From: Viktor Dukhovni <openssl-users@dukhovni.org>
Date: Tue, 10 Feb 2026 15:45:02 +0000 (+1100)
Subject: New SM2 "tls-version" signature parameter
X-Git-Tag: openssl-4.0.0-alpha1~224
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1409546f57e109ef2f38bb2bfc87c37a7d3afbdb;p=thirdparty%2Fopenssl.git

New SM2 "tls-version" signature parameter

When the version is TLS 1.3, this sets the SM2 distinguished identifier to
the RFC8998 specified value: "TLSv1.3+GM+Cipher+Suite".

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Yang <paulyang.inf@gmail.com>
MergeDate: Sat Feb 21 13:25:39 2026
(Merged from https://github.com/openssl/openssl/pull/29953)
---

diff --git a/providers/implementations/signature/sm2_sig.c b/providers/implementations/signature/sm2_sig.c
index 96d1c6892aa..4b40a660934 100644
--- a/providers/implementations/signature/sm2_sig.c
+++ b/providers/implementations/signature/sm2_sig.c
@@ -21,6 +21,7 @@
 #include <openssl/params.h>
 #include <openssl/evp.h>
 #include <openssl/err.h>
+#include <openssl/prov_ssl.h>
 #include <openssl/proverr.h>
 #include "internal/nelem.h"
 #include "internal/sizes.h"
@@ -432,6 +433,22 @@ static const OSSL_PARAM *sm2sig_gettable_ctx_params(ossl_unused void *vpsm2ctx,
 
 static int sm2sig_set_ctx_params(void *vpsm2ctx, const OSSL_PARAM params[])
 {
+    /*
+     * (https://datatracker.ietf.org/doc/html/rfc8998#section-3.2.1)
+     *
+     * The SM2 signature algorithm requests an identifier value when generating
+     * or verifying a signature. In all uses except when a client of a server
+     * needs to verify a peer's SM2 certificate in the Certificate message, an
+     * implementation of this document MUST use the following ASCII string
+     * value as the SM2 identifier when doing a TLS 1.3 key exchange:
+     *
+     * TLSv1.3+GM+Cipher+Suite
+     */
+    static const uint8_t sm2_tls_id[] = {
+        0x54, 0x4c, 0x53, 0x76, 0x31, 0x2e, 0x33, 0x2b,
+        0x47, 0x4d, 0x2b, 0x43, 0x69, 0x70, 0x68, 0x65,
+        0x72, 0x2b, 0x53, 0x75, 0x69, 0x74, 0x65
+    };
     PROV_SM2_CTX *psm2ctx = (PROV_SM2_CTX *)vpsm2ctx;
     struct sm2sig_set_ctx_params_st p;
     size_t mdsize;
@@ -455,6 +472,17 @@ static int sm2sig_set_ctx_params(void *vpsm2ctx, const OSSL_PARAM params[])
         OPENSSL_free(psm2ctx->id);
         psm2ctx->id = tmp_id;
         psm2ctx->id_len = tmp_idlen;
+    } else if (p.tlsver != NULL) {
+        unsigned int ver = 0;
+
+        if (!psm2ctx->flag_compute_z_digest
+            || !OSSL_PARAM_get_uint(p.tlsver, &ver))
+            return 0;
+        if (ver == TLS1_3_VERSION) {
+            OPENSSL_free(psm2ctx->id);
+            psm2ctx->id_len = sizeof(sm2_tls_id);
+            psm2ctx->id = OPENSSL_memdup(sm2_tls_id, psm2ctx->id_len);
+        }
     }
 
     /*
diff --git a/providers/implementations/signature/sm2_sig.inc.in b/providers/implementations/signature/sm2_sig.inc.in
index f410d74a47d..3a34316609b 100644
--- a/providers/implementations/signature/sm2_sig.inc.in
+++ b/providers/implementations/signature/sm2_sig.inc.in
@@ -21,4 +21,5 @@ use OpenSSL::paramnames qw(produce_param_decoder);
                          (['OSSL_SIGNATURE_PARAM_DIGEST_SIZE', 'size',   'size_t'],
                           ['OSSL_SIGNATURE_PARAM_DIGEST',      'digest', 'utf8_string'],
                           ['OSSL_PKEY_PARAM_DIST_ID',          'distid', 'octet_string'],
+                          ['OSSL_SIGNATURE_PARAM_TLS_VERSION', 'tlsver', 'uint'],
                          )); -}
diff --git a/util/perl/OpenSSL/paramnames.pm b/util/perl/OpenSSL/paramnames.pm
index 680f4f3317b..a99cade68fc 100644
--- a/util/perl/OpenSSL/paramnames.pm
+++ b/util/perl/OpenSSL/paramnames.pm
@@ -513,6 +513,7 @@ my %params = (
     'OSSL_SIGNATURE_PARAM_MU' =>                 "mu", # int
     'OSSL_SIGNATURE_PARAM_TEST_ENTROPY' =>       "test-entropy",
     'OSSL_SIGNATURE_PARAM_ADD_RANDOM' =>         "additional-random",
+    'OSSL_SIGNATURE_PARAM_TLS_VERSION' =>        "tls-version",
 
 # Asym cipher parameters
     'OSSL_ASYM_CIPHER_PARAM_DIGEST' =>                   '*OSSL_PKEY_PARAM_DIGEST',