error:03000098:digital envelope routines:do_sigver_init:invalid digest:crypto/evp/m_sigver.c:342:
make[1]: *** [/home/xxx/kernel/common/certs/Makefile:94: certs/signing_key.pem] Error 1
make[1]: *** Deleting file 'certs/signing_key.pem'
make: *** [/home/xxx/kernel/common/Makefile:1998: certs] Error 2
make: *** Waiting for unfinished jobs....
This error might occur durring kernel build. It is happening because newer versions of OpenSSL disallow using SHA-1.