Under certain circumstances it may call log(3), which is not async-
signal-safe.
For now just remove the blacklist integration from this path, which
means that blacklistd will not detect and firewall hosts that establish
a connection but do nothing further.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D46203
This fixes a clang 19 warning:
crypto/heimdal/lib/krb5/deprecated.c:75:17: error: comparison of different enumeration types ('krb5_keytype' (aka 'enum ENCTYPE') and 'enum krb5_keytype_old') [-Werror,-Wenum-compare]
75 | if (keytype != KEYTYPE_DES || context->etypes_des == NULL)
| ~~~~~~~ ^ ~~~~~~~~~~~
In https://github.com/heimdal/heimdal/commit/3bebbe5323 this was solved
by adding a cast. That commit is rather large, so I'm only applying the
one-liner here.
MFC after: 3 days
GCC 14 (but not earlier versions) warns about a missing prototype
for getrandom(). Include <sys/random.h> explicitly to bring in the
prototype rather than depending on a nested include. While here,
stop defining sysctl_random() since it is no longer used.
Reviewed by: brooks
Fixes: 838b6caaba openssl: use getrandom(2) instead of probing for getentropy(2)
Differential Revision: https://reviews.freebsd.org/D45995
The probing for getentropy(2) relies on re-declaring getentropy(2)
as weak and checking the address, but this is incompatible with
the _FORTIFY_SOURCE symbol renaming scheme. It's always present on
all supported FreeBSD versions now so we could cut it down to
unconditional use, but there's another segment for getrandom(2)
already that's cleaner to just add us to.
We should upstream this.
Reviewed by: kib (earlier version), markj
Sponsored by: Klara, Inc.
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D45976
Cherry-pick fix:
upstream: when sending ObscureKeystrokeTiming chaff packets, we
can't rely on channel_did_enqueue to tell that there is data to send. This
flag indicates that the channels code enqueued a packet on _this_ ppoll()
iteration, not that data was enqueued in _any_ ppoll() iteration in the
timeslice. ok markus@
OpenBSD-Commit-ID: 009b74fd2769b36b5284a0188ade182f00564136
Obtained from: openssh-portable 146c420d29d0
Reviewed by: gordon
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45823
Autoconf 2.72 uses '' rather tha `' in comments in config.h, from
autoconf commit 64df9b4523fe ("Autoconf now quotes 'like this' instead
of `like this'").
Switch quoting style now to minimize diffs on the next OpenSSH update
and config.h regen.
Reviewed by: gordon, philip
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45840
This release resolves 3 upstream found CVEs:
- Fixed potential use after free after SSL_free_buffers() is called (CVE-2024-4741)
- Fixed an issue where checking excessively long DSA keys or parameters may be very slow (CVE-2024-4603)
- Fixed unbounded memory growth with session handling in TLSv1.3 (CVE-2024-2511)
MFC after: 3 days
Merge commit '1070e7dca8223387baf5155524b28f62bfe7da3c'
This release resolves 3 upstream found CVEs:
- Fixed potential use after free after SSL_free_buffers() is called (CVE-2024-4741)
- Fixed an issue where checking excessively long DSA keys or parameters may be very slow (CVE-2024-4603)
- Fixed unbounded memory growth with session handling in TLSv1.3 (CVE-2024-2511)
FreeBSD also defines {make|swap|get|set}context for backward
compatibility, despite also exposing POSIX_VERSION 200809L in FreeBSD
15-current.
FreeBSD has defined these interfaces since FreeBSD 4.7, released over 20
years ago, so no further nuance in FreeBSD version number is necessary.
Pull Request: https://github.com/openssl/openssl/pull/23885
Sponsored by: Netflix
This change is still under review and should not have been merged
directly to main (yet).
This is a case and point for using `push.default` to nothing instead of
matching or simple.
This reverts commit 42ce242e35.
This change introduces a static copy of the fips and legacy linker version maps
generated by the OpenSSL 3.0.13 build process.
This unbreaks the fips and legacy providers by not exposing unnecessary
symbols from the fips/legacy provider shared objects shared with other
providers (base, default) and libcrypto.
