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Remove direct dependency on byteorder crate

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link2xt
2022-01-29 23:23:46 +00:00
parent e73107006e
commit 0cb9e7922a
4 changed files with 17 additions and 56 deletions
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70
src/dc_tools.rs
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@@ -195,44 +195,26 @@ async fn maybe_warn_on_outdated(context: &Context, now: i64, approx_compile_time
}
/* Message-ID tools */
/// Generate an ID. The generated ID should be as short and as unique as possible:
/// - short, because it may also used as part of Message-ID headers or in QR codes
/// - unique as two IDs generated on two devices should not be the same. However, collisions are not world-wide but only by the few contacts.
/// IDs generated by this function are 66 bit wide and are returned as 11 base64 characters.
///
/// Additional information when used as a message-id or group-id:
/// - for OUTGOING messages this ID is written to the header as `Chat-Group-ID:` and is added to the message ID as Gr.<grpid>.<random>@<random>
/// - for INCOMING messages, the ID is taken from the Chat-Group-ID-header or from the Message-ID in the In-Reply-To: or References:-Header
/// - the group-id should be a string with the characters [a-zA-Z0-9\-_]
pub(crate) fn dc_create_id() -> String {
/* generate an id. the generated ID should be as short and as unique as possible:
- short, because it may also used as part of Message-ID headers or in QR codes
- unique as two IDs generated on two devices should not be the same. However, collisions are not world-wide but only by the few contacts.
IDs generated by this function are 66 bit wide and are returned as 11 base64 characters.
If possible, RNG of OpenSSL is used.
Additional information when used as a message-id or group-id:
- for OUTGOING messages this ID is written to the header as `Chat-Group-ID:` and is added to the message ID as Gr.<grpid>.<random>@<random>
- for INCOMING messages, the ID is taken from the Chat-Group-ID-header or from the Message-ID in the In-Reply-To: or References:-Header
- the group-id should be a string with the characters [a-zA-Z0-9\-_] */
// ThreadRng implements CryptoRng trait and is supposed to be cryptographically secure.
let mut rng = thread_rng();
let buf: [u32; 3] = [rng.gen(), rng.gen(), rng.gen()];
encode_66bits_as_base64(buf[0usize], buf[1usize], buf[2usize])
}
// Generate 72 random bits.
let mut arr = [0u8; 9];
rng.fill(&mut arr[..]);
/// Encode 66 bits as a base64 string.
/// This is useful for ID generating with short strings as we save 5 character
/// in each id compared to 64 bit hex encoding. For a typical group ID, these
/// are 10 characters (grpid+msgid):
/// hex: 64 bit, 4 bits/character, length = 64/4 = 16 characters
/// base64: 64 bit, 6 bits/character, length = 64/6 = 11 characters (plus 2 additional bits)
/// Only the lower 2 bits of `fill` are used.
fn encode_66bits_as_base64(v1: u32, v2: u32, fill: u32) -> String {
use byteorder::{BigEndian, WriteBytesExt};
let mut wrapped_writer = Vec::new();
{
let mut enc = base64::write::EncoderWriter::new(&mut wrapped_writer, base64::URL_SAFE);
enc.write_u32::<BigEndian>(v1).unwrap();
enc.write_u32::<BigEndian>(v2).unwrap();
enc.write_u8(((fill & 0x3) as u8) << 6).unwrap();
enc.finish().unwrap();
}
assert_eq!(wrapped_writer.pop(), Some(b'A')); // Remove last "A"
String::from_utf8(wrapped_writer).unwrap()
// Take 11 base64 characters containing 66 random bits.
base64::encode(&arr).chars().take(11).collect()
}
/// Function generates a Message-ID that can be used for a new outgoing message.
@@ -780,26 +762,6 @@ Hop: From: hq5.example.org; By: hq5.example.org; Date: Mon, 27 Dec 2021 11:21:22
assert_eq!(buf.len(), 11);
}
#[test]
fn test_encode_66bits_as_base64() {
assert_eq!(
encode_66bits_as_base64(0x01234567, 0x89abcdef, 0),
"ASNFZ4mrze8"
);
assert_eq!(
encode_66bits_as_base64(0x01234567, 0x89abcdef, 1),
"ASNFZ4mrze9"
);
assert_eq!(
encode_66bits_as_base64(0x01234567, 0x89abcdef, 2),
"ASNFZ4mrze-"
);
assert_eq!(
encode_66bits_as_base64(0x01234567, 0x89abcdef, 3),
"ASNFZ4mrze_"
);
}
#[test]
fn test_dc_extract_grpid_from_rfc724_mid() {
// Should return None if we pass invalid mid