MEDIUM: ssl: add FIPS TLS 1.3 ciphersuite check for AWS-LC

AWS-LC does not expose TLS 1.3 ciphersuites set via SSL_CTX_set_ciphersuites()
through SSL_CTX_get_ciphers(), so the existing NID-based cipher check in
ssl_fips_check_ciphers() cannot catch non-FIPS TLS 1.3 suites.  This is
further compounded by a defect in the AWS-LC-FIPS 3.x branch where TLS 1.3
ciphers are missing from SSL_get_ciphers() entirely (fixed in
https://github.com/aws/aws-lc/pull/2092), making any SSL_CTX-based
inspection unreliable across versions.

Add ssl_fips_check_ciphersuites() which validates the ciphersuite string
directly against a FIPS-approved allowlist (TLS_AES_128_GCM_SHA256 and
TLS_AES_256_GCM_SHA384).  A NULL string is silently accepted since the
global defaults were already overwritten with FIPS values at init time.

The new check is called right after SSL_CTX_set_ciphersuites() in both
the bind (ssl_sock_prepare_ctx) and server (ssl_sock_prepare_srv_ssl_ctx)
configuration paths.

diff --git a/include/haproxy/fips.h b/include/haproxy/fips.h
index 031adb3809432329a6b8fe38532991722e0f3524..02198fede765055d44dd8bd0eb677a3555915ecf 100644 (file)
--- a/include/haproxy/fips.h
+++ b/include/haproxy/fips.h
@@ -9,6 +9,7 @@
 
 #if defined(OPENSSL_IS_AWSLC)
 int ssl_fips_check_ciphers(SSL_CTX *ctx, const enum obj_type *obj, char **err);
+int ssl_fips_check_ciphersuites(const char *ciphersuites, const enum obj_type *obj, char **err);
 int ssl_fips_check_version(int min_ver, const enum obj_type *obj);
 #endif
 

diff --git a/src/fips.c b/src/fips.c
index 5c4d6599cc57e99f0f3610485dff4b28c777cfd6..fc7c994d1a8ec5f8d2f324a4b3db9165b3a0680a 100644 (file)
--- a/src/fips.c
+++ b/src/fips.c
@@ -20,6 +20,15 @@ static const int fips_approved_cipher_nids[] = {
        NID_undef
 };
 
+/* FIPS-approved TLS 1.3 ciphersuite names.  NULL terminates the list.
+ * TLS_AES_128_CCM_SHA256 is FIPS-approved but not implemented by AWS-LC. */
+static const char *fips_approved_ciphersuites[] = {
+       "TLS_AES_128_GCM_SHA256",
+       "TLS_AES_256_GCM_SHA384",
+       "TLS_AES_128_CCM_SHA256",
+       NULL
+};
+
 /* Fill display fields from <obj> for use in error messages. */
 static void fips_obj_info(const enum obj_type *obj,
                           const char **proxy_name, const char **type_str,
@@ -52,6 +61,48 @@ static void fips_obj_info(const enum obj_type *obj,
        }
 }
 
+/* Check that the TLS 1.3 ciphersuite list <ciphersuites> is FIPS-compliant. */
+int ssl_fips_check_ciphersuites(const char *ciphersuites, const enum obj_type *obj, char **err)
+{
+       const char *proxy_name, *type_str, *obj_name, *file;
+       const char *p, *end;
+       char *list = NULL;
+       int i, line;
+       size_t len;
+
+       if (!FIPS_mode() || !ciphersuites)
+               return 0;
+
+       p = ciphersuites;
+       while (p && *p) {
+               end = strchr(p, ':');
+               len = end ? (size_t)(end - p) : strlen(p);
+
+               for (i = 0; fips_approved_ciphersuites[i]; i++) {
+                       if (strlen(fips_approved_ciphersuites[i]) == len &&
+                           strncmp(p, fips_approved_ciphersuites[i], len) == 0)
+                               goto next;
+               }
+               memprintf(&list, "%s%s'%.*s'", list ? list : "",
+                         list ? ", " : "", (int)len, p);
+       next:
+               p = end ? end + 1 : NULL;
+       }
+
+       if (list) {
+               fips_obj_info(obj, &proxy_name, &type_str, &obj_name, &file, &line);
+               if (file)
+                       memprintf(err, "%s[%s:%d] %s '%s/%s': FIPS mode active but non-FIPS ciphersuite(s) configured: %s.\n",
+                                 (err && *err) ? *err : "", file, line, type_str, proxy_name, obj_name, list);
+               else
+                       memprintf(err, "%s%s '%s/%s': FIPS mode active but non-FIPS ciphersuite(s) configured: %s.\n",
+                                 (err && *err) ? *err : "", type_str, proxy_name, obj_name, list);
+               free(list);
+               return ERR_ALERT | ERR_ABORT | ERR_FATAL;
+       }
+       return 0;
+}
+
 /* Check that the TLS 1.2 cipher list configured on <ctx> is FIPS-compliant. */
 int ssl_fips_check_ciphers(SSL_CTX *ctx, const enum obj_type *obj, char **err)
 {

diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 0fb4b695158a1a98d7f215e10a5b682751a57b73..dddf8c164d514ea2b525bf87b72f864a179d0395 100644 (file)
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -4730,6 +4730,10 @@ static int ssl_sock_prepare_ctx(struct bind_conf *bind_conf, struct ssl_bind_con
                          err && *err ? *err : "", curproxy->id, conf_ciphersuites, bind_conf->arg, bind_conf->file, bind_conf->line);
                cfgerr |= ERR_ALERT | ERR_FATAL;
        }
+#if defined(OPENSSL_IS_AWSLC)
+       cfgerr |= ssl_fips_check_ciphersuites(conf_ciphersuites,
+                                             &LIST_ELEM(bind_conf->listeners.n, struct listener *, by_bind)->obj_type, err);
+#endif
 #endif
 
 #if defined(OPENSSL_IS_AWSLC)
@@ -5282,6 +5286,13 @@ static int ssl_sock_prepare_srv_ssl_ctx(const struct server *srv, SSL_CTX *ctx)
                         srv->ssl_ctx.ciphersuites);
                cfgerr++;
        }
+#if defined(OPENSSL_IS_AWSLC)
+       if (ssl_fips_check_ciphersuites(srv->ssl_ctx.ciphersuites, &srv->obj_type, &err)) {
+               ha_alert("%s", err);
+               ha_free(&err);
+               cfgerr++;
+       }
+#endif
 #endif
 
 #if defined(OPENSSL_IS_AWSLC)