1 files changed, 57 insertions, 0 deletions
diff --git a/pkgs/profpatsch/gpg-private-offline-key/default.nix b/pkgs/profpatsch/gpg-private-offline-key/default.nix
new file mode 100644
index 00000000..d0e5ceb7
--- /dev/null
+++ b/pkgs/profpatsch/gpg-private-offline-key/default.nix
@@ -0,0 +1,57 @@
+{ pkgs, writeExecline, getBins }:
+
+let
+# split
+
+  bins = getBins pkgs.coreutils [ "split" "mktemp" "rm" "rmdir" ]
+      // getBins pkgs.lr [ "lr" ]
+      // getBins pkgs.xe [ "xe" ]
+      // getBins pkgs.qrencode [ "qrencode" ]
+      // getBins pkgs.zbar [ "zbarimg" ]
+      // getBins pkgs.sane-backends [ "scanimg" ];
+
+  qr-code-props = {
+    # second highest redundancy level
+    level = "Q";
+    # max amount of bytes that level Q can encode
+    bytes = "1700";
+  };
+
+  # Takes a private GPG key encoded with paperkey on stdin
+  # and execs into the argv for each qr code image (on stdin).
+  print-qr-codes = writeExecline "print-qr-codes" {} [
+    split-stdin
+    "pipeline" [
+      bins.qrencode
+      "--level=${qr-code-props.level}"
+      "--dpi=300"
+      "-o-"
+    ]
+    "$@"
+  ];
+
+  split-stdin = pkgs.writers.writePython3 "split-stdin" {} ''
+    import sys
+    import subprocess
+
+    while True:
+        str = sys.stdin.buffer.read(${qr-code-props.bytes})
+        if str == "":
+            break
+        ret = subprocess.run(sys.argv[1:], input=str)
+        code = ret.returncode
+        if code != 0:
+            sys.exit(code if code > 0 else 128 - code)
+  '';
+
+  test = writeExecline "test12" {} [
+    "foreground" [ print-qr-codes "feh" "-" ]
+  ];
+
+  
+# scanning:
+# for i in (seq 0 9); scanimage --device=\'fujitsu:ScanSnap iX500:1527308\' --mode=gray --resolution=100 --format=png | zbarimg -Sdisable -Sqrcode.enable --raw - | head --bytes=-1; end > out
+
+in {
+  inherit print-qr-codes;
+}