add gm algorithm support.

chench246 · chench246 · commit 49e4eaf4e1a1 · 2026-01-08T14:13:35.000+08:00
Signed-off-by: chench246 &lt;chench246@hotmail.com&gt;
diff --git a/include/tpm2-tss-engine.h b/include/tpm2-tss-engine.h
@@ -87,6 +87,8 @@ int
 tpm2tss_ecc_genkey(EC_KEY *key, TPMI_ECC_CURVE curve, const char *password,
                    TPM2_HANDLE parentHandle);
 
+int add_sm2_asn1_meths(void);
+
 TPM2_DATA *
 #if OPENSSL_VERSION_NUMBER < 0x10100000
 tpm2tss_ecc_getappdata(EC_KEY *key);
diff --git a/src/tpm2-tss-engine-common.c b/src/tpm2-tss-engine-common.c
@@ -214,6 +214,11 @@ tpm2tss_tpm2data_readtpm(uint32_t handle, TPM2_DATA **tpm2Datap)
     ESYS_TR keyHandle = ESYS_TR_NONE;
     ESYS_CONTEXT *esys_ctx = NULL;
     TPM2B_PUBLIC *outPublic;
+    TPMT_SYM_DEF sym = {.algorithm = TPM2_ALG_AES,
+                        .keyBits = {.aes = 128},
+                        .mode = {.aes = TPM2_ALG_CFB}
+    };
+    TPM2_ALG_ID hash_alg = TPM2_ALG_SHA256;
 
     tpm2Data = OPENSSL_malloc(sizeof(*tpm2Data));
     if (tpm2Data == NULL) {
@@ -247,15 +252,19 @@ tpm2tss_tpm2data_readtpm(uint32_t handle, TPM2_DATA **tpm2Datap)
         goto error;
     }
 
+    if (outPublic->publicArea.parameters.eccDetail.curveID == TPM2_ECC_SM2_P256) {
+        sym.algorithm = TPM2_ALG_SM4;
+        sym.keyBits.sm4 = 128;
+        sym.mode.sm4 = TPM2_ALG_CFB;
+
+        hash_alg = TPM2_ALG_SM3_256;
+    }
+
     /* If the persistent key has the NODA flag set, we check whether it does
        have an empty authValue. If NODA is not set, then we don't check because
        that would increment the DA lockout counter */
     if ((outPublic->publicArea.objectAttributes & TPMA_OBJECT_NODA) != 0) {
         ESYS_TR session;
-        TPMT_SYM_DEF sym = {.algorithm = TPM2_ALG_AES,
-                            .keyBits = {.aes = 128},
-                            .mode = {.aes = TPM2_ALG_CFB}
-        };
 
         /* Esys_StartAuthSession() and session handling use OpenSSL for random
            bytes and thus might end up inside this engine again. This becomes
@@ -271,7 +280,7 @@ tpm2tss_tpm2data_readtpm(uint32_t handle, TPM2_DATA **tpm2Datap)
            very cheap command. */
         r = Esys_StartAuthSession(esys_ctx, ESYS_TR_NONE, keyHandle,
                                   ESYS_TR_NONE, ESYS_TR_NONE, ESYS_TR_NONE,
-                                  NULL, TPM2_SE_HMAC, &sym, TPM2_ALG_SHA256,
+                                  NULL, TPM2_SE_HMAC, &sym, hash_alg,
                                   &session);
         /* Though this response code is sub-optimal, it's the only way to
            detect the bug in ESYS. */
diff --git a/src/tpm2-tss-engine-digest-sign.c b/src/tpm2-tss-engine-digest-sign.c
@@ -79,6 +79,9 @@ digest_init(EVP_MD_CTX *ctx, TPM2_SIG_DATA *data)
     case NID_sha512:
         data->hash_alg = TPM2_ALG_SHA512;
         break;
+    case NID_sm3:
+        data->hash_alg = TPM2_ALG_SM3_256;
+        break;
     default:
         ERR(digest_init, TPM2TSS_R_UNKNOWN_ALG);
         return 0;
diff --git a/src/tpm2-tss-engine-ecc.c b/src/tpm2-tss-engine-ecc.c
@@ -34,6 +34,9 @@
 #include <openssl/engine.h>
 #include <openssl/ec.h>
 #include <openssl/ecdsa.h>
+#include <openssl/objects.h>
+#include <openssl/x509.h>
+#include <openssl/evp.h>
 
