Add blurb about JWTs for padding changes

README

@@ -164,6 +164,11 @@ Padding Methods
     Version 0.38 sets the appropriate padding for each operation unless
     use_no_padding is called before either operation.
 
+    Note: while "pkcs1-pss" is the effective replacement for "pkcs1" your
+    use case may require some additional steps.  JSON Web Tokens (JWT) for
+    instance require the algorithm to be changed from "RS256" for "pkcs1"
+    (SHA1256) to "PS256" for "pkcs1-pss" (SHA-256 and MGF1 with SHA-256)
+
     use_no_padding
         Use raw RSA encryption. This mode should only be used to implement
         cryptographically sound padding modes in the application code.

README.md

@@ -190,6 +190,11 @@ While **use\_no\_padding** can be used for encryption or signature operations
 Version 0.38 sets the appropriate padding for each operation unless
 **use\_no\_padding** is called before either operation.
 
+**Note:** while "pkcs1-pss" is the effective replacement for "pkcs1" your
+use case may require some additional steps.  JSON Web Tokens (JWT) for
+instance require the algorithm to be changed from "RS256" for "pkcs1"
+(SHA1256) to "PS256" for "pkcs1-pss" (SHA-256 and MGF1 with SHA-256)
+
 - use\_no\_padding
 
     Use raw RSA encryption. This mode should only be used to implement

RSA.pm

@@ -255,6 +255,11 @@ B<use_pkcs1_oaep_padding> is used for encryption operations.
 Version 0.38 sets the appropriate padding for each operation unless
 B<use_no_padding> is called before either operation.
 
+B<Note:> while C<pkcs1-pss> is the effective replacement for <pkcs1> your
+use case may require some additional steps.  JSON Web Tokens (JWT) for
+instance require the algorithm to be changed from "RS256" for "pkcs1"
+(SHA1256) to "PS256" for "pkcs1-pss" (SHA-256 and MGF1 with SHA-256)
+
 =over
 
 =item use_no_padding