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Diffstat (limited to 'vendor/der/src/asn1/integer.rs')
| -rw-r--r-- | vendor/der/src/asn1/integer.rs | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/vendor/der/src/asn1/integer.rs b/vendor/der/src/asn1/integer.rs new file mode 100644 index 0000000..a6e913d --- /dev/null +++ b/vendor/der/src/asn1/integer.rs @@ -0,0 +1,161 @@ +//! ASN.1 `INTEGER` support. + +pub(super) mod int; +pub(super) mod uint; + +use core::{cmp::Ordering, mem}; + +use crate::{EncodeValue, Result, SliceWriter}; + +/// Is the highest bit of the first byte in the slice set to `1`? (if present) +#[inline] +fn is_highest_bit_set(bytes: &[u8]) -> bool { + bytes + .first() + .map(|byte| byte & 0b10000000 != 0) + .unwrap_or(false) +} + +/// Compare two integer values +fn value_cmp<T>(a: T, b: T) -> Result<Ordering> +where + T: Copy + EncodeValue + Sized, +{ + const MAX_INT_SIZE: usize = 16; + debug_assert!(mem::size_of::<T>() <= MAX_INT_SIZE); + + let mut buf1 = [0u8; MAX_INT_SIZE]; + let mut encoder1 = SliceWriter::new(&mut buf1); + a.encode_value(&mut encoder1)?; + + let mut buf2 = [0u8; MAX_INT_SIZE]; + let mut encoder2 = SliceWriter::new(&mut buf2); + b.encode_value(&mut encoder2)?; + + Ok(encoder1.finish()?.cmp(encoder2.finish()?)) +} + +#[cfg(test)] +pub(crate) mod tests { + use crate::{Decode, Encode}; + + // Vectors from Section 5.7 of: + // https://luca.ntop.org/Teaching/Appunti/asn1.html + pub(crate) const I0_BYTES: &[u8] = &[0x02, 0x01, 0x00]; + pub(crate) const I127_BYTES: &[u8] = &[0x02, 0x01, 0x7F]; + pub(crate) const I128_BYTES: &[u8] = &[0x02, 0x02, 0x00, 0x80]; + pub(crate) const I256_BYTES: &[u8] = &[0x02, 0x02, 0x01, 0x00]; + pub(crate) const INEG128_BYTES: &[u8] = &[0x02, 0x01, 0x80]; + pub(crate) const INEG129_BYTES: &[u8] = &[0x02, 0x02, 0xFF, 0x7F]; + + // Additional vectors + pub(crate) const I255_BYTES: &[u8] = &[0x02, 0x02, 0x00, 0xFF]; + pub(crate) const I32767_BYTES: &[u8] = &[0x02, 0x02, 0x7F, 0xFF]; + pub(crate) const I65535_BYTES: &[u8] = &[0x02, 0x03, 0x00, 0xFF, 0xFF]; + pub(crate) const INEG32768_BYTES: &[u8] = &[0x02, 0x02, 0x80, 0x00]; + + #[test] + fn decode_i8() { + assert_eq!(0, i8::from_der(I0_BYTES).unwrap()); + assert_eq!(127, i8::from_der(I127_BYTES).unwrap()); + assert_eq!(-128, i8::from_der(INEG128_BYTES).unwrap()); + } + + #[test] + fn decode_i16() { + assert_eq!(0, i16::from_der(I0_BYTES).unwrap()); + assert_eq!(127, i16::from_der(I127_BYTES).unwrap()); + assert_eq!(128, i16::from_der(I128_BYTES).unwrap()); + assert_eq!(255, i16::from_der(I255_BYTES).unwrap()); + assert_eq!(256, i16::from_der(I256_BYTES).unwrap()); + assert_eq!(32767, i16::from_der(I32767_BYTES).unwrap()); + assert_eq!(-128, i16::from_der(INEG128_BYTES).unwrap()); + assert_eq!(-129, i16::from_der(INEG129_BYTES).unwrap()); + assert_eq!(-32768, i16::from_der(INEG32768_BYTES).unwrap()); + } + + #[test] + fn decode_u8() { + assert_eq!(0, u8::from_der(I0_BYTES).unwrap()); + assert_eq!(127, u8::from_der(I127_BYTES).unwrap()); + assert_eq!(255, u8::from_der(I255_BYTES).unwrap()); + } + + #[test] + fn decode_u16() { + assert_eq!(0, u16::from_der(I0_BYTES).unwrap()); + assert_eq!(127, u16::from_der(I127_BYTES).unwrap()); + assert_eq!(255, u16::from_der(I255_BYTES).unwrap()); + assert_eq!(256, u16::from_der(I256_BYTES).unwrap()); + assert_eq!(32767, u16::from_der(I32767_BYTES).unwrap()); + assert_eq!(65535, u16::from_der(I65535_BYTES).unwrap()); + } + + #[test] + fn encode_i8() { + let mut buffer = [0u8; 3]; + + assert_eq!(I0_BYTES, 0i8.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I127_BYTES, 127i8.encode_to_slice(&mut buffer).unwrap()); + + assert_eq!( + INEG128_BYTES, + (-128i8).encode_to_slice(&mut buffer).unwrap() + ); + } + + #[test] + fn encode_i16() { + let mut buffer = [0u8; 4]; + assert_eq!(I0_BYTES, 0i16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I127_BYTES, 127i16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I128_BYTES, 128i16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I255_BYTES, 255i16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I256_BYTES, 256i16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I32767_BYTES, 32767i16.encode_to_slice(&mut buffer).unwrap()); + + assert_eq!( + INEG128_BYTES, + (-128i16).encode_to_slice(&mut buffer).unwrap() + ); + + assert_eq!( + INEG129_BYTES, + (-129i16).encode_to_slice(&mut buffer).unwrap() + ); + + assert_eq!( + INEG32768_BYTES, + (-32768i16).encode_to_slice(&mut buffer).unwrap() + ); + } + + #[test] + fn encode_u8() { + let mut buffer = [0u8; 4]; + assert_eq!(I0_BYTES, 0u8.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I127_BYTES, 127u8.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I255_BYTES, 255u8.encode_to_slice(&mut buffer).unwrap()); + } + + #[test] + fn encode_u16() { + let mut buffer = [0u8; 5]; + assert_eq!(I0_BYTES, 0u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I127_BYTES, 127u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I128_BYTES, 128u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I255_BYTES, 255u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I256_BYTES, 256u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I32767_BYTES, 32767u16.encode_to_slice(&mut buffer).unwrap()); + assert_eq!(I65535_BYTES, 65535u16.encode_to_slice(&mut buffer).unwrap()); + } + + /// Integers must be encoded with a minimum number of octets + #[test] + fn reject_non_canonical() { + assert!(i8::from_der(&[0x02, 0x02, 0x00, 0x00]).is_err()); + assert!(i16::from_der(&[0x02, 0x02, 0x00, 0x00]).is_err()); + assert!(u8::from_der(&[0x02, 0x02, 0x00, 0x00]).is_err()); + assert!(u16::from_der(&[0x02, 0x02, 0x00, 0x00]).is_err()); + } +} |