 #include <tss2/tss2_mu.h>
 #include <tss2/tss2_esys.h>
@@ -54,6 +57,26 @@ EC_KEY_METHOD *ecc_methods = NULL;
 #ifdef HAVE_OPENSSL_DIGEST_SIGN
 static int (*ecdsa_pkey_orig_copy)(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src);
 static void (*ecdsa_pkey_orig_cleanup)(EVP_PKEY_CTX *ctx);
+static int (*sm2_digest_custom_default) (EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx) = NULL;
+static int (*pkey_sm2_sign_default) (EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
+                         const unsigned char *tbs, size_t tbslen) = NULL;
+static int (*sm2_sign_init_default)(EVP_PKEY_CTX*) = NULL;
+static int (*sm2_ctrl_default)(EVP_PKEY_CTX*, int, int, void*) = NULL;
+static int (*sm2_ctrl_str_default)(EVP_PKEY_CTX*, const char*, const char*) = NULL;
+
+/* The default user id as specified in GM/T 0009-2012.
+ * For details, please refer to GM/T 0003.1-2012 -- 0003.5-2012 SM2 and
+ * described at http://www.gmbz.org.cn/upload/2024-11-18/1731899635265027729.pdf
+ */
+#define SM2_DEFAULT_USERID "1234567812345678"
+#define SM2_DEFAULT_USERID_LEN (sizeof(SM2_DEFAULT_USERID) - 1)
+
+/* ec_sm2 caches the last seen TPM2 SM2 public key.
+ * The cache is needed since pkey_sm2_sign needs to get ahold of the actual
+ * key which is inaccessible inside the EVP_PKEY is an opaque struct.
+ */
+EC_KEY *ec_sm2 = NULL;
+
 #endif /* HAVE_OPENSSL_DIGEST_SIGN */
 
 static TPM2B_DATA allOutsideInfo = {
@@ -238,7 +261,7 @@ ecdsa_sign(ESYS_CONTEXT *esys_ctx, ESYS_TR key_handle,
 	   TPM2_ALG_ID hash_alg)
 {
     TPMT_SIG_SCHEME inScheme = {
-      .scheme = TPM2_ALG_ECDSA,
+      .scheme = (hash_alg == TPM2_ALG_SM3_256) ? TPM2_ALG_SM2 : TPM2_ALG_ECDSA,
       .details.ecdsa.hashAlg = hash_alg,
     };
     BIGNUM *bns = NULL, *bnr = NULL;
@@ -360,8 +383,11 @@ ecdsa_ec_key_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv,
 	    dgst_len = SHA_DIGEST_LENGTH;
     } else if (dgst_len == SHA256_DIGEST_LENGTH ||
 	(curve_len <= SHA256_DIGEST_LENGTH && dgst_len > SHA256_DIGEST_LENGTH)) {
-	    hash_alg = TPM2_ALG_SHA256;
-	    dgst_len = SHA256_DIGEST_LENGTH;
+        if (EC_GROUP_get_curve_name(EC_KEY_get0_group(eckey)) == NID_sm2)
+            hash_alg = TPM2_ALG_SM3_256;
+        else
+            hash_alg = TPM2_ALG_SHA256;
+        dgst_len = SHA256_DIGEST_LENGTH;
     } else if (dgst_len == SHA384_DIGEST_LENGTH ||
 	(curve_len <= SHA384_DIGEST_LENGTH && dgst_len > SHA384_DIGEST_LENGTH)) {
 	    hash_alg = TPM2_ALG_SHA384;
@@ -516,6 +542,9 @@ populate_ecc(EC_KEY *key)
     case TPM2_ECC_NIST_P384:
         nid = EC_curve_nist2nid("P-384");
         break;
+    case TPM2_ECC_SM2_P256:
+        nid = NID_sm2;
+        break;
     default:
         nid = -1;
     }
@@ -560,6 +589,55 @@ populate_ecc(EC_KEY *key)
     return 1;
 }
 
