* guix/scripts/authenticate.scm (signature-sexp): Remove.
(guix-authenticate): Upon '-verify', check whether the signature's
public key passes 'authorized-key?'.
* guix/scripts/authenticate.scm (signature-sexp): New procedure.
(guix-authenticate): Use it to produce the signature. Adjust
verification code accordingly.
* tests/store.scm ("import corrupt path"): Adjust test accordingly.
* guix/pk-crypto.scm: Rename procedures, variables, etc. from
'gcry-sexp' to 'canonical-sexp'. Add comment with references.
* guix/scripts/authenticate.scm, tests/pk-crypto.scm: Adjust
accordingly.
Ludovic Courtès