On the other hand, the type-specific
|CBS_get_optional_asn1_octet_string| must have a valid pointer and we
should check this in the “present” case or there could be a lucking
crash in some user waiting for an expected value to be missing.
Change-Id: Ida40e069ac7f0e50967e3f6c6b3fc01e49bd8894
Reviewed-on: https://boringssl-review.googlesource.com/26564
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Change-Id: I7932258890b0b2226ff6841af45926e1b11979ba
Reviewed-on: https://boringssl-review.googlesource.com/24844
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
The Chromium certificate verifier ends up encoding a SET OF when
canonicalizing X.509 names. Requiring the caller canonicalize a SET OF
is complicated enough that we should probably sort it for folks. (We
really need to get this name canonicalization insanity out of X.509...)
This would remove the extra level of indirection in Chromium
net/cert/internal/verify_name_match.cc CBB usage.
Note this is not quite the same order as SET, but SET is kind of
useless. Since it's encoding heterogeneous values, it is reasonable to
require the caller just encode them in the correct order. In fact, a DER
SET is just SEQUENCE with a post-processing step on the definition to
fix the ordering of the fields. (Unless the SET contains an untagged
CHOICE, in which case the ordering is weird, but SETs are not really
used in the real world, much less SETs with untagged CHOICEs.)
Bug: 11
Change-Id: I51e7938a81529243e7514360f867330359ae4f2c
Reviewed-on: https://boringssl-review.googlesource.com/24444
Reviewed-by: Adam Langley <agl@google.com>
This is a reland of https://boringssl-review.googlesource.com/2330. I
believe I've now cleared the fallout.
Android's attestion format uses some ludicrously large tag numbers:
https://developer.android.com/training/articles/security-key-attestation.html#certificate_schema
Add support for these in CBS/CBB. The public API does not change for
callers who were using the CBS_ASN1_* constants, but it is no longer the
case that tag representations match their DER encodings for small tag
numbers. When passing tags into CBS/CBB, use CBS_ASN1_* constants. When
working with DER byte arrays (most commonly test vectors), use the
numbers themselves.
Bug: 214
Update-Note: The in-memory representation of CBS/CBB tags changes.
Additionally, we now support tag numbers above 30. I believe I've now
actually cleared the fallout of the former. There is one test in
Chromium and the same test in the internal repository that needs
fixing.
Change-Id: I49b9d30df01f023c646d31156360ff69c91626a3
Reviewed-on: https://boringssl-review.googlesource.com/24404
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This reverts commit 66801feb17. This
turned out to break a lot more than expected. Hopefully we can reland it
soon, but we need to fix up some consumers first.
Note due to work that went in later, this is not a trivial revert and
should be re-reviewed.
Change-Id: I6474b67cce9a8aa03f722f37ad45914b76466bea
Reviewed-on: https://boringssl-review.googlesource.com/23644
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
We need it in both directions. Also I missed that in OBJ_obj2txt we
allowed uint64_t components, but in my new OBJ_txt2obj we only allowed
uint32_t. For consistency, upgrade that to uint64_t.
Bug: chromium:706445
Change-Id: I38cfeea8ff64b9acf7998e552727c6c3b2cc600f
Reviewed-on: https://boringssl-review.googlesource.com/23544
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
OBJ_txt2obj is currently implemented using BIGNUMs which is absurd. It
also depends on the giant OID table, which is undesirable. Write a new
one and expose the low-level function so Chromium can use it without the
OID table.
Bug: chromium:706445
Change-Id: I61ff750a914194f8776cb8d81ba5d3eb5eaa3c3d
Reviewed-on: https://boringssl-review.googlesource.com/23364
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
They are exactly the same structure. Doing it in CBS allows us to switch
bssl::Span to absl::Span or a standard std::span in the future.
Bug: 132
Change-Id: Ibc96673c23233d557a1dd4d8768d2659d7a4ca0c
Reviewed-on: https://boringssl-review.googlesource.com/20669
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
ssl is all that's left. Will do that once that's at a quiet point.
Change-Id: Ia183aed5671e3b2de333def138d7f2c9296fb517
Reviewed-on: https://boringssl-review.googlesource.com/19564
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This also fixes TestGetUint to actually test CBS_get_last_u8's behavior.
Right now it can't distinguish CBS_get_last_u8 and CBS_get_u8.
BUG=129
Change-Id: Ie431bb1a828f1c6877938ba7e75c82305b54cf13
Reviewed-on: https://boringssl-review.googlesource.com/15007
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Querying a bit in a BIT STRING is a little finicky. Add some functions
to help with this.
