This will let us avoid a scratch buffer when assembling DTLS handshake
packets in the write_message-less flow.

BUG=72

Change-Id: I15e78efe3a9e3933c307e599f0043427330f4a9e
Reviewed-on: https://boringssl-review.googlesource.com/13262
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>

Change-Id: Ifc28887cbf91c7a80bdaf56e3bf80b2f8cfa7d53
Reviewed-on: https://boringssl-review.googlesource.com/13260
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>

Most C standard library functions are undefined if passed NULL, even
when the corresponding length is zero. This gives them (and, in turn,
all functions which call them) surprising behavior on empty arrays.
Some compilers will miscompile code due to this rule. See also
https://www.imperialviolet.org/2016/06/26/nonnull.html

Add OPENSSL_memcpy, etc., wrappers which avoid this problem.

BUG=23

Change-Id: I95f42b23e92945af0e681264fffaf578e7f8465e
Reviewed-on: https://boringssl-review.googlesource.com/12928
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>

This should never happen, but the SSL_AEAD_CTX_new layer should enforce
key sizes as it's not locally obvious at the call site the caller didn't
get confused. There's still a mess of asserts below, but those should be
fixed by cutting the SSL_CIPHER/SSL_AEAD_CTX boundary differently.

(enc_key_len is validated by virtue of being passed into EVP_AEAD.)

BUG=chromium:659593

Change-Id: I8c91609bcef14ca1509c87aab981bbad6556975f
Reviewed-on: https://boringssl-review.googlesource.com/11940
Reviewed-by: Steven Valdez <svaldez@google.com>
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>

This was done just by grepping for 'size_t i;' and 'size_t j;'. I left
everything in crypto/x509 and friends alone.

There's some instances in gcm.c that are non-trivial and pulled into a
separate CL for ease of review.

Change-Id: I6515804e3097f7e90855f1e7610868ee87117223
Reviewed-on: https://boringssl-review.googlesource.com/10801
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>

In TLS 1.3, the iv_length is equal to the explicit AEAD nonce length,
and is required to be at least 8 bytes.

Change-Id: Ib258f227d0a02c5abfc7b65adb4e4a689feffe33
Reviewed-on: https://boringssl-review.googlesource.com/8304
Reviewed-by: David Benjamin <davidben@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>

The TLS 1.3 spec has an explicit nonce construction for AEADs that
requires xoring the IV and sequence number.

Change-Id: I77145e12f7946ffb35ebeeb9b2947aa51058cbe9
Reviewed-on: https://boringssl-review.googlesource.com/8042
Reviewed-by: Adam Langley <agl@google.com>

Both sides' signature and Finished checks still occur, but the results
are ignored. Also, all ciphers behave like the NULL cipher.
Conveniently, this isn't that much code since all ciphers and their size
computations funnel into SSL_AEAD_CTX.

This does carry some risk that we'll mess up this code. Up until now, we've
tried to avoid test-only changes to the SSL stack.

There is little risk that anyone will ship a BORINGSSL_UNSAFE_FUZZER_MODE build
for anything since it doesn't interop anyway. There is some risk that we'll end
up messing up the disableable checks. However, both skipped checks have
negative tests in runner (see tests that set InvalidSKXSignature and
BadFinished). For good measure, I've added a server variant of the existing
BadFinished test to this CL, although they hit the same code.

Change-Id: I37f6b4d62b43bc08fab7411965589b423d86f4b8
Reviewed-on: https://boringssl-review.googlesource.com/7287
Reviewed-by: Adam Langley <agl@google.com>

C has implicit conversion of |void *| to other pointer types so these
casts are unnecessary. Clean them up to make the code easier to read
and to make it easier to find dangerous casts.

Change-Id: I26988a672e8ed4d69c75cfbb284413999b475464
Reviewed-on: https://boringssl-review.googlesource.com/7102
Reviewed-by: David Benjamin <davidben@google.com>

Only ECDHE-based ciphers are implemented. To ease the transition, the
pre-standard cipher shares a name with the standard one. The cipher rule parser
is hacked up to match the name to both ciphers. From the perspective of the
cipher suite configuration language, there is only one cipher.

