Fix a sig algs bug and add some tests

[mattcaswell]

Checklist

• tests are added or updated
• CLA is signed

Description of change

This PR fixes a bug in the SSL_set1_sigalgs() macro. Prior to this fix, use of the macro results in a compilation failure. The bug was actually already fixed once in commit 75fdee0, but the fix was only applied to the 1.0.2 branch for some reason.

I've also added some tests for this.

The first 2 commits are for 1.1.0 and master. The third commit is only for master as it is TLSv1.3 specific.

[t-j-h]

+1 with minor comment fix applied

[mattcaswell]

I pushed a new version to fix a travis failure (variables in the new test were not declared static). I also fixed the comment while I was at it.

@t-j-h please reconfirm

[t-j-h]

I dont see any new commits on this pull request since my +1 - am I missing something?

[mattcaswell]

I modified the existing commits and force pushed.

The only difference is the comment change and all these variables are now declared static where they weren't before:

static const int validlist1[] = {NID_sha256, EVP_PKEY_RSA};
static const int validlist2[] = {NID_sha256, EVP_PKEY_RSA, NID_sha512, EVP_PKEY_EC};
static const int validlist3[] = {NID_sha512, EVP_PKEY_EC};
static const int invalidlist1[] = {NID_undef, EVP_PKEY_RSA};
static const int invalidlist2[] = {NID_sha256, NID_undef};
static const int invalidlist3[] = {NID_sha256, EVP_PKEY_RSA, NID_sha256};
static const int invalidlist4[] = {NID_sha256};
static const sigalgs_list testsigalgs[] = {

[t-j-h]

+1

[mattcaswell]

Pushed. Thanks.