Remove RSA MIN_KEY_SIZE.

This will be implemented in the `rsa` crate instead of here.

See: #336

Author: WesleyAC

ssh-key/src/private/rsa.rs

@@ -138,18 +138,10 @@ pub struct RsaKeypair {
 }
 
 impl RsaKeypair {
-    /// Minimum allowed RSA key size.
-    #[cfg(feature = "rsa")]
-    pub(crate) const MIN_KEY_SIZE: usize = 2048;
-
     /// Generate a random RSA keypair of the given size.
     #[cfg(feature = "rsa")]
     pub fn random<R: CryptoRng + ?Sized>(rng: &mut R, bit_size: usize) -> Result<Self> {
-        if bit_size >= Self::MIN_KEY_SIZE {
-            rsa::RsaPrivateKey::new(rng, bit_size)?.try_into()
-        } else {
-            Err(Error::Crypto)
-        }
+        rsa::RsaPrivateKey::new(rng, bit_size)?.try_into()
     }
 
     /// Create a new keypair from the given `public` and `private` key components.
@@ -261,11 +253,7 @@ impl TryFrom<&RsaKeypair> for rsa::RsaPrivateKey {
             ],
         )?;
 
-        if ret.size().saturating_mul(8) >= RsaKeypair::MIN_KEY_SIZE {
-            Ok(ret)
-        } else {
-            Err(Error::Crypto)
-        }
+        Ok(ret)
     }
 }
 

ssh-key/src/public/rsa.rs

@@ -6,7 +6,6 @@ use encoding::{CheckedSum, Decode, Encode, Reader, Writer};
 
 #[cfg(feature = "rsa")]
 use {
-    crate::private::RsaKeypair,
     encoding::Uint,
     rsa::{pkcs1v15, traits::PublicKeyParts},
     sha2::{Digest, digest::const_oid::AssociatedOid},
@@ -28,10 +27,6 @@ pub struct RsaPublicKey {
 }
 
 impl RsaPublicKey {
-    /// Minimum allowed RSA key size.
-    #[cfg(feature = "rsa")]
-    pub(crate) const MIN_KEY_SIZE: usize = RsaKeypair::MIN_KEY_SIZE;
-
     /// Create a new [`RsaPublicKey`] with the given components:
     ///
     /// - `e`: RSA public exponent.
@@ -116,11 +111,7 @@ impl TryFrom<&RsaPublicKey> for rsa::RsaPublicKey {
         let e = Uint::try_from(&key.e)?;
         let ret = rsa::RsaPublicKey::new(n, e).map_err(|_| Error::Crypto)?;
 
-        if ret.size().saturating_mul(8) >= RsaPublicKey::MIN_KEY_SIZE {
-            Ok(ret)
-        } else {
-            Err(Error::Crypto)
-        }
+        Ok(ret)
     }
 }