diff options
Diffstat (limited to 'guix')
| -rw-r--r-- | guix/base64.scm | 212 | ||||
| -rwxr-xr-x | guix/scripts/substitute-binary.scm | 168 |
2 files changed, 336 insertions, 44 deletions
diff --git a/guix/base64.scm b/guix/base64.scm new file mode 100644 index 0000000000..f7f7f5f4e1 --- /dev/null +++ b/guix/base64.scm @@ -0,0 +1,212 @@ +;; -*- mode: scheme; coding: utf-8 -*- +;; +;; This module was renamed from (weinholt text base64 (1 0 20100612)) to +;; (guix base64) by Nikita Karetnikov <nikita@karetnikov.org> on +;; February 12, 2014. +;; +;; Copyright © 2009, 2010 Göran Weinholt <goran@weinholt.se> +;; +;; This program is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. +;; +;; This program is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. +;; +;; You should have received a copy of the GNU General Public License +;; along with this program. If not, see <http://www.gnu.org/licenses/>. +#!r6rs + +;; RFC 4648 Base-N Encodings + +(library (guix base64) + (export base64-encode + base64-decode + base64-alphabet + base64url-alphabet + get-delimited-base64 + put-delimited-base64) + (import (rnrs) + (only (srfi :13 strings) + string-index + string-prefix? string-suffix? + string-concatenate string-trim-both)) + + (define base64-alphabet + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/") + + (define base64url-alphabet + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_") + + (define base64-encode + (case-lambda + ;; Simple interface. Returns a string containing the canonical + ;; base64 representation of the given bytevector. + ((bv) + (base64-encode bv 0 (bytevector-length bv) #f #f base64-alphabet #f)) + ((bv start) + (base64-encode bv start (bytevector-length bv) #f #f base64-alphabet #f)) + ((bv start end) + (base64-encode bv start end #f #f base64-alphabet #f)) + ((bv start end line-length) + (base64-encode bv start end line-length #f base64-alphabet #f)) + ((bv start end line-length no-padding) + (base64-encode bv start end line-length no-padding base64-alphabet #f)) + ((bv start end line-length no-padding alphabet) + (base64-encode bv start end line-length no-padding alphabet #f)) + ;; Base64 encodes the bytes [start,end[ in the given bytevector. + ;; Lines are limited to line-length characters (unless #f), + ;; which must be a multiple of four. To omit the padding + ;; characters (#\=) set no-padding to a true value. If port is + ;; #f, returns a string. + ((bv start end line-length no-padding alphabet port) + (assert (or (not line-length) (zero? (mod line-length 4)))) + (let-values (((p extract) (if port + (values port (lambda () (values))) + (open-string-output-port)))) + (letrec ((put (if line-length + (let ((chars 0)) + (lambda (p c) + (when (fx=? chars line-length) + (set! chars 0) + (put-char p #\linefeed)) + (set! chars (fx+ chars 1)) + (put-char p c))) + put-char))) + (let lp ((i start)) + (cond ((= i end)) + ((<= (+ i 3) end) + (let ((x (bytevector-uint-ref bv i (endianness big) 3))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (put p (string-ref alphabet (fxbit-field x 6 12))) + (put p (string-ref alphabet (fxbit-field x 0 6))) + (lp (+ i 3)))) + ((<= (+ i 2) end) + (let ((x (fxarithmetic-shift-left (bytevector-u16-ref bv i (endianness big)) 8))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (put p (string-ref alphabet (fxbit-field x 6 12))) + (unless no-padding + (put p #\=)))) + (else + (let ((x (fxarithmetic-shift-left (bytevector-u8-ref bv i) 16))) + (put p (string-ref alphabet (fxbit-field x 18 24))) + (put p (string-ref alphabet (fxbit-field x 12 18))) + (unless no-padding + (put p #\=) + (put p #\=))))))) + (extract))))) + + ;; Decodes a base64 string. The string must contain only pure + ;; unpadded base64 data. + (define base64-decode + (case-lambda + ((str) + (base64-decode str base64-alphabet #f)) + ((str alphabet) + (base64-decode str alphabet #f)) + ((str alphabet