More discussion:
Prior to this change, loading the fips provider indirectly from a
FreeBSD 14.0-CURRENT and 15.0-CURRENT host would result in a
process-wide deadlock when invoking select OpenSSL APIs
(CONF_modules_load* in this particular example).
Speaking with the upstream maintainers [1], it became obvious that
the FreeBSD base system was incorrectly building/linking the fips
provider, resulting in a symbol collision at runtime, and thus a
process-wide deadlock in specific circumstances. The fips provider
would deadlock when trying to acquire a write lock on internal
structures which should have only been available to the base and
default providers, as certain preprocessor ifdefs only allow specific
internal calls to be made with the base and default providers.
1. https://github.com/openssl/openssl/issues/24202
Differential Revision: https://reviews.freebsd.org/D44892
Import upstream 6747e1628:
asn1: Use unsigned bitfields for named bitsets
Signed 1-bit bitfields are undefined in C.
This should fix the following warnings, which for unknown reasons are
errors in CI:
/usr/src/crypto/heimdal/lib/hx509/ca.c:1020:22: warning: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]
1020 | ku.digitalSignature = 1;
| ^ ~
/usr/src/crypto/heimdal/lib/hx509/ca.c:1021:21: warning: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]
1021 | ku.keyEncipherment = 1;
| ^ ~
/usr/src/crypto/heimdal/lib/hx509/ca.c:1028:17: warning: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]
1028 | ku.keyCertSign = 1;
| ^ ~
/usr/src/crypto/heimdal/lib/hx509/ca.c:1029:13: warning: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]
1029 | ku.cRLSign = 1;
| ^ ~
PR: 276960
Fixes: 1b74875929
MFC after: 1 week
Import upstream 19d378f44:
ASN.1 INTEGERs will now compile to C int64_t or uint64_t, depending
on whether the constraint ranges include numbers that cannot be
represented in 32-bit ints and whether they include negative
numbers.
Template backend support included. check-template is now built with
--template, so we know we're testing it.
Tests included.
Also adjusts the generated files:
* asn1parse.c, asn1parse.h (not strictly necessary, but nice to have)
* der-protos.h, which needs a bunch of new prototypes. I copied these
from a der-protos.h generated by the upstream build system, which
uses a perl script for this.
* adjust printf format strings for int64_t. Upstream uses %lld for this,
but that is not portable, and leads to lots of -Werror warnings.
This should fix target-dependent differences between headers generated
by asn1_compile. For example, when cross compiling world from amd64 to
i386, the generated cms_asn1.h header has:
CMSRC2CBCParameter ::= SEQUENCE {
rc2ParameterVersion INTEGER (0..-1),
iv OCTET STRING,
}
while a native build on i386 has:
CMSRC2CBCParameter ::= SEQUENCE {
rc2ParameterVersion INTEGER (0..2147483647),
iv OCTET STRING,
}
These are _both_ wrong, since the source file, cms.asn1, has:
CMSRC2CBCParameter ::= SEQUENCE {
rc2ParameterVersion INTEGER (0..4294967295),
iv OCTET STRING -- exactly 8 octets
}
PR: 276960
Reviewed by: cy, emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D44814
Differential Revision: https://reviews.freebsd.org/D44815
Support for a client VersionAddendum was removed in bffe60ead0, but
the option was retained (as oDeprecated) as a transition aid.
Sufficient time has passed that it can be removed.
Sponsored by: The FreeBSD Foundation
This release contains mostly bugfixes.
It also makes support for the DSA signature algorithm a compile-time
option, with plans to disable it upstream later this year and remove
support entirely in 2025.
Full release notes at https://www.openssh.com/txt/release-9.7
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
For one reason or another these symbols aren't present so don't try to
make them available for linkage.
In the case of libroken these seem to be compatability bits we don't
need a thus don't compile. For others it seems to rot upstream, but
I've not investigated deeply.
Reviewed by: cy
Differential Revision: https://reviews.freebsd.org/D44246
This symbol table entry came in with the 1.5 import (commit
7c450da7b4), but the only other mention is a commented out entry in
lib/wind/libwind-exports.def.
