diff options
Diffstat (limited to 'guix/scripts/authenticate.scm')
| -rw-r--r-- | guix/scripts/authenticate.scm | 224 |
1 files changed, 159 insertions, 65 deletions
diff --git a/guix/scripts/authenticate.scm b/guix/scripts/authenticate.scm index f1fd8ee895..0bac13edee 100644 --- a/guix/scripts/authenticate.scm +++ b/guix/scripts/authenticate.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2020 Ludovic Courtès <ludo@gnu.org> ;;; ;;; This file is part of GNU Guix. ;;; @@ -17,14 +17,20 @@ ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. (define-module (guix scripts authenticate) - #:use-module (guix config) + #:use-module (guix scripts) #:use-module (guix base16) #:use-module (gcrypt pk-crypto) #:use-module (guix pki) #:use-module (guix ui) + #:use-module (guix diagnostics) + #:use-module (srfi srfi-34) + #:use-module (srfi srfi-35) + #:use-module (srfi srfi-71) + #:use-module (rnrs bytevectors) #:use-module (ice-9 binary-ports) #:use-module (ice-9 rdelim) #:use-module (ice-9 match) + #:use-module (ice-9 vlist) #:export (guix-authenticate)) ;;; Commentary: @@ -39,58 +45,129 @@ ;; Read a gcrypt sexp from a port and return it. (compose string->canonical-sexp read-string)) -(define (read-hash-data port key-type) - "Read sha256 hash data from PORT and return it as a gcrypt sexp. KEY-TYPE -is a symbol representing the type of public key algo being used." - (let* ((hex (read-string port)) - (bv (base16-string->bytevector (string-trim-both hex)))) - (bytevector->hash-data bv #:key-type key-type))) - -(define (sign-with-key key-file port) - "Sign the hash read from PORT with KEY-FILE, and write an sexp that includes -both the hash and the actual signature." - (let* ((secret-key (call-with-input-file key-file read-canonical-sexp)) - (public-key (if (string-suffix? ".sec" key-file) - (call-with-input-file +(define (load-key-pair key-file) + "Load the key pair whose secret key lives at KEY-FILE. Return a pair of +canonical sexps representing those keys." + (catch 'system-error + (lambda () + (let* ((secret-key (call-with-input-file key-file read-canonical-sexp)) + (public-key (call-with-input-file (string-append (string-drop-right key-file 4) ".pub") - read-canonical-sexp) - (leave - (G_ "cannot find public key for secret key '~a'~%") - key-file))) - (data (read-hash-data port (key-type public-key))) - (signature (signature-sexp data secret-key public-key))) - (display (canonical-sexp->string signature)) - #t)) - -(define (validate-signature port) - "Read the signature from PORT (which is as produced above), check whether -its public key is authorized, verify the signature, and print the signed data -to stdout upon success." - (let* ((signature (read-canonical-sexp port)) - (subject (signature-subject signature)) - (data (signature-signed-data signature))) + read-canonical-sexp))) + (cons public-key secret-key))) + (lambda args + (let ((errno (system-error-errno args))) + (raise + (formatted-message + (G_ "failed to load key pair at '~a': ~a~%") + key-file (strerror errno))))))) + +(define (sign-with-key public-key secret-key sha256) + "Sign the hash SHA256 (a bytevector) with SECRET-KEY (a canonical sexp), and +return the signature as a canonical sexp that includes SHA256, PUBLIC-KEY, and +the actual signature." + (let ((data (bytevector->hash-data sha256 + #:key-type (key-type public-key)))) + (signature-sexp data secret-key public-key))) + +(define (validate-signature signature acl) + "Validate SIGNATURE, a canonical sexp. Check whether its public key is +authorized in ACL, verify the signature, and return the signed data (a +bytevector) upon success." + (let* ((subject (signature-subject signature)) + (data (signature-signed-data signature))) (if (and data subject) - (if (authorized-key? subject) + (if (authorized-key? subject acl) (if (valid-signature? signature) - (let ((hash (hash-data->bytevector data))) - (display (bytevector->base16-string hash)) - #t) ; success - (leave (G_ "error: invalid signature: ~a~%") - (canonical-sexp->string signature))) - (leave (G_ "error: unauthorized public key: ~a~%") - (canonical-sexp->string subject))) - (leave (G_ "error: corrupt signature data: ~a~%") - (canonical-sexp->string signature))))) + (hash-data->bytevector data) ; success + (raise + (formatted-message (G_ "invalid signature: ~a") + (canonical-sexp->string signature)))) + (raise + (formatted-message (G_ "unauthorized public key: ~a") + (canonical-sexp->string subject)))) + (raise + (formatted-message (G_ "corrupt signature data: ~a") + (canonical-sexp->string signature)))))) + +(define (read-command port) + "Read a command from PORT and return the command and arguments as a list of +strings. Return the