def eval_contract(block, transaction_list, tx):
sys.stderr.write("evaluating contract\n")
address = tx.to
# Initialize stack
stack = []
index = 0
stepcounter = 0
contract = block.get_contract(address)
if not contract:
return
while 1:
# Convert the data item into a code piece
val_at_index = decode(contract.get(encode(index, 256, 32)), 256)
code = [int(val_at_index / (256**i)) % 256 for i in range(6)]
code[0] = scriptcode_map.get(code[0], 'INVALID')
sys.stderr.write("Evaluating: " + str(code) + "\n")
# Invalid code instruction or STOP code stops execution sans fee
if val_at_index >= 256 or code[0] in ['STOP', 'INVALID']:
sys.stderr.write("stop code, exiting\n")
break
# Calculate fee
minerfee = 0
nullfee = 0
stepcounter += 1
if stepcounter > 16:
minerfee += getfee("stepfee")
c = scriptcode_map[code[0]]
if c in ['STORE', 'LOAD']:
minerfee += getfee("datafee")
if c in ['EXTRO', 'BALANCE']:
minerfee += getfee("extrofee")
if c in [
'SHA256', 'RIPEMD-160', 'ECMUL', 'ECADD', 'ECSIGN', 'ECRECOVER'
]:
minerfee += getfee("cryptofee")
if c == 'STORE':
existing = block.get_contract_state(address, code[2])
if reg[code[1]] != 0: nullfee += getfee("memoryfee")
if existing: nullfee -= getfee("memoryfee")
# If we can't pay the fee, break, otherwise pay it
if block.get_balance(address) < minerfee + nullfee:
sys.stderr.write("insufficient fee, exiting\n")
break
block.set_balance(address,
block.get_balance(address) - nullfee - minerfee)
block.reward += minerfee
sys.stderr.write("evaluating operation\n")
exit = False
def stack_pop(n):
if len(stack) < n:
sys.stderr.write("Stack height insufficient, exiting")
exit = True
return [0] * n
o = stack[-n:]
stack = stack[:-n]
return o
# Evaluate operations
if c == 'ADD':
x, y = stack_pop(2)
stack.append((x + y) % 2**256)
elif c == 'MUL':
x, y = stack_pop(2)
stack.append((x * y) % 2**256)
elif c == 'SUB':
x, y = stack_pop(2)
stack.append((x - y) % 2**256)
elif c == 'DIV':
x, y = stack_pop(2)
if y == 0: break
stack.append(int(x / y))
elif c == 'SDIV':
x, y = stack_pop(2)
if y == 0: break
sign = (1 if x < 2**255 else -1) * (1 if y < 2**255 else -1)
xx = x if x < 2**255 else 2**256 - x
yy = y if y < 2**255 else 2**256 - y
z = int(xx / yy)
stack.append(z if sign == 1 else 2**256 - z)
elif code == 'MOD':
x, y = stack_pop(2)
if y == 0: break
stack.append(x % y)
elif code == 'SMOD':
x, y = stack_pop(2)
if y == 0: break
sign = (1 if x < 2**255 else -1) * (1 if y < 2**255 else -1)
xx = x if x < 2**255 else 2**256 - x
yy = y if y < 2**255 else 2**256 - y
z = xx % yy
stack.append(z if sign == 1 else 2**256 - z)
elif code == 'EXP':
x, y = stack_pop(2)
stack.append(pow(x, y, 2**256))
elif code == 'NEG':
stack.append(2**256 - stack.pop(1)[0])
elif code == 'LT':
x, y = stack_pop(2)
stack.append(1 if x < y else 0)
elif code == 'LE':
x, y = stack_pop(2)
stack.append(1 if x <= y else 0)
elif code == 'GT':
x, y = stack_pop(2)
stack.append(1 if x > y else 0)
elif code == 'GE':
x, y = stack_pop(2)
stack.append(1 if x >= y else 0)
elif code == 'EQ':
x, y = stack_pop(2)
stack.append(1 if x == y else 0)
elif code == 'NOT':
stack.append(1 if stack.pop(1)[0] == 0 else 0)