Reviewed by: cy
Differential Revision: https://reviews.freebsd.org/D44245
A flawed logical condition allows a malicious actor to remotely
trigger a NULL pointer dereference using a crafted negTokenInit
token.
Upstream notes:
Reported to Heimdal by Michał Kępień <michal@isc.org>.
From the report:
Acknowledgement
---------------
This flaw was found while working on addressing ZDI-CAN-12302: ISC BIND
TKEY Query Heap-based Buffer Overflow Remote Code Execution
Vulnerability, which was reported to ISC by Trend Micro's Zero Day
Security: CVE-2022-3116
Obtained from: upstream 7a19658c1
MFC after: 1 week
Import upstream 38c797e1a.
Upstream notes:
RFC8062 Section 7 requires verification of the PA-PKINIT-KX key
excahnge when anonymous PKINIT is used. Failure to do so can
permit an active attacker to become a man-in-the-middle.
Reported by: emaste
Obtained from: upstream 38c797e1a
Security: CVE-2019-12098
MFC after: 1 week
Apply upstream 22749e918 to fix a buffer overflow.
Upstream notes:
If len_len is equal to total_len - 1 (i.e. the input consists only of a
0x60 byte and a length), the expression 'total_len - 1 - len_len - 1',
used as the 'len' parameter to der_get_length(), will overflow to
SIZE_MAX. Then der_get_length() will proceed to read, unconstrained,
whatever data follows in memory. Add a check to ensure that doesn't
happen
This is similar to samba CVE-2022-3437.
Reported by: emaste
Security: CVE-2022-41916
Obtained from: upstream 22749e918
MFC after: 1 week
Upstream's explanation of the problem:
S4U2Self is an extension to Kerberos used in Active Directory to allow
a service to request a kerberos ticket to itself from the Kerberos Key
Distribution Center (KDC) for a non-Kerberos authenticated user
(principal in Kerboros parlance). This is useful to allow internal
code paths to be standardized around Kerberos.
S4U2Proxy (constrained-delegation) is an extension of this mechanism
allowing this impersonation to a second service over the network. It
allows a privileged server that obtained a S4U2Self ticket to itself
to then assert the identity of that principal to a second service and
present itself as that principal to get services from the second
service.
There is a flaw in Samba's AD DC in the Heimdal KDC. When the Heimdal
KDC checks the checksum that is placed on the S4U2Self packet by the
server to protect the requested principal against modification, it
does not confirm that the checksum algorithm that protects the user
name (principal) in the request is keyed. This allows a
man-in-the-middle attacker who can intercept the request to the KDC to
modify the packet by replacing the user name (principal) in the
request with any desired user name (principal) that exists in the KDC
and replace the checksum protecting that name with a CRC32 checksum
(which requires no prior knowledge to compute).
This would allow a S4U2Self ticket requested on behalf of user name
(principal) user@EXAMPLE.COM to any service to be changed to a
S4U2Self ticket with a user name (principal) of
Administrator@EXAMPLE.COM. This ticket would then contain the PAC of
the modified user name (principal).
Reported by: emaste
Security: CVE-2018-16860
Obtained from: Upstream c6257cc2c
MFC after: 1 week
Apply upstream b1e699103. This fixes a bug introduced by upstream
f469fc6 which may in some cases enable bypass of capath policy.
Upstream writes in their commit log:
Note, this may break sites that rely on the bug. With the bug some
incomplete [capaths] worked, that should not have. These may now break
authentication in some cross-realm configurations.
Reported by: emaste
Security: CVE-2017-6594
Obtained from: upstream b1e699103
MFC after: 1 week
* Fixed PKCS12 Decoding crashes ([CVE-2024-0727])
* Fixed Excessive time spent checking invalid RSA public keys
([CVE-2023-6237])
* Fixed POLY1305 MAC implementation corrupting vector registers on
PowerPC CPUs which support PowerISA 2.07 ([CVE-2023-6129])
* Fix excessive time spent in DH check / generation with large Q
parameter value ([CVE-2023-5678])
Release notes can be found at
https://www.openssl.org/news/openssl-3.0-notes.html.
