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Merge pull request bitcoin#196 from jonasnick/update-ref
Update reference code and test vectors
2 parents 9abbfa5 + 9bfa53e commit f71b5cb

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3 files changed

+115
-74
lines changed

3 files changed

+115
-74
lines changed

bip-0340/reference.py

Lines changed: 30 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -51,7 +51,10 @@ def bytes_from_int(x):
5151
def bytes_from_point(P):
5252
return bytes_from_int(x(P))
5353

54-
def point_from_bytes(b):
54+
def xor_bytes(b0, b1):
55+
return bytes(x ^ y for (x, y) in zip(b0, b1))
56+
57+
def lift_x_square_y(b):
5558
x = int_from_bytes(b)
5659
if x >= p:
5760
return None
@@ -61,6 +64,13 @@ def point_from_bytes(b):
6164
return None
6265
return [x, y]
6366

67+
def lift_x_even_y(b):
68+
P = lift_x_square_y(b)
69+
if P is None:
70+
return None
71+
else:
72+
return [x(P), y(P) if y(P) % 2 == 0 else p - y(P)]
73+
6474
def int_from_bytes(b):
6575
return int.from_bytes(b, byteorder="big")
6676

@@ -73,28 +83,37 @@ def is_square(x):
7383
def has_square_y(P):
7484
return not is_infinity(P) and is_square(y(P))
7585

86+
def has_even_y(P):
87+
return y(P) % 2 == 0
88+
7689
def pubkey_gen(seckey):
7790
x = int_from_bytes(seckey)
7891
if not (1 <= x <= n - 1):
7992
raise ValueError('The secret key must be an integer in the range 1..n-1.')
8093
P = point_mul(G, x)
8194
return bytes_from_point(P)
8295

83-
def schnorr_sign(msg, seckey0):
96+
def schnorr_sign(msg, seckey0, aux_rand):
8497
if len(msg) != 32:
8598
raise ValueError('The message must be a 32-byte array.')
8699
seckey0 = int_from_bytes(seckey0)
87100
if not (1 <= seckey0 <= n - 1):
88101
raise ValueError('The secret key must be an integer in the range 1..n-1.')
102+
if len(aux_rand) != 32:
103+
raise ValueError('aux_rand must be 32 bytes instead of %i.' % len(aux_rand))
89104
P = point_mul(G, seckey0)
90-
seckey = seckey0 if has_square_y(P) else n - seckey0
91-
k0 = int_from_bytes(tagged_hash("BIPSchnorrDerive", bytes_from_int(seckey) + msg)) % n
105+
seckey = seckey0 if has_even_y(P) else n - seckey0
106+
t = xor_bytes(bytes_from_int(seckey), tagged_hash("BIP340/aux", aux_rand))
107+
k0 = int_from_bytes(tagged_hash("BIP340/nonce", t + bytes_from_point(P) + msg)) % n
92108
if k0 == 0:
93109
raise RuntimeError('Failure. This happens only with negligible probability.')
94110
R = point_mul(G, k0)
95111
k = n - k0 if not has_square_y(R) else k0
96-
e = int_from_bytes(tagged_hash("BIPSchnorr", bytes_from_point(R) + bytes_from_point(P) + msg)) % n
97-
return bytes_from_point(R) + bytes_from_int((k + e * seckey) % n)
112+
e = int_from_bytes(tagged_hash("BIP340/challenge", bytes_from_point(R) + bytes_from_point(P) + msg)) % n
113+
sig = bytes_from_point(R) + bytes_from_int((k + e * seckey) % n)
114+
if not schnorr_verify(msg, bytes_from_point(P), sig):
115+
raise RuntimeError('The signature does not pass verification.')
116+
return sig
98117

