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authorLudovic Courtès <ludo@gnu.org>2020-06-01 17:48:11 +0200
committerLudovic Courtès <ludo@gnu.org>2020-06-05 22:54:06 +0200
commit41f443c90af57f9537eccb1a1a45c6e11b377a32 (patch)
tree99e5855f87e72d71b74f5fe0d6152c1848158208 /build-aux
parentecab53c320b1584a08f811b17a92bd9a50a50ff3 (diff)
Add (guix git-authenticate).
* build-aux/git-authenticate.scm (commit-signing-key) (read-authorizations, commit-authorized-keys, authenticate-commit) (load-keyring-from-blob, load-keyring-from-reference) (authenticate-commits, authenticated-commit-cache-file) (previously-authenticated-commits, cache-authenticated-commit): Remove. * build-aux/git-authenticate.scm (git-authenticate): Pass #:default-authorizations to 'authenticate-commits'. * guix/git-authenticate.scm: New file, with code taken from 'build-aux/git-authenticate.scm'. Remove references to '%historical-authorized-signing-keys' and add #:default-authorizations parameter instead. * Makefile.am (MODULES): Add it. (authenticate): Depend on guix/git-authenticate.go.
Diffstat (limited to 'build-aux')
-rw-r--r--build-aux/git-authenticate.scm203
1 files changed, 7 insertions, 196 deletions
diff --git a/build-aux/git-authenticate.scm b/build-aux/git-authenticate.scm
index 8e679fd5e5..5e1fdaaa24 100644
--- a/build-aux/git-authenticate.scm
+++ b/build-aux/git-authenticate.scm
@@ -22,21 +22,16 @@
;;;
(use-modules (git)
- (guix git)
- (guix openpgp)
(guix base16)
- ((guix utils)
- #:select (cache-directory with-atomic-file-output))
- ((guix build utils) #:select (mkdir-p))
+ (guix git)
+ (guix git-authenticate)
(guix i18n)
+ ((guix openpgp)
+ #:select (openpgp-public-key-fingerprint
+ openpgp-format-fingerprint))
(guix progress)
(srfi srfi-1)
- (srfi srfi-11)
(srfi srfi-26)
- (srfi srfi-34)
- (srfi srfi-35)
- (rnrs bytevectors)
- (rnrs io ports)
(ice-9 match)
(ice-9 format)
(ice-9 pretty-print))
@@ -231,197 +226,11 @@
;; Commits lacking a signature.
'())
-(define (commit-signing-key repo commit-id keyring)
- "Return the OpenPGP key that signed COMMIT-ID (an OID). Raise an exception
-if the commit is unsigned, has an invalid signature, or if its signing key is
-not in KEYRING."
- (let-values (((signature signed-data)
- (catch 'git-error
- (lambda ()
- (commit-extract-signature repo commit-id))
- (lambda _
- (values #f #f)))))
- (unless signature
- (raise (condition
- (&message
- (message (format #f (G_ "commit ~a lacks a signature")
- commit-id))))))
-
- (let ((signature (string->openpgp-packet signature)))
- (with-fluids ((%default-port-encoding "UTF-8"))
- (let-values (((status data)
- (verify-openpgp-signature signature keyring
- (open-input-string signed-data))))
- (match status
- ('bad-signature
- ;; There's a signature but it's invalid.
- (raise (condition
- (&message
- (message (format #f (G_ "signature verification failed \
-for commit ~a")
- (oid->string commit-id)))))))
- ('missing-key
- (raise (condition
- (&message
- (message (format #f (G_ "could not authenticate \
-commit ~a: key ~a is missing")
- (oid->string commit-id)
- data))))))
- ('good-signature data)))))))
-
-(define (read-authorizations port)
- "Read authorizations in the '.guix-authorizations' format from PORT, and
-return a list of authorized fingerprints."
- (match (read port)
- (('authorizations ('version 0)
- (((? string? fingerprints) _ ...) ...)
- _ ...)
- (map (lambda (fingerprint)
- (base16-string->bytevector
- (string-downcase (string-filter char-set:graphic fingerprint))))
- fingerprints))))
-
-(define* (commit-authorized-keys repository commit
- #:optional (default-authorizations '()))
- "Return the list of OpenPGP fingerprints authorized to sign COMMIT, based on
-authorizations listed in its parent commits. If one of the parent commits
-does not specify anything, fall back to DEFAULT-AUTHORIZATIONS."
- (define (commit-authorizations commit)
- (catch 'git-error
- (lambda ()
- (let* ((tree (commit-tree commit))
- (entry (tree-entry-bypath tree ".guix-authorizations"))
- (blob (blob-lookup repository (tree-entry-id entry))))
- (read-authorizations
- (open-bytevector-input-port (blob-content blob)))))
- (lambda (key error)
- (if (= (git-error-code error) GIT_ENOTFOUND)
- default-authorizations
- (throw key error)))))
-
- (apply lset-intersection bytevector=?
