如何解决无效的AES密钥长度？(How to fix Invalid AES key length?)
java
我正在开发一个基于Web的文本加密和解密项目（在Struts 2之后）
每当我输入密码和纯文本时，我都会收到一个无效的AES密钥长度错误。
服务类（SymAES.java）
package com.anoncrypt.services; import java.security.Key; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class SymAES { private static final String ALGORITHM = "AES"; private static byte[] keyValue= new byte[] { 'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y' }; public String encode(String valueToEnc) throws Exception { System.out.println("The Key byte value"+keyValue ); Key key = generateKey(); Cipher c = Cipher.getInstance(ALGORITHM); c.init(Cipher.ENCRYPT_MODE, key); byte[] encValue = c.doFinal(valueToEnc.getBytes()); String encryptedValue = new BASE64Encoder().encode(encValue); return encryptedValue; } public String decode(String encryptedValue) throws Exception { Key key = generateKey(); Cipher c = Cipher.getInstance(ALGORITHM); c.init(Cipher.DECRYPT_MODE, key); byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedValue); byte[] decValue = c.doFinal(decordedValue); String decryptedValue = new String(decValue); return decryptedValue; } private static Key generateKey() throws Exception { //System.out.println("passs value"+pass); System.out.println("The Key byte value instde genkey"+keyValue ); Key key = new SecretKeySpec(keyValue, ALGORITHM); return key; } public void start(String passcode)throws Exception { keyValue = passcode.getBytes(); System.out.println("passcode"+passcode); System.out.println("The Key byte value inside start"+keyValue ); } }这里是Action类（SymEncrypt.java）
package com.anoncrypt.actions; import com.anoncrypt.services.SymAES; public class SymEncrypt { private String encrypt; private String encrypted; private String password; boolean TEMP; public String execute() throws Exception { SymAES ob=new SymAES(); ob.start(getPassword()); setEncrypted( ob.encode(getEncrypt())); System.out.println("into action class "+getEncrypted()); if(getEncrypted().equals(null)) return "error"; else return "success"; } public String getEncrypted() { return encrypted; } public void setEncrypted(String encrypted) { this.encrypted = encrypted; } public String getEncrypt() { return encrypt; } public void setEncrypt(String encrypt) { this.encrypt = encrypt; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }这是错误
java.security.InvalidKeyException: Invalid AES key length: 6 bytes com.sun.crypto.provider.AESCrypt.init(AESCrypt.java:87) com.sun.crypto.provider.ElectronicCodeBook.init(ElectronicCodeBook.java:93) com.sun.crypto.provider.CipherCore.init(CipherCore.java:582) com.sun.crypto.provider.CipherCore.init(CipherCore.java:458) com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:307) javax.crypto.Cipher.implInit(Cipher.java:797) javax.crypto.Cipher.chooseProvider(Cipher.java:859) javax.crypto.Cipher.init(Cipher.java:1229) javax.crypto.Cipher.init(Cipher.java:1166) com.anoncrypt.services.SymAES.encode(SymAES.java:35) com.anoncrypt.actions.SymEncrypt.execute(SymEncrypt.java:24) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) java.lang.reflect.Method.invoke(Unknown Source) ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:870) ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1293) ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68) com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:117) com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:108) ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1369) ognl.ASTMethod.getValueBody(ASTMethod.java:90) ognl.SimpleNode.evaluateGetValueBody(SimpleNode.java:212) ognl.SimpleNode.getValue(SimpleNode.java:258) ognl.Ognl.getValue(Ognl.java:494) ognl.Ognl.getValue(Ognl.java:458) com.opensymphony.xwork2.ognl.OgnlUtil$2.execute(OgnlUtil.java:309) com.opensymphony.xwork2.ognl.OgnlUtil.compileAndExecute(OgnlUtil.java:340) com.opensymphony.xwork2.ognl.OgnlUtil.getValue(OgnlUtil.java:307) com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:423) com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:287) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:250) org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244) org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564) org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81) org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)I am working on a text encryption and decryption project (following Struts 2)
Whenever I enter the password and the plain text I get a Invalid AES Key Length error.
