Move copy_with_left_pad to algorithms

Author: roblabla

src/algorithms.rs

@@ -111,3 +111,13 @@ pub fn generate_multi_prime_key<R: Rng>(
         primes,
     ))
 }
+
+#[inline]
+pub fn copy_with_left_pad(dest: &mut [u8], src: &[u8]) {
+    // left pad with zeros
+    let padding_bytes = dest.len() - src.len();
+    for el in dest.iter_mut().take(padding_bytes) {
+        *el = 0;
+    }
+    dest[padding_bytes..].copy_from_slice(src);
+}

src/pkcs1v15.rs

@@ -4,6 +4,7 @@ use rand::Rng;
 use subtle::{Choice, ConditionallySelectable, ConstantTimeEq};
 use zeroize::Zeroize;
 
+use crate::algorithms::copy_with_left_pad;
 use crate::errors::{Error, Result};
 use crate::hash::Hash;
 use crate::internals;
@@ -171,16 +172,6 @@ fn hash_info<H: Hash>(hash: Option<&H>, digest_len: usize) -> Result<(usize, &'s
     }
 }
 
-#[inline]
-pub fn copy_with_left_pad(dest: &mut [u8], src: &[u8]) {
-    // left pad with zeros
-    let padding_bytes = dest.len() - src.len();
-    for el in dest.iter_mut().take(padding_bytes) {
-        *el = 0;
-    }
-    dest[padding_bytes..].copy_from_slice(src);
-}
-
 /// Decrypts ciphertext using `priv_key` and blinds the operation if
 /// `rng` is given. It returns one or zero in valid that indicates whether the
 /// plaintext was correctly structured. In either case, the plaintext is

src/pss.rs

@@ -1,4 +1,4 @@
-use crate::pkcs1v15::copy_with_left_pad;
+use crate::algorithms::copy_with_left_pad;
 use crate::internals;
 use crate::key::{RSAPrivateKey, RSAPublicKey};
 use crate::errors::{Error, Result};