From be72e0e4dc08ede35c6e561901ecb780c4f57360 Mon Sep 17 00:00:00 2001 From: Justus Winter Date: Tue, 3 Dec 2019 14:24:25 +0100 Subject: openpgp: Move byte order conversion functions. --- openpgp/src/utils.rs | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 openpgp/src/utils.rs (limited to 'openpgp/src/utils.rs') diff --git a/openpgp/src/utils.rs b/openpgp/src/utils.rs new file mode 100644 index 00000000..5abc968b --- /dev/null +++ b/openpgp/src/utils.rs @@ -0,0 +1,38 @@ +//! Utility functions that don't fit anywhere else. + +pub fn read_be_u64(b: &[u8]) -> u64 { + assert_eq!(b.len(), 8); + ((b[0] as u64) << 56) as u64 + | ((b[1] as u64) << 48) + | ((b[2] as u64) << 40) + | ((b[3] as u64) << 32) + | ((b[4] as u64) << 24) + | ((b[5] as u64) << 16) + | ((b[6] as u64) << 8) + | ((b[7] as u64) << 0) +} + +pub fn write_be_u64(b: &mut [u8], n: u64) { + assert_eq!(b.len(), 8); + b[0] = (n >> 56) as u8; + b[1] = (n >> 48) as u8; + b[2] = (n >> 40) as u8; + b[3] = (n >> 32) as u8; + b[4] = (n >> 24) as u8; + b[5] = (n >> 16) as u8; + b[6] = (n >> 8) as u8; + b[7] = (n >> 0) as u8; +} + +#[cfg(test)] +mod test { + use super::*; + + quickcheck! { + fn be_u64_roundtrip(n: u64) -> bool { + let mut b = [0; 8]; + write_be_u64(&mut b, n); + n == read_be_u64(&b) + } + } +} -- cgit v1.2.3