Feature flag algorithms

Cargo.toml

@@ -20,30 +20,34 @@ resolver = "1" # Hack to enable the `custom` feature of `getrandom`
 [dependencies]
 aead = { version = "0.6", default-features = false }
 aes-gcm = { version = "0.11", default-features = false, features = ["aes", "alloc"] }
-chacha20poly1305 = { version = "0.11", default-features = false }
+chacha20poly1305 = { version = "0.11", default-features = false, optional = true }
 crypto-common = { version = "0.2", default-features = false }
 der = { version = "0.8", default-features = false }
 digest = { version = "0.11", default-features = false }
-ecdsa = { version = "0.17", default-features = false, features = ["alloc"] }
+ecdsa = { version = "0.17", default-features = false, features = ["alloc"], optional = true }
 ed25519-dalek = { version = "3", default-features = false, features = ["pkcs8"] }
 getrandom = { version = "0.4", default-features = false, features = ["sys_rng"] }
 hmac = { version = "0.13", default-features = false }
-p256 = { version = "0.14", default-features = false, features = ["pem", "ecdsa", "ecdh"] }
-p384 = { version = "0.14", default-features = false, features = ["pem", "ecdsa", "ecdh"] }
+p256 = { version = "0.14", default-features = false, features = ["pem", "ecdsa", "ecdh"], optional = true }
+p384 = { version = "0.14", default-features = false, features = ["pem", "ecdsa", "ecdh"], optional = true }
 paste = { version = "1", default-features = false }
 pkcs8 = { version = "0.11", default-features = false }
 pki-types = { package = "rustls-pki-types", version = "1", default-features = false }
-rsa = { version = "0.10.0-rc.18", default-features = false, features = ["sha2", "encoding"] }
+rsa = { version = "0.10.0-rc.18", default-features = false, features = ["sha2", "encoding"], optional = true }
 rustls = { version = "0.23", default-features = false }
-sec1 = { version = "0.8", default-features = false }
+sec1 = { version = "0.8", default-features = false, optional = true }
 sha2 = { version = "0.11", default-features = false }
 signature = { version = "3", default-features = false }
 x25519-dalek = { version = "3", default-features = false }
 
 [features]
-default = ["std", "tls12", "zeroize"]
+default = ["std", "tls12", "zeroize", "chacha20poly1305", "p256", "p384", "rsa"]
 logging = ["rustls/logging"]
 tls12 = ["rustls/tls12"]
+chacha20poly1305 = ["dep:chacha20poly1305"]
+p256 = ["dep:p256", "dep:ecdsa", "dep:sec1"]
+p384 = ["dep:p384", "dep:ecdsa", "dep:sec1"]
+rsa = ["dep:rsa"]
 
 # Only enable feature in upstream if there is an overall effect e.g. aead/alloc in-place
 # zeroize is another typical that can be turned off

src/aead.rs

@@ -1,6 +1,7 @@
 use aead::Buffer;
 use rustls::crypto::cipher::{BorrowedPayload, PrefixedPayload};
 
+#[cfg(feature = "chacha20poly1305")]
 pub mod chacha20;
 pub mod gcm;
 

src/kx.rs

@@ -2,8 +2,10 @@
 use alloc::boxed::Box;
 
 use crypto::{SharedSecret, SupportedKxGroup};
+#[cfg(any(feature = "p256", feature = "p384"))]
 use crypto_common::Generate;
 use getrandom::rand_core::UnwrapErr;
+#[cfg(any(feature = "p256", feature = "p384"))]
 use paste::paste;
 use rustls::crypto;
 
@@ -49,6 +51,7 @@ impl crypto::ActiveKeyExchange for X25519KeyExchange {
     }
 }
 
+#[cfg(any(feature = "p256", feature = "p384"))]
 macro_rules! impl_kx {
     ($name:ident, $kx_name:ty, $secret:ty, $public_key:ty) => {
         paste! {
@@ -106,7 +109,15 @@ macro_rules! impl_kx {
     };
 }
 
+#[cfg(feature = "p256")]
 impl_kx! {SecP256R1, rustls::NamedGroup::secp256r1, p256::ecdh::EphemeralSecret, p256::PublicKey}
+#[cfg(feature = "p384")]
 impl_kx! {SecP384R1, rustls::NamedGroup::secp384r1, p384::ecdh::EphemeralSecret, p384::PublicKey}
 
