[PATCH v4 2/4] selftests: net: tls: check if FIPS mode is enabled

[Magali Lemes <magali.lemes@xxxxxxxxxxxxx>]

TLS selftests use the ChaCha20-Poly1305 and SM4 algorithms, which are not
FIPS compliant. When fips=1, this set of tests fails. Add a check and only
run these tests if not in FIPS mode.

Fixes: 4f336e88a870 ("selftests/tls: add CHACHA20-POLY1305 to tls selftests")
Fixes: e506342a03c7 ("selftests/tls: add SM4 GCM/CCM to tls selftests")
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Magali Lemes <magali.lemes@xxxxxxxxxxxxx>
---
Changes in v4:
 - Add R-b tag.
 - Remove extra newline.
 
Changes in v3:
 - No need to initialize static variable to zero.
 - Skip tests during test setup only.
 - Use the constructor attribute to set fips_enabled before entering
 main().
 
Changes in v2:
 - Put fips_non_compliant into the variants.
 - Turn fips_enabled into a static global variable.
 - Read /proc/sys/crypto/fips_enabled only once at main().

 tools/testing/selftests/net/tls.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c
index e699548d4247..ff36844d14b4 100644
--- a/tools/testing/selftests/net/tls.c
+++ b/tools/testing/selftests/net/tls.c
@@ -25,6 +25,8 @@
 #define TLS_PAYLOAD_MAX_LEN 16384
 #define SOL_TLS 282
 
+static int fips_enabled;
+
 struct tls_crypto_info_keys {
 	union {
 		struct tls12_crypto_info_aes_gcm_128 aes128;
@@ -235,7 +237,7 @@ FIXTURE_VARIANT(tls)
 {
 	uint16_t tls_version;
 	uint16_t cipher_type;
-	bool nopad;
+	bool nopad, fips_non_compliant;
 };
 
 FIXTURE_VARIANT_ADD(tls, 12_aes_gcm)
@@ -254,24 +256,28 @@ FIXTURE_VARIANT_ADD(tls, 12_chacha)
 {
 	.tls_version = TLS_1_2_VERSION,
 	.cipher_type = TLS_CIPHER_CHACHA20_POLY1305,
+	.fips_non_compliant = true,
 };
 
 FIXTURE_VARIANT_ADD(tls, 13_chacha)
 {
 	.tls_version = TLS_1_3_VERSION,
 	.cipher_type = TLS_CIPHER_CHACHA20_POLY1305,
+	.fips_non_compliant = true,
 };
 
 FIXTURE_VARIANT_ADD(tls, 13_sm4_gcm)
 {
 	.tls_version = TLS_1_3_VERSION,
 	.cipher_type = TLS_CIPHER_SM4_GCM,
+	.fips_non_compliant = true,
 };
 
 FIXTURE_VARIANT_ADD(tls, 13_sm4_ccm)
 {
 	.tls_version = TLS_1_3_VERSION,
 	.cipher_type = TLS_CIPHER_SM4_CCM,
+	.fips_non_compliant = true,
 };
 
 FIXTURE_VARIANT_ADD(tls, 12_aes_ccm)
@@ -311,6 +317,9 @@ FIXTURE_SETUP(tls)
 	int one = 1;
 	int ret;
 
+	if (fips_enabled && variant->fips_non_compliant)
+		SKIP(return, "Unsupported cipher in FIPS mode");
+
 	tls_crypto_info_init(variant->tls_version, variant->cipher_type,
 			     &tls12);
 
@@ -1865,4 +1874,17 @@ TEST(prequeue) {
 	close(cfd);
 }
 
+static void __attribute__((constructor)) fips_check(void) {
+	int res;
+	FILE *f;
+
+	f = fopen("/proc/sys/crypto/fips_enabled", "r");
+	if (f) {
+		res = fscanf(f, "%d", &fips_enabled);
+		if (res != 1)
+			ksft_print_msg("ERROR: Couldn't read /proc/sys/crypto/fips_enabled\n");
+		fclose(f);
+	}
+}
+
 TEST_HARNESS_MAIN
-- 
2.34.1