diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/device/mod.rs | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/src/device/mod.rs b/src/device/mod.rs index 16d6b11..0234bf0 100644 --- a/src/device/mod.rs +++ b/src/device/mod.rs @@ -5,7 +5,6 @@ mod pro; mod storage; mod wrapper; -use std::cmp; use std::convert::{TryFrom, TryInto}; use std::ffi; use std::fmt; @@ -120,21 +119,38 @@ impl fmt::Display for DeviceInfo { /// Parses a serial number returned by hidapi and transforms it to the Nitrokey format. /// -/// If the serial number is all zero, this function returns `None`. Otherwise, all leading zeros -/// (except the last eight characters) are stripped and `Some(_)` is returned. If the serial -/// number has less than eight characters, leading zeros are added. +/// If the serial number is all zero, this function returns `None`. Otherwise, it uses the last +/// eight characters. If these are all zero, the first eight characters are used instead. This +/// function also makes sure that the returned string is lowercase, consistent with libnitrokey’s +/// hex string formatting. +/// +/// The reason for this behavior is that the Nitrokey Storage does not report its serial number at +/// all (all zero value), while the Nitrokey Pro with firmware 0.9 or later writes its serial +/// number to the last eight characters. Nitrokey Pro devices with firmware 0.8 or earlier wrote +/// their serial number to the first eight characters. fn get_hidapi_serial_number(serial_number: &str) -> Option<String> { - let mut iter = serial_number.char_indices().skip_while(|(_, c)| *c == '0'); - let first_non_null = iter.next(); + let len = serial_number.len(); + if len < 8 { + // The serial number in the USB descriptor has 12 bytes, we need at least four of them + return None; + } + + let iter = serial_number.char_indices().rev(); + let first_non_null = iter.skip_while(|(_, c)| *c == '0').next(); if let Some((i, _)) = first_non_null { - // keep at least the last 8 characters - let len = serial_number.len(); - let cut = cmp::min(len.saturating_sub(8), i); - let (_, suffix) = serial_number.split_at(cut); - // if necessary, add leading zeros to reach 8 characters - let fill = 8usize.saturating_sub(len); - Some("0".repeat(fill) + suffix) + if len - i < 8 { + // The last eight characters contain at least one non-zero character --> use them + let mut serial_number = serial_number.split_at(len - 8).1.to_string(); + serial_number.make_ascii_lowercase(); + Some(serial_number) + } else { + // The last eight characters are all zero --> use the first eight + let mut serial_number = serial_number.split_at(8).0.to_string(); + serial_number.make_ascii_lowercase(); + Some(serial_number) + } } else { + // The serial number is all zero None } } @@ -615,10 +631,7 @@ mod tests { fn hidapi_serial_number() { assert_eq!(None, get_hidapi_serial_number("")); assert_eq!(None, get_hidapi_serial_number("00000000000000000")); - assert_eq!( - Some("00001234".to_string()), - get_hidapi_serial_number("1234") - ); + assert_eq!(None, get_hidapi_serial_number("1234")); assert_eq!( Some("00001234".to_string()), get_hidapi_serial_number("00001234") @@ -628,12 +641,28 @@ mod tests { get_hidapi_serial_number("000000001234") ); assert_eq!( - Some("100000001234".to_string()), + Some("00001234".to_string()), get_hidapi_serial_number("100000001234") ); assert_eq!( - Some("10000001234".to_string()), - get_hidapi_serial_number("010000001234") + Some("12340000".to_string()), + get_hidapi_serial_number("123400000000") + ); + assert_eq!( + Some("00005678".to_string()), + get_hidapi_serial_number("000000000000000000005678") + ); + assert_eq!( + Some("00001234".to_string()), + get_hidapi_serial_number("000012340000000000000000") + ); + assert_eq!( + Some("0000ffff".to_string()), + get_hidapi_serial_number("00000000000000000000FFFF") + ); + assert_eq!( + Some("0000ffff".to_string()), + get_hidapi_serial_number("00000000000000000000ffff") ); } } |