Older Android devices

[griffin]

@bruncsak

The web site waverley.smartcitiestransport.com is using the recent non-default chain, or the older chain (I do not know, are they the same?).

@jillian

For certificates with RSA keys

Through May 3, 2021

• Default chain: End-entity certificate ← R3 ← DST Root CA X3
• Alternate chain: End-entity certificate ← R3 ← ISRG Root X1

Starting May 4, 2021

• Default chain: End-entity certificate ← R3 ← ISRG Root X1 ← DST Root CA X3

  • This chain will remain compatible with many Android devices, thanks to the cross-sign! Extending Android Device Compatibility for Let's Encrypt Certificates - Let's Encrypt

• Alternate chain: End-entity certificate ← R3 ← ISRG Root X1

  • This is a shorter chain, available to people through the API who do not need the Android compatibility of the longer chain. You can choose this chain with many ACME clients, please see your chosen ACME client documentation for more information.

ignore this

This is a 20+ character message to satisfy the silly requirement.