As with CRYPTO_ctr128_encrypt_ctr32, NULL in and out are legal in the
degenerate case when len is 0. This fixes one of the two failures on the bots.

Change-Id: If6016dfc3963d9c06c849fc8eba9908556f66666
Reviewed-on: https://boringssl-review.googlesource.com/4721
Reviewed-by: Adam Langley <agl@google.com>

NULL in and out are legal in the degenerate case when len is 0.

Change-Id: Ibf0600a4f635a03103b1ae914918fdcf23a75a39
Reviewed-on: https://boringssl-review.googlesource.com/4705
Reviewed-by: Adam Langley <agl@google.com>

Everything else.

Change-Id: Iac02b144465b4e7b6d69ea22ff2aaf52695ae732

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>

Change-Id: I2bf0144aaa8b670ff00b8e8dfe36bd4d237b9a8a
Reviewed-on: https://boringssl-review.googlesource.com/3140
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.)