openpgp: Move conversion functions.

1 files changed, 34 insertions, 0 deletions

diff --git a/openpgp/src/conversions.rs b/openpgp/src/conversions.rs
index b7dbd891..77236fbd 100644
--- a/openpgp/src/conversions.rs
+++ b/openpgp/src/conversions.rs
@@ -140,8 +140,34 @@ pub(crate) fn from_hex(hex: &str, pretty: bool) -> Result<Vec<u8>> {
     Ok(bytes)
 }
 
+pub(crate) 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(crate) 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::*;
+
     #[test]
     fn from_hex() {
         use super::from_hex as fh;
@@ -201,4 +227,12 @@ mod test {
             data == super::from_hex(&hex, true).unwrap()
         }
     }
+
+    quickcheck! {
+        fn be_u64_roundtrip(n: u64) -> bool {
+            let mut b = [0; 8];
+            write_be_u64(&mut b, n);
+            n == read_be_u64(&b)
+        }
+    }
 }