This is a very very basic sanity check on k generation, but it helps
make sure we haven't *completely* disconnected the RNG.
Change-Id: If7ae5dd6be3d0866962cd966b8c1ed1cdedffb50
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45865
Reviewed-by: Adam Langley <agl@google.com>
CVE-2021-23840
(Imported from upstream's 6a51b9e1d0cf0bf8515f7201b68fb0a3482b3dc1.)
This differs slightly from upstream's version:
- EVP_R_OUTPUT_WOULD_OVERFLOW didn't seem necessary when ERR_R_OVERFLOW
already exists. (Also since we use CIPHER_R_*, it wouldn't have helped
with compatibility anyway. Though there's probably something to be
said for us folding CIPHER_R_* back into EVP_R_*.)
- For simplicity, just check in_len + bl at the top, rather than trying
to predict the exact number of bytes written.
Update-Note: Passing extremely large input lengths into EVP_CipherUpdate
will now fail. Use EVP_AEAD instead, which is size_t-based and has more
explicit output bounds.
Change-Id: I31835c89dcdecb6b112828f57deb798dc7187db5
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45685
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
test_fips probably needs to exercise everything that we have self-tests
for.
(The following change will eliminate the duplication of the code to
create the FFDH group. For reasons, that can't be done in this change.)
Change-Id: Ia72064db77381e7cf396a34b4723b2607f26f00b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45404
Reviewed-by: Adam Langley <alangley@gmail.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
This fixes the build for folks not using bcm.c.
Change-Id: I47935d8af7cb5a12ff2918ee2a8774182681d930
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45384
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
This invovles a |2048|^|225| modexp, which is far from ideal, but is now
required in FIPS mode.
Change-Id: Id7384b4ba92aa74e971231bc44fa0f10434d18e2
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45085
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
In order to support cross-compiling:
1) inject-hash needs to know to use SHA-256 for the hash function
on Android. Since that's a good idea on Aarch64 in general
(due to common hardware support), do it for all Aarch64.
2) We need to use the compiler to run the preprocessor, not plain
cpp, because the compiler will get the built-in #defines right.
Change-Id: Ie00d46e9e6d489fcb9e3f3e5e625aa289c7e0d73
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45044
Reviewed-by: David Benjamin <davidben@google.com>
We clear all heap memory on free now, thus the difference between these
functions is quite small. There are some differences though:
Firstly, BN_clear_free will attempt to zero out static limb data. But
static data is probably read-only and thus trying to zero it will crash.
Secondly it will try to zero out the BIGNUM structure itself. But either
it's on the heap, and will be zeroed anyway, or else it's on the stack,
and we don't try and clear the stack in general because the compiler is
duplicating bits of it at will anyway.
Change-Id: I8a07385a102cfd308b555432942225c25eb7c12d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45084
Reviewed-by: David Benjamin <davidben@google.com>
OpenSSL has a fixed-width version of DH_compute_key nowadays. Searching
around callers of DH_compute_key, many of them go back and re-pad the
secret anyway. Uses of DH should migrate to modern primitives but, in
the meantime, DH_compute_key_padded seems worthwhile for OpenSSL
compatibility and giving fixed-width users a function to avoid the
timing leak.
Bump BORINGSSL_API_VERSION since one of the uses is in wpa_supplicant
and they like to compile against a wide range of Android revisions.
Update-Note: No compatibility impact, but callers that use
DH_compute_key and then fix up the removed leading zeros can switch to
this function. Then they should migrate to something else.
Change-Id: Icf8b2ace3972fa174a0f08ece39710f7599f96f2
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45004
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Aarch64 perlasm outputs need to be run via the C preprocessor before
being parsed by delocate.
Change-Id: Ie420388e0e1707cb064d696ee8f87728cab9a36e
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44847
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Windows on Arm (WoA) builds are currently using the C implementations
of the various functions within BoringSSL. This patch enables feature
detection for the Neon and hardware crypto optimizations, and updates
the perl script to generate AArch64 .S files for WoA.
Note these files use GNU assembler syntax (specifically tested with
Clang assembler), not armasm.
