Describe the bug
According to "What's new in Spring Security 7", "The Spring Security Kerberos Extension is now part of Spring Security"
However, Kerberos authentication fails with

java.lang.ClassNotFoundException: org.springframework.security.crypto.codec.Base64
 at org.springframework.security.kerberos.web.authentication.SpnegoAuthenticationProcessingFilter.doFilterInternal(SpnegoAuthenticationProcessingFilter.java:147)

To Reproduce
See spring-projects/spring-security-kerberos#338 and spring-projects/spring-security-kerberos#340

Expected behavior
Spring Security Kerberos, if integrated with Spring Security 7, should not use classes which have been removed.

Sample

See links under "To Reproduce"