bip32

commit 9696a67e84a765c53c4636cad30ce900b358520a
parent bc489462835f853d58970fc53d5ce359932eacc5
Author: Jared Tobin <jared@jtobin.io>
Date:   Thu, 19 Jun 2025 16:55:29 +0400

lib: use updated secp256k1 api

Diffstat:
M
flake.lock
 | 
16
++++++++--------
M
lib/Crypto/HDKey/BIP32.hs
 | 
24
+++++++++++++-----------

2 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/flake.lock b/flake.lock
@@ -85,11 +85,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1740802926,
-        "narHash": "sha256-STkzNGx6DakFA+3tZVXurxEU/rEHtkcylNueyh3jLl4=",
+        "lastModified": 1750335817,
+        "narHash": "sha256-XReE3NMudmbpWgvMGwvsMt5SO3DkKYFYVLvsh5waDRg=",
         "ref": "master",
-        "rev": "66e9deb21aaf7910ed44363a5c72e29d05e9e15d",
-        "revCount": 23,
+        "rev": "10c667ad8dc7583407fd1545259dc140497e2b17",
+        "revCount": 27,
         "type": "git",
         "url": "git://git.ppad.tech/base58.git"
       },
@@ -216,11 +216,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1741950137,
-        "narHash": "sha256-9NTMZ+WSZ+81Ys9RBkLqDo06ZPo0hgcCAwvy8ehbDIA=",
+        "lastModified": 1750336608,
+        "narHash": "sha256-hNTKr/dkUjiWkqg0qzCl+hVrY51Xc6lkmC3QnpBs5cg=",
         "ref": "master",
-        "rev": "f179ea0c298a8d9d0bc20649003554e5d22939b7",
-        "revCount": 155,
+        "rev": "0216aa125e71d3e23f890084bb80345a7cb13e2f",
+        "revCount": 171,
         "type": "git",
         "url": "git://git.ppad.tech/secp256k1.git"
       },
diff --git a/lib/Crypto/HDKey/BIP32.hs b/lib/Crypto/HDKey/BIP32.hs
@@ -142,10 +142,11 @@ instance Extended XPub where
     in  RIPEMD160.hash (SHA256.hash ser)
 
 instance Extended XPrv where
-  identifier (XPrv (X sec _)) =
-    let p = Secp256k1.mul Secp256k1._CURVE_G sec
-        ser = Secp256k1.serialize_point p
-    in  RIPEMD160.hash (SHA256.hash ser)
+  identifier (XPrv (X sec _)) = case Secp256k1.mul Secp256k1._CURVE_G sec of
+    Nothing -> error "ppad-bip32 (identifier): evil extended key"
+    Just p ->
+      let ser = Secp256k1.serialize_point p
+      in  RIPEMD160.hash (SHA256.hash ser)
 
 -- internal key derivation functions-------------------------------------------
 
@@ -175,9 +176,9 @@ ckd_priv _xprv@(XPrv (X sec cod)) i =
         else XPrv (X ki ci)
   where
     dat | hardened i = BS.singleton 0x00 <> ser256 sec <> ser32 i
-        | otherwise  =
-            let p = Secp256k1.mul Secp256k1._CURVE_G sec
-            in  Secp256k1.serialize_point p <> ser32 i
+        | otherwise  = case Secp256k1.mul Secp256k1._CURVE_G sec of
+            Nothing -> error "ppad-bip32 (ckd_priv): evil extended key"
+            Just p  -> Secp256k1.serialize_point p <> ser32 i
 
 -- public parent key -> public child key
 ckd_pub :: XPub -> Word32 -> Maybe XPub
@@ -188,16 +189,17 @@ ckd_pub _xpub@(XPub (X pub cod)) i
           l   = SHA512.hmac cod dat
           (il, ci) = BS.splitAt 32 l
           pil = parse256 il -- safe due to 512-bit hmac
-          ki = Secp256k1.mul_unsafe Secp256k1._CURVE_G pil `Secp256k1.add` pub
+      pt <- Secp256k1.mul_unsafe Secp256k1._CURVE_G pil
+      let  ki = pt `Secp256k1.add` pub
       if   pil >= Secp256k1._CURVE_Q || ki == Secp256k1._CURVE_ZERO -- negl
       then ckd_pub _xpub (succ i)
       else pure (XPub (X ki ci))
 
 -- private parent key -> public child key
 n :: XPrv -> XPub
-n (XPrv (X sec cod)) =
-  let p = Secp256k1.mul Secp256k1._CURVE_G sec
-  in  XPub (X p cod)
+n (XPrv (X sec cod)) = case Secp256k1.mul Secp256k1._CURVE_G sec of
+  Nothing -> error "ppad-bip32 (n): evil extended key"
+  Just p -> XPub (X p cod)
 
 -- hierarchical deterministic keys --------------------------------------------