Change-Id: Id8841f4db0498ec16215095a4e6bd60d427cd54b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43304
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Change-Id: I814f55742910c519e9b64aca1b15a4d754adc541
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44944
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
This change eliminates an Aarch64 assembly pattern that only appears
in this case. It's easier to change this code than to pile more things
on top of the delocate parser.
Change-Id: I6bbbe9df744ec2ad4178d74456d8f4fecc3a2dae
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44845
Reviewed-by: David Benjamin <davidben@google.com>
Newer versions of LLVM may use profile information to put code in
sections named .text.unlikely.*. Make sure those sections end up in
our .text section.
Change-Id: Ia0224fd8e683f5e77c60dd3ad34d59b33f9b41ab
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44804
Commit-Queue: Peter Collingbourne <pcc@google.com>
Reviewed-by: Adam Langley <agl@google.com>
This moved, en masse, into the FIPS module in e7f08827d2. But we want to
minimise the amount that's in the FIPS module and it doesn't appear that
we need this at the current time.
Change-Id: Ib2c243aad461b716314eeeb6a460955818a7aa22
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44605
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
If using precompiled headers then this is needed otherwise bn/internal.h
doesn't have a definition for BN_ULONG etc.
Change-Id: I41b331465abae7108f255722a156d2ffb3016ba3
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44604
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
This involves adding a new function |DH_compute_key_hashed| that
combines the FFDH with the output hashing inside the FIPS module. This
new function uses the padded FFDH output, as newly specified in SP
800-56Ar3.
Change-Id: Iafcb7e276f16d39bf7d25d3b2f163b5cd6f67883
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44504
Reviewed-by: David Benjamin <davidben@google.com>
This change also drops ex_data from DH objects. The global would need
special handling in the FIPS module, which isn't hard, but just dropping
it saves some of the code-size costs of this change and I cannot find
any signs of use of this functionality.
Change-Id: I984bd70698c2ec329f340d294b3b9ec169cd0c4e
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44524
Reviewed-by: David Benjamin <davidben@google.com>
Rather than the FIPS module actively collecting entropy from the CPU or
OS, this change configures Android FIPS to passively receive entropy.
See FIPS IG 7.14 section two.
Change-Id: Ibfc5c5042e560718474b89970199d35b67c21296
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44305
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
8846533744 added a “power-on” test for the TLS KDF, but omitted to add
it to the documented list of these tests.
Change-Id: I13dbad4b9359e7dae0938d02ac53e5e011f50824
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44505
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
This imports d741debb320bf54e8575d35603a44d4eb40fa1f9 from upstream.
We've been managing the shared libraries already because our
arm-xlate.pl automatically adds .hidden to .extern lines, but nice to
reduce the diff. (This does result in some duplicate .hidden lines in
the generated output, but we still want the arm-xlate.pl patch to
automatically hide .globl.)
Removing .comm lines does change the generated output, but having each
asm file define its own copy of OPENSSL_armcap_P as a common symbol
always seemed odd. I recall some weird issue where the armv4.pl files
subtly rely on it for iOS's strange .indirect_symbol machinery. (Not
actually because iOS wants a common symbol but because arm-xlate.pl
repurposes .comm to trigger .indirect_symbol.) Fortunately, aarch64 is
much better about PC-relative addressing, so it should be a no-op.
The .comm lines have also previously caused weird issues
(https://boringssl-review.googlesource.com/c/boringssl/+/32324), so
it's generally nice to get rid of them.
Update-Note: If aarch64 builds get some weird error about relocations,
it's this CL's fault.
Change-Id: I763ffa6cda750d99694ded8a5b68d7b27b09cfc9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44464
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
It's insufficient to signal an error when the PWCT fails. We
additionally need to ensure that the invalid key material is not
returned.