port) + (unless (zero? (mod (string-length str) 4)) + (error 'base64-decode + "input string must be a multiple of four characters")) + (let-values (((p extract) (if port + (values port (lambda () (values))) + (open-bytevector-output-port)))) + (do ((i 0 (+ i 4))) + ((= i (string-length str)) + (extract)) + (let ((c1 (string-ref str i)) + (c2 (string-ref str (+ i 1))) + (c3 (string-ref str (+ i 2))) + (c4 (string-ref str (+ i 3)))) + ;; TODO: be more clever than string-index + (let ((i1 (string-index alphabet c1)) + (i2 (string-index alphabet c2)) + (i3 (string-index alphabet c3)) + (i4 (string-index alphabet c4))) + (cond ((and i1 i2 i3 i4) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12) + (fxarithmetic-shift-left i3 6) + i4))) + (put-u8 p (fxbit-field x 16 24)) + (put-u8 p (fxbit-field x 8 16)) + (put-u8 p (fxbit-field x 0 8)))) + ((and i1 i2 i3 (char=? c4 #\=) + (= i (- (string-length str) 4))) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12) + (fxarithmetic-shift-left i3 6)))) + (put-u8 p (fxbit-field x 16 24)) + (put-u8 p (fxbit-field x 8 16)))) + ((and i1 i2 (char=? c3 #\=) (char=? c4 #\=) + (= i (- (string-length str) 4))) + (let ((x (fxior (fxarithmetic-shift-left i1 18) + (fxarithmetic-shift-left i2 12)))) + (put-u8 p (fxbit-field x 16 24)))) + (else + (error 'base64-decode "invalid input" + (list c1 c2 c3 c4))))))))))) + + (define (get-line-comp f port) + (if (port-eof? port) + (eof-object) + (f (get-line port)))) + + ;; Reads the common -----BEGIN/END type----- delimited format from + ;; the given port. Returns two values: a string with the type and a + ;; bytevector containing the base64 decoded data. The second value + ;; is the eof object if there is an eof before the BEGIN delimiter. + (define (get-delimited-base64 port) + (define (get-first-data-line port) + ;; Some MIME data has header fields in the same format as mail + ;; or http. These are ignored. + (let ((line (get-line-comp string-trim-both port))) + (cond ((eof-object? line) line) + ((string-index line #\:) + (let lp () ;read until empty line + (let ((line (get-line-comp string-trim-both port))) + (if (string=? line "") + (get-line-comp string-trim-both port) + (lp))))) + (else line)))) + (let ((line (get-line-comp string-trim-both port))) + (cond ((eof-object? line) + (values "" (eof-object))) + ((string=? line "") + (get-delimited-base64 port)) + ((and (string-prefix? "-----BEGIN " line) + (string-suffix? "-----" line)) + (let* ((type (substring line 11 (- (string-length line) 5))) + (endline (string-append "-----END " type "-----"))) + (let-values (((outp extract) (open-bytevector-output-port))) + (let lp ((line (get-first-data-line port))) + (cond ((eof-object? line) + (error 'get-delimited-base64 + "unexpected end of file")) + ((string-prefix? "-" line) + (unless (string=? line endline) + (error 'get-delimited-base64 + "bad end delimiter" type line)) + (values type (extract))) + (else + (unless (and (= (string-length line) 5) + (string-prefix? "=" line)) ;Skip Radix-64 checksum + (base64-decode line base64-alphabet outp)) + (lp (get-line-comp string-trim-both port)))))))) + (else ;skip garbage (like in openssl x509 -in foo -text output). + (get-delimited-base64 port))))) + + (define put-delimited-base64 + (case-lambda + ((port type bv line-length) + (display (string-append "-----BEGIN " type "-----\n") port) + (base64-encode bv 0 (bytevector-length bv) + line-length #f base64-alphabet port) + (display (string-append "\n-----END " type "-----\n") port)) + ((port type bv) + (put-delimited-base64 port type bv 76)))))
