(feat): support building against AWS-LC as the libcrypto

cmake/findcoredeps.cmake

@@ -8,6 +8,7 @@ set(CORE_DIR ${CMAKE_CURRENT_LIST_DIR}/..)
 
 set(DEP_DIR ${CORE_DIR}/../deps CACHE PATH "Dependencies")
 option(USE_MBEDTLS "Use mbed TLS instead of OpenSSL")
+option(USE_AWSLC "Use AWS-LC as the crypto/SSL backend instead of the default")
 
 option(USE_WERROR "Treat compiler warnings as errors (-Werror)")
 option(USE_WCONVERSION "Enable -Wconversion")
@@ -43,6 +44,15 @@ function(add_ssl_library target)
             set(SSL_LIBRARY mbedTLS::mbedTLS)
         endif ()
         target_compile_definitions(${target} PRIVATE -DUSE_MBEDTLS)
+    elseif (${USE_AWSLC})
+        if (NOT OPENSSL_ROOT_DIR)
+            message(FATAL_ERROR "USE_AWSLC requires -DOPENSSL_ROOT_DIR=/path/to/aws-lc/install")
+        endif ()
+        find_package(OpenSSL REQUIRED)
+        set(SSL_LIBRARY OpenSSL::SSL OpenSSL::Crypto)
+        include_directories(BEFORE SYSTEM "${OPENSSL_INCLUDE_DIR}")
+        message(STATUS "Using AWS-LC from: ${OPENSSL_ROOT_DIR}")
+        target_compile_definitions(${target} PRIVATE -DUSE_OPENSSL)
     else ()
         pkg_search_module(OpenSSL REQUIRED IMPORTED_TARGET openssl)
         SET(SSL_LIBRARY PkgConfig::OpenSSL)