+/* add sm2 asn1 method copy from ecc asn1 */
+int
+add_sm2_asn1_meths(void)
+{
+    const EVP_PKEY_ASN1_METHOD *ec_ameth = NULL;
+    EVP_PKEY_ASN1_METHOD *sm2_ameth = NULL;
+
+    ec_ameth = EVP_PKEY_asn1_find(NULL, EVP_PKEY_EC);
+    if (!ec_ameth) {
+        DBG("find ec_asn1_method failed.\n");
+        return 0;
+    }
+
+    sm2_ameth = EVP_PKEY_asn1_new(EVP_PKEY_SM2, 0, "ec-wrap", "EC with SM2 alias");
+    if (!sm2_ameth) {
+        DBG("set new sm2_asn1_method failed.\n");
+        return 0;
+    }
+
+    EVP_PKEY_asn1_copy(sm2_ameth, ec_ameth);
+
+    if (!EVP_PKEY_asn1_add0(sm2_ameth)) {
+
+        EVP_PKEY_asn1_free(sm2_ameth);
+        return 0;
+    }
+
+    return 1;
+}
+
+static void
+add_sm2_sm3_sig_alg_mapping(void)
+{
+    int nid_sm3    = OBJ_txt2nid("SM3");                  /* 1143 */
+    int nid_sm2    = EVP_PKEY_SM2;                        /* 1172 */
+    int nid_sm2sig = OBJ_txt2nid("sm2sign-with-sm3");
+
+    /* If it is NID_undef, then register the OID. */
+    if (nid_sm2sig == NID_undef) {
+        /* offical OID：1.2.156.10197.1.501 */
+        nid_sm2sig = OBJ_create("1.2.156.10197.1.501",
+                                "SM2Sign-with-SM3",
+                                "sm2sign-with-sm3");
+    }
+    if (nid_sm3 != NID_undef && nid_sm2 != NID_undef && nid_sm2sig != NID_undef) {
+        OBJ_add_sigid(nid_sm2sig, nid_sm3, nid_sm2);
+    }
+}
+
 /** Helper to load an ECC key from a tpm2Data
  *
  * This function creates a key object given a TPM2_DATA object. The resulting
@@ -600,10 +678,19 @@ tpm2tss_ecc_makekey(TPM2_DATA *tpm2Data)
         goto error;
     }
 
-    if (!EVP_PKEY_assign_EC_KEY(pkey, eckey)) {
-        ERR(tpm2tss_ecc_makekey, TPM2TSS_R_GENERAL_FAILURE);
-        EC_KEY_free(eckey);
-        goto error;
+    if (tpm2Data->pub.publicArea.parameters.eccDetail.curveID == TPM2_ECC_SM2_P256) {
+        if (!EVP_PKEY_assign(pkey, EVP_PKEY_SM2, (char *)(eckey))) {
+            ERR(tpm2tss_ecc_makekey, TPM2TSS_R_GENERAL_FAILURE);
+            EC_KEY_free(eckey);
+            goto error;
+        }
+        ec_sm2 = eckey;
+    } else {
+        if (!EVP_PKEY_assign_EC_KEY(pkey, eckey)) {
+            ERR(tpm2tss_ecc_makekey, TPM2TSS_R_GENERAL_FAILURE);
+            EC_KEY_free(eckey);
+            goto error;
+        }
     }
 
     if (!tpm2tss_ecc_setappdata(eckey, tpm2Data)) {
@@ -796,6 +883,91 @@ tpm2tss_ecc_genkey(EC_KEY *key, TPMI_ECC_CURVE curve, const char *password,
     return (r == TSS2_RC_SUCCESS);
 }
 
