BASE64
- 编码对象: ascill字符
- 原理:
- 将每个字符的8位ascill码组合在一起，保证组合后的长度是24的倍数，不足的在后面添0
- 将组合好的字符串以6位一组拆分
将六位二进制转为十进制，并查字符表
| 数值 | 字符 | 数值 | 字符 | 数值 | 字符 | 数值 | 字符 |
| 0 | A | 16 | Q | 32 | g | 48 | w |
| 1 | B | 17 | R | 33 | h | 49 | x |
| 2 | C | 18 | S | 34 | i | 50 | y |
| 3 | D | 19 | T | 35 | j | 51 | z |
| 4 | E | 20 | U | 36 | k | 52 | 0 |
| 5 | F | 21 | V | 37 | l | 53 | 1 |
| 6 | G | 22 | W | 38 | m | 54 | 2 |
| 7 | H | 23 | X | 39 | n | 55 | 3 |
| 8 | I | 24 | Y | 40 | o | 56 | 4 |
| 9 | J | 25 | Z | 41 | p | 57 | 5 |
| 10 | K | 26 | a | 42 | q | 58 | 6 |
| 11 | L | 27 | b | 43 | r | 59 | 7 |
| 12 | M | 28 | c | 44 | s | 60 | 8 |
| 13 | N | 29 | d | 45 | t | 61 | 9 |
| 14 | O | 30 | e | 46 | u | 62 | + |
| 15 | P | 31 | f | 47 | v | 63 | / |
- 注意，最后面的数为0的不需要查表，替换为"="
- 举例
- 编码: ab
转为ascill码: 01100001 01100010
长度为12，不是24的倍数，补0 : 01100001 01100010 00000000
分组: 011000 010110 001000 000000
转为10进制: 24 22 8 0
最后有一个0，替换为"+", 其余查表: Y W I =
所以ab编码后的密文为: YWI=
代码
# write in 2021/6/21 import re DIC = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" def is_ascii(char): if ord(char) >= 0 and ord(char) <= 127: return True return False def encrypt_base64(string): bin_string = "" ciphertext = "" num = 0 length = len(string) for char in string: # 异常检测 if not is_ascii(char): return -1 bin_string += ("00000000" + str(bin(ord(char)))[2::])[-8::] #print(length) if length % 3 == 1: bin_string += "0"*4 num = 2 elif length % 3 == 2: bin_string += "0"*8 num = 1 bin_list = re.findall(".{6}",bin_string) for i in bin_list: ciphertext += DIC[int(i,2)] return ciphertext + "="*num def decrypt_base64(ciphertext): plaintext = "" bin_string = "" print(ciphertext) num = ciphertext.count("=") #print(num) if num: ciphertext = ciphertext[0:-num:] #print(ciphertext) for i in ciphertext: # 异常检测 if i not in DIC: return -1 bin_string += ("0"*6 + str(bin(DIC.index(i)))[2::])[-6::] bin_list = re.findall(".{8}", bin_string) print(bin_list) for i in bin_list: plaintext += chr(int(i, 2)) return plaintext # 01000000 if __name__ == '__main__': print("Aabc ",encrypt_base64("Aabc")) print("Aabc ",decrypt_base64(encrypt_base64("Aabc")))
BASE32
- 编码对象: ascill字符
- 原理：
- 将每个字符转为8位ascill码，组合在一起，需要保证长度是40的倍数， 不足的在后面补0
- 将组合后的串以每五位分割开来
- 将五位的二进制转为十进制，在查表:
| 数值 | 字符 | 数值 | 字符 | 数值 | 字符 | 数值 | 字符 |
| 0 | A | 8 | I | 16 | Q | 24 | Y |
| 1 | B | 9 | j | 17 | R | 25 | Z |
| 2 | C | 10 | K | 18 | S | 26 | 2 |
| 3 | D | 11 | L | 19 | T | 27 | 3 |
| 4 | E | 12 | M | 20 | U | 28 | 4 |
| 5 | F | 13 | N | 21 | V | 29 | 5 |
| 6 | G | 14 | O | 22 | W | 30 | 6 |
| 7 | H | 15 | P | 23 | X | 31 | 7 |
- 注意：最后的0不需要查表, 替换为"="
- 代码
# write in 2021/6/22 import re DIC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567" def is_ascii(char): if ord(char) >= 0 and ord(char) <= 127: return True return False def encrypt_base32(string): bin_string = "" ciphertext = "" num = 0 length = len(string) for char in string: # 异常检测 if not is_ascii(char): return -1 bin_string += ("00000000" + str(bin(ord(char)))[2::])[-8::] #print(length) if length % 5 == 1: bin_string += "0"*2 num = 6 elif length % 5 == 2: bin_string += "0"*4 num = 4 elif length % 5 == 3: bin_string += "0" num = 3 elif length % 5 == 4: bin_string += "0"*3 num = 1 bin_list = re.findall(".{5}",bin_string) print(bin_list) for i in bin_list: ciphertext += DIC[int(i,2)] return ciphertext + "="*num def decrypt_base32(ciphertext): plaintext = "" bin_string = "" #print(ciphertext) num = ciphertext.count("=") print(num) if num: ciphertext = ciphertext[0:-num:] #print(ciphertext) for i in ciphertext: # 异常检测 if i not in DIC: return -1 bin_string += ("0"*5 + str(bin(DIC.index(i)))[2::])[-5::] bin_list = re.findall(".{8}",bin_string) for i in bin_list: plaintext += chr(int(i,2)) return plaintext if __name__ == '__main__': print("Aabc ",encrypt_base32("Aabc")) print("Aabc ",decrypt_base32(encrypt_base32("Aabc")))
BASE16
- 编码对象: ascill字符
- 原理:
- 将字符转为8位ascill码，并组合在一起
- 将字符以每4位一组分割
- 将4位二进制转为十进制
- 查表:
| 数值 | 字符 | 数值 | 字符 | 数值 | 字符 | 数值 | 字符 |
| 0 | 0 | 4 | 4 | 8 | 8 | 12 | c |
| 1 | 1 | 5 | 5 | 9 | 9 | 13 | d |
| 2 | 2 | 6 | 6 | 10 | a | 14 | e |
| 3 | 3 | 7 | 7 | 11 | b | 15 | f |
- 代码
# write in 2021/6/22 import re DIC = "0123456789ABCDEF" def is_ascii(char): if ord(char) >= 0 and ord(char) <= 127: return True return False def encrypt_base16(string): bin_string = "" ciphertext = "" length = len(string) for char in string: # 异常检测 if not is_ascii(char): return -1 bin_string += ("00000000" + str(bin(ord(char)))[2::])[-8::] #print(length) bin_list = re.findall(".{4}",bin_string) print(bin_list) for i in bin_list: ciphertext += DIC[int(i,2)] return ciphertext def decrypt_base16(ciphertext): plaintext = "" bin_string = "" #print(ciphertext) for i in ciphertext: # 异常检测 if i not in DIC: return -1 bin_string += ("0"*4 + str(bin(DIC.index(i)))[2::])[-4::] bin_list = re.findall(".{8}",bin_string) for i in bin_list: plaintext += chr(int(i,2)) return plaintext if __name__ == '__main__': print("Aabc ",decrypt_base16("Aabc")) print("Aabc ",decrypt_base16(encrypt_base16("Aabc")))
