First batch of the alphabet.

Change-Id: If4e60f4fbb69e04eb4b70aa1b2240e329251bfa5
Reviewed-on: https://boringssl-review.googlesource.com/4514
Reviewed-by: Adam Langley <agl@google.com>

Tag number 31 is a long form tag that requires multiple octets.  It
cannot be handled by adding a single uint8.  Changed CBB_add_asn1()
to return 0 when it is passed in the extension for tag 31.

Change-Id: Ia33936d4f174d1a7176eb11da0b5c7370efb9416

CBB_init_fixed() should not call free because it can lead to use after
free or double free bugs.  The caller should be responsible for
creating and destroying the buffer.

In the current code, ssl3_get_v2_client_hello() may free s->init_buf->data
via CBB_init_fixed().  It can also be freed via SSL_free(s) since
ssl3_get_v2_client_hello() doesn't set it to NULL and CBB_init_fixed()
can't set the caller's pointer to NULL.

Change-Id: Ia05a67ae25af7eb4fb04f08f20d50d912b41e38b

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>

Companion to CBS_get_asn1_uint64. Also add tests for both the parsing and the
serializing.

Change-Id: Ic5e9a0089c88b300f874712d0e9964cb35a8c40b
Reviewed-on: https://boringssl-review.googlesource.com/1999
Reviewed-by: Adam Langley <agl@google.com>

ssl23_get_client_hello has lots of remnants of SSLv2 support and remnants of an
even older SSL_OP_NON_EXPORT_FIRST option (see upstream's
d92f0bb6e9) which complicates the logic.

Split it into three states and move V2ClientHello parsing into its own
function. Port it to CBS and CBB to give bounds checks on the V2ClientHello
parse.

This fixes a minor bug where, if the SSL_accept call in ssl23_get_client_hello
failed, cb would not be NULL'd and SSL_CB_ACCEPT_LOOP would get reported an
extra time.

It also unbreaks the invariant between s->packet, s->packet_length,
s->s3->rbuf.buf, and s->s3->rbuf.offset at the point the switch, although this
was of no consequence because the first ssl3_read_n call passes extend = 0
which resets s->packet and s->packet_length.

It also makes us tolerant to major version bumps in the ClientHello. Add tests
for TLS tolerance of both minor and major version bumps as well as the HTTP
request error codes.

Change-Id: I948337f4dc483f4ebe1742d3eba53b045b260257
Reviewed-on: https://boringssl-review.googlesource.com/1455
Reviewed-by: Adam Langley <agl@google.com>

This function serialises a PKCS#7 structure containing a number of
certificates.

Change-Id: Iaf15887e1060d5d201d5a3dd3dca8d51105ee6d6
Reviewed-on: https://boringssl-review.googlesource.com/1431
Reviewed-by: Adam Langley <agl@google.com>

When shifting data because extra ASN.1 length bytes were needed, the
data was moved from the start of the ASN.1 length, not the start of the
ASN.1 data.

Change-Id: Ib13d5e4e878774df2af0505c0297eff6cf781728
Reviewed-on: https://boringssl-review.googlesource.com/1430
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.)