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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
/*
* Support for ENcoding ASN.1 data based on BER/DER (Basic/Distinguished
* Encoding Rules).
*/
#include "secasn1.h"
typedef enum {
beforeHeader,
duringContents,
duringGroup,
duringSequence,
afterContents,
afterImplicit,
afterInline,
afterPointer,
afterChoice,
notInUse
} sec_asn1e_parse_place;
typedef enum {
allDone,
encodeError,
keepGoing,
needBytes
} sec_asn1e_parse_status;
typedef enum {
hdr_normal = 0, /* encode header normally */
hdr_any = 1, /* header already encoded in content */
hdr_decoder = 2, /* template only used by decoder. skip it. */
hdr_optional = 3, /* optional component, to be omitted */
hdr_placeholder = 4 /* place holder for from_buf content */
} sec_asn1e_hdr_encoding;
typedef struct sec_asn1e_state_struct {
SEC_ASN1EncoderContext *top;
const SEC_ASN1Template *theTemplate;
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 isExplicit, /* we are handling an isExplicit 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 */
disallowStreaming; /* disallow streaming in all sub-templates */
} 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 {
PLArenaPool *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 *theTemplate,
const void *src, PRBool new_depth)
{
sec_asn1e_state *state, *new_state;
if (theTemplate == NULL) {
cx->status = encodeError;
return NULL;
}
state = cx->current;
new_state = (sec_asn1e_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->theTemplate = theTemplate;
new_state->place = notInUse;
if (src != NULL)
new_state->src = (char *)src + theTemplate->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 isExplicit, is_string, may_stream, optional, universal;
PRBool disallowStreaming;
unsigned char tag_modifiers;
unsigned long encode_kind, under_kind;
unsigned long tag_number;
PRBool isInline = PR_FALSE;
encode_kind = state->theTemplate->kind;
universal = ((encode_kind & SEC_ASN1_CLASS_MASK) == SEC_ASN1_UNIVERSAL)
? PR_TRUE
: PR_FALSE;
isExplicit = (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(!(isExplicit && universal)); /* bad templates */
may_stream = (encode_kind & SEC_ASN1_MAY_STREAM) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_MAY_STREAM;
disallowStreaming = (encode_kind & SEC_ASN1_NO_STREAM) ? PR_TRUE : PR_FALSE;
encode_kind &= ~SEC_ASN1_NO_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_CHOICE) {
under_kind = SEC_ASN1_CHOICE;
} else if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) ||
(!universal && !isExplicit)) {
const SEC_ASN1Template *subt;
void *src = NULL;
PORT_Assert((encode_kind & (SEC_ASN1_ANY | SEC_ASN1_SKIP)) == 0);
sec_asn1e_scrub_state(state);
if (encode_kind & SEC_ASN1_POINTER) {
src = *(void **)state->src;
state->place = afterPointer;
if (src == NULL) {
/*
* If this is optional, but NULL, then the field does
* not need to be encoded. In this case we are done;
* we do not want to push a subtemplate.
*/
if (optional)
return state;
/*
* XXX this is an error; need to figure out
* how to handle this
*/
}
} 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;
isInline = PR_TRUE;
} else {
/*
* Save the tag modifiers and tag number here before moving
* on to the next state in case this is a member of a
* SEQUENCE OF
*/
state->tag_modifiers = (unsigned char)(encode_kind & (SEC_ASN1_TAG_MASK & ~SEC_ASN1_TAGNUM_MASK));
state->tag_number = (unsigned char)(encode_kind & SEC_ASN1_TAGNUM_MASK);
state->place = afterImplicit;
state->optional = optional;
}
}
subt = SEC_ASN1GetSubtemplate(state->theTemplate, state->src, PR_TRUE);
if (isInline && optional) {
/* we only handle a very limited set of optional inline cases at
this time */
if (PR_FALSE != SEC_ASN1IsTemplateSimple(subt)) {
/* we now know that the target is a SECItem*, so we can check
if the source contains one */
SECItem *target = (SECItem *)state->src;
if (!target || !target->data || !target->len) {
/* no valid data to encode subtemplate */
return state;
}
} else {
PORT_Assert(0); /* complex templates are not handled as
inline optional */
}
}
state = sec_asn1e_push_state(state->top, subt, src, PR_FALSE);
if (state == NULL)
return state;
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.).
