最近工作需要将对方公司生成的RSA加密公钥进行明文加密和解密，发现了几点贴出来做个笔记。
RSA单次加密是有长度限制！微软封装的加密方法如果出现长度超出指定范围的话报错是直接报“该项不适于在指定状态下使用”...
如需加密只能分段加密！
直接将现在使用的封装类贴出来吧。
新建一个类，里面有很多扩展函数
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.ComponentModel; using System.Runtime.InteropServices; using System.Security.Cryptography; using System.Security.Cryptography.X509Certificates; using Org.BouncyCastle; using Org.BouncyCastle.Crypto; using Org.BouncyCastle.Math; using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Security; using Org.BouncyCastle.Crypto.Generators; using Org.BouncyCastle.Crypto.Engines; using Org.BouncyCastle.Asn1.X509; using Org.BouncyCastle.X509; using Org.BouncyCastle.Utilities.Collections; using Org.BouncyCastle.Asn1.Pkcs; using Org.BouncyCastle.Pkcs; using Org.BouncyCastle.Asn1; namespace TAPI.Common { public static class RSAExtensions { /// <summary> /// 把java的私钥转换成.net的xml格式 /// </summary> /// <param name="rsa"></param> /// <param name="privateJavaKey"></param> /// <returns></returns> public static string ConvertToXmlPrivateKey(this RSA rsa, string privateJavaKey) { RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateJavaKey)); string xmlPrivateKey = string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>", Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()), Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned())); return xmlPrivateKey; } /// <summary> /// RSA加载JAVA PrivateKey /// </summary> /// <param name="privateJavaKey">java提供的第三方私钥</param> /// <returns></returns> public static void FromPrivateKeyJavaString(this RSA rsa, string privateJavaKey) { string xmlPrivateKey = rsa.ConvertToXmlPrivateKey(privateJavaKey); rsa.FromXmlString(xmlPrivateKey); } /// <summary> /// 把java的公钥转换成.net的xml格式 /// </summary> /// <param name="publicJavaKey">java提供的第三方公钥</param> /// <returns></returns> public static string ConvertToXmlPublicJavaKey(this RSA rsa, string publicJavaKey) { RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicJavaKey)); string xmlpublicKey = string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>", Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()), Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned())); return xmlpublicKey; } /// <summary> /// 把java的私钥转换成.net的xml格式 /// </summary> /// <param name="publicJavaKey">java提供的第三方公钥</param> /// <returns></returns> public static void FromPublicKeyJavaString(this RSA rsa, string publicJavaKey) { string xmlpublicKey = rsa.ConvertToXmlPublicJavaKey(publicJavaKey); rsa.FromXmlString(xmlpublicKey); } ///// <summary> ///// RSA公钥格式转换，java->.net ///// </summary> ///// <param name="publicKey">java生成的公钥</param> ///// <returns></returns> //private static string ConvertJavaPublicKeyToDotNet(this RSA rsa,string publicKey) //{ // RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey)); // return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>", // Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()), // Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned())); //} /// <summary>Extension method for initializing a RSACryptoServiceProvider from PEM data string.</summary> #region Methods /// <summary>Extension method which initializes an RSACryptoServiceProvider from a DER public key blob.</summary> public static void LoadPublicKeyDER(this RSACryptoServiceProvider provider, byte[] DERData) { byte[] RSAData = GetRSAFromDER(DERData); byte[] publicKeyBlob = GetPublicKeyBlobFromRSA(RSAData); provider.ImportCspBlob(publicKeyBlob); } /// <summary>Extension method which initializes an RSACryptoServiceProvider from a DER private key blob.</summary> public static void LoadPrivateKeyDER(this RSACryptoServiceProvider provider, byte[] DERData) { byte[] privateKeyBlob = GetPrivateKeyDER(DERData); provider.ImportCspBlob(privateKeyBlob); } /// <summary>Extension method which initializes an RSACryptoServiceProvider from a PEM public key string.