+/** Customize the pkey_sm2_sign interface
+ *
+ * Customize the pkey_sm2_sign interface. When there is a tpm key extension value, call the ecdsa_ec_key_sign interface to sign.
+ * @retval 1 on success
+ * @retval 0 on failure
+ */
+static int pkey_sm2_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
+                         const unsigned char *tbs, size_t tbslen)
+{
+    (void)ctx;
+
+    EC_KEY *ec = ec_sm2;
+    if (!ec)
+        return 0;
+
+    /* call tpm sig function */
+    const int sig_sz = ECDSA_size(ec);
+    if (sig_sz <= 0) {
+        return 0;
+    }
+    if (sig == NULL) {
+        *siglen = (size_t)sig_sz;
+        return 1;
+    }
+    if (*siglen < (size_t)sig_sz)
+        return 0;
+    ECDSA_SIG *sig_res = ecdsa_ec_key_sign(tbs, tbslen, NULL, NULL, ec);
+
+    int siglen_temp = i2d_ECDSA_SIG(sig_res, &sig);
+    ECDSA_SIG_free(sig_res);
+    if (siglen_temp < 0)
+        return 0;
+    *siglen = siglen_temp;
+
+    return 1;
+}
+
+static int sm2_ctrl_wrap(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
+{
+    switch (type) {
+    case EVP_PKEY_CTRL_DIGESTINIT:
+        /* Ignore explicit digest selection.*/
+        return 1;
+    default:
+        return sm2_ctrl_default ? sm2_ctrl_default(ctx, type, p1, p2) : 1;
+    }
+}
+
+static int sm2_ctrl_str_wrap(EVP_PKEY_CTX *ctx, const char *type, const char *value)
+{
+    if (type) {
+        if (!strcmp(type, "digest") || !strcmp(type, "md")) {
+            /* Swallow "digest=sm3" coming from -sm3 to avoid unsupported ctrl; always return success. */
+            return 1;
+        }
+        if (!strcmp(type, "distid") || !strcmp(type, "sm2_id")) {
+            /* Let default ctrl_str handle ID parsing/storage. */
+            return sm2_ctrl_default ? sm2_ctrl_default(ctx, EVP_PKEY_CTRL_SET1_ID, (int)strlen(value), (void*)value) : 1;
+        }
+    }
+    return sm2_ctrl_str_default ? sm2_ctrl_str_default(ctx, type, value) : 1;
+}
+
+static int pkey_sm2_digest_custom_wrap(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
+{
+    int ret;
+    int id_len = 0;
+
+    ret = sm2_ctrl_default ? sm2_ctrl_default(ctx, EVP_PKEY_CTRL_GET1_ID_LEN, 0, (void*)(&id_len)) : 0;
+    if (ret != 1) {
+        DBG("Get id len failed.\n");
+        return 0;
+    }
+
+    if (id_len == 0) {
+        ret = sm2_ctrl_default ? sm2_ctrl_default(ctx, EVP_PKEY_CTRL_SET1_ID, (int)SM2_DEFAULT_USERID_LEN, (void *)SM2_DEFAULT_USERID) : 0;
+        if (ret != 1) {
+            DBG("Set default id failed.\n");
+            return 0;
+        }
+    }
+
+    return sm2_digest_custom_default ? sm2_digest_custom_default(ctx, mctx) : 1;
+}
+
 /** Initialize the tpm2tss engine's ecc submodule
  *
  * Initialize the tpm2tss engine's submodule by setting function pointer.
@@ -869,6 +1041,28 @@ init_ecc(ENGINE *e)
     EVP_PKEY_meth_set_signctx(pkey_ecc_methods, NULL, ecdsa_signctx);
     EVP_PKEY_meth_set_digest_custom(pkey_ecc_methods, ecdsa_digest_custom);
     EVP_PKEY_meth_add0(pkey_ecc_methods);
+
+    /* add engine for sm2*/
+    const EVP_PKEY_METHOD *pkey_orig_sm2_methods = EVP_PKEY_meth_find(EVP_PKEY_SM2);
+    if (pkey_orig_sm2_methods == NULL) {
+        return 0;
+    }
+    EVP_PKEY_METHOD *pkey_sm2_methods = EVP_PKEY_meth_new(EVP_PKEY_SM2, 0);
+    if (pkey_sm2_methods == NULL)
+        return 0;
+    EVP_PKEY_meth_copy(pkey_sm2_methods, pkey_orig_sm2_methods);
+
+    EVP_PKEY_meth_get_digest_custom((EVP_PKEY_METHOD *)(uintptr_t)(pkey_orig_sm2_methods), &sm2_digest_custom_default);
+    EVP_PKEY_meth_get_sign(pkey_orig_sm2_methods, &sm2_sign_init_default, &pkey_sm2_sign_default);
+    EVP_PKEY_meth_get_ctrl(pkey_orig_sm2_methods, &sm2_ctrl_default, &sm2_ctrl_str_default);
+
+    EVP_PKEY_meth_set_digest_custom(pkey_sm2_methods, pkey_sm2_digest_custom_wrap);
+    EVP_PKEY_meth_set_sign(pkey_sm2_methods, sm2_sign_init_default, pkey_sm2_sign);
+    EVP_PKEY_meth_set_ctrl(pkey_sm2_methods, sm2_ctrl_wrap, sm2_ctrl_str_wrap);
+    EVP_PKEY_meth_add0(pkey_sm2_methods);
+
+    add_sm2_sm3_sig_alg_mapping();
+
 #endif /* HAVE_OPENSSL_DIGEST_SIGN */
 
