DotNET Core RSA Guide and Enhanced Extensions RSAExtensions

I. Introduction

As the most commonly used asymmetric encryption algorithm, RSA is still quite common in our actual use, especially when it comes to docking payments, or other business scenarios that require data security. In the .NET Framework and .NET Core <3.0, the RSA object that comes with .NET only supports Keys expressed in XML standard form. This has undoubtedly caused many difficulties in interfacing with other languages. For example, the commonly used key format in Java is PKCS # 8. , JavaScript generally uses PKCS # 1, which is invariable. Although these keys have different formats, as long as we import them into .NET RSA objects, we can support them. Previously we mainly relied on a third party library BouncyCastle to implement these support.

Earlier I wrapped a component based on BouncyCastle to support PKCS # 1 and PKCS # 8.

Now .NET Core 3.0 officially adds support for PKCS # 1 and PKCS # 8 (password) Key import and export. This is really very nice, please see the breakdown below for details.

2. RSA Key Cognition

Here mainly introduces the key of three commonly used formats, XML, PKCS # 1, PKCS # 8

XML private key:

<RSAKeyValue>
  <Modulus>09Hvw+dbHzi8x+9A1b2S0/128nA61ZyiaazJcDCUety4yHg0cdp5NOnyH35njYR4u2XO5l4GptwzJQfkEzCNoAniofBkb/WMQjvUhJ30eVpa7p/aq+4cgnMYuwYRCOLAB3jpldzIvii1+BOr3oLeT+1blK9f8u3T5liIxV3DBFxEWbnhQWHMgYXpDBIV9cjVhLYZLznefoWZ8N9bVdg1aucgYSWiPbURdfZusyS2fUJgiDLu63KQw8Bhc9cIMnUh6fq2UIBMk1mg/zuKyuMzCM8FX/VvleXJwS11LAgkEhtkOKQXo2xB65+zxPAUl0mKWGKSP9gY8p0+cav4nFCSLQ==</Modulus>
  <Exponent>AQAB</Exponent>
  <P>6ZEU55sugjc/qcPW0u0fSxy5tJYI+8tFsKfw/5AAm4pq2SVfDQHkRODlv5Zr8DnFQz7WN2L7FL6f11qdIjO4/dF9oo5YlD+jlmTOdaZovNLT0w0KGnN3ChFnnyxyNSG33sxlwgUrBppY2W4Sh0rzNQ4VIBhGes6dHxuMg0hWCKM=</P>
  <Q>6ComYZkP5fJrT5tWNSTkb+UGyUwxquXWAgZB8GCkAzrc5t3QgPe+1W0bUSJOVddPX6mxx6yaM+ZMFc5pwdcyxYJ90+T/m2NNviMOC2fHB457OWr4HO0DloYHlWbniXfkOLGrWHshcbIEwbsYWnVYF3mOF2b/xDuDUB57B71Flu8=</Q>
  <DP>k9guL1zfV7W5KrC4btOCF32bX2AJV7kX5/amal6ww8QeVk19mTI1WBQz2c5RjMJEx4gi+PRCkqMHcr388QVkd+X/bMJF97FAz5YHyhkH+15IjzOVzaCBHXJe8TalJFSvmuwvDV1QGuHgk+FFATbENDUx0hsLofjfJC3AB+nl65k=</DP>
  <DQ>v80qvlDUuJUpILBlbSxYaTTeAWmoUtbkkfGXgj5k4aI8o6K3QgTrLKmh+sqLyxFBKvgnvp2TG7N0QkOwTYs7D795spgqr7Y/oQiW7sdCv7RviwUbi9Int7BtDXnhaUmaS1hFBalb/PEkSuUF/p2ZNHOg9yaJwRWlq4gy/jbZChM=</DQ>
  <InverseQ>EydINmQ+aX8+2W7ZxU66P+0XSYsA2M/m7eF0cn5B+N3E2TOYgwunWqjPksyprEtNlP/puf7li/g8G5j3fQ0Xy/KrVwR2emcvCZMqpjzkYhSn9KcVHUVJg/LHb7BDVx/uSZwj9Ok2qDX73PSa91DEsIPiKPQjkVw1QJJ19wlJMiQ=</InverseQ>
  <D>MzwYbp5LYCXtI78vQ4PzO+uXFdUnpfuZHU55+vUFNSKmX3cT2GYr4yyjMBL3ITflrA5YGUis+zdP96kM9cdMumUpuFnZMWuHXY3zPZCnTaMZU5a+4c9afgMw/CvfevK92BDbDzC0LarTOQopDE1DULns6O3ym2QDWTgY/QRM44StLMEaLjNdVhLS3lMZJPrMCtk1k044RStUkL/7yiLMUYtXV+Lpy/08dyHWdXfBcakusKw8EEZZ53skFeR6mkWT51wyKmBFf7D6rfUC+e282i8OGayu79zXvA0UutmUGa1Q9eAP8qsBrc/i++qa/X3JnfBrFyEwQBfQV3kiOM3T0Q==</D>
</RSAKeyValue>