elif code == 'MYADDRESS':
stack.append(address)
elif code == 'TXSENDER':
stack.append(decode(tx.sender, 256))
elif code == 'TXVALUE':
stack.append(tx.value)
elif code == 'TXDATAN':
stack.append(len(tx.data))
elif code == 'TXDATA':
x, = stack_pop(1)
stack.append(0 if x >= len(tx.data) else tx.data[x])
elif code == 'BLK_PREVHASH':
stack.append(decode(block.prevhash, 256))
elif code == 'BLK_COINBASE':
stack.append(decode(block.coinbase, 160))
elif code == 'BLK_TIMESTAMP':
stack.append(block.timestamp)
elif code == 'BLK_NUMBER':
stack.append(block.number)
elif code == 'BLK_DIFFICULTY':
stack.append(block.difficulty)
elif code == 'SHA256':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x, 256, 32) for x in hdataitems])[:L]
stack.append(decode(hashlib.sha256(hdata).digest(), 256))
elif code == 'RIPEMD-160':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x, 256, 32) for x in hdataitems])[:L]
stack.append(decode(hashlib.new('ripemd160', hdata).digest(), 256))
elif code == 'ECMUL':
n, x, y = stack_pop(3)
# Point at infinity
if x == 0 and y == 0:
stack.extend([0, 0])
# Point not on curve, coerce to infinity
elif x >= P or y >= P or (x**3 + 7 - y**2) % P != 0:
stack.extend([0, 0])
# Legitimate point
else:
x2, y2 = base10_multiply((x, y), n)
stack.extend([x2, y2])
elif code == 'ECADD':
x1, y1, x2, y2 = stack_pop(4)
# Invalid point 1
if x1 >= P or y1 >= P or (x1**3 + 7 - y1**2) % P != 0:
stack.extend([0, 0])
# Invalid point 2
elif x2 >= P or y2 >= P or (x2**3 + 7 - y2**2) % P != 0:
stack.extend([0, 0])
# Legitimate points
else:
x3, y3 = base10_add((x1, y1), (x2, y2))
stack.extend([x3, y3])
elif code == 'ECSIGN':
k, h = stack_pop(2)
v, r, s = ecdsa_raw_sign(h, k)
stack.extend([v, r, s])
elif code == 'ECRECOVER':
h, v, r, s = stack_pop(4)
x, y = ecdsa_raw_recover((v, r, s), h)
stack.extend([x, y])
elif code == 'SHA3':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x, 256, 32) for x in hdataitems])[:L]
stack.append(decode(sha3.sha3_256(hdata).digest(), 256))
elif code == 'PUSH':
stack.append(contract.get(encode(index + 1, 256, 32)))
index += 1
elif code == 'POP':
stack_pop(1)
elif code == 'DUP':
x, = stack_pop(1)
stack.extend([x, x])
elif code == 'SWAP':
x, y = stack_pop(2)
stack.extend([y, x])
elif code == 'SLOAD':
stack.append(contract.get(encode(stack_pop(1)[0], 256, 32)))
elif code == 'SSTORE':
x, y = stack_pop(2)
if exit: break
contract.update(encode(x, 256, 32), y)
elif code == 'JMP':
index = stack_pop(1)[0]
elif code == 'JMPI':
newpos, c = stack_pop(2)
if c != 0: index = newpos
elif code == 'IND':
stack.append(index)
elif code == 'EXTRO':
ind, addr = stack_pop(2)
stack.push(
block.get_contract(encode(addr, 256,
20)).get(encode(ind, 256, 32)))
elif code == 'BALANCE':
stack.push(block.get_balance(encode(stack_pop(1)[0], 256, 20)))
elif code == 'MKTX':
datan, fee, value, to = stack_pop(4)
if exit:
break
elif (value + fee) > block.get_balance(address):
break
else:
data = stack_pop(datan)
tx = Transaction(0, encode(to, 256, 20), value, fee, data)
tx.sender = address
transaction_list.insert(0, tx)
elif code == 'SUICIDE':
sz = contract.get_size()