Change-Id: I813b9b6f2d952d61d8717b47bca1344f0ad4b7d1
Reviewed-on: https://boringssl-review.googlesource.com/12800
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
We have CBS_get_asn1 / CBS_get_asn1_element, but not the "any" variants
of them. Without this, a consumer walking a DER structure must manually
CBS_skip the header, which is a little annoying.
Change-Id: I7735c37eb9e5aaad2bde8407669bce5492e1ccf6
Reviewed-on: https://boringssl-review.googlesource.com/11404
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
The high-level documentation for CBB describes using CBB_flush when a
child goes out of scope, but the function level documentation for
CBB_flush is less clear that CBB_flush will result in the CBB being
safe to use after the children go out of scope.
Change-Id: I58bf9e59a87d2be31a969097455aeeae6381efb3
Reviewed-on: https://boringssl-review.googlesource.com/11261
Reviewed-by: David Benjamin <davidben@google.com>
Now that we have the extern "C++" trick, we can just embed them in the
normal headers. Move the EVP_CIPHER_CTX deleter to cipher.h and, in
doing so, take away a little bit of boilerplate in defining deleters.
Change-Id: I4a4b8d0db5274a3607914d94e76a38996bd611ec
Reviewed-on: https://boringssl-review.googlesource.com/10804
Reviewed-by: Matt Braithwaite <mab@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
We may need to implement high tag number form someday. CBS_get_asn1 has
an unsigned output to allow for this, but CBB_add_asn1 takes a uint8_t
(I think this might be my fault). Fix that which also fixes a
-Wconversion warning.
Simply leaving room in tag representation will still cause troubles
because the class and constructed bits overlap with bits for tag numbers
above 31. Probably the cleanest option would be to shift them to the top
3 bits of a u32 and thus not quite match the DER representation. Then
CBS_get_asn1 and CBB_add_asn1 will internally munge that into the DER
representation and consumers may continue to write things like:
tag_number | CBS_ASN1_CONTEXT_SPECIFIC
I haven't done that here, but in preparation for that, document that
consumers need to use the values and should refrain from assuming the
correspond to DER.
Change-Id: Ibc76e51f0bc3b843e48e89adddfe2eaba4843d12
Reviewed-on: https://boringssl-review.googlesource.com/10502
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Our CBB patterns do not make it safe to use a CBB after any operation
failed. Suppose one does:
int add_to_cbb(CBB *cbb) {
CBB child;
return CBB_add_u8(cbb, 1) &&
CBB_add_u8_length_prefixed(cbb, &child) &&
CBB_add_u8(&child, 2) &&
/* Flush |cbb| before |child| goes out of scoped. */
CBB_flush(cbb);
}
If one of the earlier operations fails, any attempt to use |cbb| (except
CBB_cleanup) would hit a memory error. Doing this would be a bug anyway,
since the CBB would be in an undefined state anyway (wrote only half my
object), but the memory error is bad manners.
Officially document that using a CBB after failure is illegal and, to
avoid the memory error, set a poison bit on the cbb_buffer_st to prevent
all future operations. In theory we could make failure +
CBB_discard_child work, but this is not very useful and would require a
more complex CBB pattern.
Change-Id: I4303ee1c326785849ce12b5f7aa8bbde6b95d2ec
Reviewed-on: https://boringssl-review.googlesource.com/8840
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This reverts commits:
8d79ed674019fdcb52348d79ed6740
Because WebRTC (at least) includes our headers in an extern "C" block,
which precludes having any C++ in them.
Change-Id: Ia849f43795a40034cbd45b22ea680b51aab28b2d
MSVC doesn't define __cplusplus as 201103 to indicate C++11 support, so
just assume that the compiler supports C++11 if _MSC_VER is defined.
Change-Id: I27f6eeefe6e8dc522470f36fab76ab36d85eebac
Reviewed-on: https://boringssl-review.googlesource.com/8734
Reviewed-by: David Benjamin <davidben@google.com>
This change scatters the contents of the two scoped_types.h files into
the headers for each of the areas of the code. The types are now in the
|bssl| namespace.
Change-Id: I802b8de68fba4786b6a0ac1bacd11d81d5842423
Reviewed-on: https://boringssl-review.googlesource.com/8731
Reviewed-by: Adam Langley <agl@google.com>
It was missing. Writing NewSessionTicket will need it.