*
* NB: ALL the following flags in the subtemplate are disallowed
* and/or ignored: EXPLICIT, OPTIONAL, INNER, INLINE, POINTER.
*/
under_kind = state->theTemplate->kind;
if ((under_kind & SEC_ASN1_MAY_STREAM) && !disallowStreaming) {
may_stream = PR_TRUE;
}
under_kind &= ~(SEC_ASN1_MAY_STREAM | SEC_ASN1_DYNAMIC);
} 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?)
*/
#define UNEXPECTED_FLAGS \
(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)
PORT_Assert((under_kind & UNEXPECTED_FLAGS) == 0);
under_kind &= ~UNEXPECTED_FLAGS;
#undef UNEXPECTED_FLAGS
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 = (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.
*/
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_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:
/*
* 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 = (unsigned char)tag_number;
state->underlying_kind = under_kind;
state->isExplicit = isExplicit;
state->may_stream = may_stream;
state->is_string = is_string;
state->optional = optional;
state->disallowStreaming = disallowStreaming;
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);
}
int
SEC_ASN1EncodeLength(unsigned char *buf, int value)
{
int lenlen;
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);
}
return lenlen;
}
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_ASN1EncodeLength(buf, value);
}
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 int
sec_asn1e_which_choice(
void *src,
const SEC_ASN1Template *theTemplate)
{
int rv;
unsigned int which = *(unsigned int *)src;
for (rv = 1, theTemplate++; theTemplate->kind != 0; rv++, theTemplate++) {
if (which == theTemplate->size) {
return rv;
}
}
return 0;
}
static unsigned long
sec_asn1e_contents_length(const SEC_ASN1Template *theTemplate, void *src,
PRBool disallowStreaming, PRBool insideIndefinite,
sec_asn1e_hdr_encoding *pHdrException)
{
unsigned long encode_kind, underlying_kind;
PRBool isExplicit, optional, universal, may_stream;
unsigned long len;
/*
* This function currently calculates the length in all cases
* except the following: when writing out the contents of a
* template that belongs to a state where it was a sub-template
* with the SEC_ASN1_MAY_STREAM bit set and it's parent had the
* optional bit set. The information that the parent is optional
* and that we should return the length of 0 when that length is
* present since that means the optional field is no longer present.
* So we add the disallowStreaming flag which is passed in when
* writing the contents, but for all recursive calls to
* sec_asn1e_contents_length, we pass PR_FALSE, because this
* function correctly calculates the length for children templates
* from that point on. Confused yet? At least you didn't have
* to figure it out. ;) -javi
*/
encode_kind = theTemplate->kind;
universal = ((encode_kind & SEC_ASN1_CLASS_MASK) == SEC_ASN1_UNIVERSAL)
? PR_TRUE
: PR_FALSE;
isExplicit = (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(!(isExplicit && 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_NO_STREAM) {
disallowStreaming = PR_TRUE;
}
encode_kind &= ~SEC_ASN1_NO_STREAM;
if (encode_kind & SEC_ASN1_CHOICE) {
void *src2;
int indx = sec_asn1e_which_choice(src, theTemplate);
if (0 == indx) {
/* XXX set an error? "choice not found" */
/* state->top->status = encodeError; */
return 0;
}
src2 = (void *)((char *)src - theTemplate->offset + theTemplate[indx].offset);
return sec_asn1e_contents_length(&theTemplate[indx], src2,
disallowStreaming, insideIndefinite,
pHdrException);
}
if ((encode_kind & (SEC_ASN1_POINTER | SEC_ASN1_INLINE)) || !universal) {
/* XXX any bits we want to disallow (PORT_Assert against) here? */
theTemplate = SEC_ASN1GetSubtemplate(theTemplate, src, PR_TRUE);
if (encode_kind & SEC_ASN1_POINTER) {
src = *(void **)src;
if (src == NULL) {
*pHdrException = optional ? hdr_optional : hdr_normal;
return 0;
}
} else if (encode_kind & SEC_ASN1_INLINE) {
/* check that there are no extraneous bits */
if (optional) {
if (PR_FALSE != SEC_ASN1IsTemplateSimple(theTemplate)) {
/* we now know that the target is a SECItem*, so we can check
if the source contains one */
SECItem *target = (SECItem *)src;
if (!target || !target->data || !target->len) {
/* no valid data to encode subtemplate */
*pHdrException = hdr_optional;
return 0;
}
} else {
PORT_Assert(0); /* complex templates not handled as inline
optional */
}
}
}
src = (char *)src + theTemplate->offset;
/* recurse to find the length of the subtemplate */
len = sec_asn1e_contents_length(theTemplate, src, disallowStreaming,
insideIndefinite, pHdrException);
if (len == 0 && optional) {
*pHdrException = hdr_optional;
