From 3bd42dc88ff062bf9ede2b593e1ad1afa6f68f62 Mon Sep 17 00:00:00 2001
From: Daiki Ueno <ueno@gnu.org>
Date: Wed, 16 Nov 2022 23:02:13 +0900
Subject: [PATCH] nettle: mark non-compliant RSA-PSS salt length to be
not-approved
According to FIPS 186-5 5.4, the salt length must be in the range
between 0 and the hash length inclusive. While the use of those salt
lengths is still allowed for compatibility, it is reported as
non-approved operation through FIPS service indicator.
Signed-off-by: Daiki Ueno <ueno@gnu.org>
---
lib/nettle/pk.c | 9 ++++++++
tests/rsa-rsa-pss.c | 54 ++++++++++++++++++++++++++++++++++++---------
2 files changed, 53 insertions(+), 10 deletions(-)
diff --git a/lib/nettle/pk.c b/lib/nettle/pk.c
index c098e2aa45..7732e90542 100644
--- a/lib/nettle/pk.c
+++ b/lib/nettle/pk.c
@@ -1316,6 +1316,15 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
mpz_init(s);
+ me = hash_to_entry(sign_params->rsa_pss_dig);
+
+ /* According to FIPS 186-5 5.4, the salt length must be
+ * in the range between 0 and the hash length inclusive.
+ */
+ if (sign_params->salt_size > _gnutls_mac_get_algo_len(me)) {
+ not_approved = true;
+ }
+
ret =
_rsa_pss_sign_digest_tr(sign_params->rsa_pss_dig,
&pub, &priv,
diff --git a/tests/rsa-rsa-pss.c b/tests/rsa-rsa-pss.c
index 19a175b722..d7799c1961 100644
--- a/tests/rsa-rsa-pss.c
+++ b/tests/rsa-rsa-pss.c
@@ -46,6 +46,8 @@ const gnutls_datum_t raw_data = {
11
};
+static gnutls_fips140_context_t fips_context;
+
static void inv_sign_check(unsigned sigalgo,
gnutls_privkey_t privkey, int exp_error)
{
@@ -86,13 +88,16 @@ static void inv_encryption_check(gnutls_pk_algorithm_t algorithm,
static void sign_verify_data(unsigned sigalgo, gnutls_privkey_t privkey,
unsigned int sign_flags, unsigned int verify_flags,
- int sign_exp_error, int verify_exp_error)
+ int sign_exp_error, int verify_exp_error,
+ gnutls_fips140_operation_state_t sign_exp_state)
{
int ret;
gnutls_datum_t signature = { NULL, 0 };
+ fips_push_context(fips_context);
ret = gnutls_privkey_sign_data2(privkey, sigalgo, sign_flags,
&raw_data, &signature);
+ fips_pop_context(fips_context, sign_exp_state);
if (ret != sign_exp_error)
fail("gnutls_x509_privkey_sign_data returned unexpected error: %s\n",
gnutls_strerror(ret));
@@ -180,11 +185,16 @@ void doit(void)
if (debug)
gnutls_global_set_log_level(4711);
+ assert(gnutls_fips140_context_init(&fips_context) >= 0);
+
prepare_keys(&pkey_rsa_pss, &pkey_rsa, GNUTLS_DIG_SHA256, 32);
- sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss, 0, 0, 0, 0);
- sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0);
- sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa, 0, 0, 0, 0);
+ sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss, 0, 0, 0, 0,
+ GNUTLS_FIPS140_OP_APPROVED);
+ sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0,
+ GNUTLS_FIPS140_OP_APPROVED);
+ sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa, 0, 0, 0, 0,
+ GNUTLS_FIPS140_OP_APPROVED);
if (debug)
success("success signing with RSA-PSS-SHA256\n");
@@ -213,41 +223,65 @@ void doit(void)
gnutls_privkey_deinit(pkey_rsa_pss);
gnutls_privkey_deinit(pkey_rsa);
+ /* Restrict key to use salt length larger than hash output
+ * length (not approved in FIPS).
+ */
+ prepare_keys(&pkey_rsa_pss, &pkey_rsa, GNUTLS_DIG_SHA256, 33);
+
+ sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss, 0, 0, 0, 0,
+ GNUTLS_FIPS140_OP_NOT_APPROVED);
+
+ gnutls_privkey_deinit(pkey_rsa_pss);
+ gnutls_privkey_deinit(pkey_rsa);
+
/* Use the mismatched salt length with the digest length */
prepare_keys(&pkey_rsa_pss, &pkey_rsa, GNUTLS_DIG_SHA256, 48);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa_pss,
- 0, 0, 0, 0);
+ 0, 0, 0, 0, GNUTLS_FIPS140_OP_NOT_APPROVED);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss,
GNUTLS_PRIVKEY_FLAG_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_CONSTRAINT_ERROR,
- 0);
+ 0,
+ /* The error is caught before calling the actual
+ * signing operation.
+ */
+ GNUTLS_FIPS140_OP_INITIAL);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss,
0,
GNUTLS_VERIFY_RSA_PSS_FIXED_SALT_LENGTH,
0,
- GNUTLS_E_PK_SIG_VERIFY_FAILED);
+ GNUTLS_E_PK_SIG_VERIFY_FAILED,
+ GNUTLS_FIPS140_OP_NOT_APPROVED);
assert(gnutls_x509_spki_init(&spki)>=0);
gnutls_x509_spki_set_rsa_pss_params(spki, GNUTLS_DIG_SHA256, 48);
assert(gnutls_privkey_set_spki(pkey_rsa, spki, 0)>=0);
- sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0);
+ sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0,
+ GNUTLS_FIPS140_OP_NOT_APPROVED);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa,
GNUTLS_PRIVKEY_FLAG_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_CONSTRAINT_ERROR,
- 0);
+ 0,
+ /* The error is caught before calling the actual
+ * signing operation.
+ */
+ GNUTLS_FIPS140_OP_INITIAL);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa,
0,
GNUTLS_VERIFY_RSA_PSS_FIXED_SALT_LENGTH,
0,
- GNUTLS_E_PK_SIG_VERIFY_FAILED);
+ GNUTLS_E_PK_SIG_VERIFY_FAILED,
+ GNUTLS_FIPS140_OP_NOT_APPROVED);
gnutls_privkey_deinit(pkey_rsa_pss);
gnutls_privkey_deinit(pkey_rsa);
gnutls_x509_spki_deinit(spki);
+ gnutls_fips140_context_deinit(fips_context);
+
gnutls_global_deinit();
}
--
2.38.1