fix: ossl3 legacy provider mem leak

codebuild/spec/buildspec_omnibus.yml

@@ -48,6 +48,17 @@ batch:
         variables:
           TESTS: sidetrail
 
+    - identifier: s2nValgrindOpenSSL3
+      buildspec: codebuild/spec/buildspec_ubuntu.yml
+      env:
+        privileged-mode: true
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu18codebuild
+        variables:
+          TESTS: valgrind
+          GCC_VERSION: 9
+          S2N_LIBCRYPTO: openssl-3.0
+          BUILD_S2N: true
 
     - identifier: s2nValgrindOpenSSL102Gcc6Fips
       buildspec: codebuild/spec/buildspec_ubuntu.yml
@@ -122,6 +133,18 @@ batch:
           BUILD_S2N: 'true'
           S2N_COVERAGE: 'true'
 
+    - identifier: s2nAsanOpenssl3
+      buildspec: codebuild/spec/buildspec_ubuntu.yml
+      env:
+        privileged-mode: true
+        compute-type: BUILD_GENERAL1_LARGE
+        image: 024603541914.dkr.ecr.us-west-2.amazonaws.com/docker:ubuntu18codebuild
+        variables:
+          TESTS: asan
+          GCC_VERSION: '6'
+          S2N_LIBCRYPTO: 'openssl-3.0'
+          BUILD_S2N: 'true'
+
     - identifier: s2nAsanOpenssl102
       buildspec: codebuild/spec/buildspec_ubuntu.yml
       env:

crypto/s2n_stream_cipher_rc4.c

@@ -21,60 +21,28 @@
 #include "utils/s2n_blob.h"
 #include "utils/s2n_safety.h"
 
-#if S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)
-    #include "openssl/provider.h"
-DEFINE_POINTER_CLEANUP_FUNC(OSSL_LIB_CTX *, OSSL_LIB_CTX_free);
-#endif
-
-static EVP_CIPHER *s2n_rc4_cipher = NULL;
-
-S2N_RESULT s2n_rc4_init()
-{
-    /* In Openssl-3.0, RC4 is only available from the "legacy" provider,
-     * which is not loaded in the default library context.
-     */
-#if defined(S2N_LIBCRYPTO_SUPPORTS_EVP_RC4) && S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)
-    DEFER_CLEANUP(OSSL_LIB_CTX *lib_ctx = OSSL_LIB_CTX_new(), OSSL_LIB_CTX_free_pointer);
-    RESULT_ENSURE_REF(lib_ctx);
-    RESULT_ENSURE_REF(OSSL_PROVIDER_load(lib_ctx, "legacy"));
-    s2n_rc4_cipher = EVP_CIPHER_fetch(lib_ctx, "rc4", "provider=legacy");
-    RESULT_ENSURE_REF(s2n_rc4_cipher);
-#endif
-    return S2N_RESULT_OK;
-}
-
-S2N_RESULT s2n_rc4_cleanup()
+static const EVP_CIPHER *s2n_evp_rc4()
 {
-#if S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)
-    EVP_CIPHER_free(s2n_rc4_cipher);
+#ifdef S2N_LIBCRYPTO_SUPPORTS_EVP_RC4
+    return EVP_rc4();
+#else
+    return NULL;
 #endif
-    return S2N_RESULT_OK;
 }
 
-static S2N_RESULT s2n_get_rc4_cipher(const EVP_CIPHER **cipher)
+static uint8_t s2n_stream_cipher_rc4_available()
 {
-    RESULT_ENSURE_REF(cipher);
-    *cipher = NULL;
     if (s2n_is_in_fips_mode()) {
-        *cipher = NULL;
-    } else if (s2n_rc4_cipher) {
-        *cipher = s2n_rc4_cipher;
-#if S2N_LIBCRYPTO_SUPPORTS_EVP_RC4
-    } else {
-        *cipher = EVP_rc4();
-#endif
+        return 0;
     }
-    RESULT_ENSURE(*cipher, S2N_ERR_UNIMPLEMENTED);
-    return S2N_RESULT_OK;
-}
-
-static uint8_t s2n_stream_cipher_rc4_available()
-{
-    const EVP_CIPHER *cipher = NULL;
-    if (s2n_result_is_ok(s2n_get_rc4_cipher(&cipher)) && cipher) {
-        return 1;
+    /* RC4 MIGHT be available in Openssl-3.0, depending on whether or not the
+     * "legacy" provider is loaded. However, for simplicity, assume that RC4
+     * is unavailable.
+     */
+    if (S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)) {
+        return 0;
     }
-    return 0;
+    return (s2n_evp_rc4() ? 1 : 0);
 }
 