Change-Id: I39de237894f2e8356bd6861da2b8a4d805dcd2d6
Reviewed-on: https://boringssl-review.googlesource.com/8439
Reviewed-by: Adam Langley <agl@google.com>
The business with ssl_record_prefix_len is rather a hassle. Instead, have
tls_open_record always decrypt in-place and give back a CBS to where the body
is.
This way the caller doesn't need to do an extra check all to avoid creating an
invalid pointer and underflow in subtraction.
Change-Id: I4e12b25a760870d8f8a503673ab00a2d774fc9ee
Reviewed-on: https://boringssl-review.googlesource.com/8173
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CBS_asn1_ber_to_der currently uses heuristics because implicitly-tagged
constructed strings in BER are ambiguous with implicitly-tagged sequences. It's
not possible to convert BER to DER without knowing the schema.
Fortunately, implicitly tagged strings don't appear often so instead split the
job up: CBS_asn1_ber_to_der fixes indefinite-length elements and constructed
strings it can see. Implicitly-tagged strings it leaves uncoverted, but they
will only nest one level down (because BER kindly allows one to nest
constructed strings arbitrarily!).
CBS_get_asn1_implicit_string then performs the final concatenation at parse
time. This isn't much more complex and lets us parse BER more accurately and
also reject a number of mis-encoded values (e.g. constructed INTEGERs are not a
thing) we'd previously let through. The downside is the post-conversion parsing
code must be aware of this limitation of CBS_asn1_ber_to_der. Fortunately,
there's only one implicitly-tagged string in our PKCS#12 code.
(In the category of things that really really don't matter, but I had spare
cycles and the old BER converter is weird.)
Change-Id: Iebdd13b08559fa158b308ef83a5bb07bfdf80ae8
Reviewed-on: https://boringssl-review.googlesource.com/7052
Reviewed-by: Adam Langley <agl@google.com>
There is some messiness around saving and restoring the CBB, but this is
still significantly clearer.
Note that the BUF_MEM_grow line is gone in favor of a fixed CBB like the
other functions ported thus far. This line was never necessary as
init_buf is initialized to 16k and none of our key exchanges get that
large. (The largest one can get is DHE_RSA. Even so, it'd take a roughly
30k-bit DH group with a 30k-bit RSA key.)
Having such limits and tight assumptions on init_buf's initial size is
poor (but on par for the old code which usually just blindly assumed the
message would not get too large) and the size of the certificate chain
is much less obviously bounded, so those BUF_MEM_grows can't easily go.
My current plan is convert everything but those which legitimately need
BUF_MEM_grow to CBB, then atomically convert the rest, remove init_buf,
and switch everything to non-fixed CBBs. This will hopefully also
simplify async resumption. In the meantime, having a story for
resumption means the future atomic change is smaller and, more
importantly, relieves some complexity budget in the ServerKeyExchange
code for adding Curve25519.
Change-Id: I1de6af9856caaed353453d92a502ba461a938fbd
Reviewed-on: https://boringssl-review.googlesource.com/6770
Reviewed-by: Adam Langley <agl@google.com>
These will be needed when we start writing variable-length things to a
CBB.
Change-Id: Ie7b9b140f5f875b43adedc8203ce9d3f4068dfea
Reviewed-on: https://boringssl-review.googlesource.com/6764
Reviewed-by: Adam Langley <agl@google.com>
Rather than the length of the top-level CBB, which is kind of odd when ASN.1
length prefixes are not yet determined, return the number of bytes written to
the CBB so far. This can be computed without increasing the size of CBB at all.
Have offset and pending_*.
This means functions which take in a CBB as argument will not be sensitive to
whether the CBB is a top-level or child CBB. The extensions logic had to be
careful to only ever compare differences of lengths, which was awkward.
