core: crypto add support for SM2 DSA

Adds SM2 Digital Signature Algorithm [1] using LibTomCrypt. The TA
interface complies with the GlobalPlatform TEE Internal Core API
version 1.2.

SM2 DSA is enabled with CFG_CRYPTO_SM2_DSA=y (default y) which currently
requires that CFG_CRYPTOLIB_NAME=tomcrypt. An Mbed TLS implementation
could be added later if needed.

[1] http://www.gmbz.org.cn/main/postDetail.html?id=20180724110812

Signed-off-by: Jerome Forissier <jerome@forissier.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

5 files changed, 65 insertions, 1 deletions

diff --git a/core/crypto.mk b/core/crypto.mk
index d7b5a074..0fdbac63 100644
--- a/core/crypto.mk
+++ b/core/crypto.mk
@@ -41,10 +41,14 @@ CFG_CRYPTO_DH ?= y
 CFG_CRYPTO_ECC ?= y
 ifeq ($(CFG_CRYPTOLIB_NAME),tomcrypt)
 CFG_CRYPTO_SM2_PKE ?= y
+CFG_CRYPTO_SM2_DSA ?= y
 endif
 ifeq ($(CFG_CRYPTOLIB_NAME)-$(CFG_CRYPTO_SM2_PKE),mbedtls-y)
 $(error Error: CFG_CRYPTO_SM2_PKE=y requires CFG_CRYPTOLIB_NAME=tomcrypt)
 endif
+ifeq ($(CFG_CRYPTOLIB_NAME)-$(CFG_CRYPTO_SM2_DSA),mbedtls-y)
+$(error Error: CFG_CRYPTO_SM2_DSA=y requires CFG_CRYPTOLIB_NAME=tomcrypt)
+endif
 
 # Authenticated encryption
 CFG_CRYPTO_CCM ?= y
@@ -137,6 +141,7 @@ $(eval $(call cryp-dep-one, AES, ECB CBC CTR CTS XTS))
 $(eval $(call cryp-dep-one, DES, ECB CBC))
 # SM2 is Elliptic Curve Cryptography, it uses some generic ECC functions
 $(eval $(call cryp-dep-one, SM2_PKE, ECC))
+$(eval $(call cryp-dep-one, SM2_DSA, ECC))
 
 ###############################################################
 # libtomcrypt (LTC) specifics, phase #1
@@ -168,6 +173,7 @@ core-ltc-vars += SHA1_ARM32_CE SHA1_ARM64_CE
 core-ltc-vars += SHA256_ARM32_CE SHA256_ARM64_CE
 core-ltc-vars += SIZE_OPTIMIZATION
 core-ltc-vars += SM2_PKE
+core-ltc-vars += SM2_DSA
 # Assigned selected CFG_CRYPTO_xxx as _CFG_CORE_LTC_xxx
 $(foreach v, $(core-ltc-vars), $(eval _CFG_CORE_LTC_$(v) := $(CFG_CRYPTO_$(v))))
 _CFG_CORE_LTC_MPI := $(CFG_CORE_MBEDTLS_MPI)
diff --git a/core/crypto/crypto.c b/core/crypto/crypto.c
index eeaa269b..578514da 100644
--- a/core/crypto/crypto.c
+++ b/core/crypto/crypto.c
@@ -711,3 +711,25 @@ TEE_Result crypto_acipher_sm2_pke_encrypt(struct ecc_public_key *key __unused,
 	return TEE_ERROR_NOT_IMPLEMENTED;
 }
 #endif /* !CFG_CRYPTO_SM2_PKE */
+
+#if !defined(CFG_CRYPTO_SM2_DSA)
+TEE_Result crypto_acipher_sm2_dsa_sign(uint32_t algo __unused,
+				       struct ecc_keypair *key __unused,
+				       const uint8_t *msg __unused,
+				       size_t msg_len __unused,
+				       uint8_t *sig __unused,
+				       size_t *sig_len __unused)
+{
+	return TEE_ERROR_NOT_IMPLEMENTED;
+}
+
+TEE_Result crypto_acipher_sm2_dsa_verify(uint32_t algo __unused,
+					 struct ecc_public_key *key __unused,
+					 const uint8_t *msg __unused,
+					 size_t msg_len __unused,
+					 const uint8_t *sig __unused,
+					 size_t sig_len __unused)
+{
+	return TEE_ERROR_NOT_IMPLEMENTED;
+}
+#endif /* !CFG_CRYPTO_SM2_DSA */
diff --git a/core/include/crypto/crypto.h b/core/include/crypto/crypto.h
index 7da74461..e9138758 100644
--- a/core/include/crypto/crypto.h
+++ b/core/include/crypto/crypto.h
@@ -244,6 +244,13 @@ TEE_Result crypto_acipher_sm2_pke_decrypt(struct ecc_keypair *key,
 TEE_Result crypto_acipher_sm2_pke_encrypt(struct ecc_public_key *key,
 					  const uint8_t *src, size_t src_len,
 					  uint8_t *dst, size_t *dst_len);
+TEE_Result crypto_acipher_sm2_dsa_sign(uint32_t algo, struct ecc_keypair *key,
+				       const uint8_t *msg, size_t msg_len,
+				       uint8_t *sig, size_t *sig_len);
+TEE_Result crypto_acipher_sm2_dsa_verify(uint32_t algo,
+					 struct ecc_public_key *key,
+					 const uint8_t *msg, size_t msg_len,
+					 const uint8_t *sig, size_t sig_len);
 
