From 97528038e40b38cdc64df812b73288df88d10829 Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Thu, 22 Jul 2021 18:46:46 -0400
Subject: [PATCH] Add a tool for extracting the public key from a signing key
---
PaymentServer.cabal | 9 ++++++++
get-public-key/Main.hs | 21 +++++++++++++++++++
.../PaymentServer.nix | 10 +++++++++
src/PaymentServer/Ristretto.hs | 12 +++++++++++
4 files changed, 52 insertions(+)
create mode 100644 get-public-key/Main.hs
diff --git a/PaymentServer.cabal b/PaymentServer.cabal
index 1a96e00..1b29cf0 100644
--- a/PaymentServer.cabal
+++ b/PaymentServer.cabal
@@ -67,6 +67,15 @@ executable PaymentServer-generate-key
, PaymentServer
default-language: Haskell2010
+executable PaymentServer-get-public-key
+ hs-source-dirs: get-public-key
+ main-is: Main.hs
+ ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wmissing-import-lists -Wunused-imports
+ build-depends: base
+ , text
+ , PaymentServer
+ default-language: Haskell2010
+
test-suite PaymentServer-tests
type: exitcode-stdio-1.0
hs-source-dirs: test
diff --git a/get-public-key/Main.hs b/get-public-key/Main.hs
new file mode 100644
index 0000000..952caef
--- /dev/null
+++ b/get-public-key/Main.hs
@@ -0,0 +1,21 @@
+-- | Extract a public key from Ristretto-flavored PrivacyPass signing key read from stdin.
+module Main
+ ( main
+ ) where
+
+import Prelude hiding
+ ( putStrLn
+ , getLine
+ )
+
+import Data.Text.IO
+ ( putStrLn
+ , getLine
+ )
+
+import PaymentServer.Ristretto
+ ( getPublicKey
+ )
+
+main :: IO ()
+main = getLine >>= getPublicKey >>= putStrLn
diff --git a/nix/materialized.paymentserver/PaymentServer.nix b/nix/materialized.paymentserver/PaymentServer.nix
index e77024c..842157c 100644
--- a/nix/materialized.paymentserver/PaymentServer.nix
+++ b/nix/materialized.paymentserver/PaymentServer.nix
@@ -93,6 +93,16 @@
hsSourceDirs = [ "generate-key" ];
mainPath = [ "Main.hs" ];
};
+ "PaymentServer-get-public-key" = {
+ depends = [
+ (hsPkgs."base" or (errorHandler.buildDepError "base"))
+ (hsPkgs."text" or (errorHandler.buildDepError "text"))
+ (hsPkgs."PaymentServer" or (errorHandler.buildDepError "PaymentServer"))
+ ];
+ buildable = true;
+ hsSourceDirs = [ "get-public-key" ];
+ mainPath = [ "Main.hs" ];
+ };
};
tests = {
"PaymentServer-tests" = {
diff --git a/src/PaymentServer/Ristretto.hs b/src/PaymentServer/Ristretto.hs
index 7c06520..1018eb5 100644
--- a/src/PaymentServer/Ristretto.hs
+++ b/src/PaymentServer/Ristretto.hs
@@ -4,6 +4,7 @@
module PaymentServer.Ristretto
( Issuance(Issuance)
, randomSigningKey
+ , getPublicKey
, ristretto
) where
@@ -159,3 +160,14 @@ randomSigningKey = do
result <- peekCString cString
free cString
return $ pack result
+
+-- | getPublicKey returns the base64 encoded public key corresponding to the
+-- base64 encoded signing key passed to it.
+getPublicKey :: Text -> IO Text
+getPublicKey enc_skey = do
+ enc_cstr_skey <- newCString . unpack $ enc_skey
+ skey <- signing_key_decode_base64 $ enc_cstr_skey
+ pkey <- signing_key_get_public_key skey
+ enc_cstr_pkey <- public_key_encode_base64 pkey
+ enc_pkey <- peekCString enc_cstr_pkey
+ return $ pack enc_pkey
--
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