Change-Id: Ic5ff719a688985a61c52540ce6d1ed279a493d27
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44306
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Change-Id: Iba527924a79733b28b12b65d8e1f613d7819eb34
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44345
Commit-Queue: Adam Langley <alangley@gmail.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
ARM Cortex-A57 and Cortex-A72 cores running in 32-bit mode are affected
by silicon errata #1742098 [0] and #1655431 [1], respectively, where the
second instruction of a AES instruction pair may execute twice if an
interrupt is taken right after the first instruction consumes an input
register of which a single 32-bit lane has been updated the last time it
was modified.
Shuffle the counter assignments around a bit so that the most recent
updates when the AES instruction pair executes are 128-bit wide.
[0] ARM-EPM-049219 v23 Cortex-A57 MPCore Software Developers Errata Notice
[1] ARM-EPM-012079 v11.0 Cortex-A72 MPCore Software Developers Errata Notice
(This is imported from upstream's
409c59e8f44ae56f2587cdd8a7ce611d0e3d91d9.)
The change is applied to both 32-bit and 64-bit for simplicity, but there
was no measurable performance difference, so leaving them aligned is
easiest.
Change-Id: Ic8e5f656f59ae8c2ecb2762a066c2c9064bb34c5
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44284
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
This covers the use of EVP_sha256() added in 8846533744.
Change-Id: I8cd4c8e271de6a0b9a926e7186c7b24ffe849d67
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44224
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Change-Id: I08cc198f326f02b3f38234b938208ea49a13fab6
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/44164
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
For FIPS reasons, one might wish to ensure that a random AES-GCM nonce
was generated entirely within the FIPS module. If so, then these are the
AEADs for you.
Change-Id: Ic2b7864b089f446401f700d7d55bfa6336c61e23
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43686
Commit-Queue: Adam Langley <alangley@gmail.com>
Reviewed-by: David Benjamin <davidben@google.com>
We use this constant a lot in e_aes.c, but we write it out every time.
Change-Id: Iaa92efb391def6640349940c682d9f70ddaa23d5
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43685
Reviewed-by: David Benjamin <davidben@google.com>
Sometimes the linker will generate rodata subsections even if we don't
have -fdata-sections enabled. That's ok, so include them in the FIPS
module. The other subsections continue to be discarded to ensure that
unexpected sections don't appear and escape the module.
Bug: b/142971559
Change-Id: Icebcf40bd3d0e63f20456e44f6c2564f4316b561
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43324
Commit-Queue: Adam Langley <alangley@gmail.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
See b/169780122. This CL should be a no-op (the only other OPENSSL_LINUX
defines are in urandom/getrandom logic, which Trusty doesn't use), but
should be easier to work for future code.
Change-Id: I7676ce234a20ddaf54a881f2da1e1fcd680d1c78
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43224
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Trusty doesn't have madvise() or sysconf() and more importantly,
doesn't have fork() (confirmed chatting to ncbray), so the
no-op #if branch in fork_detect.c seems appropriate.
Change-Id: I41b41e79d59919bae6c6ece0e0efd3872105e9b1
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43204
Commit-Queue: Pete Bentley <prb@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Most asymmetric operations scale superlinearly, which makes them
potential DoS vectors. This (and other problems) are mitigated with
fixed sizes, like RSA-2048, P-256, or curve25519.
In older algorithms like RSA and DSA, these sizes are conventions rather
than well-defined algorithms. "Everyone" uses RSA-2048, but code which
imports an RSA key may see an arbitrary key size, possibly from an
untrusted source. This is commonly a public key, so we bound RSA key
sizes in check_modulus_and_exponent_sizes.
However, some applications import external private keys, and may need
tighter bounds. These typically parse the key then check the result.
However, parsing itself can perform superlinear work (RSA_check_key or
recovering the DSA public key).
This CL does the following:
- Rename check_modulus_and_exponent_sizes to rsa_check_public_key and
additionally call it from RSA_check_key.
- Fix a bug where RSA_check_key, on CRT-less keys, did not bound d, and
bound p and q before multiplying (quadratic).
- Our DSA verifier had stricter checks on q (160-, 224-, and 256-bit
only) than our DSA signer (multiple of 8 bits). Aligner the signer to
the verifier's checks.
- Validate DSA group sizes on parse, as well as priv_key < q, to bound
the running time.