negfee = -sz * getfee("memoryfee")
toaddress = encode(stack_pop(1)[0], 256, 20)
block.pay_fee(toaddress, negfee, False)
contract.root = ''
break
if exit: break
block.update_contract(address, contract)
def eval_contract(block,transaction_list,tx):
sys.stderr.write("evaluating contract\n")
address = tx.to
# Initialize registers
reg = [0] * 256
reg[0] = decode(tx.sender,256)
reg[1] = decode(tx.to,256)
reg[2] = tx.value
reg[3] = tx.fee
index = 0
stepcounter = 0
contract = block.get_contract(address)
if not contract:
return
while 1:
# Convert the data item into a code piece
val_at_index = decode(contract.get(encode(index,256,32)),256)
code = [ int(val_at_index / (256**i)) % 256 for i in range(6) ]
code[0] = scriptcode_map.get(code[0],'INVALID')
sys.stderr.write("Evaluating: "+ str(code)+"\n")
# Invalid code instruction or STOP code stops execution sans fee
if val_at_index >= 256**6 or code[0] in ['STOP','INVALID']:
sys.stderr.write("stop code, exiting\n")
break
# Calculate fee
minerfee = 0
nullfee = 0
stepcounter += 1
if stepcounter > 16:
minerfee += params["stepfee"]
c = scriptcode_map[code[0]]
if c in ['STORE','LOAD']:
minerfee += params["datafee"]
if c in ['EXTRO','BALANCE']:
minerfee += params["extrofee"]
if c in ['SHA256','RIPEMD-160','ECMUL','ECADD','ECSIGN','ECRECOVER']:
minerfee += params["cryptofee"]
if c == 'STORE':
existing = block.get_contract_state(address,code[2])
if reg[code[1]] != 0: nullfee += params["memoryfee"]
if existing: nullfee -= params["memoryfee"]
# If we can't pay the fee, break, otherwise pay it
if block.get_balance(address) < minerfee + nullfee:
sys.stderr.write("insufficient fee, exiting\n")
break
block.set_balance(address,block.get_balance(address) - nullfee - minerfee)
block.reward += minerfee
sys.stderr.write("evaluating operation\n")
# Evaluate operations
if c == 'ADD':
reg[code[3]] = (reg[code[1]] + reg[code[2]]) % 2**256
elif c == 'MUL':
reg[code[3]] = (reg[code[1]] * reg[code[2]]) % 2**256
elif c == 'SUB':
reg[code[3]] = (reg[code[1]] + 2**256 - reg[code[2]]) % 2**256
elif c == 'DIV':
reg[code[3]] = int(reg[code[1]] / reg[code[2]])
elif c == 'SDIV':
sign = 1
sign *= (1 if reg[code[1]] < 2**255 else -1)
sign *= (1 if reg[code[2]] < 2**255 else -1)
x = reg[code[1]] if reg[code[1]] < 2**255 else 2**256 - reg[code[1]]
y = reg[code[2]] if reg[code[2]] < 2**255 else 2**256 - reg[code[2]]
z = int(x/y)
reg[code[3]] = z if sign == 1 else 2**256 - z
elif code == 'MOD':
reg[code[3]] = reg[code[1]] % reg[code[2]]
elif code == 'SMOD':
sign = 1
sign *= (1 if reg[code[1]] < 2**255 else -1)
sign *= (1 if reg[code[2]] < 2**255 else -1)
x = reg[code[1]] if reg[code[1]] < 2**255 else 2**256 - reg[code[1]]
y = reg[code[2]] if reg[code[2]] < 2**255 else 2**256 - reg[code[2]]
z = x%y
reg[code[3]] = z if sign == 1 else 2**256 - z
elif code == 'EXP':
reg[code[3]] = pow(reg[code[1]],reg[code[2]],2**256)
elif code == 'NEG':
reg[code[2]] = 2**256 - reg[code[1]]
elif code == 'LT':
reg[code[3]] = 1 if reg[code[1]] < reg[code[2]] else 0
elif code == 'LE':
reg[code[3]] = 1 if reg[code[1]] <= reg[code[2]] else 0
elif code == 'GT':
