fix sm2 bugs

hutool-crypto/src/main/java/cn/hutool/crypto/BCUtil.java

@@ -41,15 +41,28 @@ public class BCUtil {
 	}
 
 	/**
-	 * 编码压缩EC公钥（基于BouncyCastle）<br>
+	 * 编码压缩EC公钥（基于BouncyCastle），即Q值<br>
 	 * 见：https://www.cnblogs.com/xinzhao/p/8963724.html
 	 *
 	 * @param publicKey {@link PublicKey}，必须为org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey
-	 * @return 压缩得到的X
+	 * @return 压缩得到的Q
 	 * @since 4.4.4
 	 */
 	public static byte[] encodeECPublicKey(PublicKey publicKey) {
-		return ((BCECPublicKey) publicKey).getQ().getEncoded(true);
+		return encodeECPublicKey(publicKey, true);
+	}
+
+	/**
+	 * 编码压缩EC公钥（基于BouncyCastle），即Q值<br>
+	 * 见：https://www.cnblogs.com/xinzhao/p/8963724.html
+	 *
+	 * @param publicKey {@link PublicKey}，必须为org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey
+	 * @param isCompressed 是否压缩
+	 * @return 得到的Q
+	 * @since 5.5.9
+	 */
+	public static byte[] encodeECPublicKey(PublicKey publicKey, boolean isCompressed) {
+		return ((BCECPublicKey) publicKey).getQ().getEncoded(isCompressed);
 	}
 
 	/**

hutool-crypto/src/main/java/cn/hutool/crypto/ECKeyUtil.java

@@ -87,7 +87,7 @@ public class ECKeyUtil {
 	 * @param x             公钥X
 	 * @param y             公钥Y
 	 * @param domainParameters ECDomainParameters
-	 * @return ECPublicKeyParameters
+	 * @return ECPublicKeyParameters，x或y为{@code null}则返回{@code null}
 	 */
 	public static ECPublicKeyParameters toPublicParams(String x, String y, ECDomainParameters domainParameters) {
 		return toPublicParams(SecureUtil.decode(x), SecureUtil.decode(y), domainParameters);
@@ -102,6 +102,9 @@ public class ECKeyUtil {
 	 * @return ECPublicKeyParameters
 	 */
 	public static ECPublicKeyParameters toPublicParams(byte[] xBytes, byte[] yBytes, ECDomainParameters domainParameters) {
+		if(null == xBytes || null == yBytes){
+			return null;
+		}
 		return toPublicParams(BigIntegers.fromUnsignedByteArray(xBytes), BigIntegers.fromUnsignedByteArray(yBytes), domainParameters);
 	}
 

hutool-crypto/src/main/java/cn/hutool/crypto/SmUtil.java

@@ -26,7 +26,7 @@ import java.math.BigInteger;
 
 /**
  * SM国密算法工具类<br>
- * 此工具类依赖org.bouncycastle:bcpkix-jdk15on
+ * 此工具类依赖org.bouncycastle:bcprov-jdk15to18
  *
  * @author looly
  * @since 4.3.2

hutool-crypto/src/main/java/cn/hutool/crypto/asymmetric/SM2.java

@@ -471,6 +471,27 @@ public class SM2 extends AbstractAsymmetricCrypto<SM2> {
 		return this;
 	}
 
+	/**
+	 * 获得私钥D值（编码后的私钥）
+	 *
+	 * @return D值
+	 * @since 5.5.9
+	 */
+	public byte[] getD() {
+		return this.privateKeyParams.getD().toByteArray();
+	}
+
+	/**
+	 * 获得公钥Q值（编码后的公钥）
+	 *
+	 * @param isCompressed 是否压缩
+	 * @return Q值
+	 * @since 5.5.9
+	 */
+	public byte[] getQ(boolean isCompressed) {
+		return this.publicKeyParams.getQ().getEncoded(isCompressed);
+	}
+
 	// ------------------------------------------------------------------------------------------------------------------------- Private method start
 
 	/**