As noted by @buxm, previous fix didn't work for all versions of DSM 6.
The better fix appears to be simply not outputting the "as_default"
parameter unless we are doing something with the default certificate.
For some DSM installs, it appears that setting the "default" flag to the
string "false" actually sets it to true. This causes Synology to set
the last updated certificate to be the default certificate. Using an
empty string appears to still be accepted as a false-y value for DSMs
where this isn't happening and corrects the behavior in the cases that
it was.
Credit to @Run-King for identifying the fix and @buxm for reporting.
Small changes for DSM 6:
All fields (except enable_syno_token as explained below) must either be in the GET params or the POST params, you can't mix GET and POST params
enable_syno_token=yes must be in both the GET and POST params.
If enable_syno_token=yes is only in the POST fields, then DSM6 returns a synotoken of --------. If enable_syno_token=yes is only in the GET params, then it returns no synotoken at all. It must be in both to work.
Need to use /webapi/auth.cgi instead of /webapi/entry.cgi
Verified with DSM 6.2.3-25426 Update 2 and DSM 7.0-40850
This allows us to get the cookie and the token (as it appears to be only in the body in DSM 7.) HTTP_HEADERS is only guarenteed to be output with POST for both wget and curl.
I'm actually not entirely sure why/how this worked with curl but not wget, but it did. The short answer is that using a GET does not result in the HTTP_HEADER file being written, instead you must pass in the http_headers param ($2) which will return the HTTP headers as a string. Luckily, the Token is in both the body and the header. We need it and the id (and smid if 2fa) cookie to proceed. So now we parrse the response for that instead of the HTTP_HEADER file.
Interesting side note: wget is fine if the URL contains a \r or \n, but curl will barf on it. So we need to make sure those are stripped from the token as it will be passed in the URL later.
This allows you to update a key on a Synology DSM using the existing API.
Handles restarting the necessary services the certificate is attached to and all other internal stuff (copying the certificate around, etc.)
This is way less error prone than most articles I've found on how to update a Synology DSM certificate.
