allDone);
#endif
return SECSuccess;
}
SECStatus
SEC_ASN1DecoderFinish (SEC_ASN1DecoderContext *cx)
{
SECStatus rv;
if (cx->status == needBytes) {
PORT_SetError (SEC_ERROR_BAD_DER);
rv = SECFailure;
} else {
rv = SECSuccess;
}
/*
* XXX anything else that needs to be finished?
*/
PORT_FreeArena (cx->our_pool, PR_TRUE);
return rv;
}
SEC_ASN1DecoderContext *
SEC_ASN1DecoderStart (PLArenaPool *their_pool, void *dest,
const SEC_ASN1Template *theTemplate)
{
PLArenaPool *our_pool;
SEC_ASN1DecoderContext *cx;
our_pool = PORT_NewArena (SEC_ASN1_DEFAULT_ARENA_SIZE);
if (our_pool == NULL)
return NULL;
cx = (SEC_ASN1DecoderContext*)PORT_ArenaZAlloc (our_pool, sizeof(*cx));
if (cx == NULL) {
PORT_FreeArena (our_pool, PR_FALSE);
return NULL;
}
cx->our_pool = our_pool;
if (their_pool != NULL) {
cx->their_pool = their_pool;
#ifdef SEC_ASN1D_FREE_ON_ERROR
cx->their_mark = PORT_ArenaMark (their_pool);
#endif
}
cx->status = needBytes;
if (sec_asn1d_push_state(cx, theTemplate, dest, PR_FALSE) == NULL
|| sec_asn1d_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;
}
void
SEC_ASN1DecoderSetFilterProc (SEC_ASN1DecoderContext *cx,
SEC_ASN1WriteProc fn, void *arg,
PRBool only)
{
/* check that we are "between" fields here */
PORT_Assert (cx->during_notify);
cx->filter_proc = fn;
cx->filter_arg = arg;
cx->filter_only = only;
}
void
SEC_ASN1DecoderClearFilterProc (SEC_ASN1DecoderContext *cx)
{
/* check that we are "between" fields here */
PORT_Assert (cx->during_notify);
cx->filter_proc = NULL;
cx->filter_arg = NULL;
cx->filter_only = PR_FALSE;
}
void
SEC_ASN1DecoderSetNotifyProc (SEC_ASN1DecoderContext *cx,
SEC_ASN1NotifyProc fn, void *arg)
{
cx->notify_proc = fn;
cx->notify_arg = arg;
}
void
SEC_ASN1DecoderClearNotifyProc (SEC_ASN1DecoderContext *cx)
{
cx->notify_proc = NULL;
cx->notify_arg = NULL; /* not necessary; just being clean */
}
void
SEC_ASN1DecoderAbort(SEC_ASN1DecoderContext *cx, int error)
{
PORT_Assert(cx);
PORT_SetError(error);
cx->status = decodeError;
}
SECStatus
SEC_ASN1Decode (PLArenaPool *poolp, void *dest,
const SEC_ASN1Template *theTemplate,
const char *buf, long len)
{
SEC_ASN1DecoderContext *dcx;
SECStatus urv, frv;
dcx = SEC_ASN1DecoderStart (poolp, dest, theTemplate);
if (dcx == NULL)
return SECFailure;
urv = SEC_ASN1DecoderUpdate (dcx, buf, len);
frv = SEC_ASN1DecoderFinish (dcx);
if (urv != SECSuccess)
return urv;
return frv;
}
SECStatus
SEC_ASN1DecodeItem (PLArenaPool *poolp, void *dest,
const SEC_ASN1Template *theTemplate,
const SECItem *src)
{
return SEC_ASN1Decode (poolp, dest, theTemplate,
(const char *)src->data, src->len);
}
#ifdef DEBUG_ASN1D_STATES
void sec_asn1d_Assert(const char *s, const char *file, PRIntn ln)
{
printf("Assertion failed, \"%s\", file %s, line %d\n", s, file, ln);
fflush(stdout);
}
#endif
/*
* Generic templates for individual/simple items and pointers to
* and sets of same.
*
* If you need to add a new one, please note the following:
* - For each new basic type you should add *four* templates:
* one plain, one PointerTo, one SequenceOf and one SetOf.
* - If the new type can be constructed (meaning, it is a
* *string* type according to BER/DER rules), then you should
* or-in SEC_ASN1_MAY_STREAM to the type in the basic template.
* See the definition of the OctetString template for an example.
* - It may not be obvious, but these are in *alphabetical*
* order based on the SEC_ASN1_XXX name; so put new ones in
* the appropriate place.
