From 8559b9c668db9c90c9f409c705240a90eaab35f9 Mon Sep 17 00:00:00 2001
From: The MMGen Project <mmgen@tuta.io>
Date: Fri, 24 Sep 2021 20:07:05 +0000
Subject: [PATCH] do_hashlib_scrypt(): cleanups

---
 mmgen/crypto.py     | 35 ++++++++++++++++++++++++-----------
 mmgen/globalvars.py | 15 ++++++++-------
 mmgen/util.py       |  2 +-
 mmgen/wallet.py     |  2 +-
 4 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/mmgen/crypto.py b/mmgen/crypto.py
index 0fef50ab..e71a35c7 100755
--- a/mmgen/crypto.py
+++ b/mmgen/crypto.py
@@ -96,26 +96,39 @@ def scrypt_hash_passphrase(passwd,salt,hash_preset,buflen=32):
 
 	# Buflen arg is for brainwallets only, which use this function to generate
 	# the seed directly.
-	N,r,p = get_hash_params(hash_preset)
-	if isinstance(passwd,str): passwd = passwd.encode()
+	ps = get_hash_params(hash_preset)
+
+	if isinstance(passwd,str):
+		passwd = passwd.encode()
 
 	def do_hashlib_scrypt():
-		from hashlib import scrypt # Python >= v3.6
-		return scrypt(passwd,salt=salt,n=2**N,r=r,p=p,maxmem=0,dklen=buflen)
+		from hashlib import scrypt
+		return scrypt(
+			password = passwd,
+			salt     = salt,
+			n        = 2**ps.N,
+			r        = ps.r,
+			p        = ps.p,
+			maxmem   = 0,
+			dklen    = buflen )
 
 	def do_standalone_scrypt():
 		import scrypt
-		return scrypt.hash(passwd,salt,2**N,r,p,buflen=buflen)
+		return scrypt.hash(
+			password = passwd,
+			salt     = salt,
+			N        = 2**ps.N,
+			r        = ps.r,
+			p        = ps.p,
+			buflen   = buflen )
 
 	if int(hash_preset) > 3:
 		msg_r('Hashing passphrase, please wait...')
 
-	# hashlib.scrypt doesn't support N > 14 (hash preset 3)
-	if N > 14 or g.force_standalone_scrypt_module:
-		ret = do_standalone_scrypt()
-	else:
-		try: ret = do_hashlib_scrypt()
-		except: ret = do_standalone_scrypt()
+	# hashlib.scrypt doesn't support N > 14 (hash preset > 3)
+	ret = (
+		do_standalone_scrypt() if ps.N > 14 or g.force_standalone_scrypt_module else
+		do_hashlib_scrypt() )
 
 	if int(hash_preset) > 3:
 		msg_r('\b'*34 + ' '*34 + '\b'*34)
diff --git a/mmgen/globalvars.py b/mmgen/globalvars.py
index 4a74398b..04ea4fb8 100755
--- a/mmgen/globalvars.py
+++ b/mmgen/globalvars.py
@@ -282,14 +282,15 @@ class GlobalContext(Lockable):
 	# Scrypt params: 'id_num': [N, r, p] (N is an exponent of two)
 	# NB: hashlib.scrypt in Python (>=v3.6) supports max N value of 14.  This means that
 	# for hash presets > 3 the standalone scrypt library must be used!
+	_hp = namedtuple('scrypt_preset',['N','r','p'])
 	hash_presets = {
-		'1': [12, 8, 1],
-		'2': [13, 8, 4],
-		'3': [14, 8, 8],
-		'4': [15, 8, 12],
-		'5': [16, 8, 16],
-		'6': [17, 8, 20],
-		'7': [18, 8, 24],
+		'1': _hp(12, 8, 1),
+		'2': _hp(13, 8, 4),
+		'3': _hp(14, 8, 8),
+		'4': _hp(15, 8, 12),
+		'5': _hp(16, 8, 16),
+		'6': _hp(17, 8, 20),
+		'7': _hp(18, 8, 24),
 	}
 
 	if os.getenv('MMGEN_TEST_SUITE'):
diff --git a/mmgen/util.py b/mmgen/util.py
index 6ae30a24..536e1697 100755
--- a/mmgen/util.py
+++ b/mmgen/util.py
@@ -426,7 +426,7 @@ def strip_comments(lines):
 
 def get_hash_params(hash_preset):
 	if hash_preset in g.hash_presets:
-		return g.hash_presets[hash_preset] # N,p,r,buflen
+		return g.hash_presets[hash_preset] # N,r,p
 	else: # Shouldn't be here
 		die(3,f"{hash_preset}: invalid 'hash_preset' value")
 
diff --git a/mmgen/wallet.py b/mmgen/wallet.py
index 98a0bffc..4704a7d1 100755
--- a/mmgen/wallet.py
+++ b/mmgen/wallet.py
@@ -815,7 +815,7 @@ class MMGenWallet(WalletEnc):
 		if opt.hash_preset and opt.hash_preset != hp:
 			qmsg('Warning: ignoring user-requested hash preset {opt.hash_preset}')
 
-		hash_params = list(map(int,hpdata[1:]))
+		hash_params = tuple(map(int,hpdata[1:]))
 
 		if hash_params != get_hash_params(d.hash_preset):
 			msg(f"Hash parameters {' '.join(hash_params)!r} don't match hash preset {d.hash_preset!r}")