 /*
  * Verifies a SHA-256 hash, doesn't require crypto_init() to be called in
diff --git a/core/lib/libtomcrypt/ecc.c b/core/lib/libtomcrypt/ecc.c
index 051da77e..92d773af 100644
--- a/core/lib/libtomcrypt/ecc.c
+++ b/core/lib/libtomcrypt/ecc.c
@@ -128,7 +128,8 @@ static TEE_Result ecc_get_curve_info(uint32_t curve, uint32_t algo,
 		size_bits = 256;
 		size_bytes = 32;
 		name = "SM2";
-		if ((algo != 0) && (algo != TEE_ALG_SM2_PKE))
+		if ((algo != 0) && (algo != TEE_ALG_SM2_PKE) &&
+		    (algo != TEE_ALG_SM2_DSA_SM3))
 			return TEE_ERROR_BAD_PARAMETERS;
 		break;
 	default:
diff --git a/core/tee/tee_svc_cryp.c b/core/tee/tee_svc_cryp.c
index 622fd299..17d8decf 100644
--- a/core/tee/tee_svc_cryp.c
+++ b/core/tee/tee_svc_cryp.c
@@ -487,6 +487,14 @@ static const struct tee_cryp_obj_type_props tee_cryp_obj_props[] = {
 		sizeof(struct ecc_keypair),
 		tee_cryp_obj_ecc_keypair_attrs),
 
+	PROP(TEE_TYPE_SM2_DSA_PUBLIC_KEY, 1, 256, 256,
+	     sizeof(struct ecc_public_key),
+	     tee_cryp_obj_ecc_pub_key_attrs),
+
+	PROP(TEE_TYPE_SM2_DSA_KEYPAIR, 1, 256, 256,
+	     sizeof(struct ecc_keypair),
+	     tee_cryp_obj_ecc_keypair_attrs),
+
 	PROP(TEE_TYPE_SM2_PKE_PUBLIC_KEY, 1, 256, 256,
 	     sizeof(struct ecc_public_key),
 	     tee_cryp_obj_ecc_pub_key_attrs),
@@ -1145,6 +1153,9 @@ TEE_Result tee_obj_attr_copy_from(struct tee_obj *o, const struct tee_obj *src)
 		} else if (o->info.objectType == TEE_TYPE_ECDH_PUBLIC_KEY) {
 			if (src->info.objectType != TEE_TYPE_ECDH_KEYPAIR)
 				return TEE_ERROR_BAD_PARAMETERS;
+		} else if (o->info.objectType == TEE_TYPE_SM2_DSA_PUBLIC_KEY) {
+			if (src->info.objectType != TEE_TYPE_SM2_DSA_KEYPAIR)
+				return TEE_ERROR_BAD_PARAMETERS;
 		} else if (o->info.objectType == TEE_TYPE_SM2_PKE_PUBLIC_KEY) {
 			if (src->info.objectType != TEE_TYPE_SM2_PKE_KEYPAIR)
 				return TEE_ERROR_BAD_PARAMETERS;
@@ -1236,12 +1247,14 @@ TEE_Result tee_obj_set_type(struct tee_obj *o, uint32_t obj_type,
 		break;
 	case TEE_TYPE_ECDSA_PUBLIC_KEY:
 	case TEE_TYPE_ECDH_PUBLIC_KEY:
+	case TEE_TYPE_SM2_DSA_PUBLIC_KEY:
 	case TEE_TYPE_SM2_PKE_PUBLIC_KEY:
 		res = crypto_acipher_alloc_ecc_public_key(o->attr,
 							  max_key_size);
 		break;
 	case TEE_TYPE_ECDSA_KEYPAIR:
 	case TEE_TYPE_ECDH_KEYPAIR:
+	case TEE_TYPE_SM2_DSA_KEYPAIR:
 	case TEE_TYPE_SM2_PKE_KEYPAIR:
 		res = crypto_acipher_alloc_ecc_keypair(o->attr, max_key_size);
 		break;
@@ -2033,6 +2046,12 @@ static TEE_Result tee_svc_cryp_check_key_type(const struct tee_obj *o,
 		else
 			req_key_type = TEE_TYPE_SM2_PKE_KEYPAIR;
 		break;
+	case TEE_MAIN_ALGO_SM2_DSA_SM3:
+		if (mode == TEE_MODE_VERIFY)
+			req_key_type = TEE_TYPE_SM2_DSA_PUBLIC_KEY;
+		else
+			req_key_type = TEE_TYPE_SM2_DSA_KEYPAIR;
+		break;
 #if defined(CFG_CRYPTO_HKDF)
 	case TEE_MAIN_ALGO_HKDF:
 		req_key_type = TEE_TYPE_HKDF_IKM;
@@ -3505,6 +3524,10 @@ TEE_Result syscall_asymm_operate(unsigned long state,
 		res = crypto_acipher_ecc_sign(cs->algo, o->attr, src_data,
 					      src_len, dst_data, &dlen);
 		break;
+	case TEE_ALG_SM2_DSA_SM3:
+		res = crypto_acipher_sm2_dsa_sign(cs->algo, o->attr, src_data,
+						  src_len, dst_data, &dlen);
+		break;
 
 	default:
 		res = TEE_ERROR_BAD_PARAMETERS;
@@ -3628,6 +3651,11 @@ TEE_Result syscall_asymm_verify(unsigned long state,
 						data_len, sig, sig_len);
 		break;
 
+	case TEE_MAIN_ALGO_SM2_DSA_SM3:
+		res = crypto_acipher_sm2_dsa_verify(cs->algo, o->attr, data,
+						    data_len, sig, sig_len);
+		break;
+
 	default:
 		res = TEE_ERROR_NOT_SUPPORTED;
 	}