reg[code[3]] = 1 if reg[code[1]] > reg[code[2]] else 0
elif code == 'GE':
reg[code[3]] = 1 if reg[code[1]] >= reg[code[2]] else 0
elif code == 'EQ':
reg[code[3]] = 1 if reg[code[1]] == reg[code[2]] else 0
elif code == 'NOT':
reg[code[2]] = 1 if reg[code[1]] == 0 else 0
elif code == 'SHA256':
inp = encode(reg[code[1]],256,32)
reg[code[2]] = decode(hashlib.sha256(inp).digest(),256)
elif code == 'RIPEMD-160':
inp = encode(reg[code[1]],256,32)
reg[code[2]] = decode(hashlib.new('ripemd160',inp).digest(),256)
elif code == 'ECMUL':
pt = (reg[code[1]],reg[code[2]])
# Point at infinity
if pt[0] == 0 and pt[1] == 0:
reg[code[4]], reg[code[5]] = 0,0
# Point not on curve, coerce to infinity
elif (pt[0] ** 3 + 7 - pt[1] ** 2) % N != 0:
reg[code[4]], reg[code[5]] = 0,0
# Legitimate point
else:
pt2 = base10_multiply(pt,reg[code[3]])
reg[code[4]], reg[code[5]] = pt2[0], pt2[1]
elif code == 'ECADD':
pt1 = (reg[code[1]],reg[code[2]])
pt2 = (reg[code[3]],reg[code[4]])
# Invalid point 1
if (pt1[0] ** 3 + 7 - pt1[1] ** 2) % N != 0:
reg[code[5]], reg[code[6]] = 0,0
# Invalid point 2
elif (pt2[0] ** 3 + 7 - pt2[1] ** 2) % N != 0:
reg[code[5]], reg[code[6]] = 0,0
# Legitimate points
else:
pt3 = base10_add(pt1,pt2)
reg[code[5]], reg[code[6]] = pt3[0], pt3[1]
elif code == 'ECSIGN':
reg[code[3]], reg[code[4]], reg[code[5]] = ecdsa_raw_sign(reg[code[1]],reg[code[2]])
elif code == 'ECRECOVER':
pt = ecdsa_raw_recover((reg[code[2]],reg[code[3]],reg[code[4]]),reg[code[1]])
reg[code[5]] = pt[0]
reg[code[6]] = pt[1]
elif code == 'COPY':
reg[code[2]] = reg[code[1]]
elif code == 'STORE':
contract.update(encode(reg[code[2]],256,32),reg[code[1]])
elif code == 'LOAD':
reg[code[2]] = contract.get(encode(reg[code[1]],256,32))
elif code == 'SET':
reg[code[1]] = (code[2] + 256 * code[3] + 65536 * code[4] + 16777216 * code[5]) * 2**code[6] % 2**256
elif code == 'JMP':
index = reg[code[1]]
elif code == 'JMPI':
if reg[code[1]]: index = reg[code[2]]
elif code == 'IND':
reg[code[1]] = index
elif code == 'EXTRO':
if reg[code[1]] >= 2**160:
reg[code[3]] = 0
else:
address = encode(reg[code[1]],256,20)
field = encode(reg[code[2]])
reg[code[3]] = block.get_contract(address).get(field)
elif code == 'BALANCE':
if reg[code[1]] >= 2**160:
reg[code[2]] = 0
else:
address = encode(reg[code[1]],256,20)
reg[code[2]] = block.get_balance(address)
elif code == 'MKTX':
to = encode(reg[code[1]],256,32)
value = reg[code[2]]
fee = reg[code[3]]
if (value + fee) > block.get_balance(address):
pass
else:
datan = reg[code[4]]
data = []
for i in range(datan):
ind = encode((reg[code[5]] + i) % 2**256,256,32)
data.append(contract.get(ind))
tx = Transaction(0,to,value,fee,data)
tx.sender = address
transaction_list.insert(0,tx)
elif code == 'DATA':
reg[code[2]] = tx.data[reg[code[1]]]
elif code == 'DATAN':
reg[code[1]] = len(tx.data)
elif code == 'MYADDRESS':
reg[code[1]] = address
elif code == 'BLKHASH':
reg[code[1]] = decode(block.hash())
elif code == 'SUICIDE':
sz = contract.get_size()
negfee = -sz * params["memoryfee"]
toaddress = encode(reg[code[1]],256,20)
block.pay_fee(roaddress,negfee,False)
contract.root = ''
break
block.update_contract(address,contract)
