LibCrypto: Use OpenSSL to generate RSA keys

Replace our slow, possibly incorrect RSA key generation with OpenSSL.

This should fix many WPT tests that are timing out because we were too
slow at computing keys.

Libraries/LibCrypto/PK/RSA.cpp

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, Ali Mohammad Pur <[email protected]>
+ * Copyright (c) 2024, Altomani Gianluca <[email protected]>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -11,8 +12,14 @@
 #include <LibCrypto/ASN1/DER.h>
 #include <LibCrypto/ASN1/PEM.h>
 #include <LibCrypto/Certificate/Certificate.h>
+#include <LibCrypto/OpenSSL.h>
 #include <LibCrypto/PK/RSA.h>
 
+#include <openssl/core_names.h>
+#include <openssl/evp.h>
+#include <openssl/param_build.h>
+#include <openssl/rsa.h>
+
 namespace Crypto::PK {
 
 ErrorOr<RSA::KeyPairType> RSA::parse_rsa_key(ReadonlyBytes der, bool is_private, Vector<StringView> current_scope)
@@ -113,28 +120,49 @@ ErrorOr<RSA::KeyPairType> RSA::parse_rsa_key(ReadonlyBytes der, bool is_private,
     }
 }
 
+#define OPENSSL_GET_KEY_PARAM(param, openssl_name)                                \
+    auto param##_bn = TRY(OpenSSL_BN::create());                                  \
+    auto* param##_bn_ptr = param##_bn.ptr();                                      \
+    OPENSSL_TRY(EVP_PKEY_get_bn_param(key.ptr(), openssl_name, &param##_bn_ptr)); \
+    auto param = TRY(openssl_bignum_to_unsigned_big_integer(param##_bn));
+
 ErrorOr<RSA::KeyPairType> RSA::generate_key_pair(size_t bits, IntegerType e)
 {
-    IntegerType p;
-    IntegerType q;
-    IntegerType lambda;
+    auto ctx = TRY(OpenSSL_PKEY_CTX::wrap(EVP_PKEY_CTX_new_from_name(nullptr, "RSA", nullptr)));
+
+    OPENSSL_TRY(EVP_PKEY_keygen_init(ctx.ptr()));
+
+    auto e_bn = TRY(unsigned_big_integer_to_openssl_bignum(e));
 
-    do {
-        p = NumberTheory::random_big_prime(bits / 2);
-        q = NumberTheory::random_big_prime(bits / 2);
-        lambda = NumberTheory::LCM(p.minus(1), q.minus(1));
-    } while (!(NumberTheory::GCD(e, lambda) == 1));
+    auto* params_bld = OPENSSL_TRY_PTR(OSSL_PARAM_BLD_new());
+    ArmedScopeGuard const free_params_bld = [&] { OSSL_PARAM_BLD_free(params_bld); };
 
-    auto n = p.multiplied_by(q);
+    OPENSSL_TRY(OSSL_PARAM_BLD_push_size_t(params_bld, OSSL_PKEY_PARAM_RSA_BITS, bits));
+    OPENSSL_TRY(OSSL_PARAM_BLD_push_BN(params_bld, OSSL_PKEY_PARAM_RSA_E, e_bn.ptr()));
+
+    OPENSSL_TRY(EVP_PKEY_CTX_set_params(ctx.ptr(), OSSL_PARAM_BLD_to_param(params_bld)));
+
+    auto key = TRY(OpenSSL_PKEY::create());
+    auto* key_ptr = key.ptr();
+    OPENSSL_TRY(EVP_PKEY_generate(ctx.ptr(), &key_ptr));
+
+    OPENSSL_GET_KEY_PARAM(n, OSSL_PKEY_PARAM_RSA_N);
+    OPENSSL_GET_KEY_PARAM(d, OSSL_PKEY_PARAM_RSA_D);
+    OPENSSL_GET_KEY_PARAM(p, OSSL_PKEY_PARAM_RSA_FACTOR1);
+    OPENSSL_GET_KEY_PARAM(q, OSSL_PKEY_PARAM_RSA_FACTOR2);
+    OPENSSL_GET_KEY_PARAM(dp, OSSL_PKEY_PARAM_RSA_EXPONENT1);
+    OPENSSL_GET_KEY_PARAM(dq, OSSL_PKEY_PARAM_RSA_EXPONENT2);
+    OPENSSL_GET_KEY_PARAM(qinv, OSSL_PKEY_PARAM_RSA_COEFFICIENT1);
 
-    auto d = NumberTheory::ModularInverse(e, lambda);
     RSAKeyPair<PublicKeyType, PrivateKeyType> keys {
         { n, e },
-        { n, d, e, p, q }
+        { n, d, e, p, q, dp, dq, qinv }
     };
     return keys;
 }
 
+#undef OPENSSL_GET_KEY_PARAM
+
 ErrorOr<void> RSA::encrypt(ReadonlyBytes in, Bytes& out)
 {
     dbgln_if(CRYPTO_DEBUG, "in size: {}", in.size());