     return 1;
diff --git a/src/tpm2-tss-engine.c b/src/tpm2-tss-engine.c
@@ -347,6 +347,11 @@ bind(ENGINE *e, const char *id)
         goto end;
     }
 
+    if (!ENGINE_set_load_pubkey_function(e, loadkey)) {
+        DBG("ENGINE_set_load_pubkey_function failed\n");
+        goto end;
+    }
+
     if (!ENGINE_set_destroy_function(e, destroy_engine)) {
         DBG("ENGINE_set_destroy_function failed\n");
         goto end;
@@ -362,6 +367,11 @@ bind(ENGINE *e, const char *id)
         goto end;
     }
 
+    if (!add_sm2_asn1_meths()) {
+        DBG("created sm2_asn1_meths failed\n");
+        goto end;
+    }
+
     ERR_load_TPM2TSS_strings();
     return 1;
  end:
diff --git a/src/tpm2tss-genkey.c b/src/tpm2tss-genkey.c
@@ -52,7 +52,7 @@ char *help =
     "Arguments:\n"
     "    <filename>      storage for the encrypted private key\n"
     "Options:\n"
-    "    -a, --alg       public key algorithm (rsa, ecdsa) (default: rsa)\n"
+    "    -a, --alg       public key algorithm (rsa, ecdsa, sm2) (default: rsa)\n"
     "    -c, --curve     curve for ecc (default: nist_p256)\n"
     "    -e, --exponent  exponent for rsa (default: 65537)\n"
     "    -h, --help      print help\n"
@@ -148,6 +148,9 @@ parse_opts(int argc, char **argv)
             } else if (strcasecmp(optarg, "ecdsa") == 0) {
                 opt.alg = TPM2_ALG_ECDSA;
                 break;
+            } else if (strcasecmp(optarg, "sm2") == 0) {
+                opt.alg = TPM2_ALG_SM2;
+                break;
             } else {
                 ERR("Unknown algorithm.\n");
                 exit(1);
@@ -159,6 +162,9 @@ parse_opts(int argc, char **argv)
             } else if (strcasecmp(optarg, "nist_p384") == 0) {
                 opt.curve = TPM2_ECC_NIST_P384;
                 break;
+            } else if (strcasecmp(optarg, "sm2_p256") == 0) {
+                opt.curve = TPM2_ECC_SM2_P256;
+                break;
             } else {
                 ERR("Unknown curve.\n");
                 exit(1);
@@ -390,6 +396,10 @@ main(int argc, char **argv)
         VERB("Generating the ecdsa key\n");
         tpm2Data = genkey_ecdsa();
         break;
+    case TPM2_ALG_SM2:
+        VERB("Generating the sm2 key\n");
+        tpm2Data = genkey_ecdsa();
+        break;
     default:
         break;
     }