XML public key:

<RSAKeyValue>
  <Modulus>o9AYbnx0a9YHjhnaE8E8w1plNsmyqg2tW41sakkoELxRz5PlDAsmc31caXUveSzBY8obp5Jt0hF9EIqY5wzLZQ==</Modulus>
  <Exponent>AQAB</Exponent>
</RSAKeyValue>

PKCS # 1 private key:

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

PKCS # 8 private key:

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

PKCS # 1 public key:

MEgCQQDQViO4nQdwtCq9sOQb99evu/Pjkhk4TpEnn+6uXMz2LaS9xmUtX8lOVCMMlzoSNdu6vPskfUgMGud2hOpcgnLdAgMBAAE=

The keys of PKCS # 1 and PKCS # 8 are encoded by Base64. The public key has only the form of PKCS # 1. That is, the public key corresponding to the private key in the PKCS # 8 format is also in the form of PKCS # 1. Public key.

It is difficult to distinguish the PKCS # 1 and PKCS # 8 private keys from the naked eye.

The XML Key standard expression form shows several parts of the RSA algorithm, mainly: Modulus, Exponent, P, Q, DP, DQ, InverseQ, D. The private key contains all parts, and the public key only contains two parts, Modulus and Exponent, so the public key can be derived with the private key.

Three. Key PEM

PEM is a format of the Key to make it easier to identify. Based on the ordinary string Key above, it splits the string, mainly adding a prefix and suffix and splitting each line into 64 characters.

PKCS # 1 public key

-----BEGIN RSA PUBLIC KEY-----
BASE64 ENCODED DATA
-----END RSA PUBLIC KEY-----

PKCS # 8 public key

-----BEGIN PUBLIC KEY-----
BASE64 ENCODED DATA
-----END PUBLIC KEY-----

PKCS # 1 private key

-----BEGIN RSA PRIVATE KEY-----
BASE64 ENCODED DATA
-----END RSA PRIVATE KEY-----

PKCS # 8 private key

-----BEGIN PRIVATE KEY-----
BASE64 ENCODED DATA
-----END PRIVATE KEY-----

The PKCS # 8 public key mentioned here is not the real public key in the PKCS # 8 format, but the PEM corresponding to the PKCS # 8 Key, that is, the suffixes are different, and their content bodies are the same.

The suffixes of PKCS # 1 and PKCS # 8 are mainly different from “RSA” characters.

Example: PKCS # 8 PEM private key

What’s New in .NET Core 3.0 RSA

.NET Core 3.0 officially adds support for PKCS # 1 and PKCS # 8 (password) Key import and export. PKCS # 1 is the default format.

Method name
Description

ExportRSAPrivateKey	Export PKCS # 1 private key
ExportRSAPublicKey	Export PKCS # 1 public key
ExportPkcs8PrivateKey	Export PKCS # 8 private key
ExportEncryptedPkcs8PrivateKey	Export PKCS # 8 encrypted private key
ImportRSAPrivateKey	Import PKCS # 1 private key
ImportRSAPublicKey	Import PKCS # 1 public key
ImportPkcs8PrivateKey	Import PKCS # 8 private key
ImportEncryptedPkcs8PrivateKey	Import PKCS # 8 encrypted private key

Take the PKCS # 1 format as an example, the usage is as follows:

var rsa = RSA.Create();

//导出
Console.WriteLine("RSA PKCS#1 私钥：");
Console.WriteLine(Convert.ToBase64String(rsa.ExportRSAPrivateKey()));
Console.WriteLine("RSA PKCS#1 公钥：");
Console.WriteLine(Convert.ToBase64String(rsa.ExportRSAPublicKey()));