def eval_contract(block,transaction_list,tx):
sys.stderr.write("evaluating contract\n")
address = tx.to
# Initialize stack
stack = []
index = 0
stepcounter = 0
contract = block.get_contract(address)
if not contract:
return
while 1:
# Convert the data item into a code piece
val_at_index = decode(contract.get(encode(index,256,32)),256)
code = [ int(val_at_index / (256**i)) % 256 for i in range(6) ]
code[0] = scriptcode_map.get(code[0],'INVALID')
sys.stderr.write("Evaluating: "+ str(code)+"\n")
# Invalid code instruction or STOP code stops execution sans fee
if val_at_index >= 256 or code[0] in ['STOP','INVALID']:
sys.stderr.write("stop code, exiting\n")
break
# Calculate fee
minerfee = 0
nullfee = 0
stepcounter += 1
if stepcounter > 16:
minerfee += getfee("stepfee")
c = scriptcode_map[code[0]]
if c in ['STORE','LOAD']:
minerfee += getfee("datafee")
if c in ['EXTRO','BALANCE']:
minerfee += getfee("extrofee")
if c in ['SHA256','RIPEMD-160','ECMUL','ECADD','ECSIGN','ECRECOVER']:
minerfee += getfee("cryptofee")
if c == 'STORE':
existing = block.get_contract_state(address,code[2])
if reg[code[1]] != 0: nullfee += getfee("memoryfee")
if existing: nullfee -= getfee("memoryfee")
# If we can't pay the fee, break, otherwise pay it
if block.get_balance(address) < minerfee + nullfee:
sys.stderr.write("insufficient fee, exiting\n")
break
block.set_balance(address,block.get_balance(address) - nullfee - minerfee)
block.reward += minerfee
sys.stderr.write("evaluating operation\n")
exit = False
def stack_pop(n):
if len(stack) < n:
sys.stderr.write("Stack height insufficient, exiting")
exit = True
return [0] * n
o = stack[-n:]
stack = stack[:-n]
return o
# Evaluate operations
if c == 'ADD':
x,y = stack_pop(2)
stack.append((x + y) % 2**256)
elif c == 'MUL':
x,y = stack_pop(2)
stack.append((x * y) % 2**256)
elif c == 'SUB':
x,y = stack_pop(2)
stack.append((x - y) % 2**256)
elif c == 'DIV':
x,y = stack_pop(2)
if y == 0: break
stack.append(int(x / y))
elif c == 'SDIV':
x,y = stack_pop(2)
if y == 0: break
sign = (1 if x < 2**255 else -1) * (1 if y < 2**255 else -1)
xx = x if x < 2**255 else 2**256 - x
yy = y if y < 2**255 else 2**256 - y
z = int(xx/yy)
stack.append(z if sign == 1 else 2**256 - z)
elif code == 'MOD':
x,y = stack_pop(2)
if y == 0: break
stack.append(x % y)
elif code == 'SMOD':
x,y = stack_pop(2)
if y == 0: break
sign = (1 if x < 2**255 else -1) * (1 if y < 2**255 else -1)
xx = x if x < 2**255 else 2**256 - x
yy = y if y < 2**255 else 2**256 - y
z = xx%yy
stack.append(z if sign == 1 else 2**256 - z)
elif code == 'EXP':
x,y = stack_pop(2)
stack.append(pow(x,y,2**256))
elif code == 'NEG':
stack.append(2**256 - stack.pop(1)[0])
elif code == 'LT':
x,y = stack_pop(2)
stack.append(1 if x < y else 0)
elif code == 'LE':
x,y = stack_pop(2)
stack.append(1 if x <= y else 0)
elif code == 'GT':
x,y = stack_pop(2)
stack.append(1 if x > y else 0)
elif code == 'GE':
x,y = stack_pop(2)
stack.append(1 if x >= y else 0)
elif code == 'EQ':
x,y = stack_pop(2)
stack.append(1 if x == y else 0)
elif code == 'NOT':
stack.append(1 if stack.pop(1)[0] == 0 else 0)
elif code == 'MYADDRESS':