-pub const ALL_KX_GROUPS: &[&dyn SupportedKxGroup] = &[&X25519, &SecP256R1, &SecP384R1];
+pub const ALL_KX_GROUPS: &[&dyn SupportedKxGroup] = &[
+    &X25519,
+    #[cfg(feature = "p256")]
+    &SecP256R1,
+    #[cfg(feature = "p384")]
+    &SecP384R1,
+];

src/lib.rs

@@ -125,7 +125,7 @@ pub const TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384: SupportedCipherSuite =
         aead_alg: &aead::gcm::Tls12Aes256Gcm,
     });
 
-#[cfg(feature = "tls12")]
+#[cfg(all(feature = "tls12", feature = "chacha20poly1305"))]
 pub const TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
     SupportedCipherSuite::Tls12(&rustls::Tls12CipherSuite {
         common: CipherSuiteCommon {
@@ -143,6 +143,7 @@ pub const TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
 const TLS_ECDHE_ECDSA_SUITES: &[SupportedCipherSuite] = &[
     TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
     TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+    #[cfg(feature = "chacha20poly1305")]
     TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
 ];
 
@@ -174,7 +175,7 @@ pub const TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384: SupportedCipherSuite =
         aead_alg: &aead::gcm::Tls12Aes256Gcm,
     });
 
-#[cfg(feature = "tls12")]
+#[cfg(all(feature = "tls12", feature = "chacha20poly1305"))]
 pub const TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
     SupportedCipherSuite::Tls12(&rustls::Tls12CipherSuite {
         common: CipherSuiteCommon {
@@ -192,6 +193,7 @@ pub const TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
 const TLS_ECDHE_RSA_SUITES: &[SupportedCipherSuite] = &[
     TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
     TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+    #[cfg(feature = "chacha20poly1305")]
     TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
 ];
 
@@ -232,6 +234,7 @@ pub const TLS13_AES_256_GCM_SHA384: SupportedCipherSuite =
 const TLS13_AES_SUITES: &[SupportedCipherSuite] =
     &[TLS13_AES_128_GCM_SHA256, TLS13_AES_256_GCM_SHA384];
 
+#[cfg(feature = "chacha20poly1305")]
 pub const TLS13_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
     SupportedCipherSuite::Tls13(&Tls13CipherSuite {
         common: CipherSuiteCommon {
@@ -244,12 +247,16 @@ pub const TLS13_CHACHA20_POLY1305_SHA256: SupportedCipherSuite =
         quic: None,
     });
 
+#[cfg(feature = "chacha20poly1305")]
 const TLS13_SUITES: &[SupportedCipherSuite] = misc::const_concat_slices!(
     SupportedCipherSuite,
     TLS13_AES_SUITES,
     &[TLS13_CHACHA20_POLY1305_SHA256]
 );
 
+#[cfg(not(feature = "chacha20poly1305"))]
+const TLS13_SUITES: &[SupportedCipherSuite] = TLS13_AES_SUITES;
+
 static ALL_CIPHER_SUITES: &[SupportedCipherSuite] = misc::const_concat_slices!(
     SupportedCipherSuite,
     if cfg!(feature = "tls12") {
@@ -265,6 +272,7 @@ mod hash;
 mod hmac;
 mod kx;
 mod misc;
+#[cfg(feature = "chacha20poly1305")]
 pub mod quic;
 pub mod sign;
 mod verify;

src/sign.rs

@@ -2,16 +2,25 @@
 use alloc::{sync::Arc, vec::Vec};
 use core::marker::PhantomData;
 
-use self::ecdsa::{EcdsaSigningKeyP256, EcdsaSigningKeyP384};
+#[cfg(feature = "p256")]
+use self::ecdsa::EcdsaSigningKeyP256;
+#[cfg(feature = "p384")]
+use self::ecdsa::EcdsaSigningKeyP384;
 use self::eddsa::Ed25519SigningKey;
+#[cfg(feature = "rsa")]
 use self::rsa::RsaSigningKey;
 