openvpn/openssl/aws-lc-compat.hpp

@@ -0,0 +1,122 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012- OpenVPN Inc.
+//
+//    SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
+//
+
+#pragma once
+
+#include <openssl/bio.h>
+#include <openssl/bn.h>
+#include <openssl/cipher.h>
+#include <openssl/digest.h>
+#include <openssl/ec_key.h>
+#include <openssl/ecdsa.h>
+#include <openssl/err.h>
+#include <openssl/kdf.h>
+#include <openssl/pkcs7.h>
+#include <openssl/rsa.h>
+#include <openssl/x509.h>
+#include <openssl/x509_vfy.h>
+
+
+#define BIO_F_MEM_WRITE 0
+#define BIO_F_MEM_READ 0
+#define BIOerr(f, r) ERR_put_error(ERR_LIB_BIO, (f), (r), __FILE__, __LINE__)
+
+#define EVP_PKEY_DSA1 (-101)
+#define EVP_PKEY_DSA2 (-102)
+#define EVP_PKEY_DSA3 (-103)
+#define EVP_PKEY_DSA4 (-104)
+
+/* AWS-LC's GCM reads a NULL input as "finalize", so empty AAD/data (in=NULL, inl=0)
+ * would prematurely compute the tag. Substitute a valid zero length buffer so it
+ * stays a no-op. */
+static inline int
+EVP_EncryptUpdate_wrapper(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, const unsigned char *in, int inl)
+{
+    static unsigned char empty_buf[1] = {0};
+    if (inl == 0 && in == nullptr)
+        in = empty_buf;
+    return EVP_EncryptUpdate(ctx, out, outl, in, inl);
+}
+#define EVP_EncryptUpdate EVP_EncryptUpdate_wrapper
+
+static inline int
+EVP_DecryptUpdate_wrapper(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, const unsigned char *in, int inl)
+{
+    static unsigned char empty_buf[1] = {0};
+    if (inl == 0 && in == nullptr)
+        in = empty_buf;
+    return EVP_DecryptUpdate(ctx, out, outl, in, inl);
+}
+#define EVP_DecryptUpdate EVP_DecryptUpdate_wrapper
+
+
+/* AWS-LC has no RSA_set_app_data or RSA_get_app_data. Re-provide them so a
+ * pointer can be attached to an RSA object and read back later. */
+static inline int RSA_app_data_index()
+{
+    static int idx = RSA_get_ex_new_index(0, nullptr, nullptr, nullptr, nullptr);
+    return idx;
+}
+
+static inline int RSA_set_app_data(RSA *rsa, void *data)
+{
+    return RSA_set_ex_data(rsa, RSA_app_data_index(), data);
+}
+
+static inline void *RSA_get_app_data(const RSA *rsa)
+{
+    return RSA_get_ex_data(rsa, RSA_app_data_index());
+}
+
+/* AWS-LC defines EC_KEY_METHOD_set_sign as a macro that static_asserts
+ * |sign_setup| == NULL. Override it to accept and drop |sign_setup| instead. */
+static inline void
+EC_KEY_METHOD_set_sign_wrapper(
+    EC_KEY_METHOD *meth,
+    int (*sign)(int type, const unsigned char *dgst, int dlen,
+                unsigned char *sig, unsigned int *siglen,
+                const BIGNUM *kinv, const BIGNUM *r, EC_KEY *eckey),
+    int (*)(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinvp, BIGNUM **rp),
+    ECDSA_SIG *(*sign_sig)(const unsigned char *dgst, int dgst_len,
+                           const BIGNUM *in_kinv, const BIGNUM *in_r,
+                           EC_KEY *eckey))
+{
+    EC_KEY_METHOD_set_sign_awslc(meth, sign, sign_sig);
+}
+#undef EC_KEY_METHOD_set_sign
+#define EC_KEY_METHOD_set_sign EC_KEY_METHOD_set_sign_wrapper
+
+/* AWS-LC's PKCS7_verify rejects a NULL store even under PKCS7_NOVERIFY, where it
+ * goes unused. Pass an empty store when none is given. */
+static inline int
+PKCS7_verify_wrapper(PKCS7 *p7, STACK_OF(X509) *certs, X509_STORE *store, BIO *indata, BIO *out, int flags)
+{
+    static X509_STORE *empty_store = X509_STORE_new();
+    return PKCS7_verify(p7, certs, store ? store : empty_store, indata, out, flags);
+}
+#define PKCS7_verify PKCS7_verify_wrapper
+
+static inline bool
+CRYPTO_tls1_prf_wrapper(unsigned char *out,
+                        size_t out_len,
+                        const unsigned char *secret,
+                        size_t secret_len,
+                        const unsigned char *label,
+                        size_t label_len)
+{
+    return CRYPTO_tls1_prf(EVP_md5_sha1(),
+                           out, out_len,
+                           secret, secret_len,
+                           reinterpret_cast<const char *>(label), label_len,
+                           nullptr, 0,
+                           nullptr, 0)
+           == 1;
+}

openvpn/openssl/bio/bio_memq_dgram.hpp

@@ -20,6 +20,7 @@
 #include <openssl/err.h>
 #include <openssl/bio.h>
 
+#include <openvpn/openssl/compat.hpp>
 #include <openvpn/common/size.hpp>
 #include <openvpn/common/exception.hpp>
 #include <openvpn/frame/frame.hpp>

openvpn/openssl/compat.hpp

@@ -20,7 +20,11 @@
 #include <openssl/evp.h>
 #include <openssl/ec.h>
 #include <openssl/objects.h>
+#include <openssl/rsa.h>
 
+#ifdef OPENSSL_IS_AWSLC
+  #include <openvpn/openssl/aws-lc-compat.hpp>
+#endif
 
 /* Note that this is not a perfect emulation of the new function but
  * is good enough for our case of printing certificate details during

openvpn/openssl/crypto/cipheraead.hpp

@@ -26,6 +26,7 @@
 #include <openvpn/crypto/cryptoalgs.hpp>
 #include <openvpn/crypto/aead_usage_limit.hpp>
 #include <openvpn/openssl/util/error.hpp>
+#include <openvpn/openssl/compat.hpp>
 
