Nicer error report on signature failure

[dragetd]

When the signature is invalid, a panic is triggered. We might 'want' this behavior - then feel free to close this issue @MMulthaupt .

Otherwise the Log-Output might be nice (enough).

Example:

I 0.000 [pkg/logging/logging.go:Initialize():56] Arch=amd64, Args=[/home/draget/.local/share/Setlog/yyyy_xxx_tu/yyyy_xxx_TU -log-index 1 -log-instance 2], Binary=/home/draget/.local/share/Setlog/yyyy_xxx_tu/yyyy_xxx_TU, Local Time=2021-06-15 14:18:25.086478569 +0200 CEST m=+0.002560235, Log=/home/draget/.cache/Setlog/yyyy_xxx_tu/log/0001c.yyyy_xxx_tu.2021-06-15_12-18-25.log, OS=linux, Program=/home/draget/.local/share/Setlog/yyyy_xxx_tu/yyyy_xxx_TU, UTC Time=2021-06-15 12:18:25.086478569 +0000 UTC
I 0.000 Git description of this build: v1.4.6; Commit hash: 0646cb7e; Branch: unknown; Built with go1.13.15 [main.go:logState():140]
W 0.000 Could not run xdg-user-dir to locate DESKTOP folder: exec: "xdg-user-dir": executable file not found in $PATH. Falling back to $HOME/Desktop [launcher/places/places_xdg.go:reportResults():44]
I 0.000 globalSettingFolder: /home/draget/.local/share [launcher/places/places_xdg.go:reportResults():46]
I 0.000 localSettingFolder: /home/draget/.local/share [launcher/places/places_xdg.go:reportResults():47]
I 0.000 localCacheFolder: /home/draget/.cache [launcher/places/places_xdg.go:reportResults():48]
I 0.000 desktopFolder: /home/draget/Desktop [launcher/places/places_xdg.go:reportResults():49]
I 0.000 Environment proxy: HTTPProxy: ""; HTTPSProxy: "". [main.go:printProxySettings():165]
I 0.000 Automatic proxy: false; Preconfigured URL: "". [main.go:printProxySettings():167]
I 0.000 Static proxy: false, Protocols: map[], No proxy: "". [main.go:printProxySettings():168]
I 0.000 Initializing GUI. [launcher/gui/gui.go:Main():179] showMainWindow=true, title=yyyy xxx
I 0.232 Owning the Launcher Lock. [launcher/locking/launcher_signature.go:AcquireLock():33]
I 0.232 Goal of this launcher instance: Run. [launcher/launcher/entry.go:Branch():46]
I 0.232 Downloading deployment config from "https://landingpage.yyyy-ng.foo.bar/downloads/xxx/deployment-config.json". [launcher/bundle/updater.go:(*Updater)():72]
I 0.232 Proxy for request with URL https://landingpage.yyyy-ng.foo.bar/downloads/xxx/deployment-config.json.signature determined proxy URL <nil>. [pkg/fetching/helpers.go:GetProxyLoggingFunc():43]
I 0.232 Proxy for request with URL https://landingpage.yyyy-ng.foo.bar/downloads/xxx/deployment-config.json determined proxy URL <nil>. [pkg/fetching/helpers.go:GetProxyLoggingFunc():43]
W 0.383 None of the public keys matched. They were the following: [pkg/signatures/signatures.go:IsSignatureValid():33]
W 0.383 Public key (E: 65537, N: 7906244284…) does not match. [pkg/signatures/signatures.go:IsSignatureValid():35]
W 0.383 Public key (E: 65537, N: 7460519835…) does not match. [pkg/signatures/signatures.go:IsSignatureValid():35]
P 0.383 Invalid signature of resource https://landingpage.yyyy-ng.foo.bar/downloads/xxx/deployment-config.json. [pkg/fetching/downloader.go:(*Downloader)():68]
W 0.383 Unrecoverable state: &{0xc0000ea460 map[] 2021-06-15 14:18:25.469282809 +0200 CEST m=+0.385364457 panic 0xc0002385f0 Invalid signature of resource https://landingpage.yyyy-ng.foo.bar/downloads/xxx/deployment-config.json. <nil> <nil> }