99118
def schnorr_verify(msg, pubkey, sig):
100119
if len(msg) != 32:
@@ -103,14 +122,14 @@ def schnorr_verify(msg, pubkey, sig):
103122
raise ValueError('The public key must be a 32-byte array.')
104123
if len(sig) != 64:
105124
raise ValueError('The signature must be a 64-byte array.')
106-
P = point_from_bytes(pubkey)
125+
P = lift_x_even_y(pubkey)
107126
if (P is None):
108127
return False
109128
r = int_from_bytes(sig[0:32])
110129
s = int_from_bytes(sig[32:64])
111130
if (r >= p or s >= n):
112131
return False
113-
e = int_from_bytes(tagged_hash("BIPSchnorr", sig[0:32] + pubkey + msg)) % n
132+
e = int_from_bytes(tagged_hash("BIP340/challenge", sig[0:32] + pubkey + msg)) % n
114133
R = point_add(point_mul(G, s), point_mul(P, n - e))
115134
if R is None or not has_square_y(R) or x(R) != r:
116135
return False
@@ -127,7 +146,7 @@ def test_vectors():
127146
reader = csv.reader(csvfile)
128147
reader.__next__()
129148
for row in reader:
130-
(index, seckey, pubkey, msg, sig, result, comment) = row
149+
(index, seckey, pubkey, aux_rand, msg, sig, result, comment) = row
131150
pubkey = bytes.fromhex(pubkey)
132151
msg = bytes.fromhex(msg)
133152
sig = bytes.fromhex(sig)
@@ -140,7 +159,8 @@ def test_vectors():
140159
print(' * Failed key generation.')
141160
print(' Expected key:', pubkey.hex().upper())
142161
print(' Actual key:', pubkey_actual.hex().upper())
143-
sig_actual = schnorr_sign(msg, seckey)
162+
aux_rand = bytes.fromhex(aux_rand)
163+
sig_actual = schnorr_sign(msg, seckey, aux_rand)
144164
if sig == sig_actual:
145165
print(' * Passed signing test.')
146166
else:

bip-0340/test-vectors.csv

Lines changed: 16 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -1,16 +1,16 @@
1-
index,secret key,public key,message,signature,verification result,comment
2-
0,0000000000000000000000000000000000000000000000000000000000000001,79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798,0000000000000000000000000000000000000000000000000000000000000000,528F745793E8472C0329742A463F59E58F3A3F1A4AC09C28F6F8514D4D0322A258BD08398F82CF67B812AB2C7717CE566F877C2F8795C846146978E8F04782AE,TRUE,
3-
1,B7E151628AED2A6ABF7158809CF4F3C762E7160F38B4DA56A784D9045190CFEF,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,667C2F778E0616E611BD0C14B8A600C5884551701A949EF0EBFD72D452D64E844160BCFC3F466ECB8FACD19ADE57D8699D74E7207D78C6AEDC3799B52A8E0598,TRUE,
4-
2,C90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B14E5C9,DD308AFEC5777E13121FA72B9CC1B7CC0139715309B086C960E18FD969774EB8,5E2D58D8B3BCDF1ABADEC7829054F90DDA9805AAB56C77333024B9D0A508B75C,2D941B38E32624BF0AC7669C0971B990994AF6F9B18426BF4F4E7EC10E6CDF386CF646C6DDAFCFA7F1993EEB2E4D66416AEAD1DDAE2F22D63CAD901412D116C6,TRUE,
5-
3,0B432B2677937381AEF05BB02A66ECD012773062CF3FA2549E44F58ED2401710,25D1DFF95105F5253C4022F628A996AD3A0D95FBF21D468A1B33F8C160D8F517,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF,8BD2C11604B0A87A443FCC2E5D90E5328F934161B18864FB48CE10CB59B45FB9B5B2A0F129BD88F5BDC05D5C21E5C57176B913002335784F9777A24BD317CD36,TRUE,test fails if msg is reduced modulo p or n
6-
4,,D69C3509BB99E412E68B0FE8544E72837DFA30746D8BE2AA65975F29D22DC7B9,4DF3C3F68FCC83B27E9D42C90431A72499F17875C81A599B566C9889B9696703,00000000000000000000003B78CE563F89A0ED9414F5AA28AD0D96D6795F9C63EE374AC7FAE927D334CCB190F6FB8FD27A2DDC639CCEE46D43F113A4035A2C7F,TRUE,
7-
5,,EEFDEA4CDB677750A420FEE807EACF21EB9898AE79B9768766E4FAA04A2D4A34,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,667C2F778E0616E611BD0C14B8A600C5884551701A949EF0EBFD72D452D64E844160BCFC3F466ECB8FACD19ADE57D8699D74E7207D78C6AEDC3799B52A8E0598,FALSE,public key not on the curve
8-
6,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F9935554D1AA5F0374E5CDAACB3925035C7C169B27C4426DF0A6B19AF3BAEAB138,FALSE,has_square_y(R) is false
9-
7,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,10AC49A6A2EBF604189C5F40FC75AF2D42D77DE9A2782709B1EB4EAF1CFE9108D7003B703A3499D5E29529D39BA040A44955127140F81A8A89A96F992AC0FE79,FALSE,negated message
10-
8,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,667C2F778E0616E611BD0C14B8A600C5884551701A949EF0EBFD72D452D64E84BE9F4303C0B9913470532E6521A827951D39F5C631CFD98CE39AC4D7A5A83BA9,FALSE,negated s value
11-
9,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,000000000000000000000000000000000000000000000000000000000000000099D2F0EBC2996808208633CD9926BF7EC3DAB73DAAD36E85B3040A698E6D1CE0,FALSE,sG - eP is infinite. Test fails in single verification if has_square_y(inf) is defined as true and x(inf) as 0
12-
10,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,000000000000000000000000000000000000000000000000000000000000000124E81D89F01304695CE943F7D5EBD00EF726A0864B4FF33895B4E86BEADC5456,FALSE,sG - eP is infinite. Test fails in single verification if has_square_y(inf) is defined as true and x(inf) as 1
13-
11,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,4A298DACAE57395A15D0795DDBFD1DCB564DA82B0F269BC70A74F8220429BA1D4160BCFC3F466ECB8FACD19ADE57D8699D74E7207D78C6AEDC3799B52A8E0598,FALSE,sig[0:32] is not an X coordinate on the curve
14-
12,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F4160BCFC3F466ECB8FACD19ADE57D8699D74E7207D78C6AEDC3799B52A8E0598,FALSE,sig[0:32] is equal to field size
15-
13,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,667C2F778E0616E611BD0C14B8A600C5884551701A949EF0EBFD72D452D64E84FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141,FALSE,sig[32:64] is equal to curve order
16-
14,,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC30,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,667C2F778E0616E611BD0C14B8A600C5884551701A949EF0EBFD72D452D64E844160BCFC3F466ECB8FACD19ADE57D8699D74E7207D78C6AEDC3799B52A8E0598,FALSE,public key is not a valid X coordinate because it exceeds the field size
1+
index,secret key,public key,aux_rand,message,signature,verification result,comment
2+