 namespace openvpn::OpenSSLCrypto {
 class CipherContextAEAD

openvpn/openssl/crypto/tls1prf.hpp

@@ -20,6 +20,7 @@
 #include <openssl/kdf.h>
 
 #include <openvpn/common/numeric_util.hpp>
+#include <openvpn/openssl/compat.hpp>
 
 namespace openvpn::OpenSSLCrypto {
 
@@ -78,6 +79,9 @@ class TLS1PRF
                     unsigned char *out1,
                     const size_t olen)
     {
+#ifdef OPENSSL_IS_AWSLC
+        return CRYPTO_tls1_prf_wrapper(out1, olen, sec, slen, label, label_len);
+#else
         /* TODO use EVP_PKEY_CTX_new_from_name and library context for OpenSSL 3.0 but
          * this needs passing the library context down here.*/
         using EVP_PKEY_CTX_ptr = std::unique_ptr<EVP_PKEY_CTX, decltype(&::EVP_PKEY_CTX_free)>;
@@ -108,6 +112,7 @@ class TLS1PRF
             return false;
 
         return true;
+#endif
     }
 #endif
 };

openvpn/openssl/pki/extpki.hpp

@@ -46,7 +46,6 @@ class ExternalPKIRsaImpl : public ExternalPKIImpl
         RSA_meth_set_priv_dec(rsa_meth, rsa_priv_dec);
         RSA_meth_set_init(rsa_meth, nullptr);
         RSA_meth_set_finish(rsa_meth, rsa_finish);
-        RSA_meth_set0_app_data(rsa_meth, this);
 
 
         /* get the public key */
@@ -75,6 +74,7 @@ class ExternalPKIRsaImpl : public ExternalPKIImpl
         /* only set e and n as d (private key) is outside our control */
         RSA_set0_key(rsa, BN_dup(RSA_get0_n(pub_rsa)), BN_dup(RSA_get0_e(pub_rsa)), nullptr);
         RSA_set_flags(rsa, RSA_FLAG_EXT_PKEY);
+        RSA_set_app_data(rsa, this);
 
         if (!RSA_set_method(rsa, rsa_meth))
         {
@@ -122,7 +122,7 @@ class ExternalPKIRsaImpl : public ExternalPKIImpl
     static int
     rsa_priv_enc(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding)
     {
-        ExternalPKIRsaImpl *self = (ExternalPKIRsaImpl *)(RSA_meth_get0_app_data(RSA_get_method(rsa)));
+        ExternalPKIRsaImpl *self = (ExternalPKIRsaImpl *)RSA_get_app_data(rsa);
 
         try
         {
@@ -173,7 +173,7 @@ class ExternalPKIRsaImpl : public ExternalPKIImpl
 
     static void not_implemented(RSA *rsa)
     {
-        ExternalPKIRsaImpl *self = (ExternalPKIRsaImpl *)(RSA_meth_get0_app_data(RSA_get_method(rsa)));
+        ExternalPKIRsaImpl *self = (ExternalPKIRsaImpl *)RSA_get_app_data(rsa);
         ++self->n_errors;
     }
 

openvpn/openssl/sign/pkcs7verify.hpp

@@ -23,6 +23,7 @@
 #include <openvpn/common/cleanup.hpp>
 #include <openvpn/common/numeric_cast.hpp>
 #include <openvpn/openssl/pki/x509.hpp>
+#include <openvpn/openssl/compat.hpp>
 #include <openvpn/openssl/util/error.hpp>
 