} else if (isExplicit) {
if (*pHdrException == hdr_any) {
/* *we* do not want to add in a header,
** but our caller still does.
*/
*pHdrException = hdr_normal;
} else if (*pHdrException == hdr_normal) {
/* if the inner content exists, our length is
* len(identifier) + len(length) + len(innercontent)
* XXX we currently assume len(identifier) == 1;
* to support a high-tag-number this would need to be smarter.
*/
len += 1 + SEC_ASN1LengthLength(len);
}
}
return len;
}
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);
*pHdrException = hdr_decoder;
return 0;
}
#define UNEXPECTED_FLAGS \
(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)
/* Having any of these bits is not expected here... */
PORT_Assert((underlying_kind & UNEXPECTED_FLAGS) == 0);
underlying_kind &= ~UNEXPECTED_FLAGS;
#undef UNEXPECTED_FLAGS
if (underlying_kind & SEC_ASN1_CHOICE) {
void *src2;
int indx = sec_asn1e_which_choice(src, theTemplate);
if (0 == indx) {
/* XXX set an error? "choice not found" */
/* state->top->status = encodeError; */
return 0;
}
src2 = (void *)((char *)src - theTemplate->offset + theTemplate[indx].offset);
len = sec_asn1e_contents_length(&theTemplate[indx], src2,
disallowStreaming, insideIndefinite,
pHdrException);
} else {
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(theTemplate, src, PR_TRUE);
for (; *group != NULL; group++) {
sub_src = (char *)(*group) + tmpt->offset;
sub_len = sec_asn1e_contents_length(tmpt, sub_src,
disallowStreaming,
insideIndefinite,
pHdrException);
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 (*pHdrException == hdr_normal)
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 = theTemplate + 1; tmpt->kind; tmpt++) {
sub_src = (char *)src + tmpt->offset;
sub_len = sec_asn1e_contents_length(tmpt, sub_src,
disallowStreaming,
insideIndefinite,
pHdrException);
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 (*pHdrException == hdr_normal)
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;
case SEC_ASN1_INTEGER:
/* ASN.1 INTEGERs are signed.
* If the source is an unsigned integer, the encoder will need
* to handle the conversion here.
*/
{
unsigned char *buf = ((SECItem *)src)->data;
SECItemType integerType = ((SECItem *)src)->type;
len = ((SECItem *)src)->len;
while (len > 0) {
if (*buf != 0) {
if (*buf & 0x80 && integerType == siUnsignedInteger) {
len++; /* leading zero needed to make number signed */
}
break; /* reached beginning of number */
}
if (len == 1) {
break; /* the number 0 */
}
if (buf[1] & 0x80) {
break; /* leading zero already present */
}
/* extraneous leading zero, keep going */
buf++;
len--;
}
}
break;
default:
len = ((SECItem *)src)->len;
break;
} /* end switch */
#ifndef WHAT_PROBLEM_DOES_THIS_SOLVE
/* if we're streaming, we may have a secitem w/len 0 as placeholder */
if (!len && insideIndefinite && may_stream && !disallowStreaming) {
len = 1;
}
#endif
} /* end else */
if (len == 0 && optional)
*pHdrException = hdr_optional;
else if (underlying_kind == SEC_ASN1_ANY)
*pHdrException = hdr_any;
else
*pHdrException = hdr_normal;
return len;
}
static void
sec_asn1e_write_header(sec_asn1e_state *state)
{
unsigned long contents_length;
unsigned char tag_number, tag_modifiers;
sec_asn1e_hdr_encoding hdrException = hdr_normal;
PRBool indefinite = PR_FALSE;
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->underlying_kind & SEC_ASN1_CHOICE) {
int indx = sec_asn1e_which_choice(state->src, state->theTemplate);
if (0 == indx) {
/* XXX set an error? "choice not found" */
state->top->status = encodeError;
return;
}
state->place = afterChoice;
state = sec_asn1e_push_state(state->top, &state->theTemplate[indx],
(char *)state->src - state->theTemplate->offset,
PR_TRUE);
if (state) {
/*
* Do the "before" field notification.
