PR #346 added a test for version tolerance to `run_protocols()`, but I think it may now be more appropriate to remove that test. Draft -16 of TLS 1.3, which was posted on September 22, changed the way that version negotiation is handled for TLS 1.3 and above. The current version tolerance test sends a ClientHello with the version field set to "03, 05", to represent a TLS 1.4 ClientHello. While this was consistent with RFC 5246 and with drafts of TLS 1.3 up to -15, draft -16 changed the version field to `legacy_version` and declared that its value should be "03, 03" for TLS 1.2 and above. (For TLS 1.3 and above a Supported Versions extension is included to inform the server which versions of TLS the client supports.) The change in draft -16 was made as a result of the problems with servers not handling version negotiation correctly.
Since the current draft suggests that a server should never be presented with a ClientHello with a version higher than "03, 03" (even for clients that support TLS versions higher than 1.2), it seems there is no reason to include the version tolerance test anymore.
For servers that do not support TLS 1.2, the additional checks that were added by PR #346 will already detect if the server cannot perform version negotiation correctly.
This PR adds the option for `parse_sslv2_serverhello()` to extract information from the ServerHello (server key size and cipher suites supported) and write the information to `$TMPFILE` as well as to write the server's certificate to `$HOSTCERT`.
The mapping file is now only used in `show_rfc_style()`. This PR changes `show_rfc_style()` to use the `$TLS_CIPHER_HEXCODE` and `$TLS_CIPHER_RFC_NAME` arrays.
Note that `get_install_dir()` still searches for the mapping-rfc.txt in order to determine `$INSTALL_DIR`. `$INSTALL_DIR` is only used to determine the location of the CA bundles in `determine_trust()`:
```
local ca_bundles="$INSTALL_DIR/etc/*.pem"
```
This PR changes `sslv2_sockets()` so that a list of ciphers may optionally be passed as an argument. This will support the use of `sslv2_sockets()` in some places where `$OPENSSL s_client` is currently used.
