[PATCH] selftests/sgx: Use a static 3072-bit RSA key.

[Jarkko Sakkinen <jarkko@kernel.org>]

Use a static key for signing the enclave, because generating keys on the
fly can eat the kernel entropy pool. Another good reason for doing
is this is predictable builds. The RSA has been arbitiraly selected.
It's contents do not matter.

This also makes the selftest execute in a snap instead of the delay that
it had before (because of slow key generation).

Cc: Borislav Petkov <bp@alien8.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
 tools/testing/selftests/sgx/Makefile     |  6 +++-
 tools/testing/selftests/sgx/main.h       |  3 ++
 tools/testing/selftests/sgx/sign_key.S   | 12 ++++++++
 tools/testing/selftests/sgx/sign_key.pem | 39 ++++++++++++++++++++++++
 tools/testing/selftests/sgx/sigstruct.c  | 34 ++++++++-------------
 5 files changed, 71 insertions(+), 23 deletions(-)
 create mode 100644 tools/testing/selftests/sgx/sign_key.S
 create mode 100644 tools/testing/selftests/sgx/sign_key.pem

diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile
index d51c90663943..7f12d55b97f8 100644
--- a/tools/testing/selftests/sgx/Makefile
+++ b/tools/testing/selftests/sgx/Makefile
@@ -25,7 +25,8 @@ endif
 $(OUTPUT)/test_sgx: $(OUTPUT)/main.o \
 		    $(OUTPUT)/load.o \
 		    $(OUTPUT)/sigstruct.o \
-		    $(OUTPUT)/call.o
+		    $(OUTPUT)/call.o \
+		    $(OUTPUT)/sign_key.o
 	$(CC) $(HOST_CFLAGS) -o $@ $^ -lcrypto
 
 $(OUTPUT)/main.o: main.c
@@ -40,6 +41,9 @@ $(OUTPUT)/sigstruct.o: sigstruct.c
 $(OUTPUT)/call.o: call.S
 	$(CC) $(HOST_CFLAGS) -c $< -o $@
 
+$(OUTPUT)/sign_key.o: sign_key.S
+	$(CC) $(HOST_CFLAGS) -c $< -o $@
+
 $(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S
 	$(CC) $(ENCL_CFLAGS) -T $^ -o $@
 
diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h
index 45e6ab65442a..67211a708f04 100644
--- a/tools/testing/selftests/sgx/main.h
+++ b/tools/testing/selftests/sgx/main.h
@@ -27,6 +27,9 @@ struct encl {
 	struct sgx_sigstruct sigstruct;
 };
 
+extern unsigned char sign_key[];
+extern unsigned char sign_key_end[];
+
 void encl_delete(struct encl *ctx);
 bool encl_load(const char *path, struct encl *encl);
 bool encl_measure(struct encl *encl);
diff --git a/tools/testing/selftests/sgx/sign_key.S b/tools/testing/selftests/sgx/sign_key.S
new file mode 100644
index 000000000000..e4fbe948444a
--- /dev/null
+++ b/tools/testing/selftests/sgx/sign_key.S
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+* Copyright(c) 2016-20 Intel Corporation.
+*/
+
+    .section ".rodata", "a"
+
+sign_key:
+    .globl sign_key
+    .incbin "sign_key.pem"
+sign_key_end:
+    .globl sign_key_end
diff --git a/tools/testing/selftests/sgx/sign_key.pem b/tools/testing/selftests/sgx/sign_key.pem
new file mode 100644
index 000000000000..d76f21f19187
--- /dev/null
+++ b/tools/testing/selftests/sgx/sign_key.pem
@@ -0,0 +1,39 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
index cc06f108bae7..dee7a3d6c5a5 100644
--- a/tools/testing/selftests/sgx/sigstruct.c
+++ b/tools/testing/selftests/sgx/sigstruct.c
@@ -135,33 +135,21 @@ static inline const BIGNUM *get_modulus(RSA *key)
 
 static RSA *gen_sign_key(void)
 {
-	BIGNUM *e;
+	unsigned long sign_key_length;
+	BIO *bio;
 	RSA *key;
-	int ret;
 
-	e = BN_new();
-	key = RSA_new();
+	sign_key_length = (unsigned long)&sign_key_end -
+			  (unsigned long)&sign_key;
 
-	if (!e || !key)
-		goto err;
-
-	ret = BN_set_word(e, RSA_3);
-	if (ret != 1)
-		goto err;
-
-	ret = RSA_generate_key_ex(key, 3072, e, NULL);
-	if (ret != 1)
-		goto err;
+	bio = BIO_new_mem_buf(&sign_key, sign_key_length);
+	if (!bio)
+		return NULL;
 
-	BN_free(e);
+	key = PEM_read_bio_RSAPrivateKey(bio, NULL, NULL, NULL);
+	BIO_free(bio);
 
 	return key;
-
-err:
-	RSA_free(key);
-	BN_free(e);
-
-	return NULL;
 }
 
 static void reverse_bytes(void *data, int length)
@@ -339,8 +327,10 @@ bool encl_measure(struct encl *encl)
 		goto err;
 
 	key = gen_sign_key();
-	if (!key)
+	if (!key) {
+		ERR_print_errors_fp(stdout);
 		goto err;
+	}
 
 	BN_bn2bin(get_modulus(key), sigstruct->modulus);
 
-- 
2.27.0