The reversal will also allow for the following pattern in the future, once
CBB_add_space is split into, say, CBB_reserve and CBB_did_write and we add a
CBB_data:
uint8_t *signature;
size_t signature_len = 0;
if (!CBB_add_asn1(out, &cert, CBB_ASN1_SEQUENCE) ||
/* Emit the TBSCertificate. */
!CBB_add_asn1(&cert, &tbs_cert, CBS_ASN1_SEQUENCE) ||
!CBB_add_tbs_cert_stuff(&tbs_cert, stuff) ||
!CBB_flush(&cert) ||
/* Feed it into md_ctx. */
!EVP_DigestSignInit(&md_ctx, NULL, EVP_sha256(), NULL, pkey) ||
!EVP_DigestSignUpdate(&md_ctx, CBB_data(&cert), CBB_len(&cert)) ||
/* Emit the signature algorithm. */
!CBB_add_asn1(&cert, &sig_alg, CBS_ASN1_SEQUENCE) ||
!CBB_add_sigalg_stuff(&sig_alg, other_stuff) ||
/* Emit the signature. */
!EVP_DigestSignFinal(&md_ctx, NULL, &signature_len) ||
!CBB_reserve(&cert, &signature, signature_len) ||
!EVP_DigestSignFinal(&md_ctx, signature, &signature_len) ||
!CBB_did_write(&cert, signature_len)) {
goto err;
}
(Were TBSCertificate not the first field, we'd still have to sample
CBB_len(&cert), but at least that's reasonable straight-forward. The
alternative would be if CBB_data and CBB_len somehow worked on
recently-invalidated CBBs, but that would go wrong once the invalidated CBB's
parent flushed and possibly shifts everything.)
And similar for signing ServerKeyExchange.
Change-Id: I7761e492ae472d7632875b5666b6088970261b14
Reviewed-on: https://boringssl-review.googlesource.com/6681
Reviewed-by: Adam Langley <agl@google.com>
Not sure if we want to leave bio.h and bytestring.h's instance as-is, but the
evp.h ones are just baffling.
Change-Id: I485c2e355ba93764da0c4c72c48af48b055a8500
Reviewed-on: https://boringssl-review.googlesource.com/6454
Reviewed-by: Adam Langley <agl@google.com>
Start converting the ones we can right now. Some of the messier ones
resize init_buf rather than assume the initial size is sufficient, so
those will probably wait until init_buf is gone and the handshake's
undergone some more invasive surgery. The async ones will also require
some thought. But some can be incrementally converted now.
BUG=468889
Change-Id: I0bc22e4dca37d9d671a488c42eba864c51933638
Reviewed-on: https://boringssl-review.googlesource.com/6190
Reviewed-by: Adam Langley <alangley@gmail.com>
Also add an assert to that effect.
Change-Id: I1bd0571e3889f1cba968fd99041121ac42ee9e89
Reviewed-on: https://boringssl-review.googlesource.com/5990
Reviewed-by: Adam Langley <agl@google.com>
This is useful to skip an optional element, and mirrors the behaviour of
CBS_get_optional_asn1_octet_string.
Change-Id: Icb538c5e99a1d4e46412cae3c438184a94fab339
Reviewed-on: https://boringssl-review.googlesource.com/5800
Reviewed-by: Adam Langley <agl@google.com>
This begins decoupling the transport from the SSL state machine. The buffering
logic is hidden behind an opaque API. Fields like ssl->packet and
ssl->packet_length are gone.
ssl3_get_record and dtls1_get_record now call low-level tls_open_record and
dtls_open_record functions that unpack a single record independent of who owns
the buffer. Both may be called in-place. This removes ssl->rstate which was
redundant with the buffer length.
Future work will push the buffer up the stack until it is above the handshake.
Then we can expose SSL_open and SSL_seal APIs which act like *_open_record but
return a slightly larger enum due to other events being possible. Likewise the
handshake state machine will be detached from its buffer. The existing
SSL_read, SSL_write, etc., APIs will be implemented on top of SSL_open, etc.,
combined with ssl_read_buffer_* and ssl_write_buffer_*. (Which is why
ssl_read_buffer_extend still tries to abstract between TLS's and DTLS's fairly
different needs.)
The new buffering logic does not support read-ahead (removed previously) since
it lacks a memmove on ssl_read_buffer_discard for TLS, but this could be added
if desired. The old buffering logic wasn't quite right anyway; it tried to
avoid the memmove in some cases and could get stuck too far into the buffer and
not accept records. (The only time the memmove is optional is in DTLS or if
enough of the record header is available to know that the entire next record
would fit in the buffer.)
The new logic also now actually decrypts the ciphertext in-place again, rather
than almost in-place when there's an explicit nonce/IV. (That accidentally
switched in https://boringssl-review.googlesource.com/#/c/4792/; see
3d59e04bce96474099ba76786a2337e99ae14505.)
BUG=468889
Change-Id: I403c1626253c46897f47c7ae93aeab1064b767b2
Reviewed-on: https://boringssl-review.googlesource.com/5715
Reviewed-by: Adam Langley <agl@google.com>
It switched from CBB_remaining to CBB_len partway through review, but
the semantics are still CBB_remaining. Using CBB_len allows the
len_before/len_after logic to continue working even if, in the future,
handshake messages are built on a non-fixed CBB.