This does mean it is impossible to disable the old variant without a code
change, but this situation will be very short-lived, so this is fine.

Also take this opportunity to make the CK and TXT names align with convention.

Change-Id: Ie819819c55bce8ff58e533f1dbc8bef5af955c21
Reviewed-on: https://boringssl-review.googlesource.com/6686
Reviewed-by: Adam Langley <agl@google.com>

This reverts most of commit 271777f5ac. The old
ChaCha20-Poly1305, though being transitioned to the old name, should not change
in behavior. This also avoids adding a special-case to SSL_AEAD_CTX.

Also revert the name change to SSL_CIPHER_is_CHACHA20POLY1305. The one consumer
for that function doesn't need to distinguish the old and new variants, so
avoid unnecessary turbulence.

Change-Id: I5a6f97fccc5839d4d25e74e304dc002329d21b4b
Reviewed-on: https://boringssl-review.googlesource.com/6385
Reviewed-by: Adam Langley <agl@google.com>

This change reduces unnecessary copying and makes the pre-RFC-7539
nonces 96 bits just like the AES-GCM, AES-CCM, and RFC 7539
ChaCha20-Poly1305 cipher suites. Also, all the symbols related to
the pre-RFC-7539 cipher suites now have "_OLD" appended, in
preparation for adding the RFC 7539 variants.

Change-Id: I1f85bd825b383c3134df0b6214266069ded029ae
Reviewed-on: https://boringssl-review.googlesource.com/6103
Reviewed-by: Adam Langley <alangley@gmail.com>

ssl.h should be first. Also two lines after includes and the rest of the
file.

Change-Id: Icb7586e00a3e64170082c96cf3f8bfbb2b7e1611
Reviewed-on: https://boringssl-review.googlesource.com/5892
Reviewed-by: Adam Langley <agl@google.com>

It's a property of just algorithm_enc and hopefully AES-GCM will
continue to be the only true AEAD that requires this. Simpler to just
keep it in ssl_aead_ctx.c.

Change-Id: Ib7c060a3de2fa8590b2dc36c23a5d5fabff43b07
Reviewed-on: https://boringssl-review.googlesource.com/5613
Reviewed-by: Adam Langley <agl@google.com>

Much of this was done automatically with
  find . -name '*.c' | xargs sed -E -i '' -e 's/(OPENSSL_PUT_ERROR\([a-zA-Z_0-9]+, )[a-zA-Z_0-9]+, ([a-zA-Z_0-9]+\);)/\1\2/'
  find . -name '*.c' | xargs sed -E -i '' -e 's/(OPENSSL_PUT_ERROR\([a-zA-Z_0-9]+, )[a-zA-Z_0-9]+,  ([a-zA-Z_0-9]+\);)/\1\2/'

BUG=468039

Change-Id: I4c75fd95dff85ab1d4a546b05e6aed1aeeb499d8
Reviewed-on: https://boringssl-review.googlesource.com/5276
Reviewed-by: Adam Langley <agl@google.com>

tls1_enc is now SSL_AEAD_CTX_{open,seal}. This starts tidying up a bit
of the record-layer logic. This removes rr->input, as encrypting and
decrypting records no longer refers to various globals. It also removes
wrec altogether. SSL3_RECORD is now only used to maintain state about
the current incoming record. Outgoing records go straight to the write
buffer.

This also removes the outgoing alignment memcpy and simply calls
SSL_AEAD_CTX_seal with the parameters as appropriate. From bssl speed
tests, this seems to be faster on non-ARM and a bit of a wash on ARM.

Later it may be worth recasting these open/seal functions to write into
a CBB (tweaked so it can be malloc-averse), but for now they take an
out/out_len/max_out trio like their EVP_AEAD counterparts.

BUG=468889

Change-Id: Ie9266a818cc053f695d35ef611fd74c5d4def6c3
Reviewed-on: https://boringssl-review.googlesource.com/4792
Reviewed-by: Adam Langley <agl@google.com>