import hashlib, re P = 2**256-2**32-2**9-2**8-2**7-2**6-2**4-1 A = 0 Gx = 55066263022277343669578718895168534326250603453777594175500187360389116729240 Gy = 32670510020758816978083085130507043184471273380659243275938904335757337482424 G = (Gx,Gy) def inv(a,n): lm, hm = 1,0 low, high = a%n,n while low > 1: r = high/low nm, new = hm-lm*r, high-low*r lm, low, hm, high = nm, new, lm, low return lm % n def get_code_string(base): if base == 2: return '01' elif base == 10: return '0123456789' elif base == 16: return "0123456789abcdef" elif base == 58: return "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz" elif base == 256: return ''.join([chr(x) for x in range(256)]) else: raise ValueError("Invalid base!") def encode(val,base,minlen=0): code_string = get_code_string(base) result = "" while val > 0: result = code_string[val % base] + result val /= base if len(result) < minlen: result = code_string[0]*(minlen-len(result))+result return result def decode(string,base): code_string = get_code_string(base) result = 0 if base == 16: string = string.lower() while len(string) > 0: result *= base result += code_string.find(string[0]) string = string[1:] return result def changebase(string,frm,to,minlen=0): return encode(decode(string,frm),to,minlen) def base10_add(a,b): if a == None: return b[0],b[1] if b == None: return a[0],a[1] if a[0] == b[0]: if a[1] == b[1]: return base10_double(a[0],a[1]) else: return None m = ((b[1]-a[1]) * inv(b[0]-a[0],P)) % P x = (m*m-a[0]-b[0]) % P y = (m*(a[0]-x)-a[1]) % P return (x,y) def base10_double(a): if a == None: return None m = ((3*a[0]*a[0]+A)*inv(2*a[1],P)) % P x = (m*m-2*a[0]) % P y = (m*(a[0]-x)-a[1]) % P return (x,y) def base10_multiply(a,n): if n == 0: return G if n == 1: return a if (n%2) == 0: return base10_double(base10_multiply(a,n/2)) if (n%2) == 1: return base10_add(base10_double(base10_multiply(a,n/2)),a) def hex_to_point(h): return (decode(h[2:66],16),decode(h[66:],16)) def point_to_hex(p): return '04'+encode(p[0],16,64)+encode(p[1],16,64) def multiply(privkey,pubkey): return point_to_hex(base10_multiply(hex_to_point(pubkey),decode(privkey,16))) def privtopub(privkey): return point_to_hex(base10_multiply(G,decode(privkey,16))) def add(p1,p2): if (len(p1)==32): return encode(decode(p1,16) + decode(p2,16) % P,16,32) else: return point_to_hex(base10_add(hex_to_point(p1),hex_to_point(p2))) def hash_160(string): intermed = hashlib.sha256(string).digest() ripemd160 = hashlib.new('ripemd160') ripemd160.update(intermed) return ripemd160.digest() def dbl_sha256(string): return hashlib.sha256(hashlib.sha256(string).digest()).digest() def bin_to_b58check(inp): inp_fmtd = '\x00' + inp leadingzbytes = len(re.match('^\x00*',inp_fmtd).group(0)) checksum = dbl_sha256(inp_fmtd)[:4] return '1' * leadingzbytes + changebase(inp_fmtd+checksum,256,58) #Convert a public key (in hex) to a Bitcoin address def pubkey_to_address(pubkey): return bin_to_b58check(hash_160(changebase(pubkey,16,256)))