Approved by: emaste
MFC after: 3 days
Merge commit '9dd13e84fa8eca8f3462bd55485aa3da8c37f54a'
* Fixed PKCS12 Decoding crashes ([CVE-2024-0727])
* Fixed Excessive time spent checking invalid RSA public keys
([CVE-2023-6237])
* Fixed POLY1305 MAC implementation corrupting vector registers on
PowerPC CPUs which support PowerISA 2.07 ([CVE-2023-6129])
* Fix excessive time spent in DH check / generation with large Q
parameter value ([CVE-2023-5678])
Release notes can be found at
https://www.openssl.org/news/openssl-3.0-notes.html.
Weak crypto is provided by the openssl legacy provider which is
not load by default. Load the legacy providers as needed.
When the legacy provider is loaded into the default context the default
provider will no longer be automatically loaded. Without the default
provider the various kerberos applicaions and functions will abort().
This is the second attempt at this patch. Instead of linking
secure/lib/libcrypto at build time we now link it at runtime, avoiding
buildworld failures under Linux and MacOS. This is because
TARGET_ENDIANNESS is undefined at pre-build time.
PR: 272835
MFC after: 3 days
X-MFC: only to stable/14
Tested by: netchild
Joerg Pulz <Joerg.Pulz@frm2.tum.de> (previous version)
This revision breaks Linux and MacOS cross builds because
TARGET_ENDIANNESS is not define during bootstrapping on these
platforms.
I think the correct approach would be to separate the new
fbsd_ossl_provider_load() and unload functions into their own
library (instead of libroken). This avoids the less desirable
option of including bsd.cpu.mk in secure/lib/Makefile.common,
which does build but could complicate future work.
Reported by: jrtc27
This reverts commit cb350ba7bf.
Weak crypto is provided by the openssl legacy provider which is
not load by default. Load the legacy providers as needed.
When the legacy provider is loaded into the default context the default
provider will no longer be automatically loaded. Without the default
provider the various kerberos applicaions and functions will abort().
PR: 272835
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D43009
Tested by: netchild, Joerg Pulz <Joerg.Pulz@frm2.tum.de>
From the release notes,
> This release contains a number of security fixes, some small features
> and bugfixes.
The most significant change in 9.6p1 is a set of fixes for a newly-
discovered weakness in the SSH transport protocol. The fix was already
merged into FreeBSD and released as FreeBSD-SA-23:19.openssh.
Full release notes at https://www.openssh.com/txt/release-9.6
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
This adds a protocol extension to improve the integrity of the SSH
transport protocol, particular in and around the initial key exchange
(KEX) phase.
Full details of the extension are in the PROTOCOL file.
OpenBSD-Commit-ID: 2a66ac962f0a630d7945fee54004ed9e9c439f14
Approved by: so (implicit)
Obtained from: https://anongit.mindrot.org/openssh.git/patch/?id=1edb00c58f8a6875fad6a497aa2bacf37f9e6cd5
Security: CVE-2023-48795
OpenSSL 3.0.12 addresses:
* Fix incorrect key and IV resizing issues when calling
EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or EVP_CipherInit_ex2()
with OSSL_PARAM parameters that alter the key or IV length
([CVE-2023-5363]).
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
* Fix incorrect key and IV resizing issues when calling
EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or EVP_CipherInit_ex2()
with OSSL_PARAM parameters that alter the key or IV length
([CVE-2023-5363]).
Sponsored by: The FreeBSD Foundation
This removes a guard condition that prevents KTLS being enabled for
receiving in TLS 1.3. Use the correct sequence number and BIO for
receive vs transmit offload.
Obtained from: OpenSSL commit 7c78932b9a4330fb7c8db72b3fb37cbff1401f8b
- Don't unpad records, check the outer record type, or extract the
inner record type from TLS 1.3 records handled by the kernel. KTLS
performs all of these steps and returns the inner record type in the
TLS header.
- When checking the length of a received TLS 1.3 record don't allow
for the extra byte for the nested record type when KTLS is used.