0,0000000000000000000000000000000000000000000000000000000000000003,F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F9,0000000000000000000000000000000000000000000000000000000000000000,0000000000000000000000000000000000000000000000000000000000000000,067E337AD551B2276EC705E43F0920926A9CE08AC68159F9D258C9BBA412781C9F059FCDF4824F13B3D7C1305316F956704BB3FEA2C26142E18ACD90A90C947E,TRUE,
3+
1,B7E151628AED2A6ABF7158809CF4F3C762E7160F38B4DA56A784D9045190CFEF,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,0000000000000000000000000000000000000000000000000000000000000001,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,0E12B8C520948A776753A96F21ABD7FDC2D7D0C0DDC90851BE17B04E75EF86A47EF0DA46C4DC4D0D1BCB8668C2CE16C54C7C23A6716EDE303AF86774917CF928,TRUE,
4+
2,C90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B14E5C9,DD308AFEC5777E13121FA72B9CC1B7CC0139715309B086C960E18FD969774EB8,C87AA53824B4D7AE2EB035A2B5BBBCCC080E76CDC6D1692C4B0B62D798E6D906,7E2D58D8B3BCDF1ABADEC7829054F90DDA9805AAB56C77333024B9D0A508B75C,FC012F9FB8FE00A358F51EF93DCE0DC0C895F6E9A87C6C4905BC820B0C3677616B8737D14E703AF8E16E22E5B8F26227D41E5128F82D86F747244CC289C74D1D,TRUE,
5+
3,0B432B2677937381AEF05BB02A66ECD012773062CF3FA2549E44F58ED2401710,25D1DFF95105F5253C4022F628A996AD3A0D95FBF21D468A1B33F8C160D8F517,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF,FC132D4E426DFF535AEC0FA7083AC5118BC1D5FFFD848ABD8290C23F271CA0DD11AEDCEA3F55DA9BD677FE29C9DDA0CF878BCE43FDE0E313D69D1AF7A5AE8369,TRUE,test fails if msg is reduced modulo p or n
6+
4,,D69C3509BB99E412E68B0FE8544E72837DFA30746D8BE2AA65975F29D22DC7B9,,4DF3C3F68FCC83B27E9D42C90431A72499F17875C81A599B566C9889B9696703,00000000000000000000003B78CE563F89A0ED9414F5AA28AD0D96D6795F9C630EC50E5363E227ACAC6F542CE1C0B186657E0E0D1A6FFE283A33438DE4738419,TRUE,
7+
5,,EEFDEA4CDB677750A420FEE807EACF21EB9898AE79B9768766E4FAA04A2D4A34,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,7036D6BFE1837AE919631039A2CF652A295DFAC9A8BBB0806014B2F48DD7C807941607B563ABBA414287F374A332BA3636DE009EE1EF551A17796B72B68B8A24,FALSE,public key not on the curve
8+
6,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,F9308A019258C31049344F85F89D5229B531C845836F99B08601F113BCE036F995A579DA959FA739FCE39E8BD16FECB5CDCF97060B2C73CDE60E87ABCA1AA5D9,FALSE,has_square_y(R) is false
9+
7,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,F8704654F4687B7365ED32E796DE92761390A3BCC495179BFE073817B7ED32824E76B987F7C1F9A751EF5C343F7645D3CFFC7D570B9A7192EBF1898E1344E3BF,FALSE,negated message
10+
8,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,7036D6BFE1837AE919631039A2CF652A295DFAC9A8BBB0806014B2F48DD7C8076BE9F84A9C5445BEBD780C8B5CCD45C883D0DC47CD594B21A858F31A19AAB71D,FALSE,negated s value
11+
9,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,00000000000000000000000000000000000000000000000000000000000000009915EE59F07F9DBBAEDC31BFCC9B34AD49DE669CD24773BCED77DDA36D073EC8,FALSE,sG - eP is infinite. Test fails in single verification if has_square_y(inf) is defined as true and x(inf) as 0
12+
10,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,0000000000000000000000000000000000000000000000000000000000000001C7EC918B2B9CF34071BB54BED7EB4BB6BAB148E9A7E36E6B228F95DFA08B43EC,FALSE,sG - eP is infinite. Test fails in single verification if has_square_y(inf) is defined as true and x(inf) as 1
13+
11,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,4A298DACAE57395A15D0795DDBFD1DCB564DA82B0F269BC70A74F8220429BA1D941607B563ABBA414287F374A332BA3636DE009EE1EF551A17796B72B68B8A24,FALSE,sig[0:32] is not an X coordinate on the curve
14+
12,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F941607B563ABBA414287F374A332BA3636DE009EE1EF551A17796B72B68B8A24,FALSE,sig[0:32] is equal to field size
15+
13,,DFF1D77F2A671C5F36183726DB2341BE58FEAE1DA2DECED843240F7B502BA659,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,7036D6BFE1837AE919631039A2CF652A295DFAC9A8BBB0806014B2F48DD7C807FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141,FALSE,sig[32:64] is equal to curve order
16+
14,,FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC30,,243F6A8885A308D313198A2E03707344A4093822299F31D0082EFA98EC4E6C89,7036D6BFE1837AE919631039A2CF652A295DFAC9A8BBB0806014B2F48DD7C807941607B563ABBA414287F374A332BA3636DE009EE1EF551A17796B72B68B8A24,FALSE,public key is not a valid X coordinate because it exceeds the field size

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