*/
sec_asn1e_notify_before(state->top, state->src, state->depth);
(void)sec_asn1e_init_state_based_on_template(state);
}
return;
}
/* The !isString test below is apparently intended to ensure that all
** constructed types receive indefinite length encoding.
*/
indefinite = (PRBool)(state->top->streaming && state->may_stream &&
(state->top->from_buf || !state->is_string));
/*
* If we are doing a definite-length encoding, first we have to
* walk the data structure to calculate the entire contents length.
* If we are doing an indefinite-length encoding, we still need to
* know if the contents is:
* optional and to be omitted, or
* an ANY (header is pre-encoded), or
* a SAVE or some other kind of template used only by the decoder.
* So, we call this function either way.
*/
contents_length = sec_asn1e_contents_length(state->theTemplate,
state->src,
state->disallowStreaming,
indefinite,
&hdrException);
/*
* 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 (hdrException != hdr_normal ||
(contents_length == 0 && state->optional)) {
state->place = afterContents;
if (state->top->streaming &&
state->may_stream &&
state->top->from_buf) {
/* we did not find an optional indefinite string, so we
* don't encode it. However, if TakeFromBuf is on, we stop
* here anyway to give our caller a chance to intercept at the
* same point where we would stop if the field were present.
*/
state->top->status = needBytes;
}
return;
}
if (indefinite) {
/*
* We need to put out an indefinite-length encoding.
* 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).
*/
state->indefinite = PR_TRUE;
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;
}
sec_asn1e_write_identifier_bytes(state,
(unsigned char)(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->isExplicit) {
const SEC_ASN1Template *subt =
SEC_ASN1GetSubtemplate(state->theTemplate, state->src, PR_TRUE);
state->place = afterContents;
state = sec_asn1e_push_state(state->top, subt, state->src, PR_TRUE);
if (state != NULL) {
(void)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->theTemplate, state->src,
PR_TRUE);
state = sec_asn1e_push_state(state->top, subt, *group, PR_TRUE);
if (state != NULL) {
(void)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->theTemplate + 1,
state->src, PR_TRUE);
if (state != NULL) {
/*
* Do the "before" field notification.
*/
sec_asn1e_notify_before(state->top, state->src, state->depth);
(void)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_from_buf(sec_asn1e_state *state,
const char *buf, unsigned long len)
{
PORT_Assert(state->place == duringContents);
PORT_Assert(state->top->from_buf);
PORT_Assert(state->may_stream && !state->disallowStreaming);
/*
* 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 = (unsigned char)(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;
}
static void
sec_asn1e_write_contents(sec_asn1e_state *state)
{
unsigned long len = 0;
PORT_Assert(state->place == duringContents);
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 = (unsigned char)((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 */
goto process_string;
case SEC_ASN1_UNIVERSAL_STRING:
/* The number of bytes must be divisable by 4 */
if ((((SECItem *)state->src)->len) % 4) {
SEC_ASN1EncoderContext *cx;
cx = state->top;
cx->status = encodeError;
break;
}
/* otherwise, fall through to write the content */
goto process_string;
case SEC_ASN1_INTEGER:
/* ASN.1 INTEGERs are signed. If the source is an unsigned
* integer, the encoder will need to handle the conversion here.
*/
{
unsigned int blen;
unsigned char *buf;
SECItemType integerType;
blen = ((SECItem *)state->src)->len;
buf = ((SECItem *)state->src)->data;
integerType = ((SECItem *)state->src)->type;
while (blen > 0) {
if (*buf & 0x80 && integerType == siUnsignedInteger) {
char zero = 0; /* write a leading 0 */
sec_asn1e_write_contents_bytes(state, &zero, 1);
/* and then the remaining buffer */
sec_asn1e_write_contents_bytes(state,
(char *)buf, blen);
break;
}
/* Check three possibilities:
* 1. No leading zeros, msb of MSB is not 1;
* 2. The number is zero itself;
* 3. Encoding a signed integer with a leading zero,
* keep the zero so that the number is positive.