The Service Class
package com.anoncrypt.services; import java.security.Key; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class SymAES { private static final String ALGORITHM = "AES"; private static byte[] keyValue= new byte[] { 'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y' }; public String encode(String valueToEnc) throws Exception { Key key = new SecretKeySpec(keyValue, ALGORITHM); Cipher c = Cipher.getInstance(ALGORITHM); c.init(Cipher.ENCRYPT_MODE, key); byte[] encValue = c.doFinal(valueToEnc.getBytes()); String encryptedValue = new BASE64Encoder().encode(encValue); return encryptedValue; } public String decode(String encryptedValue) throws Exception { Key key = new SecretKeySpec(keyValue, ALGORITHM); Cipher c = Cipher.getInstance(ALGORITHM); c.init(Cipher.DECRYPT_MODE, key); byte[] decordedValue = new BASE64Decoder().decodeBuffer(encryptedValue); byte[] decValue = c.doFinal(decordedValue); String decryptedValue = new String(decValue); return decryptedValue; } public void start(String passcode)throws Exception { keyValue = passcode.getBytes(); } }And this is the error
java.security.InvalidKeyException: Invalid AES key length: 6 bytes com.sun.crypto.provider.AESCrypt.init(AESCrypt.java:87) com.sun.crypto.provider.ElectronicCodeBook.init(ElectronicCodeBook.java:93) com.sun.crypto.provider.CipherCore.init(CipherCore.java:582) com.sun.crypto.provider.CipherCore.init(CipherCore.java:458) com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:307) javax.crypto.Cipher.implInit(Cipher.java:797) javax.crypto.Cipher.chooseProvider(Cipher.java:859) javax.crypto.Cipher.init(Cipher.java:1229) javax.crypto.Cipher.init(Cipher.java:1166) com.anoncrypt.services.SymAES.encode(SymAES.java:35) com.anoncrypt.actions.SymEncrypt.execute(SymEncrypt.java:24)最满意答案
AES仅支持16,24或32字节的密钥。 您要么提供确切的金额，要么从您输入的内容中获得密钥。
从密码中派生密钥的方法有很多种。 Java为此提供了一个PBKDF2实现。
我用埃里克森的答案来画一幅完整的图片（只有加密，因为解密是相似的，但包括分割密文）：
SecureRandom random = new SecureRandom(); byte[] salt = new byte[16]; random.nextBytes(salt); KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 256); // AES-256 SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1"); byte[] key = f.generateSecret(spec).getEncoded(); byte[] ivBytes = new byte[16]; random.nextBytes(ivBytes); IvParameterSpec iv = new IvParameterSpec(ivBytes); Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding"); c.init(Cipher.ENCRYPT_MODE, key, iv); byte[] encValue = c.doFinal(valueToEnc.getBytes()); byte[] finalCiphertext = new byte[encValue.length+2*16]; System.arraycopy(ivBytes, 0, finalCiphertext, 0, 16); System.arraycopy(salt, 0, finalCiphertext, 16, 16); System.arraycopy(encValue, 0, finalCiphertext, 32, encValue.length); return finalCiphertext;其他事项要记住：
始终使用完全合格的密码名称。 AES在这种情况下并不合适，因为不同的JVM / JCE提供者可能会使用不同的默认值来进行操作和填充。 使用AES/CBC/PKCS5Padding 。 不要使用ECB模式，因为它在语义上不安全。 如果你不使用ECB模式，那么你需要发送IV和密文一起。 这通常是通过在密文字节数组前加IV来完成的。 IV会自动为您创建，您可以通过cipherInstance.getIV()获取它。 无论何时你发送一些东西，你都需要确保它一直没有改变。 正确使用MAC加密很难。 我建议您使用CCM或GCM等认证模式。Things to know in general:
Key != Password SecretKeySpec expects a key, not a password. See below It might be due to a policy restriction that prevents using 32 byte keys. See other answer on thatIn your case
The problem is number 1: you are passing the password instead of the key.
AES only supports key sizes of 16, 24 or 32 bytes. You either need to provide exactly that amount or you derive the key from what you type in.
There are different ways to derive the key from a passphrase. Java provides a PBKDF2 implementation for such a purpose.
I used erickson's answer to paint a complete picture (only encryption, since the decryption is similar, but includes splitting the ciphertext):
SecureRandom random = new SecureRandom(); byte[] salt = new byte[16]; random.nextBytes(salt); KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 256); // AES-256 SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1"); byte[] key = f.generateSecret(spec).getEncoded(); SecretKeySpec keySpec = new SecretKeySpec(key, "AES"); byte[] ivBytes = new byte[16]; random.nextBytes(ivBytes); IvParameterSpec iv = new IvParameterSpec(ivBytes); Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding"); c.init(Cipher.ENCRYPT_MODE, keySpec, iv); byte[] encValue = c.doFinal(valueToEnc.getBytes()); byte[] finalCiphertext = new byte[encValue.length+2*16]; System.arraycopy(ivBytes, 0, finalCiphertext, 0, 16); System.arraycopy(salt, 0, finalCiphertext, 16, 16); System.arraycopy(encValue, 0, finalCiphertext, 32, encValue.length); return finalCiphertext;Other things to keep in mind:
Always use a fully qualified Cipher name. AES is not appropriate in such a case, because different JVMs/JCE providers may use different defaults for mode of operation and padding. Use AES/CBC/PKCS5Padding. Don't use ECB mode, because it is not semantically secure. If you don't use ECB mode then you need to send the IV along with the ciphertext. This is usually done by prefixing the IV to the ciphertext byte array. The IV is automatically created for you and you can get it through cipherInstance.getIV(). Whenever you send something, you need to be sure that it wasn't altered along the way. It is hard to implement a encryption with MAC correctly. I recommend you to use an authenticated mode like CCM or GCM.更多推荐
发布评论