"valid signature" -> "trustworthy signature"

I just had a colleague get confused by the previous phrase for good
reason. "valid" sounds like an *objective* criterion, e.g. and *invalid
signature* would be one that would be trusted by no one, e.g. because it
misformatted or something.

What is actually going is that there might be a signature which is
perfectly valid to *someone else*, but not to the user, because they
don't trust the corresponding public key. This is a *subjective*
criterion, because it depends on the arbitrary and personal choice of
which public keys to trust.

I therefore think "trustworthy" is a better adjective to use. Whether
something is worthy of trust is clearly subjective, and then "trust"
within that word nicely evokes `trusted-public-keys` and friends.

src/libstore/globals.hh

@@ -560,7 +560,7 @@ public:
         R"(
           If set to `true` (the default), any non-content-addressed path added
           or copied to the Nix store (e.g. when substituting from a binary
-          cache) must have a valid signature, that is, be signed using one of
+          cache) must have a trustworthy signature, that is, be signed using one of
           the keys listed in `trusted-public-keys` or `secret-key-files`. Set
           to `false` to disable signature checking.
         )"};

src/libstore/local-store.cc

@@ -751,7 +751,7 @@ void LocalStore::registerDrvOutput(const Realisation & info, CheckSigsFlag check
     if (checkSigs == NoCheckSigs || !realisationIsUntrusted(info))
         registerDrvOutput(info);
     else
-        throw Error("cannot register realisation '%s' because it lacks a valid signature", info.outPath.to_string());
+        throw Error("cannot register realisation '%s' because it lacks a trustworthy signature", info.outPath.to_string());
 }
 
 void LocalStore::registerDrvOutput(const Realisation & info)
@@ -1266,7 +1266,7 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
     RepairFlag repair, CheckSigsFlag checkSigs)
 {
     if (checkSigs && pathInfoIsUntrusted(info))
-        throw Error("cannot add path '%s' because it lacks a valid signature", printStorePath(info.path));
+        throw Error("cannot add path '%s' because it lacks a trustworthy signature", printStorePath(info.path));
 
     addTempRoot(info.path);
 

src/nix/make-content-addressed.md

@@ -22,7 +22,7 @@ R""(
 
   ```console
   # nix copy --to /tmp/nix --trusted-public-keys '' nixpkgs#hello
-  cannot add path '/nix/store/zy9wbxwcygrwnh8n2w9qbbcr6zk87m26-libunistring-0.9.10' because it lacks a valid signature
+  cannot add path '/nix/store/zy9wbxwcygrwnh8n2w9qbbcr6zk87m26-libunistring-0.9.10' because it lacks a trustworthy signature
   ```
 
 * Create a content-addressed representation of the current NixOS

src/nix/verify.cc

@@ -41,7 +41,7 @@ struct CmdVerify : StorePathsCommand
         addFlag({
             .longName = "sigs-needed",
             .shortName = 'n',
-            .description = "Require that each path has at least *n* valid signatures.",
+            .description = "Require that each path has at least *n* trustworthy signatures.",
             .labels = {"n"},
             .handler = {&sigsNeeded}
         });

tests/signing.sh

@@ -81,7 +81,7 @@ info=$(nix path-info --store file://$cacheDir --json $outPath2)
 [[ $info =~ 'cache1.example.org' ]]
 [[ $info =~ 'cache2.example.org' ]]
 
-# Copying to a diverted store should fail due to a lack of valid signatures.
+# Copying to a diverted store should fail due to a lack of trustworthy signatures.
 chmod -R u+w $TEST_ROOT/store0 || true
 rm -rf $TEST_ROOT/store0
 (! nix copy --to $TEST_ROOT/store0 $outPath)