daemon: Simplify interface with 'guix authenticate'.

There's no reason at this point to mimic the calling convention of the
'openssl' command.

* nix/libstore/local-store.cc (LocalStore::exportPath): Add only "sign"
and HASH to ARGS.  Remove 'tmpDir' and 'hashFile'.
(LocalStore::importPath): Add only "verify" and SIGNATURE to
* guix/scripts/authenticate.scm (guix-authenticate): Adjust
accordingly; remove the OpenSSL-style clauses.
(read-hash-data): Remove.
(sign-with-key): Replace 'port' with 'sha256' and adjust accordingly.
(validate-signature): Export SIGNATURE to be a canonical sexp.
* tests/guix-authenticate.sh: Adjust tests accordingly.

3 files changed, 36 insertions, 91 deletions

diff --git a/guix/scripts/authenticate.scm b/guix/scripts/authenticate.scm
index a4b9171fc7..37e6cef53c 100644
--- a/guix/scripts/authenticate.scm
+++ b/guix/scripts/authenticate.scm
@@ -17,7 +17,6 @@
 ;;; 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)
@@ -40,16 +39,9 @@
   ;; 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."
+(define (sign-with-key key-file sha256)
+  "Sign the hash SHA256 (a bytevector) 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
@@ -59,18 +51,18 @@ both the hash and the actual signature."
                          (leave
                           (G_ "cannot find public key for secret key '~a'~%")
                           key-file)))
-         (data       (read-hash-data port (key-type public-key)))
+         (data       (bytevector->hash-data sha256
+                                            #:key-type (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)))
+(define (validate-signature signature)
+  "Validate SIGNATURE, a canonical sexp.  Check whether its public key is
+authorized, verify the signature, and print the signed data to stdout upon
+success."
+  (let* ((subject (signature-subject signature))
+         (data    (signature-signed-data signature)))
     (if (and data subject)
         (if (authorized-key? subject)
             (if (valid-signature? signature)
@@ -86,9 +78,7 @@ to stdout upon success."
 
 
 ;;;
-;;; 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-command (guix-authenticate . args)
@@ -105,22 +95,14 @@ 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)
+      (("sign" key-file hash)
+       (sign-with-key key-file (base16-string->bytevector hash)))
+      (("verify" 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)))
+           (validate-signature (string->canonical-sexp
+                                (read-string port))))))
+
       (("--help")
        (display (G_ "Usage: guix authenticate OPTION...
 Sign or verify the signature on the given file.  This tool is meant to
diff --git a/nix/libstore/local-store.cc b/nix/libstore/local-store.cc
index 7a520925e5..e6badd3721 100644
--- a/nix/libstore/local-store.cc
+++ b/nix/libstore/local-store.cc
@@ -1277,21 +1277,13 @@ void LocalStore::exportPath(const Path & path, bool sign,
 
         writeInt(1, hashAndWriteSink);
 
-        Path tmpDir = createTempDir();
-        AutoDelete delTmp(tmpDir);
-        Path hashFile = tmpDir + "/hash";
-        writeFile(hashFile, printHash(hash));
-
         Path secretKey = settings.nixConfDir + "/signing-key.sec";
         checkSecrecy(secretKey);
 
         Strings args;
-        args.push_back("rsautl");
-        args.push_back("-sign");
-        args.push_back("-inkey");
+        args.push_back("sign");
         args.push_back(secretKey);
-        args.push_back("-in");
-        args.push_back(hashFile);
+        args.push_back(printHash(hash));
 
         string signature = runAuthenticationProgram(args);
 
@@ -1376,12 +1368,7 @@ Path LocalStore::importPath(bool requireSignature, Source & source)
             writeFile(sigFile, signature);
 
