Large memory models on x86-64 allow the code/data of a shared object /
executable to be larger than 2GiB. This is typically impossible because
x86-64 code frequently uses int32 offsets from RIP.
Consider the following program:
int getpid();
int main() {
return getpid();
}
This is turned into the following assembly under a large memory model:
.L0$pb:
leaq .L0$pb(%rip), %rax
movabsq $_GLOBAL_OFFSET_TABLE_-.L0$pb, %rcx
addq %rax, %rcx
movabsq $getpid@GOT, %rdx
xorl %eax, %eax
jmpq *(%rcx,%rdx) # TAILCALL
And, with relocations:
0: 48 8d 05 f9 ff ff ff lea -0x7(%rip),%rax # 0 <main>
7: 48 b9 00 00 00 00 00 movabs $0x0,%rcx
e: 00 00 00
9: R_X86_64_GOTPC64 _GLOBAL_OFFSET_TABLE_+0x9
11: 48 01 c1 add %rax,%rcx
14: 48 ba 00 00 00 00 00 movabs $0x0,%rdx
1b: 00 00 00
16: R_X86_64_GOT64 getpid
1e: 31 c0 xor %eax,%eax
20: ff 24 11 jmpq *(%rcx,%rdx,1)
We can see that, in the large memory model, function calls involve
loading the address of _GLOBAL_OFFSET_TABLE_ (using `movabs`, which
takes a 64-bit immediate) and then indexing into it. Both cause
relocations.
If we link the binary and disassemble we get:
0000000000001120 <main>:
1120: 48 8d 05 f9 ff ff ff lea -0x7(%rip),%rax # 1120 <main>
1127: 48 b9 e0 2e 00 00 00 movabs $0x2ee0,%rcx
112e: 00 00 00
1131: 48 01 c1 add %rax,%rcx
1134: 48 ba d8 ff ff ff ff movabs $0xffffffffffffffd8,%rdx
113b: ff ff ff
113e: 31 c0 xor %eax,%eax
1140: ff 24 11 jmpq *(%rcx,%rdx,1)
Thus the _GLOBAL_OFFSET_TABLE_ symbol is at 0x1120+0x2ee0 = 0x4000.
That's the address of the .got.plt section. But the offset “into” the
table is -0x40, putting it at 0x3fd8, in .got:
Idx Name Size VMA LMA File off Algn
18 .got 00000030 0000000000003fd0 0000000000003fd0 00002fd0 2**3
19 .got.plt 00000018 0000000000004000 0000000000004000 00003000 2**3
And, indeed, there's a dynamic relocation to setup that address:
OFFSET TYPE VALUE
0000000000003fd8 R_X86_64_GLOB_DAT getpid@GLIBC_2.2.5
Accessing data or BSS works the same: the address of the variable is
stored relative to _GLOBAL_OFFSET_TABLE_.
This is a bit of a pain because we want to delocate the module into a
single .text segment so that it moves through linking unaltered. If we
took the obvious path and built our own offset table then it would need
to contain absolute addresses, but they are only available at runtime
and .text segments aren't supposed to be run-time patched. (That's why
.rela.dyn is a separate segment.) If we use a different segment then
we have the same problem as with the original offset table: the offset
to the segment is unknown when compiling the module.
Trying to pattern match this two-step lookup to do extensive rewriting
seems fragile: I'm sure the compilers will move things around and
interleave other work in time, if they don't already.
So, in order to handle movabs trying to load _GLOBAL_OFFSET_TABLE_ we
define a symbol in the same segment, but outside of the hashed region of
the module, that contains the offset from that position to
_GLOBAL_OFFSET_TABLE_:
.boringssl_got_delta:
.quad _GLOBAL_OFFSET_TABLE_-.boringssl_got_delta
Then a movabs of $_GLOBAL_OFFSET_TABLE_-.Lfoo turns into:
movq .boringssl_got_delta(%rip), %destreg
addq $.boringssl_got_delta-.Lfoo, %destreg
This works because it's calculating
_GLOBAL_OFFSET_TABLE_ - got_delta + (got_delta - .Lfoo)
When that value is added to .Lfoo, as the original code will do, the
correct address results. Also it doesn't need an extra register because
we know that 32-bit offsets are sufficient for offsets within the
module.
As for the offsets within the offset table, we have to load them from
locations outside of the hashed part of the module to get the
relocations out of the way. Again, no extra registers are needed.
Change-Id: I87b19a2f8886bd9f7ac538fd55754e526bcf3097
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42324
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Update-Note: If an SSL_QUIC_METHOD is set, connections will now fail if
ALPN is not negotiated. This new behavior can be detected by checking
if the value of BORINGSSL_API_VERSION is greater than 10.
Bug: 294
Change-Id: I42fb80aa09268e77cec4a51e49cdad79bd72fa58
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42304
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Reason codes 1000+N correspond to receiving an alert N from the peer,
rather than observing the corresponding error condition locally. This
has generally been a source of confusion for folks.
They were originally named like SSL_R_TLSV1_ALERT_DECRYPTION_FAILED, but
OpenSSL introduced a few without the "ALERT" token in
739a543ea863682f157e9aa0ee382367eb3d187c.
