import sys delta_asso = [0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,0x00, 0x00, 0x00, 0x0F, 0x00, 0x0F] check_asso = [0x0D, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x03, 0x07, 0x0B, 0x0B, 0x0B, 0x0F] delta_values =[(0x00), (0x00), (0x00), (0x13), (0x04), (0xBF), (0xBF), (0xB9), (0xB9), (0x00), (0x10), (0xC3), (0xBF), (0xBF), (0xB9), (0xB9)] check_values = [(0x80), (0x80), (0x80), (0x80), (0xCF), (0xBF), (0xD5), (0xA6), (0xB5), (0x86), (0xD1), (0x80), (0xB1), (0x80), (0x91), (0x80)] valid = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" def safechr(i): if i < 32: return '.' if i > 127: return '?' return chr(i) def safehex(x): return "0x{0:2x}".format(x) def to_signed(x): if(x >= 128): return x - 256 return x def to_unsigned(x): if(x < 0): return x + 256 return x def sat(x, y): x = to_signed(x) y = to_signed(y) z = x + y if(z > 127): return 127 if(z < -128): return to_unsigned(-128) return to_unsigned(z) def lookup(table, index): print("looking up ", hex(index)) if(index >= 128): return 0 return table[index&0xf] def quietlookup(table, index): if(index >= 128): return 0 return table[index&0xf] def process(src): shifted = (src >> 3)%256 delta_hash = (lookup(delta_asso,src) + shifted + 1) >> 1 check_hash = (lookup(check_asso,src) + shifted + 1) >> 1 out = sat(lookup(delta_values,delta_hash), src) chk = sat(lookup(check_values,check_hash), src) mask = chk & 0x80 return (out, mask) def processquiet(src): shifted = (src >> 3)%256 delta_hash = (quietlookup(delta_asso,src) + shifted + 1) >> 1 check_hash = (quietlookup(check_asso,src) + shifted + 1) >> 1 out = sat(quietlookup(delta_values,delta_hash), src) chk = sat(quietlookup(check_values,check_hash), src) mask = chk & 0x80 return (out, mask) def is_ok(i): out, mask = processquiet(i) if mask == 0: return 1 return 0 def computestring(): s = "" for i in range(256): out, mask = processquiet(i) if(mask == 0): s += safechr(i) return s print(computestring() + " " + str(len(computestring()))) def print_layout(): t={} for i in range(256): src = i shifted = (src >> 3)%256 check_hash = (quietlookup(check_asso,src) + shifted + 1) >> 1 if check_hash not in t: t[check_hash] = [] t[check_hash].append(i) for check_hash in range(16): if check_hash in t: off = quietlookup(check_values,check_hash) print(hex(check_hash), hex(off), end="") print("\t", " ".join([" "+safechr(c) for c in t[check_hash]])) else: continue def is_valid(): t={} for i in range(256): src = i shifted = (src >> 3)%256 check_hash = (quietlookup(check_asso,src) + shifted + 1) >> 1 if check_hash not in t: t[check_hash] = [] t[check_hash].append(i) for check_hash in t.keys(): if check_hash in t: array = t[check_hash] i = 0 while i < len(array) and valid.find(chr(array[i])) == -1: i += 1 while i < len(array) and valid.find(chr(array[i])) != -1: i += 1 while i < len(array) and array[i] >= 128: i += 1 if i < len(array): return False else: continue return True print_layout() print(is_valid()) valid = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_" print("----") def fun_adjust(): for zz in range(256): check_asso[ord('-')&0xf] = zz for yy in range(256): check_asso[ord('_')&0xf] = yy if(is_valid()): print("----") print_layout() print(is_valid()) print("found") return fun_adjust() #sys.exit(0) def adjust(array, start, end, check_hash): for j in range(256): is_ok = True for i in range(len(array)): valid = (sat(j,array[i])&0x80 == 0) # sat(quietlookup(check_values,check_hash), src) should_be_valid = (i>=start and i < end) is_ok = is_ok and (valid == should_be_valid) if(is_ok): check_values[check_hash&0xf] = j return raise "unexpected" chk = sat(quietlookup(check_values,check_hash), src) mask = chk & 0x80 def process_explicit(): t={} for i in range(256): src = i shifted = (src >> 3)%256 check_hash = (quietlookup(check_asso,src) + shifted + 1) >> 1 if check_hash not in t: t[check_hash] = [] t[check_hash].append(i) for check_hash in t.keys(): if check_hash in t: array = t[check_hash] i = 0 while i < len(array) and valid.find(chr(array[i])) == -1: i += 1 if i < len(array) and valid.find(chr(array[i])) != -1: start = i while i < len(array) and valid.find(chr(array[i])) != -1: i += 1 end = i adjust(array, start, end, check_hash) else: continue return True print("process") process_explicit() print("string") print(computestring()+ " "+str(len(computestring()))) for c in valid: print(c,processquiet(ord(c))) def examine(): t={} for i in valid: src = ord(i) shifted = (src >> 3)%256 check_hash = (quietlookup(delta_asso,src) + shifted + 1) >> 1 if check_hash not in t: t[check_hash] = [] t[check_hash].append(i) for check_hash in t.keys(): print(check_hash, t[check_hash]) return True examine() delta_values[10] += 1 delta_values[13] += 33 for c in valid: print(c,processquiet(ord(c))) def casthex(v): if(v >= 0x80): return "uint8_t("+"0x{:X}".format(v)+")" return "0x{:X}".format(v) def printme(c): print(",".join([casthex(i) for i in c])) print("delta_asso") printme(delta_asso) print("check_asso") printme(check_asso) print("delta_values") printme(delta_values) print("check_values") printme(check_values) def processverbose(src): print("processing ", hex(src)) shifted = (src >> 3)%256 print("shifted ", hex(shifted)) delta_hash = (lookup(delta_asso,src) + shifted + 1) >> 1 print("delta_hash ", hex(delta_hash)) check_hash = (lookup(check_asso,src) + shifted + 1) >> 1 print("check_hash ", hex(check_hash)) out = sat(lookup(delta_values,delta_hash), src) print("out ", hex(out)) chk = sat(lookup(check_values,check_hash), src) print("chk ", hex(chk)) mask = chk & 0x80 return (out, mask) processverbose(ord('-')) print(computestring()+ " "+str(len(computestring())))