stack.append(address)
elif code == 'TXSENDER':
stack.append(decode(tx.sender,256))
elif code == 'TXVALUE':
stack.append(tx.value)
elif code == 'TXDATAN':
stack.append(len(tx.data))
elif code == 'TXDATA':
x, = stack_pop(1)
stack.append(0 if x >= len(tx.data) else tx.data[x])
elif code == 'BLK_PREVHASH':
stack.append(decode(block.prevhash,256))
elif code == 'BLK_COINBASE':
stack.append(decode(block.coinbase,160))
elif code == 'BLK_TIMESTAMP':
stack.append(block.timestamp)
elif code == 'BLK_NUMBER':
stack.append(block.number)
elif code == 'BLK_DIFFICULTY':
stack.append(block.difficulty)
elif code == 'SHA256':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x,256,32) for x in hdataitems])[:L]
stack.append(decode(hashlib.sha256(hdata).digest(),256))
elif code == 'RIPEMD-160':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x,256,32) for x in hdataitems])[:L]
stack.append(decode(hashlib.new('ripemd160',hdata).digest(),256))
elif code == 'ECMUL':
n,x,y = stack_pop(3)
# Point at infinity
if x == 0 and y == 0:
stack.extend([0,0])
# Point not on curve, coerce to infinity
elif x >= P or y >= P or (x ** 3 + 7 - y ** 2) % P != 0:
stack.extend([0,0])
# Legitimate point
else:
x2,y2 = base10_multiply((x,y),n)
stack.extend([x2,y2])
elif code == 'ECADD':
x1,y1,x2,y2 = stack_pop(4)
# Invalid point 1
if x1 >= P or y1 >= P or (x1 ** 3 + 7 - y1 ** 2) % P != 0:
stack.extend([0,0])
# Invalid point 2
elif x2 >= P or y2 >= P or (x2 ** 3 + 7 - y2 ** 2) % P != 0:
stack.extend([0,0])
# Legitimate points
else:
x3,y3 = base10_add((x1,y1),(x2,y2))
stack.extend([x3,y3])
elif code == 'ECSIGN':
k,h = stack_pop(2)
v,r,s = ecdsa_raw_sign(h,k)
stack.extend([v,r,s])
elif code == 'ECRECOVER':
h,v,r,s = stack_pop(4)
x,y = ecdsa_raw_recover((v,r,s),h)
stack.extend([x,y])
elif code == 'SHA3':
L = stack_pop(1)
hdataitems = stack_pop(math.ceil(L / 32.0))
hdata = ''.join([encode(x,256,32) for x in hdataitems])[:L]
stack.append(decode(sha3.sha3_256(hdata).digest(),256))
elif code == 'PUSH':
stack.append(contract.get(encode(index + 1,256,32)))
index += 1
elif code == 'POP':
stack_pop(1)
elif code == 'DUP':
x, = stack_pop(1)
stack.extend([x,x])
elif code == 'SWAP':
x,y = stack_pop(2)
stack.extend([y,x])
elif code == 'SLOAD':
stack.append(contract.get(encode(stack_pop(1)[0],256,32)))
elif code == 'SSTORE':
x,y = stack_pop(2)
if exit: break
contract.update(encode(x,256,32),y)
elif code == 'JMP':
index = stack_pop(1)[0]
elif code == 'JMPI':
newpos,c = stack_pop(2)
if c != 0: index = newpos
elif code == 'IND':
stack.append(index)
elif code == 'EXTRO':
ind,addr = stack_pop(2)
stack.push(block.get_contract(encode(addr,256,20)).get(encode(ind,256,32)))
elif code == 'BALANCE':
stack.push(block.get_balance(encode(stack_pop(1)[0],256,20)))
elif code == 'MKTX':
datan,fee,value,to = stack_pop(4)
if exit:
break
elif (value + fee) > block.get_balance(address):
break
else:
data = stack_pop(datan)
tx = Transaction(0,encode(to,256,20),value,fee,data)
tx.sender = address
transaction_list.insert(0,tx)
elif code == 'SUICIDE':
sz = contract.get_size()
negfee = -sz * getfee("memoryfee")
toaddress = encode(stack_pop(1)[0],256,20)
