I read on stack overflow you need to use a 3rd party library for this : WolfSSL
Link to Stack Overflow

Hey Guys,

so i had 2 SIM800L modules here for project
On my modules VCC was connected to 5VDC line passing through a single Shottky diode.
According to Wikipedia:
Schottky diodes' voltage drop at forward biases of around 1 mA is in the range of 0.15 V to 0.46 V
So the resulting voltage on the Vcc pin in my case was 4.7V
This is out off spec for these modules.... Normally it should be between 3.4V and 4.4V

I then replaced the shottky with a normal diode but that didn't fix it completely either,
I think the 5V power source can be a bit flakey in supplying current to this module. (can consume up to 2A)

What worked for me is :
i removed the diode and connected the Lipo battery to the Vcc of the module intead.
Now it gets a Vcc or around 4V and the battery can supply enough current to overcome the high demands. (if it is charges at least a bit, so you could have troubel in the beginning of power on)

i've had mixed with results with different options for the Vcc, but this one worked the most stable to me
Maybe this could help in getting it to work.

Wim

wanted to let you guys know i am experiencing the exact same issue,
cheers