yggdrasil/ring
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Clarify signature_impl::MAX_LEN.

Browse Source 
Currently, the only ECC signature algorithm for which we support
generating signatures is Ed25519, but when we add ECDSA support this
adjustment will be required.
This commit is contained in:
Brian Smith 2017-05-13 00:28:26 -10:00
parent 82f3588cac
commit 21f9750087
2 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/ec/ec.rs
View File

@ -81,7 +81,7 @@ impl<'a> PrivateKey {
const ELEM_MAX_BITS: usize = 384;
pub const ELEM_MAX_BYTES: usize = (ELEM_MAX_BITS + 7) / 8;
const SCALAR_MAX_BYTES: usize = ELEM_MAX_BYTES;
pub const SCALAR_MAX_BYTES: usize = ELEM_MAX_BYTES;
/// The maximum length, in bytes, of an encoded public key.
pub const PUBLIC_KEY_MAX_LEN: usize = 1 + (2 * ELEM_MAX_BYTES);

10
src/signature_impl.rs
View File

@ -36,7 +36,9 @@ pub fn signature_from_bytes(bytes: &[u8]) -> Signature {
r
}
/// The maximum length of a signature that can be stored in a `Signature`.
///
/// In particular, this isn't used for RSA signatures.
const MAX_LEN: usize = 1 + (2 * ec::ELEM_MAX_BYTES);
/// The longest signature is an ASN.1 P-384 signature where *r* and *s* are of
/// maximum length with the leading high bit set on each. Then each component
/// will have a tag, a one-byte length, and a one-byte “I'm not negative”
/// prefix, and the outer sequence will have a two-byte length.
pub const MAX_LEN: usize = 1/*tag:SEQUENCE*/ + 2/*len*/ +
(2 * (1/*tag:INTEGER*/ + 1/*len*/ + 1/*zero*/ + ec::SCALAR_MAX_BYTES));