block.pay_fee(toaddress,negfee,False)
contract.root = ''
break
if exit: break
block.update_contract(address,contract)
def eval_contract(block, transaction_list, tx):
sys.stderr.write("evaluating contract\n")
address = tx.to
# Initialize registers
reg = [0] * 256
reg[0] = decode(tx.sender, 256)
reg[1] = decode(tx.to, 256)
reg[2] = tx.value
reg[3] = tx.fee
index = 0
stepcounter = 0
contract = block.get_contract(address)
if not contract:
return
while 1:
# Convert the data item into a code piece
val_at_index = decode(contract.get(encode(index, 256, 32)), 256)
code = [int(val_at_index / (256**i)) % 256 for i in range(6)]
code[0] = scriptcode_map.get(code[0], 'INVALID')
sys.stderr.write("Evaluating: " + str(code) + "\n")
# Invalid code instruction or STOP code stops execution sans fee
if val_at_index >= 256**6 or code[0] in ['STOP', 'INVALID']:
sys.stderr.write("stop code, exiting\n")
break
# Calculate fee
minerfee = 0
nullfee = 0
stepcounter += 1
if stepcounter > 16:
minerfee += params["stepfee"]
c = scriptcode_map[code[0]]
if c in ['STORE', 'LOAD']:
minerfee += params["datafee"]
if c in ['EXTRO', 'BALANCE']:
minerfee += params["extrofee"]
if c in [
'SHA256', 'RIPEMD-160', 'ECMUL', 'ECADD', 'ECSIGN', 'ECRECOVER'
]:
minerfee += params["cryptofee"]
if c == 'STORE':
existing = block.get_contract_state(address, code[2])
if reg[code[1]] != 0: nullfee += params["memoryfee"]
if existing: nullfee -= params["memoryfee"]
# If we can't pay the fee, break, otherwise pay it
if block.get_balance(address) < minerfee + nullfee:
sys.stderr.write("insufficient fee, exiting\n")
break
block.set_balance(address,
block.get_balance(address) - nullfee - minerfee)
block.reward += minerfee
sys.stderr.write("evaluating operation\n")
# Evaluate operations
if c == 'ADD':
reg[code[3]] = (reg[code[1]] + reg[code[2]]) % 2**256
elif c == 'MUL':
reg[code[3]] = (reg[code[1]] * reg[code[2]]) % 2**256
elif c == 'SUB':
reg[code[3]] = (reg[code[1]] + 2**256 - reg[code[2]]) % 2**256
elif c == 'DIV':
reg[code[3]] = int(reg[code[1]] / reg[code[2]])
elif c == 'SDIV':
sign = 1
sign *= (1 if reg[code[1]] < 2**255 else -1)
sign *= (1 if reg[code[2]] < 2**255 else -1)
x = reg[
code[1]] if reg[code[1]] < 2**255 else 2**256 - reg[code[1]]
y = reg[
code[2]] if reg[code[2]] < 2**255 else 2**256 - reg[code[2]]
z = int(x / y)
reg[code[3]] = z if sign == 1 else 2**256 - z
elif code == 'MOD':
reg[code[3]] = reg[code[1]] % reg[code[2]]
elif code == 'SMOD':
sign = 1
sign *= (1 if reg[code[1]] < 2**255 else -1)
sign *= (1 if reg[code[2]] < 2**255 else -1)
x = reg[
code[1]] if reg[code[1]] < 2**255 else 2**256 - reg[code[1]]
y = reg[
code[2]] if reg[code[2]] < 2**255 else 2**256 - reg[code[2]]
z = x % y
reg[code[3]] = z if sign == 1 else 2**256 - z
elif code == 'EXP':
reg[code[3]] = pow(reg[code[1]], reg[code[2]], 2**256)
elif code == 'NEG':
reg[code[2]] = 2**256 - reg[code[1]]
elif code == 'LT':
reg[code[3]] = 1 if reg[code[1]] < reg[code[2]] else 0
elif code == 'LE':
reg[code[3]] = 1 if reg[code[1]] <= reg[code[2]] else 0
elif code == 'GT':
reg[code[3]] = 1 if reg[code[1]] > reg[code[2]] else 0
