diff options
Diffstat (limited to 'build-aux/git-authenticate.scm')
| -rw-r--r-- | build-aux/git-authenticate.scm | 198 |
1 files changed, 127 insertions, 71 deletions
diff --git a/build-aux/git-authenticate.scm b/build-aux/git-authenticate.scm index bb48dddc59..7bb3af6ecb 100644 --- a/build-aux/git-authenticate.scm +++ b/build-aux/git-authenticate.scm @@ -23,8 +23,10 @@ (use-modules (git) (guix git) - (guix gnupg) - (guix utils) + (guix openpgp) + (guix base16) + ((guix utils) + #:select (cache-directory with-atomic-file-output)) ((guix build utils) #:select (mkdir-p)) (guix i18n) (guix progress) @@ -33,6 +35,7 @@ (srfi srfi-26) (srfi srfi-34) (srfi srfi-35) + (rnrs bytevectors) (rnrs io ports) (ice-9 match) (ice-9 format) @@ -215,7 +218,8 @@ ;; Fingerprint of authorized signing keys. (map (match-lambda ((name fingerprint) - (string-filter char-set:graphic fingerprint))) + (base16-string->bytevector + (string-downcase (string-filter char-set:graphic fingerprint))))) %committers)) (define %commits-with-bad-signature @@ -226,93 +230,146 @@ ;; Commits lacking a signature. '()) -(define-syntax-rule (with-temporary-files file1 file2 exp ...) - (call-with-temporary-output-file - (lambda (file1 port1) - (call-with-temporary-output-file - (lambda (file2 port2) - exp ...))))) - -(define (commit-signing-key repo commit-id) - "Return the OpenPGP key ID that signed COMMIT-ID (an OID). Raise an -exception if the commit is unsigned or has an invalid 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))))) - (if (not signature) - (raise (condition - (&message - (message (format #f (G_ "commit ~a lacks a signature") - commit-id))))) - (begin - (with-fluids ((%default-port-encoding "UTF-8")) - (with-temporary-files data-file signature-file - (call-with-output-file data-file - (cut display signed-data <>)) - (call-with-output-file signature-file - (cut display signature <>)) - - (let-values (((status data) - (with-error-to-port (%make-void-port "w") - (lambda () - (gnupg-verify* signature-file data-file - #:key-download 'always))))) - (match status - ('invalid-signature - ;; There's a signature but it's invalid. - (raise (condition - (&message - (message (format #f (G_ "signature verification failed \ + (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 \ + (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)))))) - ('valid-signature - (match data - ((fingerprint . user) - fingerprint))))))))))) - -(define (authenticate-commit repository commit) + (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)) + (commit-signing-key repository id keyring)) - (unless (member signing-key %authorized-signing-keys) + (unless (member (openpgp-public-key-fingerprint signing-key) + (commit-authorized-keys repository commit + %authorized-signing-keys)) (raise (condition (&message (message (format #f (G_ "commit ~a not signed by an authorized \ key: ~a") - (oid->string id) signing-key)))))) + (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 (reference-lookup repository reference)) + (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 (report-progress (const #t))) + #:key + (keyring-reference "refs/heads/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." - (parameterize ((current-keyring (string-append (config-directory) - "/keyrings/channels/guix.kbx"))) - (fold (lambda (commit stats) - (report-progress) - (let ((signer (authenticate-commit repository commit))) - (match (assoc signer stats) - (#f (cons `(,signer . 1) stats)) - ((_ . count) (cons `(,signer . ,(+ count 1)) - (alist-delete signer stats)))))) - '() - commits))) +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)) @@ -409,7 +466,10 @@ COMMIT-ID is written to cache, though)." (format #t (G_ "Signing statistics:~%")) (for-each (match-lambda ((signer . count) - (format #t " ~a ~10d~%" signer count))) + (format #t " ~a ~10d~%" + (openpgp-format-fingerprint + (openpgp-public-key-fingerprint signer)) + count))) (sort stats (match-lambda* (((_ . count1) (_ . count2)) @@ -423,7 +483,3 @@ COMMIT-ID is written to cache, though)." (G_ "Usage: git-authenticate START [END] Authenticate commits START to END or the current head.\n")))))) - -;;; Local Variables: -;;; eval: (put 'with-temporary-files 'scheme-indent-function 2) -;;; End: |