</summary> public static void LoadPublicKeyPEM(this RSACryptoServiceProvider provider, string sPEM) { byte[] DERData = GetDERFromPEM(sPEM); LoadPublicKeyDER(provider, DERData); } /// <summary>Extension method which initializes an RSACryptoServiceProvider from a PEM private key string.</summary> public static void LoadPrivateKeyPEM(this RSACryptoServiceProvider provider, string sPEM) { byte[] DERData = GetDERFromPEM(sPEM); LoadPrivateKeyDER(provider, DERData); } /// <summary>Returns a public key blob from an RSA public key.</summary> internal static byte[] GetPublicKeyBlobFromRSA(byte[] RSAData) { byte[] data = null; UInt32 dwCertPublicKeyBlobSize = 0; if (CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.RSA_CSP_PUBLICKEYBLOB), RSAData, (UInt32)RSAData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyBlobSize)) { data = new byte[dwCertPublicKeyBlobSize]; if (!CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.RSA_CSP_PUBLICKEYBLOB), RSAData, (UInt32)RSAData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyBlobSize)) throw new Win32Exception(Marshal.GetLastWin32Error()); } else throw new Win32Exception(Marshal.GetLastWin32Error()); return data; } /// <summary>Converts DER binary format to a CAPI CRYPT_PRIVATE_KEY_INFO structure.</summary> internal static byte[] GetPrivateKeyDER(byte[] DERData) { byte[] data = null; UInt32 dwRSAPrivateKeyBlobSize = 0; IntPtr pRSAPrivateKeyBlob = IntPtr.Zero; if (CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.PKCS_RSA_PRIVATE_KEY), DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwRSAPrivateKeyBlobSize)) { data = new byte[dwRSAPrivateKeyBlobSize]; if (!CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.PKCS_RSA_PRIVATE_KEY), DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwRSAPrivateKeyBlobSize)) throw new Win32Exception(Marshal.GetLastWin32Error()); } else throw new Win32Exception(Marshal.GetLastWin32Error()); return data; } /// <summary>Converts DER binary format to a CAPI CERT_PUBLIC_KEY_INFO structure containing an RSA key.</summary> internal static byte[] GetRSAFromDER(byte[] DERData) { byte[] data = null; byte[] publicKey = null; CERT_PUBLIC_KEY_INFO info; UInt32 dwCertPublicKeyInfoSize = 0; IntPtr pCertPublicKeyInfo = IntPtr.Zero; if (CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.X509_PUBLIC_KEY_INFO), DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyInfoSize)) { data = new byte[dwCertPublicKeyInfoSize]; if (CryptDecodeObject(CRYPT_ENCODING_FLAGS.X509_ASN_ENCODING | CRYPT_ENCODING_FLAGS.PKCS_7_ASN_ENCODING, new IntPtr((int)CRYPT_OUTPUT_TYPES.X509_PUBLIC_KEY_INFO), DERData, (UInt32)DERData.Length, CRYPT_DECODE_FLAGS.NONE, data, ref dwCertPublicKeyInfoSize)) { GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned); try { info = (CERT_PUBLIC_KEY_INFO)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(CERT_PUBLIC_KEY_INFO)); publicKey = new byte[info.PublicKey.cbData]; Marshal.Copy(info.PublicKey.pbData, publicKey, 0, publicKey.Length); } finally { handle.Free(); } } else throw new Win32Exception(Marshal.GetLastWin32Error()); } else throw new Win32Exception(Marshal.GetLastWin32Error()); return publicKey; } /// <summary>Extracts the binary data from a PEM file.</summary> internal static byte[] GetDERFromPEM(string sPEM) { UInt32 dwSkip, dwFlags; UInt32 dwBinarySize = 0; if (!CryptStringToBinary(sPEM, (UInt32)sPEM.Length, CRYPT_STRING_FLAGS.CRYPT_STRING_BASE64HEADER, null, ref dwBinarySize, out dwSkip, out dwFlags)) throw new Win32Exception(Marshal.GetLastWin32Error()); byte[] decodedData = new byte[dwBinarySize]; if (!CryptStringToBinary(sPEM, (UInt32)sPEM.Length, CRYPT_STRING_FLAGS.CRYPT_STRING_BASE64HEADER, decodedData, ref dwBinarySize, out dwSkip, out dwFlags)) throw new Win32Exception(Marshal.GetLastWin32Error()); return decodedData; } #endregion Methods #region P/Invoke Constants /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_ACQUIRE_CONTEXT_FLAGS : uint { CRYPT_NEWKEYSET = 0x8, CRYPT_DELETEKEYSET = 0x10, CRYPT_MACHINE_KEYSET = 