 static int s2n_stream_cipher_rc4_encrypt(struct s2n_session_key *key, struct s2n_blob *in, struct s2n_blob *out)
@@ -106,23 +74,15 @@ static int s2n_stream_cipher_rc4_decrypt(struct s2n_session_key *key, struct s2n
 static int s2n_stream_cipher_rc4_set_encryption_key(struct s2n_session_key *key, struct s2n_blob *in)
 {
     POSIX_ENSURE_EQ(in->size, 16);
-
-    const EVP_CIPHER *evp_rc4 = NULL;
-    POSIX_GUARD_RESULT(s2n_get_rc4_cipher(&evp_rc4));
-
-    POSIX_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, evp_rc4, NULL, in->data, NULL), S2N_ERR_KEY_INIT);
+    POSIX_GUARD_OSSL(EVP_EncryptInit_ex(key->evp_cipher_ctx, s2n_evp_rc4(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
 
     return S2N_SUCCESS;
 }
 
 static int s2n_stream_cipher_rc4_set_decryption_key(struct s2n_session_key *key, struct s2n_blob *in)
 {
     POSIX_ENSURE_EQ(in->size, 16);
-
-    const EVP_CIPHER *evp_rc4 = NULL;
-    POSIX_GUARD_RESULT(s2n_get_rc4_cipher(&evp_rc4));
-
-    POSIX_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, evp_rc4, NULL, in->data, NULL), S2N_ERR_KEY_INIT);
+    POSIX_GUARD_OSSL(EVP_DecryptInit_ex(key->evp_cipher_ctx, s2n_evp_rc4(), NULL, in->data, NULL), S2N_ERR_KEY_INIT);
 