*/
if (*buf != 0 ||
blen == 1 ||
(buf[1] & 0x80 && integerType != siUnsignedInteger)) {
sec_asn1e_write_contents_bytes(state,
(char *)buf, blen);
break;
}
/* byte is 0, continue */
buf++;
blen--;
}
}
/* done with this content */
break;
process_string:
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->theTemplate->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->theTemplate->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->theTemplate++;
if (child->theTemplate->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->theTemplate->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) {
cx->status = keepGoing;
}
while (cx->status == keepGoing) {
state = cx->current;
switch (state->place) {
case beforeHeader:
sec_asn1e_write_header(state);
break;
case duringContents:
if (cx->from_buf)
sec_asn1e_write_contents_from_buf(state, buf, len);
else
sec_asn1e_write_contents(state);
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:
case afterChoice:
/*
* 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(const void *src, const SEC_ASN1Template *theTemplate,
SEC_ASN1WriteProc output_proc, void *output_arg)
{
PLArenaPool *our_pool;
SEC_ASN1EncoderContext *cx;
our_pool = PORT_NewArena(SEC_ASN1_DEFAULT_ARENA_SIZE);
if (our_pool == NULL)
return NULL;
cx = (SEC_ASN1EncoderContext *)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, theTemplate, 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_ASN1EncoderAbort(SEC_ASN1EncoderContext *cx, int error)
{
PORT_Assert(cx);
PORT_SetError(error);
cx->status = encodeError;
}
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)
{
/*
* XXX is there a way to check that we are "between" fields here? this
* needs to include a check for being in between groups of items in
* a SET_OF or SEQUENCE_OF.
*/
PORT_Assert(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(const void *src, const SEC_ASN1Template *theTemplate,
SEC_ASN1WriteProc output_proc, void *output_arg)
{
SEC_ASN1EncoderContext *ecx;
SECStatus rv;
ecx = SEC_ASN1EncoderStart(src, theTemplate, 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 = (unsigned long *)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 = (SECItem *)arg;
PORT_Assert(dest != NULL);
if (len > 0) {
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(PLArenaPool *poolp, SECItem *dest, unsigned long len)
{
if (poolp != NULL) {
void *release;
release = PORT_ArenaMark(poolp);
if (dest == NULL)
dest = (SECItem *)PORT_ArenaAlloc(poolp, sizeof(SECItem));
if (dest != NULL) {
dest->data = (unsigned char *)PORT_ArenaAlloc(poolp, len);
if (dest->data == NULL) {
dest = NULL;
}
}
if (dest == NULL) {
/* one or both allocations failed; release everything */
PORT_ArenaRelease(poolp, release);
} else {
/* everything okay; unmark the arena */
PORT_ArenaUnmark(poolp, release);
}
} else {
SECItem *indest;
indest = dest;
if (dest == NULL)
dest = (SECItem *)PORT_Alloc(sizeof(SECItem));
if (dest != NULL) {
dest->type = siBuffer;
dest->data = (unsigned char *)PORT_Alloc(len);
if (dest->data == NULL) {
if (indest == NULL)
PORT_Free(dest);
dest = NULL;
}
}
}
return dest;
}
SECItem *
SEC_ASN1EncodeItem(PLArenaPool *poolp, SECItem *dest, const void *src,
const SEC_ASN1Template *theTemplate)
{
unsigned long encoding_length;
SECStatus rv;
PORT_Assert(dest == NULL || dest->data == NULL);
encoding_length = 0;
rv = SEC_ASN1Encode(src, theTemplate,
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, theTemplate, sec_asn1e_encode_item_store, dest);
PORT_Assert(encoding_length == dest->len);
return dest;
}
static SECItem *
sec_asn1e_integer(PLArenaPool *poolp, SECItem *dest, unsigned long value,
PRBool is_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 = (unsigned char)(copy & 0x80);
copy >>= 8;
} while (copy);
/*
* If 'value' is non-negative, 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 && (is_unsigned || (long)value >= 0))
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] = (unsigned char)value;
value >>= 8;
}
PORT_Assert(value == 0);
return dest;
}
SECItem *
SEC_ASN1EncodeInteger(PLArenaPool *poolp, SECItem *dest, long value)
{
return sec_asn1e_integer(poolp, dest, (unsigned long)value, PR_FALSE);
}
SECItem *
SEC_ASN1EncodeUnsignedInteger(PLArenaPool *poolp,
SECItem *dest, unsigned long value)
{
return sec_asn1e_integer(poolp, dest, value, PR_TRUE);
}