\ No newline at end of file diff --git a/guix/scripts/substitute-binary.scm b/guix/scripts/substitute-binary.scm index 4e49b0c3ac..de22ebaf58 100755 --- a/guix/scripts/substitute-binary.scm +++ b/guix/scripts/substitute-binary.scm @@ -1,5 +1,6 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2014 Nikita Karetnikov <nikita@karetnikov.org> ;;; ;;; This file is part of GNU Guix. ;;; @@ -23,6 +24,10 @@ #:use-module (guix config) #:use-module (guix records) #:use-module (guix nar) + #:use-module (guix hash) + #:use-module (guix base64) + #:use-module (guix pk-crypto) + #:use-module (guix pki) #:use-module ((guix build utils) #:select (mkdir-p)) #:use-module ((guix build download) #:select (progress-proc uri-abbreviation)) @@ -33,15 +38,21 @@ #:use-module (ice-9 format) #:use-module (ice-9 ftw) #:use-module (ice-9 binary-ports) + #:use-module (rnrs io ports) + #:use-module (rnrs bytevectors) #:use-module (srfi srfi-1) #:use-module (srfi srfi-9) #:use-module (srfi srfi-11) #:use-module (srfi srfi-19) #:use-module (srfi srfi-26) #:use-module (srfi srfi-34) + #:use-module (srfi srfi-35) #:use-module (web uri) #:use-module (guix http-client) - #:export (guix-substitute-binary)) + #:export (narinfo-signature->canonical-sexp + read-narinfo + write-narinfo + guix-substitute-binary)) ;;; Comment: ;;; @@ -60,6 +71,16 @@ (cut string-append <> "/guix/substitute-binary")) (string-append %state-directory "/substitute-binary/cache"))) +(define %allow-unauthenticated-substitutes? + ;; Whether to allow unchecked substitutes. This is useful for testing + ;; purposes, and should be avoided otherwise. + (and (and=> (getenv "GUIX_ALLOW_UNAUTHENTICATED_SUBSTITUTES") + (cut string-ci=? <> "yes")) + (begin + (warning (_ "authentication and authorization of substitutes \ +disabled!~%")) + #t))) + (define %narinfo-ttl ;; Number of seconds during which cached narinfo lookups are considered ;; valid. @@ -194,7 +215,7 @@ failure." (define-record-type <narinfo> (%make-narinfo path uri compression file-hash file-size nar-hash nar-size - references deriver system) + references deriver system signature contents) narinfo? (path narinfo-path) (uri narinfo-uri) @@ -205,15 +226,38 @@ failure." (nar-size narinfo-size) (references narinfo-references) (deriver narinfo-deriver) - (system narinfo-system)) - -(define (narinfo-maker cache-url) - "Return a narinfo constructor for narinfos originating from CACHE-URL." + (system narinfo-system) + (signature narinfo-signature) ; canonical sexp + ;; The original contents of a narinfo file. This field is needed because we + ;; want to preserve the exact textual representation for verification purposes. + ;; See <https://lists.gnu.org/archive/html/guix-devel/2014-02/msg00340.html> + ;; for more information. + (contents narinfo-contents)) + +(define (narinfo-signature->canonical-sexp str) + "Return the value of a narinfo's 'Signature' field as a canonical sexp." + (match (string-split str #\;) + ((version _ sig) + (let ((maybe-number (string->number version))) + (cond ((not (number? maybe-number)) + (leave (_ "signature version must be a number: ~a~%") + version)) + ;; Currently, there are no other versions. + ((not (= 1 maybe-number)) + (leave (_ "unsupported signature version: ~a~%") + maybe-number)) + (else (string->canonical-sexp + (utf8->string (base64-decode sig))))))) + (x + (leave (_ "invalid format of the signature field: ~a~%") x)))) + +(define (narinfo-maker str cache-url) + "Return a narinfo constructor for narinfos originating from CACHE-URL. STR +must contain the original contents of a narinfo file." (lambda (path url compression file-hash file-size nar-hash nar-size - references deriver system) + references deriver system signature) "Return a new <narinfo> object." (%make-narinfo path - ;; Handle the case where URL is a relative URL. (or (string->uri url) (string->uri (string-append cache-url "/" url))) @@ -226,45 +270,81 @@ failure." (match deriver ((or #f "") #f) (_ deriver)) - system))) - -(define* (read-narinfo port #:optional url) - "Read a narinfo from PORT in its standard external form. If URL is true, it -must be a string used to build full URIs from relative URIs found while -reading PORT." - (alist->record (fields->alist