BUF_MEM is actually a rather silly API for the SSL stack. There's separate
length and max fields, but init_buf effectively treats length as max and max as
nothing.

We possibly don't want to be using it long-term anyway (if nothing else, the
char*/uint8_t* thing is irritating), but in the meantime, it'll be easier to
separately fix up get_message's book-keeping and state tracking from where the
handshake gets its messages from.

Change-Id: I9e56ea008173991edc8312ec707505ead410a9ee
Reviewed-on: https://boringssl-review.googlesource.com/7947
Reviewed-by: Adam Langley <agl@google.com>

BUF_memdup tries to avoid mallocing zero bytes (and thus unduly
returning an error for a NULL return value) by testing whether the input
buffer is NULL. This goes back to the original OpenSSL code.

However, when |ext_npn_parse_serverhello| tries to use |BUF_memdup| to
copy an NPN value returned by a callback, some callbacks just set the
output /length/ to zero to indicate an empty value. Thus, when
|BUF_memdup| tests the pointer, it's an uninitialised value and MSan
throws an error.

Since passing a NULL pointer to |BUF_memdup| better imply that the
length is zero, while the reverse empirically isn't true, testing the
length seems safer.

Change-Id: I06626f7dfb761de631fd997bda60057b76b8da94

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>

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>

BUF_strlcpy still assumes |src| is a NUL-terminated string and will call strlen
on it to determine the actual length. BUF_strndup's input need not be
NUL-terminated.

Change-Id: I9ca95e92533d12f1b0283412249bda4f8cf92433
Reviewed-on: https://boringssl-review.googlesource.com/1997
Reviewed-by: Adam Langley <agl@google.com>

(Imported from upstream's 4ceb430a468e8226175aa3f169c0e746877c17e1,
4f7236edc7 and
ed693e4332)

Initial fork from f2d678e6e8 (1.0.2 beta).

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