add_user_random(): minor cleanups

mmgen/crypto.py

@@ -25,27 +25,6 @@ from cryptography.hazmat.backends import default_backend
 from hashlib import sha256
 from .common import *
 
-crmsg = {
-	'usr_rand_notice': """
-Now we're going to gather some additional input from the keyboard to
-further randomize the {d} we've already gathered.
-
-An encryption key will be created from this input, and the {d}
-will be encrypted using the key.  The resulting data is guaranteed to be at
-least as random as the original {d}, so even if you type very
-predictably no harm will be done.
-
-However, to gain the maximum benefit, try making your input as random as
-possible.  Type slowly and choose your symbols carefully.  Try to use both
-upper and lowercase as well as punctuation and numerals.  The timings between
-your keystrokes will also be used as a source of entropy, so be as
-unpredictable as possible in your timing as well.
-
-Please type {r} symbols on your keyboard.  What you type will not be displayed
-on the screen.
-"""
-}
-
 def sha256_rounds(s,n):
 	for i in range(n):
 		s = sha256(s).digest()
@@ -152,53 +131,74 @@ def make_key(passwd,salt,hash_preset,desc='encryption key',from_what='passphrase
 	dmsg('Key: {}'.format(key.hex()))
 	return key
 
-def _get_random_data_from_user(uchars,desc,test_suite=False):
-	m = 'Enter {r} random symbols' if opt.quiet or test_suite else crmsg['usr_rand_notice']
-	msg(m.format(r=uchars,d=desc))
+def _get_random_data_from_user(uchars,desc):
+	info1 = f"""
+		Now we're going to gather some additional input from the keyboard to further
+		randomize the random data {desc}.
+
+		An encryption key will be created from this input, and the random data will
+		be encrypted using the key.  The resulting data is guaranteed to be at least
+		as random as the original random data, so even if you type very predictably
+		no harm will be done.
+
+		However, to gain the maximum benefit, try making your input as random as
+		possible.  Type slowly and choose your symbols carefully.  Try to use both
+		upper and lowercase letters as well as punctuation and numerals. The timings
+		between your keystrokes will also be used as a source of entropy, so be as
+		random as possible in your timing as well.
+	"""
+	info2 = f"""
+		Please type {uchars} symbols on your keyboard.  What you type will not be displayed
+		on the screen.
+	"""
+
+	msg(f'Enter {uchars} random symbols' if opt.quiet else
+		'\n{}\n{}'.format( fmt(info1,indent='  '), fmt(info2) ))
+
 	prompt = 'You may begin typing.  {} symbols left: '
 
 	import time
 	from .term import get_char_raw
-	key_data,time_data = '',[]
+	key_data = ''
+	time_data = []
 
 	for i in range(uchars):
 		key_data += get_char_raw('\r'+prompt.format(uchars-i))
 		time_data.append(time.time())
 
-	msg_r('\r' if opt.quiet else "\rThank you.  That's enough.{}\n\n".format(' '*18))
+	msg_r( '\r' if opt.quiet else f"\rThank you.  That's enough.{' '*18}\n\n" )
 
 	time_data = ['{:.22f}'.format(t).rstrip('0') for t in time_data]
 
 	avg_prec = sum(len(t.split('.')[1]) for t in time_data) // len(time_data)
+
 	if avg_prec < g.min_time_precision:
-		m = 'WARNING: Avg. time precision of only {} decimal points.  User entropy quality is degraded!'
-		ymsg(m.format(avg_prec))
+		ymsg(f'WARNING: Avg. time precision of only {avg_prec} decimal points. User entropy quality is degraded!')
 
 	ret = key_data + '\n' + '\n'.join(time_data)
 
 	if g.debug:
-		msg('USER ENTROPY (user input + keystroke timings):\n{}'.format(ret))
+		msg(f'USER ENTROPY (user input + keystroke timings):\n{ret}')
 
-	if not test_suite:
-		my_raw_input('User random data successfully acquired.  Press ENTER to continue: ')
+	my_raw_input('User random data successfully acquired.  Press ENTER to continue: ')
 
 	return ret.encode()
 
 def get_random(length):
-	return add_user_random(os.urandom(length),'OS random data')
+	return add_user_random(
+		rand_bytes = os.urandom(length),
+		desc       = 'generated by your operating system' )
 
 def add_user_random(rand_bytes,desc):
-	assert type(rand_bytes) == bytes, (
-		"{!r}: invalid type for 'rand_bytes'".format(type(rand_bytes).__name__) )
+	assert type(rand_bytes) == bytes, 'add_user_random_chk1'
 	if opt.usr_randchars:
 		if not g.user_entropy:
-			g.user_entropy = \
-				sha256(_get_random_data_from_user(opt.usr_randchars,desc)).digest()
+			g.user_entropy = sha256(_get_random_data_from_user(opt.usr_randchars,desc)).digest()
 			urand_desc = 'user-supplied entropy'
 		else:
 			urand_desc = 'saved user-supplied entropy'
 		key = make_key(g.user_entropy,b'','2',from_what=urand_desc,verbose=True)
-		msg('Encrypting {} with key'.format(desc))
+		msg(f'Encrypting random data {desc} with key')
 		return encrypt_data(rand_bytes,key,desc=desc,verify=False)
 	else:
 		return rand_bytes

mmgen/wallet.py

@@ -565,7 +565,9 @@ class DieRollSeedFile(WalletUnenc):
 
 		if self.interactive_input and opt.usr_randchars:
 			if keypress_confirm(self.user_entropy_prompt):
-				seed_bytes = add_user_random(seed_bytes,'die roll data')
+				seed_bytes = add_user_random(
+					rand_bytes = seed_bytes,
+					desc       = 'gathered from your die rolls' )
 				self.desc += ' plus user-supplied entropy'
 
 		self.seed = Seed(seed_bytes)

test/test_py_d/ts_main.py

@@ -533,7 +533,7 @@ class TestSuiteMain(TestSuiteBase,TestSuiteShared):
 			t.usr_rand(self.usr_rand_chars)
 
 		if ocls.__name__.startswith('Incog'):
-			m = 'Encrypting OS random data with key'
+			m = 'Encrypting random data generated by your operating system with key'
 			t.expect(m)
 			t.expect(m)
 			incog_id = t.expect_getend('New Incog Wallet ID: ')

test/test_py_d/ts_wallet.py

@@ -208,7 +208,7 @@ class TestSuiteWalletConv(TestSuiteBase,TestSuiteShared):
 			t.usr_rand(self.usr_rand_chars)
 		if wcls in (IncogWallet,IncogWalletHex,IncogWalletHidden):
 			for i in (1,2,3):
-				t.expect('Encrypting OS random data with key')
+				t.expect('Encrypting random data generated by your operating system with key')
 		if wcls == IncogWalletHidden:
 			t.hincog_create(hincog_bytes)
 		if out_fmt == 'w':