port) - (narinfo-maker url) - '("StorePath" "URL" "Compression" - "FileHash" "FileSize" "NarHash" "NarSize" - "References" "Deriver" "System"))) + system + (narinfo-signature->canonical-sexp signature) + str))) + +;;; XXX: The following function is nearly an exact copy of the one from +;;; 'guix/nar.scm'. Factorize as soon as we know how to make the latter +;;; public (see <https://lists.gnu.org/archive/html/guix-devel/2014-03/msg00097.html>). +;;; Keep this one private to avoid confusion. +(define* (assert-valid-signature signature hash port + #:optional (acl (current-acl))) + "Bail out if SIGNATURE, a string (as produced by 'canonical-sexp->string'), +doesn't match HASH, a bytevector containing the expected hash for FILE." + (let* ((&nar-signature-error (@@ (guix nar) &nar-signature-error)) + (&nar-invalid-hash-error (@@ (guix nar) &nar-invalid-hash-error)) + ;; XXX: This is just to keep the errors happy; get a sensible + ;; filename. + (file #f) + (signature (catch 'gcry-error + (lambda () + (string->canonical-sexp signature)) + (lambda (err . _) + (raise (condition + (&message + (message "signature is not a valid \ +s-expression")) + (&nar-signature-error + (file file) + (signature signature) (port port))))))) + (subject (signature-subject signature)) + (data (signature-signed-data signature))) + (if (and data subject) + (if (authorized-key? subject acl) + (if (equal? (hash-data->bytevector data) hash) + (unless (valid-signature? signature) + (raise (condition + (&message (message "invalid signature")) + (&nar-signature-error + (file file) (signature signature) (port port))))) + (raise (condition (&message (message "invalid hash")) + (&nar-invalid-hash-error + (port port) (file file) + (signature signature) + (expected (hash-data->bytevector data)) + (actual hash))))) + (raise (condition (&message (message "unauthorized public key")) + (&nar-signature-error + (signature signature) (file file) (port port))))) + (raise (condition + (&message (message "corrupt signature data")) + (&nar-signature-error + (signature signature) (file file) (port port))))))) + +(define* (read-narinfo port #:optional url (acl (current-acl))) + "Read a narinfo from PORT. If URL is true, it must be a string used to +build full URIs from relative URIs found while reading PORT." + (let* ((str (utf8->string (get-bytevector-all port))) + (rx (make-regexp "(.+)^[[:blank:]]*Signature:[[:blank:]].+$")) + (res (or (regexp-exec rx str) + (leave (_ "cannot find the Signature line: ~a~%") + str))) + (hash (sha256 (string->utf8 (match:substring res 1)))) + (narinfo (alist->record (fields->alist (open-input-string str)) + (narinfo-maker str url) + '("StorePath" "URL" "Compression" + "FileHash" "FileSize" "NarHash" "NarSize" + "References" "Deriver" "System" + "Signature"))) + (signature (canonical-sexp->string (narinfo-signature narinfo)))) + (unless %allow-unauthenticated-substitutes? + (assert-valid-signature signature hash port acl)) + narinfo)) (define (write-narinfo narinfo port) "Write NARINFO to PORT." - (define (empty-string-if-false x) - (or x "")) - - (define (number-or-empty-string x) - (if (number? x) - (number->string x) - "")) - - (object->fields narinfo - `(("StorePath" . ,narinfo-path) - ("URL" . ,(compose uri->string narinfo-uri)) - ("Compression" . ,narinfo-compression) - ("FileHash" . ,(compose empty-string-if-false - narinfo-file-hash)) - ("FileSize" . ,(compose number-or-empty-string - narinfo-file-size)) - ("NarHash" . ,(compose empty-string-if-false - narinfo-hash)) - ("NarSize" . ,(compose number-or-empty-string - narinfo-size)) - ("References" . ,(compose string-join narinfo-references)) - ("Deriver" . ,(compose empty-string-if-false - narinfo-deriver)) - ("System" . ,narinfo-system)) - port)) + (put-bytevector port (string->utf8 (narinfo-contents narinfo)))) (define (narinfo->string narinfo) "Return the external representation of NARINFO." |