PR feedback (consolidate imports, feature dependencies and better error description)

Author: corrideat

rcgen/Cargo.toml

@@ -33,8 +33,8 @@ zeroize = { version = "1.2", optional = true }
 [features]
 default = ["crypto", "pem", "ring"]
 crypto = []
-aws_lc_rs = ["dep:aws-lc-rs"]
-ring = ["dep:ring"]
+aws_lc_rs = ["crypto", "dep:aws-lc-rs"]
+ring = ["crypto", "dep:ring"]
 
 
 [package.metadata.docs.rs]

rcgen/src/key_pair.rs

@@ -8,19 +8,16 @@ use yasna::DERWriter;
 #[cfg(any(feature = "crypto", feature = "pem"))]
 use crate::error::ExternalError;
 #[cfg(feature = "crypto")]
-use crate::ring_like::error as ring_error;
-#[cfg(feature = "crypto")]
-use crate::ring_like::rand::SystemRandom;
-#[cfg(feature = "crypto")]
-use crate::ring_like::signature::{
-	self, EcdsaKeyPair, Ed25519KeyPair, KeyPair as RingKeyPair, RsaEncoding, RsaKeyPair,
+use crate::ring_like::{
+	ecdsa_from_pkcs8, error as ring_error,
+	rand::SystemRandom,
+	rsa_key_pair_public_modulus_len,
+	signature::{
+		self, EcdsaKeyPair, Ed25519KeyPair, KeyPair as RingKeyPair, RsaEncoding, RsaKeyPair,
+	},
 };
 #[cfg(feature = "crypto")]
-use crate::ring_like::{ecdsa_from_pkcs8, rsa_key_pair_public_modulus_len};
-#[cfg(feature = "crypto")]
-use crate::sign_algo::algo::*;
-#[cfg(feature = "crypto")]
-use crate::sign_algo::SignAlgo;
+use crate::sign_algo::{algo::*, SignAlgo};
 #[cfg(feature = "pem")]
 use crate::ENCODE_CONFIG;
 use crate::{sign_algo::SignatureAlgorithm, Error};

rcgen/src/ring_like.rs

@@ -40,4 +40,4 @@ pub(crate) fn rsa_key_pair_public_modulus_len(kp: &signature::RsaKeyPair) -> usi
 }
 
 #[cfg(all(feature = "crypto", not(any(feature = "ring", feature = "aws_lc_rs"))))]
-compile_error!("At least one of the 'ring' or 'aws_lc_rs' features must be activated");
+compile_error!("At least one of the 'ring' or 'aws_lc_rs' features must be activated when the 'crypto' feature is enabled");