[ca] Document generating a certificate with legacy algorithms.

diff --git a/ca/README b/ca/README
index 3b3071a4938d260c656cd235a0d84b93d6c9314f..f35deb03cfa5bf9281c9ff76ef0ba913fa036312 100644 (file)
--- a/ca/README
+++ b/ca/README
@@ -47,10 +47,11 @@ Import
 ------
 
 Transform the certificate and the private key [6]. Upload the result to the
-browser [7].
+browser [7]. Add `-legacy` to ensure algorithmic interoperability with legacy
+systems.
 
 ```
-$ openssl pkcs12 -export -inkey <name>.key -in <name>.crt -out <name>.p12
+$ openssl pkcs12 -export -legacy -inkey <name>.key -in <name>.crt -out <name>.p12
 ```
 
 Renew
@@ -68,3 +69,4 @@ The CRL file expires after 30 days by defualt. Renew it by recreating the files.
 [5] https://unix.stackexchange.com/a/348488
 [6] https://superuser.com/a/1628622
 [7] https://superuser.com/a/1577753
+[8] https://stackoverflow.com/a/74792849