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>

See https://github.com/openssl/openssl/pull/1672.

Change-Id: I4c93a568b9b7ce582b03e955d3aa9cb6b0e89794
Reviewed-on: https://boringssl-review.googlesource.com/12314
Commit-Queue: David Benjamin <davidben@google.com>
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>

The functions BN_rshift and BN_lshift shift their arguments to the right or
left by a specified number of bits. Unpredicatable results (including
crashes) can occur if a negative number is supplied for the shift value.

Thanks to Mateusz Kocielski (LogicalTrust), Marek Kroemeke and Filip Palian
for discovering and reporting this issue.

(Imported from upstream's 7cc18d8158b5fc2676393d99b51c30c135502107.)

Change-Id: Ib9f5e410a46df3d7f02a61374807fba209612bd3
Reviewed-on: https://boringssl-review.googlesource.com/4892
Reviewed-by: Adam Langley <agl@google.com>

Including string.h in base.h causes any file that includes a BoringSSL
header to include string.h. Generally this wouldn't be a problem,
although string.h might slow down the compile if it wasn't otherwise
needed. However, it also causes problems for ipsec-tools in Android
because OpenSSL didn't have this behaviour.

This change removes string.h from base.h and, instead, adds it to each
.c file that requires it.

Change-Id: I5968e50b0e230fd3adf9b72dd2836e6f52d6fb37
Reviewed-on: https://boringssl-review.googlesource.com/3200
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>

Initial fork from f2d678e6e8 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)