elif code == 'GE':
reg[code[3]] = 1 if reg[code[1]] >= reg[code[2]] else 0
elif code == 'EQ':
reg[code[3]] = 1 if reg[code[1]] == reg[code[2]] else 0
elif code == 'NOT':
reg[code[2]] = 1 if reg[code[1]] == 0 else 0
elif code == 'SHA256':
inp = encode(reg[code[1]], 256, 32)
reg[code[2]] = decode(hashlib.sha256(inp).digest(), 256)
elif code == 'RIPEMD-160':
inp = encode(reg[code[1]], 256, 32)
reg[code[2]] = decode(hashlib.new('ripemd160', inp).digest(), 256)
elif code == 'ECMUL':
pt = (reg[code[1]], reg[code[2]])
# Point at infinity
if pt[0] == 0 and pt[1] == 0:
reg[code[4]], reg[code[5]] = 0, 0
# Point not on curve, coerce to infinity
elif (pt[0]**3 + 7 - pt[1]**2) % N != 0:
reg[code[4]], reg[code[5]] = 0, 0
# Legitimate point
else:
pt2 = base10_multiply(pt, reg[code[3]])
reg[code[4]], reg[code[5]] = pt2[0], pt2[1]
elif code == 'ECADD':
pt1 = (reg[code[1]], reg[code[2]])
pt2 = (reg[code[3]], reg[code[4]])
# Invalid point 1
if (pt1[0]**3 + 7 - pt1[1]**2) % N != 0:
reg[code[5]], reg[code[6]] = 0, 0
# Invalid point 2
elif (pt2[0]**3 + 7 - pt2[1]**2) % N != 0:
reg[code[5]], reg[code[6]] = 0, 0
# Legitimate points
else:
pt3 = base10_add(pt1, pt2)
reg[code[5]], reg[code[6]] = pt3[0], pt3[1]
elif code == 'ECSIGN':
reg[code[3]], reg[code[4]], reg[code[5]] = ecdsa_raw_sign(
reg[code[1]], reg[code[2]])
elif code == 'ECRECOVER':
pt = ecdsa_raw_recover((reg[code[2]], reg[code[3]], reg[code[4]]),
reg[code[1]])
reg[code[5]] = pt[0]
reg[code[6]] = pt[1]
elif code == 'COPY':
reg[code[2]] = reg[code[1]]
elif code == 'STORE':
contract.update(encode(reg[code[2]], 256, 32), reg[code[1]])
elif code == 'LOAD':
reg[code[2]] = contract.get(encode(reg[code[1]], 256, 32))
elif code == 'SET':
reg[code[1]] = (code[2] + 256 * code[3] + 65536 * code[4] +
16777216 * code[5]) * 2**code[6] % 2**256
elif code == 'JMP':
index = reg[code[1]]
elif code == 'JMPI':
if reg[code[1]]: index = reg[code[2]]
elif code == 'IND':
reg[code[1]] = index
elif code == 'EXTRO':
if reg[code[1]] >= 2**160:
reg[code[3]] = 0
else:
address = encode(reg[code[1]], 256, 20)
field = encode(reg[code[2]])
reg[code[3]] = block.get_contract(address).get(field)
elif code == 'BALANCE':
if reg[code[1]] >= 2**160:
reg[code[2]] = 0
else:
address = encode(reg[code[1]], 256, 20)
reg[code[2]] = block.get_balance(address)
elif code == 'MKTX':
to = encode(reg[code[1]], 256, 32)
value = reg[code[2]]
fee = reg[code[3]]
if (value + fee) > block.get_balance(address):
pass
else:
datan = reg[code[4]]
data = []
for i in range(datan):
ind = encode((reg[code[5]] + i) % 2**256, 256, 32)
data.append(contract.get(ind))
tx = Transaction(0, to, value, fee, data)
tx.sender = address
transaction_list.insert(0, tx)
elif code == 'DATA':
reg[code[2]] = tx.data[reg[code[1]]]
elif code == 'DATAN':
reg[code[1]] = len(tx.data)
elif code == 'MYADDRESS':
reg[code[1]] = address
elif code == 'BLKHASH':
reg[code[1]] = decode(block.hash())
elif code == 'SUICIDE':
sz = contract.get_size()
negfee = -sz * params["memoryfee"]
toaddress = encode(reg[code[1]], 256, 20)
block.pay_fee(roaddress, negfee, False)
contract.root = ''
break
block.update_contract(address, contract)