- Pass a pointer to the record type in the TLS header to the
SSL3_RT_INNER_CONTENT_TYPE message callback. For KTLS, the old
pointer pointed to the last byte of payload rather than the record
type. For the non-KTLS case, the TLS header has been updated with
the inner type before this callback is invoked.
Obtained from: OpenSSL commit a5fb9605329fb939abb536c1604d44a511741624)
When KTLS receive is enabled, pending data may still be present due to
read ahead. This data must still be processed the same as records
received without KTLS. To ease readability (especially in
consideration of additional checks which will be added for TLS 1.3),
add a helper variable 'using_ktls' that is true when the KTLS receive
path is being used to receive a record.
Obtained from: OpenSSL commit 031132c297e54cbc20404a0bf8de6ed863196399
KTLS implementations currently assume that the start of the in-kernel
socket buffer is aligned with the start of a TLS record for the
receive side. The socket option to enable KTLS specifies the TLS
sequence number of this initial record.
When read ahead is enabled, data can be pending in the SSL read buffer
after negotiating session keys. This pending data must be examined to
ensurs that the kernel's socket buffer does not contain a partial TLS
record as well as to determine the correct sequence number of the
first TLS record to be processed by the kernel.
In preparation for enabling receive kernel offload for TLS 1.3, move
the existing logic to handle read ahead from t1_enc.c into ktls.c and
invoke it from ktls_configure_crypto().
Obtained from: OpenSSL commit 85773128d0e80cd8dcc772a6931d385b8cf4acd1
OpenSSL 3.0.11 addresses:
POLY1305 MAC implementation corrupts XMM registers on Windows (CVE-2023-4807)
Relnotes: Yes
Pull request: https://github.com/freebsd/freebsd-src/pull/852
Sponsored by: The FreeBSD Foundation
Excerpts from the release notes:
Potentially incompatible changes
--------------------------------
* ssh-keygen(1): generate Ed25519 keys by default.
[NOTE: This change was already merged into FreeBSD.]
* sshd(8): the Subsystem directive now accurately preserves quoting of
subsystem commands and arguments.
New features
------------
* ssh(1): add keystroke timing obfuscation to the client.
* ssh(1), sshd(8): Introduce a transport-level ping facility.
* sshd(8): allow override of Sybsystem directives in sshd Match blocks.
Full release notes at https://www.openssh.com/txt/release-9.5
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Add missing AARCH64_VALID_CALL_TARGET to armv8_rng_probe(). Also add
these to the functions defined by gen_random(), and note that this Perl
sub prints the assembler out directly, not going via the $code xlate
mechanism (and therefore coming before the include of arm_arch.h). So
fix this too.
In KeccakF1600_int, AARCH64_SIGN_LINK_REGISTER functions as
AARCH64_VALID_CALL_TARGET on BTI-only builds, so it needs to come before
the 'adr' line.
Change-Id: If241efe71591c88253a3e36647ced00300c3c1a3
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17653)
Obtained from: OpenSSL 3a23f01268ec
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 negligible.
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
Addional Notes
--------------
This patch is a copy of the work done by Tamas Petz in boringssl. It
contains the changes from the following commits:
aarch64: support BTI and pointer authentication in assembly
Change-Id: I4335f92e2ccc8e209c7d68a0a79f1acdf3aeb791
URL: https://boringssl-review.googlesource.com/c/boringssl/+/42084
aarch64: Improve conditional compilation
Change-Id: I14902a64e5f403c2b6a117bc9f5fb1a4f4611ebf
URL: https://boringssl-review.googlesource.com/c/boringssl/+/43524
aarch64: Fix name of gnu property note section
Change-Id: I6c432d1c852129e9c273f6469a8b60e3983671ec
URL: https://boringssl-review.googlesource.com/c/boringssl/+/44024
Change-Id: I2d95ebc5e4aeb5610d3b226f9754ee80cf74a9af
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16674)
Reviewed by: emaste, Pierre Pronchery <pierre@freebsdfoundation.org>
Obtained from: OpenSSL 19e277dd19f2
Differential Revision: https://reviews.freebsd.org/D41940