+#[cfg(any(feature = "p256", feature = "p384", feature = "rsa"))]
 use getrandom::rand_core::UnwrapErr;
 use pki_types::PrivateKeyDer;
 use rustls::sign::{Signer, SigningKey};
 use rustls::{Error, SignatureScheme};
-use signature::{RandomizedSigner, SignatureEncoding};
+use signature::SignatureEncoding;
 
+#[cfg(any(feature = "p256", feature = "p384", feature = "rsa"))]
+use signature::RandomizedSigner;
+
+#[cfg(any(feature = "p256", feature = "p384", feature = "rsa"))]
 #[derive(Debug)]
 pub struct GenericRandomizedSigner<S, T>
 where
@@ -23,6 +32,7 @@ where
     scheme: SignatureScheme,
 }
 
+#[cfg(any(feature = "p256", feature = "p384", feature = "rsa"))]
 impl<T, S> Signer for GenericRandomizedSigner<S, T>
 where
     S: SignatureEncoding + Send + Sync + core::fmt::Debug,
@@ -75,21 +85,41 @@ where
 ///
 /// Returns an error if the key couldn't be decoded.
 pub fn any_supported_type(der: &PrivateKeyDer<'_>) -> Result<Arc<dyn SigningKey>, rustls::Error> {
-    RsaSigningKey::try_from(der)
-        .map(|x| Arc::new(x) as _)
-        .or_else(|_| any_ecdsa_type(der))
-        .or_else(|_| any_eddsa_type(der))
+    #[cfg(feature = "rsa")]
+    if let Ok(key) = RsaSigningKey::try_from(der) {
+        return Ok(Arc::new(key) as _);
+    }
+    #[cfg(any(feature = "p256", feature = "p384"))]
+    if let Ok(key) = any_ecdsa_type(der) {
+        return Ok(key);
+    }
+    any_eddsa_type(der)
 }
 
 /// Extract any supported ECDSA key from the given DER input.
 ///
 /// # Errors
 ///
 /// Returns an error if the key couldn't be decoded.
+#[cfg(any(feature = "p256", feature = "p384"))]
 pub fn any_ecdsa_type(der: &PrivateKeyDer<'_>) -> Result<Arc<dyn SigningKey>, rustls::Error> {
+    #[cfg(feature = "p256")]
     let p256 = |_| EcdsaSigningKeyP256::try_from(der).map(|x| Arc::new(x) as _);
+    #[cfg(feature = "p384")]
     let p384 = |_| EcdsaSigningKeyP384::try_from(der).map(|x| Arc::new(x) as _);
-    p256(()).or_else(p384)
+
+    #[cfg(all(feature = "p256", feature = "p384"))]
+    {
+        p256(()).or_else(p384)
+    }
+    #[cfg(all(feature = "p256", not(feature = "p384")))]
+    {
+        p256(())
+    }
+    #[cfg(all(not(feature = "p256"), feature = "p384"))]
+    {
+        p384(())
+    }
 }
 
 /// Extract any supported EDDSA key from the given DER input.
@@ -102,6 +132,8 @@ pub fn any_eddsa_type(der: &PrivateKeyDer<'_>) -> Result<Arc<dyn SigningKey>, ru
     Ed25519SigningKey::try_from(der).map(|x| Arc::new(x) as _)
 }
 
+#[cfg(any(feature = "p256", feature = "p384"))]
 pub mod ecdsa;
 pub mod eddsa;
+#[cfg(feature = "rsa")]
 pub mod rsa;

src/sign/ecdsa.rs

@@ -67,5 +67,7 @@ macro_rules! impl_ecdsa {
     };
 }
 
+#[cfg(feature = "p256")]
 impl_ecdsa! {P256, SignatureScheme::ECDSA_NISTP256_SHA256, p256::ecdsa::SigningKey, p256::ecdsa::DerSignature}
+#[cfg(feature = "p384")]
 impl_ecdsa! {P384, SignatureScheme::ECDSA_NISTP384_SHA384, p384::ecdsa::SigningKey, p384::ecdsa::DerSignature}

src/verify.rs

@@ -1,46 +1,73 @@
 use rustls::crypto::WebPkiSupportedAlgorithms;
 use rustls::SignatureScheme;
 