Change-Id: Id466bb341a14dbbafcdb26e4c940a04181f2787d
Reviewed-on: https://boringssl-review.googlesource.com/5371
Reviewed-by: Adam Langley <agl@google.com>
One tedious thing about using CBB is that you can't safely CBB_cleanup
until CBB_init is successful, which breaks the general 'goto err' style
of cleanup. This makes it possible:
CBB_zero ~ EVP_MD_CTX_init
CBB_init ~ EVP_DigestInit
CBB_cleanup ~ EVP_MD_CTX_cleanup
Change-Id: I085ecc4405715368886dc4de02285a47e7fc4c52
Reviewed-on: https://boringssl-review.googlesource.com/5267
Reviewed-by: Adam Langley <agl@google.com>
Rather than four massive functions that handle every extension,
organise the code by extension with four smaller functions for each.
Change-Id: I876b31dacb05aca9884ed3ae7c48462e6ffe3b49
Reviewed-on: https://boringssl-review.googlesource.com/5142
Reviewed-by: Adam Langley <agl@google.com>
Some of the documentation had the right explanation but the incorrect
function names attached.
Change-Id: I7b479dae6d71a5ac7bc86df5a3890508c3b3d09f
Reviewed-on: https://boringssl-review.googlesource.com/5090
Reviewed-by: Adam Langley <agl@google.com>
We have need of it internally.
Change-Id: I564af468728b22245e8eab384ea7018b7e88cc86
Reviewed-on: https://boringssl-review.googlesource.com/5022
Reviewed-by: Matt Braithwaite <mab@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Change-Id: Ic82ab5de4e231cdf6230ee7262c3c7539404d4a6
Reviewed-on: https://boringssl-review.googlesource.com/5020
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
This change makes |CBS_get_any_asn1_element| only handle DER elements.
Another function, |CBS_get_any_ber_asn1_element| is exposed internally
for the cases where we need to process BER data.
Change-Id: I544141a1a3d7913986352a8fd9a6d00b9f282652
Reviewed-on: https://boringssl-review.googlesource.com/4994
Reviewed-by: Adam Langley <agl@google.com>
Tag number 31 is a long form tag that requires multiple octets. It
cannot be handled by adding a single uint8. Changed CBB_add_asn1()
to return 0 when it is passed in the extension for tag 31.
Change-Id: Ia33936d4f174d1a7176eb11da0b5c7370efb9416
CBS_get_asn1() and CBS_get_any_asn1_element() only support the single
byte ASN.1 identifier octets (aka short form tags). Tag number 31 is
the start of the multi-byte long form per X.690 section 8.1.2.4.
Change-Id: I892600f4946e880a4ff03d219181116ef04f5372
Reviewed-on: https://boringssl-review.googlesource.com/3241
Reviewed-by: Adam Langley <agl@google.com>
Add some missing headers and ensure each header has a short description. doc.go
gets confused at declarations that break before the first (, so avoid doing
that. Also skip a/an/deprecated: in markupFirstWord and process pipe words in
the table of contents.
Change-Id: Ia08ec5ae8e496dd617e377e154eeea74f4abf435
Reviewed-on: https://boringssl-review.googlesource.com/2839
Reviewed-by: Adam Langley <agl@google.com>
Do away with all those unreadable macros. Also fix many many memory leaks in
the SSL_SESSION reuse case. Add a number of helper functions in CBS to help
with parsing optional fields.
Change-Id: I2ce8fd0d5b060a1b56e7f99f7780997fabc5ce41
Reviewed-on: https://boringssl-review.googlesource.com/1998
Reviewed-by: Adam Langley <agl@google.com>
Companion to CBS_get_asn1_uint64. Also add tests for both the parsing and the
serializing.
Change-Id: Ic5e9a0089c88b300f874712d0e9964cb35a8c40b
Reviewed-on: https://boringssl-review.googlesource.com/1999
Reviewed-by: Adam Langley <agl@google.com>
Intended to make parsing ASN.1 structures with OPTIONAL elements easier. (Just
attempting to parse the next tag doesn't distinguish between a malformed CBS
which has now been partially advanced and an optional tag mismatch.)
Change-Id: Idceb3dfd6ec028e87e1bc5aaddcec177b0c32150
Reviewed-on: https://boringssl-review.googlesource.com/1995
Reviewed-by: Adam Langley <agl@google.com>