 namespace openvpn::OpenSSLSign {

openvpn/openssl/ssl/sslctx.hpp

@@ -62,6 +62,7 @@
 #include <openvpn/ssl/sslapi.hpp>
 #include <openvpn/ssl/sni_handler.hpp>
 #include <openvpn/ssl/iana_ciphers.hpp>
+#include <openvpn/openssl/compat.hpp>
 #include <openvpn/openssl/util/error.hpp>
 #if ENABLE_EXTERNAL_PKI
 #if OPENSSL_VERSION_NUMBER >= 0x30000000L
@@ -1100,7 +1101,7 @@ class OpenSSLContext : public SSLFactoryAPI
             const SSL_CIPHER *ciph = SSL_get_current_cipher(ssl);
             if (ciph)
             {
-                char *desc = SSL_CIPHER_description(ciph, nullptr, 0);
+                char *desc = const_cast<char *>(SSL_CIPHER_description(ciph, nullptr, 0));
                 if (!desc)
                 {
                     os << ", cipher: Error getting TLS cipher description from SSL_CIPHER_description";
@@ -1480,12 +1481,12 @@ class OpenSSLContext : public SSLFactoryAPI
                 auto certType = EVP_PKEY_id(X509_get0_pubkey(config->cert.obj()));
                 if (certType == EVP_PKEY_RSA)
                 {
-                    epki = std::make_shared<ExternalPKIImpl>(ExternalPKIRsaImpl(ctx.get(), config->cert.obj(), config->external_pki, config->external_pki_alias));
+                    epki = std::make_shared<ExternalPKIRsaImpl>(ctx.get(), config->cert.obj(), config->external_pki, config->external_pki_alias);
                 }
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(OPENSSL_NO_EC)
                 else if (certType == EVP_PKEY_EC)
                 {
-                    epki = std::make_shared<ExternalPKIImpl>(ExternalPKIECImpl(ctx.get(), config->cert.obj(), config->external_pki, config->external_pki_alias));
+                    epki = std::make_shared<ExternalPKIECImpl>(ctx.get(), config->cert.obj(), config->external_pki, config->external_pki_alias);
                 }
 #endif
                 else

openvpn/openssl/util/error.hpp

@@ -22,6 +22,7 @@
 #include <openvpn/common/exception.hpp>
 #include <openvpn/error/error.hpp>
 #include <openvpn/error/excode.hpp>
+#include <openvpn/openssl/compat.hpp>
 
 namespace openvpn {
 
@@ -147,21 +148,27 @@ class OpenSSLException : public ExceptionCode
             case SSL_R_UNSUPPORTED_PROTOCOL:
                 set_code(Error::TLS_VERSION_MIN, true);
                 break;
+#ifdef SSL_R_CA_MD_TOO_WEAK
             case SSL_R_CA_MD_TOO_WEAK:
                 set_code(Error::SSL_CA_MD_TOO_WEAK, true);
                 break;
+#endif
+#ifdef SSL_R_CA_KEY_TOO_SMALL
             case SSL_R_CA_KEY_TOO_SMALL:
                 set_code(Error::SSL_CA_KEY_TOO_SMALL, true);
                 break;
+#endif
 #ifdef SSL_R_LEGACY_SIGALG_DISALLOWED_OR_UNSUPPORTED
                 /* This error code has been added in OpenSSL 3.0.8 */
             case SSL_R_LEGACY_SIGALG_DISALLOWED_OR_UNSUPPORTED:
                 set_code(Error::TLS_SIGALG_DISALLOWED_OR_UNSUPPORTED, true);
                 break;
 #endif
+#ifdef SSL_R_DH_KEY_TOO_SMALL
             case SSL_R_DH_KEY_TOO_SMALL:
                 set_code(Error::SSL_DH_KEY_TOO_SMALL, true);
                 break;
+#endif
             case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
                 set_code(Error::TLS_ALERT_PROTOCOL_VERSION, true);
                 break;
@@ -171,9 +178,11 @@ class OpenSSLException : public ExceptionCode
             case SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE:
                 set_code(Error::TLS_ALERT_HANDSHAKE_FAILURE, true);
                 break;
+#ifdef SSL_R_TLSV13_ALERT_CERTIFICATE_REQUIRED
             case SSL_R_TLSV13_ALERT_CERTIFICATE_REQUIRED:
                 set_code(Error::TLS_ALERT_CERTIFICATE_REQUIRED, true);
                 break;
+#endif
             case SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED:
                 set_code(Error::TLS_ALERT_CERTIFICATE_EXPIRED, true);
                 break;