RSA的加密和签名标准是类似的，加密时的摘要值结构如下

即非普通的hash摘要值，而是der编码结构的hash摘要值，用ASN1工具打开

 

 可以快速的组装成一个der编码结构的摘要值，代码如下

ByteArrayOutputStream digestInfoValueBuf = new ByteArrayOutputStream();
digestInfoValueBuf.write(signatureConfig.getHashMagic());
digestInfoValueBuf.write(hashData);
hashData = digestInfoValueBuf.toByteArray();

hashData为摘要值，signatureConfig.getHashMagic()为获取的密钥算法标识符字节值

	switch (getDigestAlgo()) {
		case sha1:
			result = new byte[] { 0x30, 0x1f, 0x30, 0x07, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x04, 0x14 };
			break;
		case sha224:
			result = new byte[] { 0x30, 0x2b, 0x30, 0x0b, 0x06, 0x09, 0x60, (byte) 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x04, 0x1c };
			break;
		case sha256:
			result = new byte[] { 0x30, 0x2f, 0x30, 0x0b, 0x06, 0x09, 0x60, (byte) 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x04, 0x20 };
			break;
		case sha384:
			result = new byte[] { 0x30, 0x3f, 0x30, 0x0b, 0x06, 0x09, 0x60, (byte) 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x04, 0x30 };
			break;
		case sha512:
			result = new byte[] { 0x30, 0x4f, 0x30, 0x0b, 0x06, 0x09, 0x60, (byte) 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x04, 0x40 };
			break;
		case ripemd128:
			result = new byte[] { 0x30, 0x1b, 0x30, 0x07, 0x06, 0x05, 0x2b, 0x24, 0x03, 0x02, 0x02, 0x04, 0x10 };
			break;
		case ripemd160:
			result = new byte[] { 0x30, 0x1f, 0x30, 0x07, 0x06, 0x05, 0x2b, 0x24, 0x03, 0x02, 0x01, 0x04, 0x14 };
			break;

0x30代表一个SEQUENCE,sha1对应的密钥算法标识为13字节，摘要值为20字节 ，拼接起来就是一个可以用ASN1工具打开的der编码结构的摘要值