//导入
rsa.ImportRSAPrivateKey(Convert.FromBase64String("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"), out _);
           rsa.ImportRSAPublicKey(Convert.FromBase64String("MIIBCgKCAQEArTLJkbnYqeNXjy1iznnEi8bZjVbP4NabvftKFMdYeCCHfeHXZEvaJFbWcybmWwfj4ZjHH+/hh1RRQVMNgQUD8uXYmdjn7bUAfeyT9ujSulEFzwM2Udm6XtnI5/K2WH9ZHEPqUqNgv0EEthV6Yz+SQYFSYO2xd+TzLMvnW/iCmgb9gQfl85L+cKVvQy2NOod3i+gbTwPM8im1fP43vqVUUE5OD+Hz1Hiwai/RJDC67ZhoSdv1Vor8t9uyg+03fa8gfPj52gFRyHh3y8d/bb1LrJwbXV3cBCLD9aw9bnW3rFRwpP+JuH9VKSpoRA3gwD3vhoz7Y8BBOsC6PSrusAm/lQIDAQAB"), out _);

Output:

DotNET_Core_RSA_Guide_and_Enhanced_Extensions_RSAExtensions_0.png

It is very simple to use. If you use PKCS # 8, change the method name of the above sample code.

The target framework used by projects using these APIs meets:

Platform name
Support version number

.NET Core	> = 3.0
.NET Standard	> = 2.1

V. Introduction to RSAExtensions

As can be seen from the above, .NET Core has native support for PKCS # 1 and PKCS # 8, which is very convenient for interfacing with other languages, but the disadvantage is that there is no support for PEM and XML format.

The RSAExtensions project is to make up for this shortcoming and supports RSA big data encryption. Extension methods based on RSA objects are also very convenient to use.

Open source address:
https://github.com/stulzq/RSAExtensions

(hope for a Star support)

Nuget:
https://www.nuget.org/packages/RSAExtensions

RSAExtensions functions are as follows:

Provides key import and export in the XML format that previous Frameworks have
Provide support for PKCS # 1, PKCS # 8 PEM format import and export
Provide unified import and export of PKCS # 1, PKCS # 8, XML format
Provides support for big data segment encryption

Added API:

Method name
Description

ExportPrivateKey	Unified export of private keys, support PKCS # 1, PKCS # 8, XML and PEM formatting
ExportPublicKey	Unified public key export, support PKCS # 1, PKCS # 8, XML and PEM formatting
ImportPrivateKey	Unified import of private keys, supporting PKCS # 1, PKCS # 8, XML, and PEM
ImportPublicKey	Unified import of public keys, supporting PKCS # 1, PKCS # 8, XML, and PEM
ImportXmlPrivateKey	Import XML private key
ImportXmlPublicKey	Import XML public key
ExportXmlPrivateKey	Export XML private key
ExportXmlPublicKey	Export XML public key
EncryptBigData	Big data segment encryption
DecryptBigData	Big data segment decryption

6. Use of RSAExtensions

using System.Security.Cryptography;

var rsa=RSA.Create();

Export

PKCS # 1 export

rsa.ExportPrivateKey(RSAKeyType.Pkcs1); //私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs1); // 公钥

Private key output:

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

PKCS # 1 PEM export

rsa.ExportPrivateKey(RSAKeyType.Pkcs1,true);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs1,true);//公钥

Private key output:

PKCS # 8 export

rsa.ExportPrivateKey(RSAKeyType.Pkcs8);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs8);//公钥

Private key output:

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

PKCS # 8 PEM export

rsa.ExportPrivateKey(RSAKeyType.Pkcs8, true);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs8, true);//公钥

Private key output:

XML export

rsa.ExportPrivateKey(RSAKeyType.Xml);//私钥
rsa.ExportPublicKey(RSAKeyType.Xml);//公钥

Private key output:

<RSAKeyValue>
  <Modulus>09Hvw+dbHzi8x+9A1b2S0/128nA61ZyiaazJcDCUety4yHg0cdp5NOnyH35njYR4u2XO5l4GptwzJQfkEzCNoAniofBkb/WMQjvUhJ30eVpa7p/aq+4cgnMYuwYRCOLAB3jpldzIvii1+BOr3oLeT+1blK9f8u3T5liIxV3DBFxEWbnhQWHMgYXpDBIV9cjVhLYZLznefoWZ8N9bVdg1aucgYSWiPbURdfZusyS2fUJgiDLu63KQw8Bhc9cIMnUh6fq2UIBMk1mg/zuKyuMzCM8FX/VvleXJwS11LAgkEhtkOKQXo2xB65+zxPAUl0mKWGKSP9gY8p0+cav4nFCSLQ==</Modulus>
  <Exponent>AQAB</Exponent>
  <P>6ZEU55sugjc/qcPW0u0fSxy5tJYI+8tFsKfw/5AAm4pq2SVfDQHkRODlv5Zr8DnFQz7WN2L7FL6f11qdIjO4/dF9oo5YlD+jlmTOdaZovNLT0w0KGnN3ChFnnyxyNSG33sxlwgUrBppY2W4Sh0rzNQ4VIBhGes6dHxuMg0hWCKM=</P>
  <Q>6ComYZkP5fJrT5tWNSTkb+UGyUwxquXWAgZB8GCkAzrc5t3QgPe+1W0bUSJOVddPX6mxx6yaM+ZMFc5pwdcyxYJ90+T/m2NNviMOC2fHB457OWr4HO0DloYHlWbniXfkOLGrWHshcbIEwbsYWnVYF3mOF2b/xDuDUB57B71Flu8=</Q>
  <DP>k9guL1zfV7W5KrC4btOCF32bX2AJV7kX5/amal6ww8QeVk19mTI1WBQz2c5RjMJEx4gi+PRCkqMHcr388QVkd+X/bMJF97FAz5YHyhkH+15IjzOVzaCBHXJe8TalJFSvmuwvDV1QGuHgk+FFATbENDUx0hsLofjfJC3AB+nl65k=</DP>
  <DQ>v80qvlDUuJUpILBlbSxYaTTeAWmoUtbkkfGXgj5k4aI8o6K3QgTrLKmh+sqLyxFBKvgnvp2TG7N0QkOwTYs7D795spgqr7Y/oQiW7sdCv7RviwUbi9Int7BtDXnhaUmaS1hFBalb/PEkSuUF/p2ZNHOg9yaJwRWlq4gy/jbZChM=</DQ>
  <InverseQ>EydINmQ+aX8+2W7ZxU66P+0XSYsA2M/m7eF0cn5B+N3E2TOYgwunWqjPksyprEtNlP/puf7li/g8G5j3fQ0Xy/KrVwR2emcvCZMqpjzkYhSn9KcVHUVJg/LHb7BDVx/uSZwj9Ok2qDX73PSa91DEsIPiKPQjkVw1QJJ19wlJMiQ=</InverseQ>
  <D>MzwYbp5LYCXtI78vQ4PzO+uXFdUnpfuZHU55+vUFNSKmX3cT2GYr4yyjMBL3ITflrA5YGUis+zdP96kM9cdMumUpuFnZMWuHXY3zPZCnTaMZU5a+4c9afgMw/CvfevK92BDbDzC0LarTOQopDE1DULns6O3ym2QDWTgY/QRM44StLMEaLjNdVhLS3lMZJPrMCtk1k044RStUkL/7yiLMUYtXV+Lpy/08dyHWdXfBcakusKw8EEZZ53skFeR6mkWT51wyKmBFf7D6rfUC+e282i8OGayu79zXvA0UutmUGa1Q9eAP8qsBrc/i++qa/X3JnfBrFyEwQBfQV3kiOM3T0Q==</D>
</RSAKeyValue>

Import

PKCS # 1 import

rsa.ImportPrivateKey(RSAKeyType.Pkcs1, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs1, "<publicKey>"); //公钥

PKCS # 1 PEM import

rsa.ImportPrivateKey(RSAKeyType.Pkcs1, "<privateKey>",true); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs1, "<publicKey>",true); //公钥

PKCS # 8 import

rsa.ImportPrivateKey(RSAKeyType.Pkcs8, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs8, "<publicKey>"); //公钥

PKCS # 8 PEM import

rsa.ImportPrivateKey(RSAKeyType.Pkcs8, "<privateKey>",true); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs8, "<publicKey>",true); //公钥

XML import

rsa.ImportPrivateKey(RSAKeyType.Xml, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Xml, "<publicKey>"); //公钥

Seven. RSAExtensions big data segment encryption

The “length” referred to below is the length in bytes.

The length of the encrypted data of the RSA algorithm is based on different padding algorithms. Generally, it supports data of equal Key modulus length. If the length exceeds this length, the data will be split and encrypted.

