Re: base-64 ignored

On Freitag, 27. Mai 2022 00:46:20 CEST [email protected] wrote:
> On Thursday, May 26, 2022 12:25:48 PM Ingo Klöcker wrote:
> > On Donnerstag, 26. Mai 2022 18:11:39 CEST gene heskett wrote:
> > > it's not 77u/ alone on a line, its all one line as displayed in kmail.
> > > is the / an illegal char in base 64?
> > 
> > Ah, okay. So the line got word-wrapped in your email. No, / is a legal
> > char
> > in base64. Maybe the end of the base64-encoded data is broken. Try
> > decoding the data with `base64 --decode`.
> 
> Some information I found says / is not a legal character in base64:
>
> "For encoding data, Base64 uses only alphabet, number and = symbol. For
> instance, c2FtcGxlCg== is a valid encoded data while b?HV3.Zh2J== is not a
> valid encoded data."

This statement is incorrect.

There are only 2*26 letters (in the English alphabet) and 10 digits. Therefore 
the base64 alphabet adds '+' and '/' to get 64 different symbols. '=' is not a 
legal base64 symbol. It is only used for padding.

See either the definite specification of Base64 at
https://datatracker.ietf.org/doc/html/rfc4648
or the more easily digestible
https://en.wikipedia.org/wiki/Base64#Base64_table_from_RFC_4648.

Regards,
Ingo

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