tests: add script to dump test keys in more parsable formats

In some cases this is binary, in others it's textual.

To better see what's in the keys, to debug them, and debug code dealing
with them. It's a manual script, not run automatically by this repo.

Closes #2574

tests/Makefile.inc

@@ -72,6 +72,7 @@ librunner_la_SOURCES = \
 EXTRA_DIST = \
   .checksrc \
   CMakeLists.txt \
+  keys-dump.sh \
   keys-generate.sh \
   keys/ca_host_ecdsa \
   keys/ca_host_ecdsa.pub \

tests/keys-dump.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+#
+# Copyright (C) Viktor Szakats
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Dump keys in more human-parsable formats
+
+for dir in keys openssh_server; do
+  [ -d "${dir}-dump" ] || mkdir "${dir}-dump"
+  rm -f "${dir}-dump"/*
+
+  find "${dir}" -maxdepth 1 \( -name 'ca_*' -o -name 'id_*' -o -name 'ssh_*' \) | while read -r f; do
+    o="${dir}-dump/$(basename "$f")"
+    echo "$f"
+    if [[ "$f" = *'.pub' ]]; then
+      b64="$(grep -o -E ' .+ ' "$f")"
+      [ -z "$b64" ] && b64="$(grep -o -E ' .+$' "$f")"
+      echo "$b64" | tr -d ' ' | base64 -d > "$o.bin"
+      if [[ "$f" = *'cert'* ]]; then
+        ssh-keygen -L -f "$f" > "$o.cert.txt"
+      fi
+    else
+      if [[ "$f" = *'pkcs8'* ]]; then
+        openssl asn1parse -dump -in "$f" > "$o.pkey.asn1.txt"
+      else
+        grep -v -E '^(-----|DEK-Info|Proc-Type)' "$f" | base64 -d > "$o.pkey.bin"
+      fi
+      openssl pkey -text -noout -passin pass:libssh2 -in "$f" >> "$o.pkey.txt" 2>/dev/null
+      [ -s "$o.pkey.txt" ] || rm -f "$o.pkey.txt"
+    fi
+    cp -p "$f" "$o"
+  done
+done
+
+openssl -version