             Strings args;
-            args.push_back("rsautl");
-            args.push_back("-verify");
-            args.push_back("-inkey");
-            args.push_back(settings.nixConfDir + "/signing-key.pub");
-            args.push_back("-pubin");
-            args.push_back("-in");
+            args.push_back("verify");
             args.push_back(sigFile);
             string hash2 = runAuthenticationProgram(args);
 
diff --git a/tests/guix-authenticate.sh b/tests/guix-authenticate.sh
index 72c3d161d7..773443453d 100644
--- a/tests/guix-authenticate.sh
+++ b/tests/guix-authenticate.sh
@@ -1,5 +1,5 @@
 # GNU Guix --- Functional package management for GNU
-# Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
+# Copyright © 2013, 2014, 2020 Ludovic Courtès <ludo@gnu.org>
 #
 # This file is part of GNU Guix.
 #
@@ -29,34 +29,18 @@ rm -f "$sig" "$hash"
 trap 'rm -f "$sig" "$hash"' EXIT
 
 # A hexadecimal string as long as a sha256 hash.
-echo "2749f0ea9f26c6c7be746a9cff8fa4c2f2a02b000070dba78429e9a11f87c6eb" \
-    > "$hash"
+hash="2749f0ea9f26c6c7be746a9cff8fa4c2f2a02b000070dba78429e9a11f87c6eb"
 
-guix authenticate rsautl -sign				\
-    -inkey "$abs_top_srcdir/tests/signing-key.sec"	\
-    -in "$hash" > "$sig"
+guix authenticate sign				\
+    "$abs_top_srcdir/tests/signing-key.sec"	\
+    "$hash" > "$sig"
 test -f "$sig"
 
-hash2="`guix authenticate rsautl -verify		\
-          -inkey $abs_top_srcdir/tests/signing-key.pub	\
-          -pubin -in $sig`"
-test "$hash2" = `cat "$hash"`
-
-# Same thing in a pipeline, using the command line syntax that Nix/Crypto.pm
-# uses.
-hash2="`						\
-  cat "$hash"						\
-  | guix authenticate rsautl -sign			\
-    -inkey "$abs_top_srcdir/tests/signing-key.sec"	\
-  | guix authenticate rsautl -verify			\
-          -inkey $abs_top_srcdir/tests/signing-key.pub	\
-          -pubin`"
-test "$hash2" = `cat "$hash"`
+hash2="`guix authenticate verify "$sig"`"
+test "$hash2" = "$hash"
 
 # Detect corrupt signatures.
-if guix authenticate rsautl -verify				\
-          -inkey "$abs_top_srcdir/tests/signing-key.pub"	\
-          -pubin -in /dev/null
+if guix authenticate verify /dev/null
 then false
 else true
 fi
@@ -66,9 +50,7 @@ fi
 # modifying this hash.
 sed -i "$sig"											\
     -e's|#[A-Z0-9]\{64\}#|#0000000000000000000000000000000000000000000000000000000000000000#|g'
-if guix authenticate rsautl -verify				\
-          -inkey "$abs_top_srcdir/tests/signing-key.pub"	\
-          -pubin -in "$sig"
+if guix authenticate verify "$sig"
 then false
 else true
 fi
@@ -76,20 +58,14 @@ fi
 
 # Test for <http://bugs.gnu.org/17312>: make sure 'guix authenticate' produces
 # valid signatures when run in the C locale.
-echo "5eff0b55c9c5f5e87b4e34cd60a2d5654ca1eb78c7b3c67c3179fed1cff07b4c" \
-    > "$hash"
+hash="5eff0b55c9c5f5e87b4e34cd60a2d5654ca1eb78c7b3c67c3179fed1cff07b4c"
 
 LC_ALL=C
 export LC_ALL
 
-guix authenticate rsautl -sign				\
-    -inkey "$abs_top_srcdir/tests/signing-key.sec"	\
-    -in "$hash" > "$sig"
+guix authenticate sign "$abs_top_srcdir/tests/signing-key.sec" "$hash" \
+     > "$sig"
 
-guix authenticate rsautl -verify			\
-        -inkey "$abs_top_srcdir/tests/signing-key.pub"	\
-        -pubin -in "$sig"
-hash2="`guix authenticate rsautl -verify		\
-          -inkey $abs_top_srcdir/tests/signing-key.pub	\
-          -pubin -in $sig`"
-test "$hash2" = `cat "$hash"`
+guix authenticate verify "$sig"
+hash2="`guix authenticate verify "$sig"`"
+test "$hash2" = "$hash"