empty list when the end-of-file is reached. + +Commands are newline-terminated and must look something like this: + + COMMAND 3:abc 5:abcde 1:x + +where COMMAND is an alphanumeric sequence and the remainder is the command +arguments. Each argument is written as its length (in characters), followed +by colon, followed by the given number of characters." + (define (consume-whitespace port) + (let ((chr (lookahead-u8 port))) + (when (eqv? chr (char->integer #\space)) + (get-u8 port) + (consume-whitespace port)))) + + (match (read-delimited " \t\n\r" port) + ((? eof-object?) + '()) + (command + (let loop ((result (list command))) + (consume-whitespace port) + (let ((next (lookahead-u8 port))) + (cond ((eqv? next (char->integer #\newline)) + (get-u8 port) + (reverse result)) + ((eof-object? next) + (reverse result)) + (else + (let* ((len (string->number (read-delimited ":" port))) + (str (utf8->string + (get-bytevector-n port len)))) + (loop (cons str result)))))))))) + +(define-syntax define-enumerate-type ;TODO: factorize + (syntax-rules () + ((_ name->int (name id) ...) + (define-syntax name->int + (syntax-rules (name ...) + ((_ name) id) ...))))) + +;; Codes used when reply to requests. +(define-enumerate-type reply-code + (success 0) + (command-not-found 404) + (command-failed 500)) ;;; -;;; Entry point with 'openssl'-compatible interface. We support this -;;; interface because that's what the daemon expects, and we want to leave it -;;; unmodified currently. +;;; Entry point. ;;; -(define (guix-authenticate . args) +(define-command (guix-authenticate . args) + (category internal) + (synopsis "sign or verify signatures on normalized archives (nars)") + + (define (send-reply code str) + ;; Send CODE and STR as a reply to our client. + (let ((bv (string->utf8 str))) + (format #t "~a ~a:" code (bytevector-length bv)) + (put-bytevector (current-output-port) bv) + (force-output (current-output-port)))) + + (define (call-with-reply thunk) + ;; Send a reply for the result of THUNK or for any exception raised during + ;; its execution. + (guard (c ((formatted-message? c) + (send-reply (reply-code command-failed) + (apply format #f + (G_ (formatted-message-string c)) + (formatted-message-arguments c))))) + (send-reply (reply-code success) (thunk)))) + + (define-syntax-rule (with-reply exp ...) + (call-with-reply (lambda () exp ...))) + ;; Signature sexps written to stdout may contain binary data, so force ;; ISO-8859-1 encoding so that things are not mangled. See ;; <http://bugs.gnu.org/17312> for details. @@ -101,29 +178,46 @@ to stdout upon success." (with-fluids ((%default-port-encoding "ISO-8859-1") (%default-port-conversion-strategy 'error)) (match args - ;; As invoked by guix-daemon. - (("rsautl" "-sign" "-inkey" key "-in" hash-file) - (call-with-input-file hash-file - (lambda (port) - (sign-with-key key port)))) - ;; As invoked by Nix/Crypto.pm (used by Hydra.) - (("rsautl" "-sign" "-inkey" key) - (sign-with-key key (current-input-port))) - ;; As invoked by guix-daemon. - (("rsautl" "-verify" "-inkey" _ "-pubin" "-in" signature-file) - (call-with-input-file signature-file - (lambda (port) - (validate-signature port)))) - ;; As invoked by Nix/Crypto.pm (used by Hydra.) - (("rsautl" "-verify" "-inkey" _ "-pubin") - (validate-signature (current-input-port))) (("--help") (display (G_ "Usage: guix authenticate OPTION... -Sign or verify the signature on the given file. This tool is meant to -be used internally by 'guix-daemon'.\n"))) +Sign data or verify signatures. This tool is meant to be used internally by +'guix-daemon'.\n"))) (("--version") (show-version-and-exit "guix authenticate")) - (else - (leave (G_ "wrong arguments")))))) + (() + (let ((acl (current-acl))) + (let loop ((key-pairs vlist-null)) + ;; Read a request on standard input and reply. + (match (read-command (current-input-port)) + (("sign" signing-key (= base16-string->bytevector hash)) + (let* ((key-pairs keys + (match (vhash-assoc signing-key key-pairs) + ((_ . keys) + (values key-pairs keys)) + (#f + (let ((keys (load-key-pair signing-key))) + (values (vhash-cons signing-key keys + key-pairs) + keys)))))) + (with-reply (canonical-sexp->string + (match keys + ((public . secret) + (sign-with-key public secret hash))))) + (loop key-pairs))) + (("verify" signature) + (with-reply (bytevector->base16-string + (validate-signature + (string->canonical-sexp signature) + acl))) + (loop key-pairs)) + (() + (exit 0)) + (commands + (warning (G_ "~s: invalid command; ignoring~%") commands) + (send-reply (reply-code command-not-found) + "invalid command") + (loop key-pairs)))))) + (_ + (leave (G_ "wrong arguments~%")))))) ;;; authenticate.scm ends here |