Ideally these invariants would be checked exactly once at construction,
but our RSA and DSA implementations suffer from some OpenSSL's API
mistakes (https://crbug.com/boringssl/316), which means it is hard to
consistently enforce invariants. This CL focuses on the parser, but
later I'd like to better rationalize the freeze_private_key logic.
Performance of parsing RSA and DSA keys, gathered on my laptop.
Did 15130 RSA-2048 parse operations in 5022458us (3012.5 ops/sec)
Did 4888 RSA-4096 parse operations in 5060606us (965.9 ops/sec)
Did 354 RSA-16384 parse operations in 5043565us (70.2 ops/sec)
Did 88 RSA-32768 parse operations in 5038293us (17.5 ops/sec) [rejected by this CL]
Did 35000 DSA-1024/256 parse operations in 5030447us (6957.6 ops/sec)
Did 11316 DSA-2048/256 parse operations in 5094664us (2221.1 ops/sec)
Did 5488 DSA-3072/256 parse operations in 5096032us (1076.9 ops/sec)
Did 3172 DSA-4096/256 parse operations in 5041220us (629.2 ops/sec)
Did 840 DSA-8192/256 parse operations in 5070616us (165.7 ops/sec)
Did 285 DSA-10000/256 parse operations in 5004033us (57.0 ops/sec)
Did 74 DSA-20000/256 parse operations in 5066299us (14.6 ops/sec) [rejected by this CL]
Update-Note: Some invalid or overly large RSA and DSA keys may
previously have been accepted that are now rejected at parse time. For
public keys, this only moves the error from verification to parsing. In
some private key cases, we would previously allow signing with those
keys, but the resulting signatures would not be accepted by BoringSSL
anyway. This CL makes us behave more consistently.
Bug: oss-fuzz:24730
Change-Id: I4ad2003ee61138b693e65d3da4c6aa00bc165251
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42504
Reviewed-by: Adam Langley <agl@google.com>
This change adds optional support for
- Armv8.3-A Pointer Authentication (PAuth) and
- Armv8.5-A Branch Target Identification (BTI)
features to the perl scripts.
Both features can be enabled with additional compiler flags.
Unless any of these are enabled explicitly there is no code change at
all.
The extensions are briefly described below. Please read the appropriate
chapters of the Arm Architecture Reference Manual for the complete
specification.
Scope
-----
This change only affects generated assembly code.
Armv8.3-A Pointer Authentication
--------------------------------
Pointer Authentication extension supports the authentication of the
contents of registers before they are used for indirect branching
or load.
PAuth provides a probabilistic method to detect corruption of register
values. PAuth signing instructions generate a Pointer Authentication
Code (PAC) based on the value of a register, a seed and a key.
The generated PAC is inserted into the original value in the register.
A PAuth authentication instruction recomputes the PAC, and if it matches
the PAC in the register, restores its original value. In case of a
mismatch, an architecturally unmapped address is generated instead.
With PAuth, mitigation against ROP (Return-oriented Programming) attacks
can be implemented. This is achieved by signing the contents of the
link-register (LR) before it is pushed to stack. Once LR is popped,
it is authenticated. This way a stack corruption which overwrites the
LR on the stack is detectable.
The PAuth extension adds several new instructions, some of which are not
recognized by older hardware. To support a single codebase for both pre
Armv8.3-A targets and newer ones, only NOP-space instructions are added
by this patch. These instructions are treated as NOPs on hardware
which does not support Armv8.3-A. Furthermore, this patch only considers
cases where LR is saved to the stack and then restored before branching
to its content. There are cases in the code where LR is pushed to stack
but it is not used later. We do not address these cases as they are not
affected by PAuth.
There are two keys available to sign an instruction address: A and B.
PACIASP and PACIBSP only differ in the used keys: A and B, respectively.
The keys are typically managed by the operating system.
To enable generating code for PAuth compile with
-mbranch-protection=<mode>:
- standard or pac-ret: add PACIASP and AUTIASP, also enables BTI
(read below)
- pac-ret+b-key: add PACIBSP and AUTIBSP
Armv8.5-A Branch Target Identification
--------------------------------------
Branch Target Identification features some new instructions which
protect the execution of instructions on guarded pages which are not
intended branch targets.