*/
const SEC_ASN1Template SEC_SequenceOfAnyTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_AnyTemplate }
};
#if 0
const SEC_ASN1Template SEC_PointerToBitStringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_BitStringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfBitStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_BitStringTemplate }
};
const SEC_ASN1Template SEC_SetOfBitStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_BitStringTemplate }
};
const SEC_ASN1Template SEC_PointerToBMPStringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_BMPStringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfBMPStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_BMPStringTemplate }
};
const SEC_ASN1Template SEC_SetOfBMPStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_BMPStringTemplate }
};
const SEC_ASN1Template SEC_PointerToBooleanTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_BooleanTemplate }
};
const SEC_ASN1Template SEC_SequenceOfBooleanTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_BooleanTemplate }
};
const SEC_ASN1Template SEC_SetOfBooleanTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_BooleanTemplate }
};
#endif
const SEC_ASN1Template SEC_EnumeratedTemplate[] = {
{ SEC_ASN1_ENUMERATED, 0, NULL, sizeof(SECItem) }
};
const SEC_ASN1Template SEC_PointerToEnumeratedTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_EnumeratedTemplate }
};
#if 0
const SEC_ASN1Template SEC_SequenceOfEnumeratedTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_EnumeratedTemplate }
};
#endif
const SEC_ASN1Template SEC_SetOfEnumeratedTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_EnumeratedTemplate }
};
const SEC_ASN1Template SEC_PointerToGeneralizedTimeTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_GeneralizedTimeTemplate }
};
#if 0
const SEC_ASN1Template SEC_SequenceOfGeneralizedTimeTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_GeneralizedTimeTemplate }
};
const SEC_ASN1Template SEC_SetOfGeneralizedTimeTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_GeneralizedTimeTemplate }
};
const SEC_ASN1Template SEC_PointerToIA5StringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_IA5StringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfIA5StringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_IA5StringTemplate }
};
const SEC_ASN1Template SEC_SetOfIA5StringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_IA5StringTemplate }
};
const SEC_ASN1Template SEC_PointerToIntegerTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_IntegerTemplate }
};
const SEC_ASN1Template SEC_SequenceOfIntegerTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_IntegerTemplate }
};
const SEC_ASN1Template SEC_SetOfIntegerTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_IntegerTemplate }
};
const SEC_ASN1Template SEC_PointerToNullTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_NullTemplate }
};
const SEC_ASN1Template SEC_SequenceOfNullTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_NullTemplate }
};
const SEC_ASN1Template SEC_SetOfNullTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_NullTemplate }
};
const SEC_ASN1Template SEC_PointerToObjectIDTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_ObjectIDTemplate }
};
#endif
const SEC_ASN1Template SEC_SequenceOfObjectIDTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_ObjectIDTemplate }
};
#if 0
const SEC_ASN1Template SEC_SetOfObjectIDTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_ObjectIDTemplate }
};
const SEC_ASN1Template SEC_SequenceOfOctetStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_OctetStringTemplate }
};
const SEC_ASN1Template SEC_SetOfOctetStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_OctetStringTemplate }
};
#endif
const SEC_ASN1Template SEC_PrintableStringTemplate[] = {
{ SEC_ASN1_PRINTABLE_STRING | SEC_ASN1_MAY_STREAM, 0, NULL, sizeof(SECItem)}
};
#if 0
const SEC_ASN1Template SEC_PointerToPrintableStringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_PrintableStringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfPrintableStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_PrintableStringTemplate }
};
const SEC_ASN1Template SEC_SetOfPrintableStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_PrintableStringTemplate }
};
#endif
const SEC_ASN1Template SEC_T61StringTemplate[] = {
{ SEC_ASN1_T61_STRING | SEC_ASN1_MAY_STREAM, 0, NULL, sizeof(SECItem) }
};
#if 0
const SEC_ASN1Template SEC_PointerToT61StringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_T61StringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfT61StringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_T61StringTemplate }
};
const SEC_ASN1Template SEC_SetOfT61StringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_T61StringTemplate }
};
#endif
const SEC_ASN1Template SEC_UniversalStringTemplate[] = {
{ SEC_ASN1_UNIVERSAL_STRING | SEC_ASN1_MAY_STREAM, 0, NULL, sizeof(SECItem)}
};
#if 0
const SEC_ASN1Template SEC_PointerToUniversalStringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_UniversalStringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfUniversalStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_UniversalStringTemplate }
};
const SEC_ASN1Template SEC_SetOfUniversalStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_UniversalStringTemplate }
};
const SEC_ASN1Template SEC_PointerToUTCTimeTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_UTCTimeTemplate }
};
const SEC_ASN1Template SEC_SequenceOfUTCTimeTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_UTCTimeTemplate }
};
const SEC_ASN1Template SEC_SetOfUTCTimeTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_UTCTimeTemplate }
};
const SEC_ASN1Template SEC_PointerToUTF8StringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_UTF8StringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfUTF8StringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_UTF8StringTemplate }
};
const SEC_ASN1Template SEC_SetOfUTF8StringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_UTF8StringTemplate }
};
#endif
const SEC_ASN1Template SEC_VisibleStringTemplate[] = {
{ SEC_ASN1_VISIBLE_STRING | SEC_ASN1_MAY_STREAM, 0, NULL, sizeof(SECItem) }
};
#if 0
const SEC_ASN1Template SEC_PointerToVisibleStringTemplate[] = {
{ SEC_ASN1_POINTER, 0, SEC_VisibleStringTemplate }
};
const SEC_ASN1Template SEC_SequenceOfVisibleStringTemplate[] = {
{ SEC_ASN1_SEQUENCE_OF, 0, SEC_VisibleStringTemplate }
};
const SEC_ASN1Template SEC_SetOfVisibleStringTemplate[] = {
{ SEC_ASN1_SET_OF, 0, SEC_VisibleStringTemplate }
};
#endif
/*
* Template for skipping a subitem.
*
* Note that it only makes sense to use this for decoding (when you want
* to decode something where you are only interested in one or two of
* the fields); you cannot encode a SKIP!
*/
const SEC_ASN1Template SEC_SkipTemplate[] = {
{ SEC_ASN1_SKIP }
};
/* These functions simply return the address of the above-declared templates.
** This is necessary for Windows DLLs. Sigh.
*/
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_EnumeratedTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_PointerToEnumeratedTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_SequenceOfAnyTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_SequenceOfObjectIDTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_SkipTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_UniversalStringTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_PrintableStringTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_T61StringTemplate)
SEC_ASN1_CHOOSER_IMPLEMENT(SEC_PointerToGeneralizedTimeTemplate)
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