- (map commit-authorizations (commit-parents commit))))
-
-(define (authenticate-commit repository commit keyring)
- "Authenticate COMMIT from REPOSITORY and return the signing key fingerprint.
-Raise an error when authentication fails."
- (define id
- (commit-id commit))
-
- (define signing-key
- (commit-signing-key repository id keyring))
-
- (unless (member (openpgp-public-key-fingerprint signing-key)
- (commit-authorized-keys repository commit
- %historical-authorized-signing-keys))
- (raise (condition
- (&message
- (message (format #f (G_ "commit ~a not signed by an authorized \
-key: ~a")
- (oid->string id)
- (openpgp-format-fingerprint
- (openpgp-public-key-fingerprint
- signing-key))))))))
-
- signing-key)
-
-(define (load-keyring-from-blob repository oid keyring)
- "Augment KEYRING with the keyring available in the blob at OID, which may or
-may not be ASCII-armored."
- (let* ((blob (blob-lookup repository oid))
- (port (open-bytevector-input-port (blob-content blob))))
- (get-openpgp-keyring (if (port-ascii-armored? port)
- (open-bytevector-input-port (read-radix-64 port))
- port)
- keyring)))
-
-(define (load-keyring-from-reference repository reference)
- "Load the '.key' files from the tree at REFERENCE in REPOSITORY and return
-an OpenPGP keyring."
- (let* ((reference (branch-lookup repository
- (string-append "origin/" reference)
- BRANCH-REMOTE))
- (target (reference-target reference))
- (commit (commit-lookup repository target))
- (tree (commit-tree commit)))
- (fold (lambda (name keyring)
- (if (string-suffix? ".key" name)
- (let ((entry (tree-entry-bypath tree name)))
- (load-keyring-from-blob repository
- (tree-entry-id entry)
- keyring))
- keyring))
- %empty-keyring
- (tree-list tree))))
-
-(define* (authenticate-commits repository commits
- #:key
- (keyring-reference "keyring")
- (report-progress (const #t)))
- "Authenticate COMMITS, a list of commit objects, calling REPORT-PROGRESS for
-each of them. Return an alist showing the number of occurrences of each key.
-The OpenPGP keyring is loaded from KEYRING-REFERENCE in REPOSITORY."
- (define keyring
- (load-keyring-from-reference repository keyring-reference))
-
- (fold (lambda (commit stats)
- (report-progress)
- (let ((signer (authenticate-commit repository commit keyring)))
- (match (assq signer stats)
- (#f (cons `(,signer . 1) stats))
- ((_ . count) (cons `(,signer . ,(+ count 1))
- (alist-delete signer stats))))))
- '()
- commits))
-
(define commit-short-id
(compose (cut string-take <> 7) oid->string commit-id))
;;;
-;;; Caching.
-;;;
-
-(define (authenticated-commit-cache-file)
- "Return the name of the file that contains the cache of
-previously-authenticated commits."
- (string-append (cache-directory) "/authentication/channels/guix"))
-
-(define (previously-authenticated-commits)
- "Return the previously-authenticated commits as a list of commit IDs (hex
-strings)."
- (catch 'system-error
- (lambda ()
- (call-with-input-file (authenticated-commit-cache-file)
- read))
- (lambda args
- (if (= ENOENT (system-error-errno args))
- '()
- (apply throw args)))))
-
-(define (cache-authenticated-commit commit-id)
- "Record in ~/.cache COMMIT-ID and its closure as authenticated (only
-COMMIT-ID is written to cache, though)."
- (define %max-cache-length
- ;; Maximum number of commits in cache.
- 200)
-
- (let ((lst (delete-duplicates
- (cons commit-id (previously-authenticated-commits))))
- (file (authenticated-commit-cache-file)))
- (mkdir-p (dirname file))
- (with-atomic-file-output file
- (lambda (port)
- (let ((lst (if (> (length lst) %max-cache-length)
- (take lst %max-cache-length) ;truncate
- lst)))
- (chmod port #o600)
- (display ";; List of previously-authenticated commits.\n\n"
- port)
- (pretty-print lst port))))))
-
-
-;;;
;;; Entry point.
;;;
@@ -462,6 +271,8 @@ COMMIT-ID is written to cache, though)."
(let ((stats (call-with-progress-reporter reporter
(lambda (report)
(authenticate-commits repository commits
+ #:default-authorizations
+ %historical-authorized-signing-keys
#:report-progress report)))))
(cache-authenticated-commit (oid->string (commit-id end-commit)))