.NET Core does not support RSA_NO_PADDING padding

Key module length = KeySize / 8

The following are the supported encrypted data lengths of the padding algorithms supported by .NET Core that I tested and sorted out:

Fill algorithm
Minimum KeySize
Maximum encrypted data length

Pkcs1	512	Die length-11
OaepSHA1	512	Die length -42
OaepSHA256	1024	Die length -66
OaepSHA384	1024	Die length -98
OaepSHA512	2048	Mold length -130

RSAExtensions has encapsulated the piecewise encryption, there is no need to care about the relationship between the data length and the module length. The usage method is as follows:

var encrypt = rsa.EncryptBigData(data, <填充算法>); //加密
var decrypt = rsa.DecryptBigData(encrypt, <填充算法>); //解密

8. Data encryption and decryption

Encryption and decryption mainly use two methods: Encryptcalculate the ciphertext, and Decryptdecrypt based on the ciphertext

example:

var rsa = RSA.Create();
var data = "aaa";
var encrypt = rsa.Encrypt(Encoding.UTF8.GetBytes(data),RSAEncryptionPadding.Pkcs1); //加密
rsa.Decrypt(encrypt, RSAEncryptionPadding.Pkcs1); //解密

RSA in .NET only supports public key encryption, private key decryption

Nine. Data signature and verification

Signing and checking use two methods: SignDatacalculating data signatures and VerifyDataverifying data signatures. Sign with public key and check with private key.

example:

var rsa = RSA.Create();
var data = "aaa";
var sign = rsa.SignData(Encoding.UTF8.GetBytes(data), HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1); //签名
rsa.VerifyData(Encoding.UTF8.GetBytes(data), sign, HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1); //验签

10. Tips for using

Key conversion

Import from one format and export using another format.

Example: Private key PKCS # 1 is converted to PKCS # 8

var rsa = RSA.Create();
rsa.ImportRSAPrivateKey(<PKCS#1私钥>,out _); //导入PKCS#1私钥
rsa.ExportPkcs8PrivateKey() //导出为PKCS#8私钥

2. Private key derived public key

var rsa = RSA.Create();
rsa.ImportRSAPrivateKey(<PKCS#1私钥>,out _); //导入PKCS#1私钥
rsa.ExportRSAPublicKey(); //导出私钥

3.PKCS # 8 encryption private key to password

var rsa = RSA.Create();
rsa.ImportEncryptedPkcs8PrivateKey(password,paivateKey); //导入加密私钥
rsa.ExportPkcs8PrivateKey(); //导出无密码私钥

4. Generate a conversion key through the command line

Open source tool DotnetRSA quickly generates and converts RSA keys

11. Common mistakes

Error code:var rsa = RSA.Create(256);

abnormal:

Unhandled exception. System.Security.Cryptography.CryptographicException: Specified key is not a valid size for this algorithm.

Solution: KeySize is not enough, increase KeySize size

Error code:rsa.Encrypt

abnormal:

Unhandled exception. Internal.Cryptography.CryptoThrowHelper+WindowsCryptographicException: 参数错误。

Solution: KeySize is not enough, increase the KeySize size or the data is too long, you need to choose large data segment encryption

Error code:rsa.Encrypt

abnormal:

Unhandled exception. System.Security.Cryptography.CryptographicException: The message exceeds the maximum allowable length for the chosen options (53).

Solution: The data is too long, you need to choose big data segment encryption

Error code: rsa.ImportxxxxImport Key

abnormal:

Unhandled exception. System.Security.Cryptography.CryptographicException: ASN1 corrupted data.

Solution: The import method does not match the Key format, replace the import method

12. End

RSAExtensions open source address:
https://github.com/stulzq/RSAExtensions

(hope a Star to support it)

Reference article:

Orignal link:https://www.cnblogs.com/stulzq/p/12053976.html

DotNET Core RSA Guide and Enhanced Extensions RSAExtensions

I. Introduction

2. RSA Key Cognition

Three. Key PEM

What’s New in .NET Core 3.0 RSA

V. Introduction to RSAExtensions

6. Use of RSAExtensions

Export

PKCS # 1 export

PKCS # 1 PEM export

PKCS # 8 export

PKCS # 8 PEM export

XML export

Import

PKCS # 1 import

PKCS # 1 PEM import

PKCS # 8 import

PKCS # 8 PEM import

XML import

Seven. RSAExtensions big data segment encryption

8. Data encryption and decryption

Nine. Data signature and verification

10. Tips for using

11. Common mistakes

12. End

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Categories

DotNET Core RSA Guide and Enhanced Extensions RSAExtensions

I. Introduction

2. RSA Key Cognition

Three. Key PEM

What’s New in .NET Core 3.0 RSA

V. Introduction to RSAExtensions

6. Use of RSAExtensions

Export

PKCS # 1 export

PKCS # 1 PEM export

PKCS # 8 export

PKCS # 8 PEM export

XML export

Import

PKCS # 1 import

PKCS # 1 PEM import

PKCS # 8 import

PKCS # 8 PEM import

XML import

Seven. RSAExtensions big data segment encryption

8. Data encryption and decryption

Nine. Data signature and verification

10. Tips for using

11. Common mistakes

12. End

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