They days of SHA-1 are quickly coming to an end. Chrome has already marked SHA-1 signed TLS/SSL certificates for having an expiration > 2015-12-31 as insecure for a few weeks now. They promised to sunset SHA-1 about 9 months ago.
So if you haven’t done so, upgrade your HTTPS (and HTTP/2 which defaults to TLS) certificates to SHA-2. A great site of help here is SHAAAAAAAAAAAAA | Check your site for weak SHA-1 certificates. It is open source at GitHub.
You’ve less than 6 months now.
More in dept-reading (especially the comments by Ryan Sleevi): Chrome 42 (next stable) will mark SHA-1 signed certs with a validation date >2015 as insecure!.
–jeroen
PS: if you really need to do the balancing act, you technically can serve old certificates to SHA-2 incompatible clients while serving more secure certificates to modern clients. But it’s a risk, so you might as well tell these old clients they’re out.
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