goroutine 27 [running]:
github.com/setlog/trivrost/pkg/misc.LogRecoveredValue(0x950f80, 0xc0004361c0)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/pkg/misc/panic.go:18 +0x26
github.com/setlog/trivrost/cmd/launcher/gui.PanicInformatively(0x950f80, 0xc0004361c0, 0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/gui/reporting.go:34 +0xa1
github.com/setlog/trivrost/cmd/launcher/gui.HandlePanic(0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/gui/reporting.go:27 +0x108
panic(0x950f80, 0xc0004361c0)
	/usr/local/go/src/runtime/panic.go:679 +0x1b2
github.com/sirupsen/logrus.Entry.log(0xc0000ea460, 0xc0005d01e0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/entry.go:239 +0x2db
github.com/sirupsen/logrus.(*Entry).Log(0xc000436000, 0x0, 0xc000159ae8, 0x1, 0x1)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/entry.go:268 +0xeb
github.com/sirupsen/logrus.(*Entry).Logf(0xc000436000, 0xc000000000, 0x966d1e, 0x21, 0xc000159c40, 0x1, 0x1)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/entry.go:314 +0xe2
github.com/sirupsen/logrus.(*Logger).Logf(0xc0000ea460, 0x0, 0x966d1e, 0x21, 0xc000159c40, 0x1, 0x1)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/logger.go:145 +0x94
github.com/sirupsen/logrus.(*Logger).Panicf(...)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/logger.go:186
github.com/sirupsen/logrus.Panicf(...)
	/builds/yyyy-ng/landingpage/pipeline/.cache/pkg/mod/github.com/sirupsen/logrus@v1.4.2/exported.go:174
github.com/setlog/trivrost/pkg/fetching.(*Downloader).DownloadSignedResources(0xc0001d0510, 0xc000159cc0, 0x1, 0x1, 0xc0000b5b60, 0x2, 0x2, 0x28, 0xc000159d50, 0x1)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/pkg/fetching/downloader.go:68 +0x43e
github.com/setlog/trivrost/pkg/fetching.(*Downloader).DownloadSignedResource(0xc0001d0510, 0xc0000d04b0, 0x50, 0xc0000b5b60, 0x2, 0x2, 0x1, 0x24, 0xc000159d40, 0x2, ...)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/pkg/fetching/downloader.go:45 +0x91
github.com/setlog/trivrost/pkg/launcher/bundle.(*Updater).Prepare(0xc000282000, 0xc0000d04b0, 0x50)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/pkg/launcher/bundle/updater.go:73 +0xfd
github.com/setlog/trivrost/cmd/launcher/launcher.Run(0xa0cfa0, 0xc0000a2b40, 0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/launcher/run.go:27 +0x12d
github.com/setlog/trivrost/cmd/launcher/launcher.Branch(0xa0cfa0, 0xc0000a2b40, 0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/launcher/entry.go:47 +0x142
github.com/setlog/trivrost/cmd/launcher/launcher.LauncherMain(0xa0cfa0, 0xc0000a2b40, 0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/launcher/entry.go:20 +0xde
main.runLauncher(0xa0cfa0, 0xc0000a2b40, 0x0, 0x0, 0xc0000a2780)
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/main.go:77 +0xfd
created by main.main
	/builds/yyyy-ng/landingpage/pipeline/trivrost/src/cmd/launcher/main.go:51 +0xfd [pkg/misc/panic.go:18]
I 1.410 Showing file "/home/draget/.cache/Setlog/yyyy_xxx_tu/log/0001c.yyyy_xxx_tu.2021-06-15_12-18-25.log" in file manager. [launcher/gui/reporting.go:showLogFolder():70]