> For some reason key servers are not very helpful these days with some > of them offering distorted behavior or appearing to be severely > overloaded. It may be that the key server used by default by Ubuntu > Linux imposes additional limitations such as regarding exposing email > addresses. The user might need to know how to specify a different > server and know which ones to use. The key server network as we knew it is dead and buried, and I would not expect any of them to provide complete or indeed reliable information. This article explains why: https://gist.github.com/rjhansen/67ab921ffb4084c865b3618d6955275f. There was some discussion at the time over on gnupg-users also.
Providing the signer's pub keys on a (secured) web site seems to be the best option for now. The key to verifying the base64 encoded checksums is a conversion from binary to hex and vice versa. od from coreutils and xxd from vim can be used. | Here are the SHA1 and SHA256 checksums: | | 91fa501ada319c4dc8f796208440d45a3f48ed13 gzip-1.12.tar.gz | W0+xTTgxTgny/IocUQ581UCj6g4+ubBCAEa4LDv0EIU gzip-1.12.tar.gz | 318107297587818c8f1e1fbb55962f4b2897bc0b gzip-1.12.tar.xz | zl4D5Rn2N+H4FAEazjXE+HszwLur7sNbr1+9NHnpGVY gzip-1.12.tar.xz $ echo "zl4D5Rn2N+H4FAEazjXE+HszwLur7sNbr1+9NHnpGVY" |base64 -d |xxd -p |tr -d '\n' base64: invalid input ce5e03e519f637e1f814011ace35c4f87b33c0bbabeec35baf5fbd3479e91956$ $ echo "zl4D5Rn2N+H4FAEazjXE+HszwLur7sNbr1+9NHnpGVY" |base64 -d | od -A n -v -t x1 |tr -d ' \n' base64: invalid input ce5e03e519f637e1f814011ace35c4f87b33c0bbabeec35baf5fbd3479e91956$ $ sha256sum gzip-1.12.tar.xz ce5e03e519f637e1f814011ace35c4f87b33c0bbabeec35baf5fbd3479e91956 gzip-1.12.tar.xz $ For the reverse operation, use xxd -r -p, or openssl sha256 -binary. The "invalid input" message above is due to missing padding. An important question has not been asked yet, IMHO - why are maintainers using this relatively obscure method for hashing?