more arguments; update README.md

README.md

@@ -10,7 +10,9 @@ Shamir Secret Sharing on paper using gfshare.
 
 ### Dependencies
 
-`gfshare` is required to split and merge the secret.
+Required and optional dependencies with example how to install them for Arch Linux.
+
+`gfshare` is required to split (`enpaper`) and merge (`depaper`) the secret.
 See `man gfshare` for an explanation of Shamir Secret Sharing in gf(2**8).
 
 ```shell
@@ -18,14 +20,14 @@ sudo pacman -S --needed libgfshare
 ```
 
 `qrencode` and `imagemagick` (`convert`) are required to create and merge QR-codes during the split process.
-One can set the according parameters of `split_encode` to `False` to skip this step.
+One can pass `-q` to `enpapaer` to skip this step.
 
 ```shell
 sudo pacman -S --needed qrencode imagemagick
 ```
 
 `enscript` and `ghostscript` (`ps2pdf`) are required to create a PDF containing the split secret in text form.
-One can set the according parameters of `split_encode` to `False` to skip this step.
+One can pass `-t` to `enpaper` to skip this step.
 
 ```shell
 sudo pacman -S --needed enscript ghostscript
@@ -33,7 +35,7 @@ sudo pacman -S --needed enscript ghostscript
 
 ## Usage
 
-Create a secret:
+Create a file with secret content:
 
 ```shell
 cat > secret.txt

setup.cfg

@@ -3,7 +3,7 @@
 
 [metadata]
 name = paper-secret
-version = 0.1.2
+version = 0.1.3
 author = Daniel Langbein
 author_email = daniel@systemli.org
 description = Shamir Secret Sharing on paper using gfshare

src/paper_secret/enpaper.py

@@ -16,10 +16,16 @@ def main():
                         action='store_false', default=True)
     parser.add_argument('--no-text-pdf', '-t', help='skip text-PDF generation',
                         action='store_false', default=True)
+    parser.add_argument('--num-shares', '-n', help='number of shares to generate',
+                        default=5, type=int)
+    parser.add_argument('--threshold', '-k', help='threshold for recombination',
+                        default=3, type=int)
     #
     args = parser.parse_args()
 
     split_encode(secret=args.secret,
+                 k=args.threshold,
+                 n=args.num_shares,
                  create_qr_codes=args.no_qr,
                  create_text_pdf=args.no_text_pdf)
 
@@ -47,6 +53,7 @@ def split_encode(
     :param n: Number of shares to generate
     :return: List of created files.
     """
+    assert n > k
     assert secret.exists(), str(secret)
     assert secret.is_file(), str(secret)