M guix/openpgp.scm => guix/openpgp.scm +39 -5
@@ 33,6 33,7 @@
openpgp-signature?
openpgp-signature-issuer
+ openpgp-signature-issuer-fingerprint
openpgp-signature-public-key-algorithm
openpgp-signature-hash-algorithm
openpgp-signature-creation-time
@@ 345,7 346,6 @@ hexadecimal format for fingerprints."
;; 12 = Revocation Key
(define SUBPACKET-ISSUER 16)
-;; TODO: hashed SUBPACKET-ISSUER-FINGERPRINT-V4
(define SUBPACKET-NOTATION-DATA 20)
(define SUBPACKET-PREFERRED-HASH-ALGORITHMS 21)
(define SUBPACKET-PREFERRED-COMPRESSION-ALGORITHMS 22)
@@ 358,8 358,8 @@ hexadecimal format for fingerprints."
(define SUBPACKET-REASON-FOR-REVOCATION 29)
(define SUBPACKET-FEATURES 30)
;; 31 = Signature Target
-
(define SUBPACKET-EMBEDDED-SIGNATURE 32)
+(define SUBPACKET-ISSUER-FINGERPRINT 33) ;defined in RFC4880bis
(define SIGNATURE-BINARY #x00)
(define SIGNATURE-TEXT #x01)
@@ 486,6 486,13 @@ hexadecimal format for fingerprints."
;; XXX: is the issuer always in the unhashed subpackets?
(else #f)))
+(define (openpgp-signature-issuer-fingerprint sig)
+ "When it's available, return the fingerprint, a bytevector, or the issuer of
+SIG. Otherwise, return #f."
+ (or (assoc-ref (openpgp-signature-hashed-subpackets sig) 'issuer-fingerprint)
+ (assoc-ref (openpgp-signature-unhashed-subpackets sig)
+ 'issuer-fingerprint)))
+
(define (openpgp-signature-creation-time sig)
(cond ((assq 'signature-ctime (openpgp-signature-hashed-subpackets sig))
=> (lambda (x) (unixtime (cdr x))))
@@ 578,6 585,14 @@ the issuer's OpenPGP public key extracted from KEYRING."
(values 'missing-key issuer))))
(values 'unsupported-signature sig)))
+(define (key-id-matches-fingerprint? key-id fingerprint)
+ "Return true if KEY-ID, a number, corresponds to the low 8 bytes of
+FINGERPRINT, a bytevector."
+ (let* ((len (bytevector-length fingerprint))
+ (low (make-bytevector 8)))
+ (bytevector-copy! fingerprint (- len 8) low 0 8)
+ (= (bytevector->uint low) key-id)))
+
(define (get-signature p)
(define (->hex n)
(string-hex-pad (number->string n 16)))
@@ 662,14 677,26 @@ the issuer's OpenPGP public key extracted from KEYRING."
;; Errata ID: 2214.
(integers->bytevector u8 #x04
u8 #xff
- u32 (+ 6 subpacket-len)))))
+ u32 (+ 6 subpacket-len))))
+ (unhashed-subpackets
+ (parse-subpackets unhashed-subpackets))
+ (hashed-subpackets (parse-subpackets hashed-subpackets))
+ (subpackets (append hashed-subpackets
+ unhashed-subpackets))
+ (issuer-key-id (assoc-ref subpackets 'issuer))
+ (issuer (assoc-ref subpackets
+ 'issuer-fingerprint)))
+ (unless (or (not issuer) (not issuer-key-id)
+ (key-id-matches-fingerprint? issuer-key-id issuer))
+ (error "issuer key id does not match fingerprint" issuer))
+
(make-openpgp-signature version type
(public-key-algorithm pkalg)
(openpgp-hash-algorithm halg)
hashl16
append-data
- (parse-subpackets hashed-subpackets)
- (parse-subpackets unhashed-subpackets)
+ hashed-subpackets
+ unhashed-subpackets
value)))))
(else
(print "Unsupported signature version: " version)
@@ 701,6 728,13 @@ the issuer's OpenPGP public key extracted from KEYRING."
((= type SUBPACKET-ISSUER)
(cons 'issuer
(bytevector-u64-ref data 0 (endianness big))))
+ ((= type SUBPACKET-ISSUER-FINGERPRINT) ;v4+ only, RFC4880bis
+ (cons 'issuer-fingerprint
+ (let* ((version (bytevector-u8-ref data 0))
+ (len (match version (4 20) (5 32)) )
+ (fingerprint (make-bytevector len)))
+ (bytevector-copy! data 1 fingerprint 0 len)
+ fingerprint)))
((= type SUBPACKET-NOTATION-DATA)
(let ((p (open-bytevector-input-port data)))
(let-values (((f1 nlen vlen)
M tests/openpgp.scm => tests/openpgp.scm +17 -5
@@ 18,6 18,7 @@
(define-module (tests-openpgp)
#:use-module (guix openpgp)
+ #:use-module (gcrypt base16)
#:use-module (gcrypt hash)
#:use-module (gcrypt pk-crypto)
#:use-module (ice-9 binary-ports)
@@ 65,6 66,16 @@ vBSFjNSiVHsuAA==
(define %dsa-key-id #x587918047BE8BD2C) ;dsa.key
(define %ed25519-key-id #x771F49CBFAAE072D) ;ed25519.key
+(define %rsa-key-fingerprint
+ (base16-string->bytevector
+ (string-downcase "385F86CFC86B665A5C165E6BAE25DA2A70DEED59")))
+(define %dsa-key-fingerprint
+ (base16-string->bytevector
+ (string-downcase "2884A980422330A4F33DD97F587918047BE8BD2C")))
+(define %ed25519-key-fingerprint
+ (base16-string->bytevector
+ (string-downcase "44D31E21AF7138F9B632280A771F49CBFAAE072D")))
+
;;; The following are detached signatures created commands like:
;;; echo 'Hello!' | gpg -sba --digest-algo sha512
@@ 160,15 171,16 @@ Pz7oopeN72xgggYUNT37ezqN3MeCqw0=
"Ludovic Courtès <ludo@gnu.org>"))))))
(test-equal "get-openpgp-detached-signature/ascii"
- (list `(,%dsa-key-id dsa sha256)
- `(,%rsa-key-id rsa sha256)
- `(,%ed25519-key-id eddsa sha256)
- `(,%ed25519-key-id eddsa sha512)
- `(,%ed25519-key-id eddsa sha1))
+ (list `(,%dsa-key-id ,%dsa-key-fingerprint dsa sha256)
+ `(,%rsa-key-id ,%rsa-key-fingerprint rsa sha256)
+ `(,%ed25519-key-id ,%ed25519-key-fingerprint eddsa sha256)
+ `(,%ed25519-key-id ,%ed25519-key-fingerprint eddsa sha512)
+ `(,%ed25519-key-id ,%ed25519-key-fingerprint eddsa sha1))
(map (lambda (str)
(let ((signature (get-openpgp-detached-signature/ascii
(open-input-string str))))
(list (openpgp-signature-issuer signature)
+ (openpgp-signature-issuer-fingerprint signature)
(openpgp-signature-public-key-algorithm signature)
(openpgp-signature-hash-algorithm signature))))
(list %hello-signature/dsa