-use self::ecdsa::{ECDSA_P256_SHA256, ECDSA_P256_SHA384, ECDSA_P384_SHA256, ECDSA_P384_SHA384};
+#[cfg(any(feature = "p256", feature = "p384"))]
+use self::ecdsa::*;
 use self::eddsa::ED25519;
-use self::rsa::{
-    RSA_PKCS1_SHA256, RSA_PKCS1_SHA384, RSA_PKCS1_SHA512, RSA_PSS_SHA256, RSA_PSS_SHA384,
-    RSA_PSS_SHA512,
-};
+#[cfg(feature = "rsa")]
+use self::rsa::*;
 
 pub static ALGORITHMS: WebPkiSupportedAlgorithms = WebPkiSupportedAlgorithms {
     all: &[
+        #[cfg(feature = "p256")]
         ECDSA_P256_SHA256,
+        #[cfg(feature = "p256")]
         ECDSA_P256_SHA384,
+        #[cfg(feature = "p384")]
         ECDSA_P384_SHA256,
+        #[cfg(feature = "p384")]
         ECDSA_P384_SHA384,
         ED25519,
+        #[cfg(feature = "rsa")]
         RSA_PKCS1_SHA256,
+        #[cfg(feature = "rsa")]
         RSA_PKCS1_SHA384,
+        #[cfg(feature = "rsa")]
         RSA_PKCS1_SHA512,
+        #[cfg(feature = "rsa")]
         RSA_PSS_SHA256,
+        #[cfg(feature = "rsa")]
         RSA_PSS_SHA384,
+        #[cfg(feature = "rsa")]
         RSA_PSS_SHA512,
     ],
     mapping: &[
+        #[cfg(feature = "p384")]
         (
             SignatureScheme::ECDSA_NISTP384_SHA384,
-            &[ECDSA_P384_SHA384, ECDSA_P256_SHA384],
+            &[
+                ECDSA_P384_SHA384,
+                #[cfg(feature = "p256")]
+                ECDSA_P256_SHA384,
+            ],
         ),
+        #[cfg(feature = "p256")]
         (
             SignatureScheme::ECDSA_NISTP256_SHA256,
-            &[ECDSA_P256_SHA256, ECDSA_P384_SHA256],
+            &[
+                ECDSA_P256_SHA256,
+                #[cfg(feature = "p384")]
+                ECDSA_P384_SHA256,
+            ],
         ),
         (SignatureScheme::ED25519, &[ED25519]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PKCS1_SHA256, &[RSA_PKCS1_SHA256]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PKCS1_SHA384, &[RSA_PKCS1_SHA384]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PKCS1_SHA512, &[RSA_PKCS1_SHA512]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PSS_SHA256, &[RSA_PSS_SHA256]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PSS_SHA384, &[RSA_PSS_SHA384]),
+        #[cfg(feature = "rsa")]
         (SignatureScheme::RSA_PSS_SHA512, &[RSA_PSS_SHA512]),
     ],
 };
 
+#[cfg(any(feature = "p256", feature = "p384"))]
 pub mod ecdsa;
 pub mod eddsa;
+#[cfg(feature = "rsa")]
 pub mod rsa;

src/verify/ecdsa.rs

@@ -47,7 +47,11 @@ macro_rules! impl_generic_ecdsa_verifer {
     };
 }
 
+#[cfg(feature = "p256")]
 impl_generic_ecdsa_verifer! {ECDSA_P256_SHA256, alg_id::ECDSA_P256, alg_id::ECDSA_SHA256, p256::ecdsa::VerifyingKey, p256::ecdsa::DerSignature, sha2::Sha256}
+#[cfg(feature = "p256")]
 impl_generic_ecdsa_verifer! {ECDSA_P256_SHA384, alg_id::ECDSA_P256, alg_id::ECDSA_SHA384, p256::ecdsa::VerifyingKey, p256::ecdsa::DerSignature, sha2::Sha384}
+#[cfg(feature = "p384")]
 impl_generic_ecdsa_verifer! {ECDSA_P384_SHA256, alg_id::ECDSA_P384, alg_id::ECDSA_SHA256, p384::ecdsa::VerifyingKey, p384::ecdsa::DerSignature, sha2::Sha256}
+#[cfg(feature = "p384")]
 impl_generic_ecdsa_verifer! {ECDSA_P384_SHA384, alg_id::ECDSA_P384, alg_id::ECDSA_SHA384, p384::ecdsa::VerifyingKey, p384::ecdsa::DerSignature, sha2::Sha384}