We then inadvertently carried the mistake over in
SSL_R_TLSV1_UNKNOWN_PSK_IDENTITY and SSL_R_TLSV1_CERTIFICATE_REQUIRED.
Fix all these to include the "ALERT" for consistency and make it
slightly less confusing. (Although perhaps it should have been
RECEIVED_ALERT or so.) Add compatibility #defines for the original
OpenSSL ones and SSL_R_TLSV1_CERTIFICATE_REQUIRED. The latter can be
removed when downstream code is fixed. The OpenSSL ones we'll probably
just leave around.
Update-Note: The renamed alerts will log slightly different strings, but
the constants used by external code are still there.
Bug: 366
Change-Id: I30c299c4ad4b2bed695bd71d0831fbe6755975a7
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42384
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
The CI should be set up to retain the Go module and build caches, so
we'll avoid downloading it multiple times. This avoids having to
replicate some code.
Update-Note: The tests now have a golang.org/x/crypto dependency. This
should be fetched transparently with Go modules. Monorepos with
different import path conventions may need to rewrite these imports.
Change-Id: If5ba52e051f180536d72109c2e690bbd13d58e7c
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42044
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
draft-ietf-tls-esni-07 uses HPKE for encryption.
Bug: 275
Change-Id: I4af39be4df534f8c1c991c4df82d38c6adcf2574
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41304
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
clang-format now reorders includes. It used to simply sort within
blocks, but later it added a "regroup" option. The regroup option is a
bit aggressive and does not take into account our project headers being
referenced in <system/header.h> style. (It also won't be able to
recognize the header corresponding to the source file, but perhaps we
should drop that rule.)
For now, just revert it to Preserve.
Change-Id: Ief82b5c3f91c16a8def14f91ef6bf6cde502bb79
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42265
Reviewed-by: Adam Langley <agl@google.com>
We should probably ponder what to do about clang-format. That we
disagree on chains of && is a little annoying, but peppering the code
with clang-format off seems problematic.
Change-Id: I0547e4e41817e8c0b585d5fabe759ef25ed00cf7
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42264
Reviewed-by: Adam Langley <agl@google.com>
gRPC are currently importing generate_build_files.py, injecting a
custom printer, and running into problems with the symlinks they set up
to make this work, as well as needing to delete duplicate generated
files.
53a5ad34c0/src/boringssl/gen_build_yaml.py (L130)https://boringssl-review.googlesource.com/c/boringssl/+/42164
Rather than layer on more hacks, add a JSON output to
generate_build_files.py. This outputs a sources.json file that folks
with especially custom builds can consume. (Looks like gRPC converts to
some home-grown YAML format which I imagine is further processed by some
other generator?) We can then add it to master-with-bazel's output.
Change-Id: I82b4ea0647386ca6c76a977f057b9962f40d41c8
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42204
Reviewed-by: 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>
This fixes a couple issues:
- Which libraries to use should be based on WIN32, not MSVC.
- Windows libraries can be specified by #pragma comment lines in the
source or by build dependencies. We specified #pragma lines in
source, but also have build dependencies in crypto_test, etc. The
latter was missing bssl.
The comment line should be sufficient, but being explicit is useful,
so fill in the missing one. This should help building with MINGW,
which is missing support for the usual Windows pragma.
Change-Id: Ide9328c7dd306738ebbb0792e47da96948fe12f4
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42105
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Sadly, we need to roll this one back for now, at least until we've
cleared all the test failures it causes. This retains the other checks
in https://boringssl-review.googlesource.com/c/boringssl/+/41746. We're
only rolling back enforcement of the DEFAULT v1 encoding.
Bug: 348, 364
Change-Id: I6a290311f5a5714ff4d5add3ae35ec4550398b32
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42104
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
This is partially imported from upstream's
54dbf42398e23349b59f258a3dd60387bbc5ba13 which does something similar.
In doing so, remove the pkcs8->broken field, which is a remnant of some
parsing hacks we long since removed (PKCS8_set_broken). The immediate
motivation is, if this sticks, this would make it easier to detach
i2d_PKCS8_PRIV_KEY_INFO and d2i_PKCS8_PRIV_KEY_INFO from the old ASN.1
code.
Update-Note: Direct accesses of PKCS8_PRIV_KEY_INFO now need to use the
accessors. Code search suggests no one uses the fields. Even the
accessors are virtually unused (the one thing which uses it doesn't need
it).
Bug: chromium:1102458
Change-Id: I57054de3fe412079f7387dc99291250e873b1471
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42006
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Code which targets OpenSSL won't use EVP_parse_public_key. X509_PUBKEY
is fairly deeply tied to the old ASN.1 stack, but there's no reason for
i2d_PUBKEY and friends to be. Move them to crypto/evp and reimplement as
wrappers over our functions.
Bug: chromium:1102458
Change-Id: Ic11766acdac797602e4abe1253b0efe33faef298
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42005
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@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>
Change-Id: I9dde27f4a6b492d5a3f49041c8cdcac642c58335
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42004
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Adam Langley
Nick Harper
David Benjamin
Daniel McArdle
Steven Valdez