Implementation of RSA digital signature with JDK method

JDK only supports Md2withrsa, Md5withrsa, Sha1withrsa

Other such as Sha512withrsa require third-party package support, such as BC (bouncy castle)

The key length of the JDK is still 1024 by default

1  PackageJdbc.pro.lin;2 3 Importjava.security.InvalidKeyException;4 Importjava.security.NoSuchAlgorithmException;5 ImportJava.security.PrivateKey;6 ImportJava.security.PublicKey;7 Importjava.security.Signature;8 Importjava.security.SignatureException;9 ImportJava.util.Map;Ten  One ImportJdbc.pro.lin.MyRSA; A  - /** - * RSA Digital signature, borrow the algorithm in Myrsa, no longer repeat the * The digital signature follows the "private key signature, public key verification" principle, because the private key is a personal authentication -  * @authorKinsley -  * -  */ +  Public classMysignature { -      +     /**Digital Signature Algorithm. JDK only provides Md2withrsa, Md5withrsa, Sha1withrsa, and other algorithms require third-party packages to support*/ A      Public Static FinalString signature_algorithm = "Sha1withrsa"; at      -      Public Static FinalString Plain_text = "ManUtd is the greatest club"; -      Public Static voidMain (string[] args) -     { -         //set up two sets of public key pairs -Map<string,byte[]> KeyMap1 =myrsa.generatekeybytes (); inPublicKey publicKey1 =Myrsa.restorepublickey (Keymap1.get (Myrsa.public_key)); -Privatekey PrivateKey1 =Myrsa.restoreprivatekey (Keymap1.get (Myrsa.private_key)); to          +Map<string,byte[]> KEYMAP2 =myrsa.generatekeybytes (); -PublicKey PublicKey2 =Myrsa.restorepublickey (Keymap2.get (Myrsa.public_key)); thePrivatekey PrivateKey2 =Myrsa.restoreprivatekey (Keymap2.get (Myrsa.private_key)); *          $         /**Suppose you now send a message to B after a signaturePanax Notoginseng * A is encrypted with the public key of B - * Sign with your private key of a the          */ +         byte[] Encodedtext =Myrsa.rsaencode (PublicKey2, Plain_text.getbytes ()); A         byte[] Signature =Sign (PrivateKey1, Plain_text.getbytes ()); the          +         /** - * Now B has received a message, take two steps $ * Decrypted with the private key of B to get plaintext $ * Check the plaintext and a's public key for the verification operation -          */ -          the         byte[] Decodedtext =Myrsa.rsadecode (PrivateKey2, Encodedtext). GetBytes (); -System.out.println ("Decoded Text:" +NewString (Decodedtext));Wuyi          theSystem.out.println ("Signature is" +Verify (PublicKey1, signature, decodedtext)); -     } Wu      -     /** About * Signature, three-step walk $ * 1. Instantiation, incoming algorithm - * 2. Initialize, incoming private key - * 3. Signature -      * @paramKey A      * @paramplaintext +      * @return the      */ -      Public Static byte[] Sign (Privatekey Privatekey,byte[] plaintext) $     { the         Try { the             //instantiation of theSignature Signature =signature.getinstance (signature_algorithm); the              -             //Initialize, incoming private key in signature.initsign (privatekey); the              the             //Update About signature.update (plaintext); the              the             //Signature the             returnsignature.sign (); +              -}Catch(NoSuchAlgorithmException | InvalidKeyException |signatureexception e) { the             //TODO auto-generated Catch blockBayi e.printstacktrace (); the         } the          -         return NULL; -     } the      the     /** the * Verification, three-step walk the * 1. Instantiation, incoming algorithm - * 2. Initialize, incoming public key the * 3. Verification the      * @paramPublicKey the      * @paramsignatureverify94      * @paramplaintext the      * @return the      */ the      Public Static BooleanVerify (PublicKey publickey,byte[] signatureverify,byte[] plaintext)98     { About         Try { -             //instantiation of101Signature Signature =signature.getinstance (signature_algorithm);102             103             //Initialize104 signature.initverify (publickey); the             106             //Update107 signature.update (plaintext);108             109             //Verification the             returnsignature.verify (signatureverify);111}Catch(NoSuchAlgorithmException | InvalidKeyException |signatureexception e) { the             //TODO auto-generated Catch block113 e.printstacktrace (); the         } the          the         return false;117     }118}

Implementation of RSA digital signature with JDK method