Range of valid character for a base 64 encoding - Stack Overflow
2012年11月2日 · RFC 4648 mentions other alphabets, such as the "URL and Filename safe" Base 64 Alphabet, where + and / are replaced with -and _. There's a table of Base64 variants which use different characters. Keep in mind that there are implementation specific rules about line separators, which you can find in the same table.
base64 - What is base 64 encoding used for? - Stack Overflow
2008年10月14日 · Each Base64 character encodes 6 bits (except the last non-pad character which can encode 2, 4 or 6 bits; and final pad characters, if any). Therefore, per Base64 encoding, a 128-bit hash requires at least ⌈128/6⌉ = 22 characters, plus pad if any. Using base64, we can produce the encoded output of our desired length (6, 8, or 10).
How can I base64 encode using a custom letter set?
2019年11月18日 · If the only characters you want to switch are + and \, you can use base64.urlsafe_b64encode() to replace with -and _ respectively. >>> base64.urlsafe_b64encode(data.encode()) b'c29tZSByYW5kb20_IGRhdGE=' Alternatively, you can replace those characters with characters of your own choice using the optional argument …
How can I decode a base64 string using a custom letter set?
2021年3月4日 · Now you have a base64 encoded string which can be decoded into something human readable. data = input() x ...
java - Error while decoding a byte array to base64 which contains ...
2018年10月3日 · This encoding should not be regarded as the same as the "base64" encoding and should not be referred to as only "base64". Unless clarified otherwise, "base64" refers to the base 64 in the previous section. This encoding is technically identical to the previous one, except for the 62:nd and 63:rd alphabet character, as indicated in Table 2.
java - Different Base64 decoders - Stack Overflow
2018年2月27日 · The encoder does not add any line feed (line separator) character. The decoder rejects data that contains characters outside the base64 alphabet. URL and Filename safe Uses the "URL and Filename safe Base64 Alphabet" as specified in Table 2 of RFC 4648 for encoding and decoding. The encoder does not add any line feed (line separator) character.
encoding - Is there an easy way to represent the base64 alphabet …
2013年2月5日 · Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question.Provide details and share your research!
java - Base64 Encoding safe for filenames? - Stack Overflow
However, if the filesystem is case-insensitive, as is the case on Windows, you can get collisions because the Base64 alphabet contains both upper and lower-case. You might want to consider using the hexadecimal representation of your MD5 hash instead, since this is a fairly standard way of representing those as a string.
decode base64 like string with different index table(s)
2017年4月26日 · Use maketrans to build a translation table and then translate from the first alphabet to the second. Then base64 decode. import string import base64 def decode(str): #make a translation table.
Why does base64 encoding require padding if the input length is …
All base64 characters can be represented in 6 bits, 2 bits short of a full byte. We can represent base64 encoding versus the byte paradigm as a fraction: 6 bits per character over 8 bits per byte. Reduced this fraction is 3 bytes over 4 characters. This ratio, 3 bytes for every 4 base64 characters, is the rule we want to follow when encoding ...
跳至内容