From ddf62dbfe2f784f3877954becaf3181dcc80a783 Mon Sep 17 00:00:00 2001
From: Heiko Schaefer <heiko@schaefer.name>
Date: Tue, 5 Oct 2021 17:11:52 +0200
Subject: [PATCH] Use the MPI::value_padded() method for left-padding.

---
 openpgp-card-sequoia/Cargo.toml     |  2 +-
 openpgp-card-sequoia/src/privkey.rs |  6 +++---
 openpgp-card-sequoia/src/util.rs    | 13 -------------
 3 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/openpgp-card-sequoia/Cargo.toml b/openpgp-card-sequoia/Cargo.toml
index 6096298..b22d3e5 100644
--- a/openpgp-card-sequoia/Cargo.toml
+++ b/openpgp-card-sequoia/Cargo.toml
@@ -12,7 +12,7 @@ repository = "https://gitlab.com/hkos/openpgp-card"
 documentation = "https://docs.rs/crate/openpgp-card-sequoia"
 
 [dependencies]
-sequoia-openpgp = "1.3"
+sequoia-openpgp = "1.4"
 nettle = "7"
 openpgp-card = { path = "../openpgp-card", version = "0.0.4" }
 openpgp-card-pcsc = { path = "../pcsc", version = "0.0.4" }
diff --git a/openpgp-card-sequoia/src/privkey.rs b/openpgp-card-sequoia/src/privkey.rs
index 1745b4f..fdc92f5 100644
--- a/openpgp-card-sequoia/src/privkey.rs
+++ b/openpgp-card-sequoia/src/privkey.rs
@@ -225,9 +225,9 @@ impl EccKey for SqEccKey {
     fn get_private(&self) -> Vec<u8> {
         // FIXME: padding for 25519?
         match self.curve {
-            Curve::NistP256 => util::left_zero_pad(self.private.value(), 0x20),
-            Curve::NistP384 => util::left_zero_pad(self.private.value(), 0x30),
-            Curve::NistP521 => util::left_zero_pad(self.private.value(), 0x42),
+            Curve::NistP256 => self.private.value_padded(0x20).to_vec(),
+            Curve::NistP384 => self.private.value_padded(0x30).to_vec(),
+            Curve::NistP521 => self.private.value_padded(0x42).to_vec(),
             _ => self.private.value().to_vec(),
         }
     }
diff --git a/openpgp-card-sequoia/src/util.rs b/openpgp-card-sequoia/src/util.rs
index 9969c54..defa580 100644
--- a/openpgp-card-sequoia/src/util.rs
+++ b/openpgp-card-sequoia/src/util.rs
@@ -305,16 +305,3 @@ pub fn decrypt(
 
     Ok(decrypted)
 }
-
-/// This fn prepends zeros to `value` so that the resulting Vec<u8> has
-/// len `size`.
-///
-/// (Leading zero-bytes may be stripped from MPIs, this fn is a helper for
-/// re-creating the non-stripped representation of an MPI)
-pub(crate) fn left_zero_pad(value: &[u8], size: usize) -> Vec<u8> {
-    let pad = size - value.len();
-    let mut res = vec![0; pad];
-    res.extend_from_slice(value);
-
-    res
-}