If Armv8.5-A is supported by the hardware, execution of an instruction
changes the value of PSTATE.BTYPE field. If an indirect branch
lands on a guarded page the target instruction must be one of the
BTI <jc> flavors, or in case of a direct call or jump it can be any
other instruction. If the target instruction is not compatible with the
value of PSTATE.BTYPE a Branch Target Exception is generated.
In short, indirect jumps are compatible with BTI <j> and <jc> while
indirect calls are compatible with BTI <c> and <jc>. Please refer to the
specification for the details.
Armv8.3-A PACIASP and PACIBSP are implicit branch target
identification instructions which are equivalent with BTI c or BTI jc
depending on system register configuration.
BTI is used to mitigate JOP (Jump-oriented Programming) attacks by
limiting the set of instructions which can be jumped to.
BTI requires active linker support to mark the pages with BTI-enabled
code as guarded. For ELF64 files BTI compatibility is recorded in the
.note.gnu.property section. For a shared object or static binary it is
required that all linked units support BTI. This means that even a
single assembly file without the required note section turns-off BTI
for the whole binary or shared object.
The new BTI instructions are treated as NOPs on hardware which does
not support Armv8.5-A or on pages which are not guarded.
To insert this new and optional instruction compile with
-mbranch-protection=standard (also enables PAuth) or +bti.
When targeting a guarded page from a non-guarded page, weaker
compatibility restrictions apply to maintain compatibility between
legacy and new code. For detailed rules please refer to the Arm ARM.
Compiler support
----------------
Compiler support requires understanding '-mbranch-protection=<mode>'
and emitting the appropriate feature macros (__ARM_FEATURE_BTI_DEFAULT
and __ARM_FEATURE_PAC_DEFAULT). The current state is the following:
-------------------------------------------------------
| Compiler | -mbranch-protection | Feature macros |
+----------+---------------------+--------------------+
| clang | 9.0.0 | 11.0.0 |
+----------+---------------------+--------------------+
| gcc | 9 | expected in 10.1+ |
-------------------------------------------------------
Available Platforms
------------------
Arm Fast Model and QEMU support both extensions.
https://developer.arm.com/tools-and-software/simulation-models/fast-modelshttps://www.qemu.org/
Implementation Notes
--------------------
This change adds BTI landing pads even to assembly functions which are
likely to be directly called only. In these cases, landing pads might
be superfluous depending on what code the linker generates.
Code size and performance impact for these cases would be negligble.
Interaction with C code
-----------------------
Pointer Authentication is a per-frame protection while Branch Target
Identification can be turned on and off only for all code pages of a
whole shared object or static binary. Because of these properties if
C/C++ code is compiled without any of the above features but assembly
files support any of them unconditionally there is no incompatibility
between the two.
Useful Links
------------
To fully understand the details of both PAuth and BTI it is advised to
read the related chapters of the Arm Architecture Reference Manual
(Arm ARM):
https://developer.arm.com/documentation/ddi0487/latest/
Additional materials:
"Providing protection for complex software"
https://developer.arm.com/architectures/learn-the-architecture/providing-protection-for-complex-software
Arm Compiler Reference Guide Version 6.14: -mbranch-protection
https://developer.arm.com/documentation/101754/0614/armclang-Reference/armclang-Command-line-Options/-mbranch-protection?lang=en
Arm C Language Extensions (ACLE)
https://developer.arm.com/docs/101028/latest
Change-Id: I4335f92e2ccc8e209c7d68a0a79f1acdf3aeb791
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42084
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Change-Id: I4d17e1e6f24b623ee39a844def8f265eb5e6c6cc
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42144
Commit-Queue: Adam Langley <alangley@gmail.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Update-Note: This gets rid of TRUST_TOKEN_experiment_v0. Existing callers
should be updated to call TRUST_TOKEN_experiment_v1.
Change-Id: I8ec9b808cbd35546425690d1548db671ff033e14
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41524
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>