GCC has a warning that complains about even more type mismatches in
printf. Some of these are a bit messy and will be fixed in separate CLs.
This covers the easy ones.
The .*s stuff is unfortunate, but printf has no size_t-clean string
printer. ALPN protocol lengths are bound by uint8_t, so it doesn't
really matter.
The IPv6 printing one is obnoxious and arguably a false positive. It's
really a C language flaw: all types smaller than int get converted to
int when you do arithmetic. So something like this first doesn't
overflow the shift because it computes over int, but then the result
overall is stored as an int.
uint8_t a, b;
(a << 8) | b
On the one hand, this fixes a "missing" cast to uint16_t before the
shift. At the same time, the incorrect final type means passing it to
%x, which expects unsigned int. The compiler has forgotten this value
actually fits in uint16_t and flags a warning. Mitigate this by storing
in a uint16_t first.
The story doesn't quite end here. Arguments passed to variadic functions
go through integer promotion[0], so the argument is still passed to
snprintf as an int! But then va_arg allows for a signedness mismatch[1],
provided the value is representable in both types. The combination means
that %x, though actually paired with unsigned, also accept uint8_t and
uint16_t, because those are guaranteed to promote to an int that meets
[1]. GCC recognizes [1] applies here.
(There's also PRI16x, but that's a bit tedious to use and, in glibc, is
defined as plain "x" anyway.)
[0] https://en.cppreference.com/w/c/language/conversion#Default_argument_promotions
[1] https://en.cppreference.com/w/c/variadic/va_arg
Bug: 450
Change-Id: Ic1d41356755a18ab922956dd2e07b560470341f4
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/50765
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
There are a lot of d2i and i2d functions, and there will be even more
once asn1.h and x509.h are properly documented. We currently replicate
the text in each, but as a result a miss a few points:
- The i2d outp != NULL, *outp == NULL case isn't documented at all.
- We should call out what to do with *inp after d2i.
- Unlike our rewritten functions, object reuse is still quite rampant
with the asn1.h functions. I hope we can get rid of that but, until we
can, it would be nice to describe it in one place.
While I'm here, update a few references to the latest PKCS#1 RFC, and
try to align how we reference ASN.1 structures a bit. The d2i/i2d
functions say "ASN.1, DER-encoded RSA private key" while the CBS/CBB
functions say "DER-encoded RSAPrivateKey structure".
Bug: 426
Change-Id: I8d9a7b0aef3d6d9c8240136053c3b1704b09fd41
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49906
Reviewed-by: Adam Langley <agl@google.com>
We have a ton of per-file rotation functions, often with generic names
that do not tell you whether they are uint32_t vs uint64_t, or rotl vs
rotr.
Additionally, (x >> r) | (x << (32 - r)) is UB at r = 0.
(x >> r) | (x << ((-r) & 31)) works for 0 <= r < 32, which is what
cast.c does. GCC and Clang recognize this pattern as a rotate, but MSVC
doesn't. MSVC does, however, provide functions for this.
We usually rotate by a non-zero constant, which makes this moot, but
rotation comes up often enough that it's worth extracting out. Some
particular changes to call out:
- I've switched sha256.c from rotl to rotr. There was a comment
explaining why it differed from the specification. Now that we have
both functions, it's simpler to just match the specification.
- I've dropped all the inline assembly from sha512.c. Compilers should
be able to recognize rotations in 2021.
Change-Id: Ia1030e8bfe94dad92514ed1c28777447c48b82f9
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49765
Reviewed-by: Adam Langley <agl@google.com>
Node.js uses EVP_PKEY_get0, which is present in OpenSSL but which
BoringSSL currently does not export. This CL adds an implementation
for it, which Electron is currently floating as a patch.
See
6a7eb32c5b
from Node.
Change-Id: I2474cacbd22882355a8037e2033739f7496b21f2
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47824
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@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>
Prior to 5d7c2f8b1d, these i2d functions would fail, rather than crash,
if passed a NULL argument. While we don't generally have much truck with
the idea that functions should be expected to handle NULL arguments
where not documented, it seems that a fair amount of code is depending
on this.
Change-Id: I928b35533aa2a7beed57d7f58ba44681a8eb05c6
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/42464
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@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>
David Benjamin
Shelley Vohr
Daniel McArdle
Adam Langley