     return S2N_SUCCESS;
 }

docs/USAGE-GUIDE.md

@@ -179,6 +179,12 @@ cd ../../ # root of project
 make
 ```
 
+### Available algorithms
+Not all algorithms are available from all versions of Openssl:
+* ChaChaPoly is not supported before Openssl-1.1.1
+* RSA-PSS is not supported before Openssl-1.1.1
+* RC4 is not supported with Openssl-3.0 or later.
+
 ## Building s2n-tls with LibreSSL
 
 To build s2n-tls with LibreSSL, do the following:

tests/integrationv2/providers.py

@@ -167,16 +167,22 @@ def supports_protocol(cls, protocol, with_cert=None):
 
     @classmethod
     def supports_cipher(cls, cipher, with_curve=None):
-        # Disable chacha20 tests in unsupported libcryptos
-        if any([
-            libcrypto in get_flag(S2N_PROVIDER_VERSION)
-            for libcrypto in [
-                "openssl-1.0.2",
-                "libressl"
-            ]
-        ]) and "CHACHA20" in cipher.name:
-            return False
+        # Disable chacha20 and RC4 tests in libcryptos that don't support those
+        # algorithms
+        unsupported_configurations = {
+            "CHACHA20": ["openssl-1.0.2", "libressl"],
+            "RC4": ["openssl-3"],
+        }
 
+        for unsupported_cipher, unsupported_libcryptos in unsupported_configurations.items():
+            # the queried cipher has some libcrypto's that don't support it
+            # e.g. "RC4" in "TLS_ECDHE_RSA_WITH_RC4_128_SHA"
+            if unsupported_cipher in cipher.name:
+                current_libcrypto = get_flag(S2N_PROVIDER_VERSION)
+                for lc in unsupported_libcryptos:
+                    # e.g. "openssl-3" in "openssl-3.0.7"
+                    if lc in current_libcrypto:
+                        return False
         return True
 
     @classmethod

tests/unit/s2n_rc4_test.c

@@ -20,6 +20,7 @@
 #include "crypto/s2n_cipher.h"
 #include "crypto/s2n_fips.h"
 #include "crypto/s2n_hmac.h"
+#include "crypto/s2n_openssl.h"
 #include "s2n_test.h"
 #include "stuffer/s2n_stuffer.h"
 #include "testlib/s2n_testlib.h"
@@ -32,6 +33,16 @@ int main(int argc, char **argv)
 {
     BEGIN_TEST();
 
+    /* Test Openssl-3.0 does not support RC4 */
+    if (S2N_OPENSSL_VERSION_AT_LEAST(3, 0, 0)) {
+        EXPECT_FALSE(s2n_rc4.is_available());
+    }
+
+    /* Test FIPS does not support RC4 */
+    if (s2n_is_in_fips_mode()) {
+        EXPECT_FALSE(s2n_rc4.is_available());
+    }
+
     struct s2n_connection *conn;
     uint8_t mac_key[] = "sample mac key";
     uint8_t rc4_key[] = "123456789012345";
@@ -55,17 +66,6 @@ int main(int argc, char **argv)
     conn->server = conn->secure;
     conn->client = conn->secure;
 
-    /* Make sure that RC4 is available when expected */
-#if defined(S2N_LIBCRYPTO_SUPPORTS_EVP_RC4)
-    if (s2n_is_in_fips_mode()) {
-        EXPECT_FALSE(s2n_rc4.is_available());
-    } else {
-        EXPECT_TRUE(s2n_rc4.is_available());
-    }
-#else
-    EXPECT_FALSE(s2n_rc4.is_available());
-#endif
-
     /* test the RC4 cipher with a SHA1 hash */
     conn->secure->cipher_suite->record_alg = &s2n_record_alg_rc4_sha;
     EXPECT_SUCCESS(conn->secure->cipher_suite->record_alg->cipher->init(&conn->secure->server_key));
@@ -128,11 +128,10 @@ int main(int argc, char **argv)
 
         EXPECT_SUCCESS(conn->secure->cipher_suite->record_alg->cipher->destroy_key(&conn->secure->server_key));
         EXPECT_SUCCESS(conn->secure->cipher_suite->record_alg->cipher->destroy_key(&conn->secure->client_key));
-        EXPECT_SUCCESS(s2n_connection_free(conn));
     } else {
-        EXPECT_FAILURE_WITH_ERRNO(conn->secure->cipher_suite->record_alg->cipher->set_decryption_key(&conn->secure->client_key, &key_iv), S2N_ERR_UNIMPLEMENTED);
-        EXPECT_FAILURE_WITH_ERRNO(conn->secure->cipher_suite->record_alg->cipher->set_encryption_key(&conn->secure->server_key, &key_iv), S2N_ERR_UNIMPLEMENTED);
+        EXPECT_FAILURE(conn->secure->cipher_suite->record_alg->cipher->set_decryption_key(&conn->secure->client_key, &key_iv));
+        EXPECT_FAILURE(conn->secure->cipher_suite->record_alg->cipher->set_encryption_key(&conn->secure->server_key, &key_iv));
     }
-
+    EXPECT_SUCCESS(s2n_connection_free(conn));
     END_TEST();
 }

tls/s2n_cipher_suites.c

@@ -971,9 +971,6 @@ int s2n_crypto_disable_init(void)
 /* Determines cipher suite availability and selects record algorithms */
 int s2n_cipher_suites_init(void)
 {
-    /* RC4 requires some extra setup */
-    POSIX_GUARD_RESULT(s2n_rc4_init());
-
     const int num_cipher_suites = s2n_array_len(s2n_all_cipher_suites);
     for (int i = 0; i < num_cipher_suites; i++) {
         struct s2n_cipher_suite *cur_suite = s2n_all_cipher_suites[i];
@@ -1054,10 +1051,6 @@ S2N_RESULT s2n_cipher_suites_cleanup(void)
         * cleanup in later versions */
 #endif
     }
-
-    /* RC4 requires some extra cleanup */
-    RESULT_GUARD(s2n_rc4_cleanup());
-
     return S2N_RESULT_OK;
 }
 
@@ -1179,7 +1172,7 @@ bool s2n_cipher_suite_uses_chacha20_alg(struct s2n_cipher_suite *cipher_suite)
     return cipher_suite && cipher_suite->record_alg && cipher_suite->record_alg->cipher == &s2n_chacha20_poly1305;
 }
 
-/* Iff the server has enabled allow_chacha20_boosting and the client has a chacha20 cipher suite as its most 
+/* Iff the server has enabled allow_chacha20_boosting and the client has a chacha20 cipher suite as its most
  * preferred cipher suite, then we have mutual chacha20 boosting support.
  */
 static S2N_RESULT s2n_validate_chacha20_boosting(const struct s2n_cipher_preferences *cipher_preferences, const uint8_t *wire,
@@ -1254,7 +1247,7 @@ static int s2n_set_cipher_as_server(struct s2n_connection *conn, uint8_t *wire,
      * other cipher suites.
      *
      * If no mutually supported cipher suites are found, we choose one with a version
-     * too high for the current connection (higher_vers_match). 
+     * too high for the current connection (higher_vers_match).
      */
     for (size_t i = 0; i < cipher_preferences->count; i++) {
         const uint8_t *ours = cipher_preferences->suites[i]->iana_value;