0x20, CRYPT_SILENT = 0x40, CRYPT_DEFAULT_CONTAINER_OPTIONAL = 0x80, CRYPT_VERIFYCONTEXT = 0xF0000000 } /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_PROVIDER_TYPE : uint { PROV_RSA_FULL = 1 } /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_DECODE_FLAGS : uint { NONE = 0, CRYPT_DECODE_ALLOC_FLAG = 0x8000 } /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_ENCODING_FLAGS : uint { PKCS_7_ASN_ENCODING = 0x00010000, X509_ASN_ENCODING = 0x00000001, } /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_OUTPUT_TYPES : int { X509_PUBLIC_KEY_INFO = 8, RSA_CSP_PUBLICKEYBLOB = 19, PKCS_RSA_PRIVATE_KEY = 43, PKCS_PRIVATE_KEY_INFO = 44 } /// <summary>Enumeration derived from Crypto API.</summary> internal enum CRYPT_STRING_FLAGS : uint { CRYPT_STRING_BASE64HEADER = 0, CRYPT_STRING_BASE64 = 1, CRYPT_STRING_BINARY = 2, CRYPT_STRING_BASE64REQUESTHEADER = 3, CRYPT_STRING_HEX = 4, CRYPT_STRING_HEXASCII = 5, CRYPT_STRING_BASE64_ANY = 6, CRYPT_STRING_ANY = 7, CRYPT_STRING_HEX_ANY = 8, CRYPT_STRING_BASE64X509CRLHEADER = 9, CRYPT_STRING_HEXADDR = 10, CRYPT_STRING_HEXASCIIADDR = 11, CRYPT_STRING_HEXRAW = 12, CRYPT_STRING_NOCRLF = 0x40000000, CRYPT_STRING_NOCR = 0x80000000 } #endregion P/Invoke Constants #region P/Invoke Structures /// <summary>Structure from Crypto API.</summary> [StructLayout(LayoutKind.Sequential)] internal struct CRYPT_OBJID_BLOB { internal UInt32 cbData; internal IntPtr pbData; } /// <summary>Structure from Crypto API.</summary> [StructLayout(LayoutKind.Sequential)] internal struct CRYPT_ALGORITHM_IDENTIFIER { internal IntPtr pszObjId; internal CRYPT_OBJID_BLOB Parameters; } /// <summary>Structure from Crypto API.</summary> [StructLayout(LayoutKind.Sequential)] struct CRYPT_BIT_BLOB { internal UInt32 cbData; internal IntPtr pbData; internal UInt32 cUnusedBits; } /// <summary>Structure from Crypto API.</summary> [StructLayout(LayoutKind.Sequential)] struct CERT_PUBLIC_KEY_INFO { internal CRYPT_ALGORITHM_IDENTIFIER Algorithm; internal CRYPT_BIT_BLOB PublicKey; } #endregion P/Invoke Structures #region P/Invoke Functions /// <summary>Function for Crypto API.</summary> [DllImport("advapi32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptDestroyKey(IntPtr hKey); /// <summary>Function for Crypto API.</summary> [DllImport("advapi32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptImportKey(IntPtr hProv, byte[] pbKeyData, UInt32 dwDataLen, IntPtr hPubKey, UInt32 dwFlags, ref IntPtr hKey); /// <summary>Function for Crypto API.</summary> [DllImport("advapi32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptReleaseContext(IntPtr hProv, Int32 dwFlags); /// <summary>Function for Crypto API.</summary> [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptAcquireContext(ref IntPtr hProv, string pszContainer, string pszProvider, CRYPT_PROVIDER_TYPE dwProvType, CRYPT_ACQUIRE_CONTEXT_FLAGS dwFlags); /// <summary>Function from Crypto API.</summary> [DllImport("crypt32.dll", SetLastError = true, CharSet = CharSet.Auto)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptStringToBinary(string sPEM, UInt32 sPEMLength, CRYPT_STRING_FLAGS dwFlags, [Out] byte[] pbBinary, ref UInt32 pcbBinary, out UInt32 pdwSkip, out UInt32 pdwFlags); /// <summary>Function from Crypto API.</summary> [DllImport("crypt32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptDecodeObjectEx(CRYPT_ENCODING_FLAGS dwCertEncodingType, IntPtr lpszStructType, byte[] pbEncoded, UInt32 cbEncoded, CRYPT_DECODE_FLAGS dwFlags, IntPtr pDecodePara, ref byte[] pvStructInfo, ref UInt32 pcbStructInfo); /// <summary>Function from Crypto API.</summary> [DllImport("crypt32.dll", SetLastError = true)] [return: MarshalAs(UnmanagedType.Bool)] internal static extern bool CryptDecodeObject(CRYPT_ENCODING_FLAGS dwCertEncodingType, IntPtr lpszStructType, byte[] pbEncoded, UInt32 cbEncoded, CRYPT_DECODE_FLAGS flags, [In, Out] byte[] pvStructInfo, ref UInt32 cbStructInfo); #endregion P/Invoke Functions } }