如何使用本机代码从XML或模数/指数导入RSA公钥，以与Windows CAPI的CryptVerifySignature一起使用？ [英] How can I import an RSA public key from either XML or modulus/exponent in native code for use with Windows CAPI's CryptVerifySignature?

问题描述

在C＃中，我可以通过以下两种方式验证针对公钥的哈希：

  //使用（RSACryptoServiceProvider rsa = new RSACryptoServiceProvider（））{
 RSAParameters rsaKeyInfo = new RSAParameters {模量=模数，指数=指数}；从原始模数和指数
导入。 
 rsa.ImportParameters（rsaKeyInfo）; 
 return rsa.VerifyHash（hash，CryptoConfig.MapNameToOID（ SHA512），签名）; 
} 
 
 //使用（RSACryptoServiceProvider rsa = new RSACryptoServiceProvider（））从XML 
导入{
 rsa.FromXmlString（xmlPublicKey）; 
 return rsa.VerifyHash（hash，CryptoConfig.MapNameToOID（ SHA512），签名）; 
} 
  

我需要知道的是如何使用CAPI完成同一件事

我具有验证哈希所需的大多数CAPI函数，除了了解如何将公共密钥导入密码提供者的上下文外：

  HCRYPTPROV hCryptProv; 
 HCRYPTHASH哈希； 
 
 CryptAcquireContext（& hCryptProv，NULL，NULL，PROV_RSA_FULL，0）; 
 CryptCreateHash（hCryptProv，CALG_SHA512，0，0，&hHash）; 
 CryptHashData（hHash，pDataToHash，lenDataToHash，0）; 
 CryptVerifySignature（hHash，pSignature，sigLength，NULL，CRYPT_NOHASHOID）; 
 CryptDestroyHash（hHash）; 
 CryptReleaseContext（hCryptProv，0）; 
  

谢谢！

解决方案

使用 CryptImportKey 和 PUBLICKEYBLOB ：

  HCRYPTKEY hPublicKey; 
 DWORD keyBlobLength = sizeof（BLOBHEADER）+ sizeof（RSAPUBKEY）+ modulusLengthInBytes; 
 BYTE * keyBlob = malloc（keyBlobLength）; 
 BLOBHEADER * blobheader =（BLOBHEADER *）keyBlob; 
 blobheader.bType = PUBLICKEYBLOB; 
 blobheader.bVersion = CUR_BLOB_VERSION; 
 blobheader.reserved = 0; 
 blobheader.aiKeyAlg = CALG_RSA_KEYX; 
 RSAPUBKEY * rsapubkey =（RSAPUBKEY *）（keyBlob + sizeof（BLOBHEADER））; 
 rsapubkey.magic = 0x31415352; 
 rsapubkey.bitlen = factorLengthInBytes * 8; 
 rsapubkey.pubexp = 65537; //或您的公开指数是多少。 
 BYTE *模数= keyBlob + sizeof（BLOBHEADER）+ sizeof（RSAPUBKEY）; 
 memcpy（modulus，...，factorLengthInBytes）; //注意：模数必须采用LSB形式，即
 //与
通常具有的相反。 
 // .NET将以
 // MSB形式给出模数，因此您将不得不
 //反转字节顺序。 
 CryptImportKey（hCryptProv，keyBlob，keyBlobLength，0，0，&hPublicKey）; 
  

In C#, I am able to validate a hash against a public key in either of the following ways:

// Import from raw modulus and exponent
using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider()) {
    RSAParameters rsaKeyInfo = new RSAParameters {Modulus = modulus, Exponent = exponent};
    rsa.ImportParameters(rsaKeyInfo);
    return rsa.VerifyHash(hash, CryptoConfig.MapNameToOID("SHA512"), signature);
}

// Import from XML
using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider()) {
    rsa.FromXmlString(xmlPublicKey);
    return rsa.VerifyHash(hash, CryptoConfig.MapNameToOID("SHA512"), signature);
}

What I need to know is how I can use CAPI to accomplish the same thing, given an inbound RSA public key?

I have most of the CAPI functions necessary to validate a hash, except for understanding how to import a public key into the cryptographic provider's context:

HCRYPTPROV hCryptProv;
HCRYPTHASH hHash;

CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0);
CryptCreateHash(hCryptProv, CALG_SHA512, 0, 0, &hHash);
CryptHashData(hHash, pDataToHash, lenDataToHash, 0);
CryptVerifySignature(hHash, pSignature, sigLength, NULL, CRYPT_NOHASHOID);
CryptDestroyHash(hHash);
CryptReleaseContext(hCryptProv, 0);

Thanks!

解决方案

Use CryptImportKey with a PUBLICKEYBLOB:

HCRYPTKEY hPublicKey;
DWORD keyBlobLength = sizeof(BLOBHEADER)+sizeof(RSAPUBKEY)+modulusLengthInBytes;
BYTE* keyBlob = malloc(keyBlobLength);
BLOBHEADER* blobheader = (BLOBHEADER*) keyBlob;
blobheader.bType    = PUBLICKEYBLOB;
blobheader.bVersion = CUR_BLOB_VERSION;
blobheader.reserved = 0;
blobheader.aiKeyAlg = CALG_RSA_KEYX;
RSAPUBKEY* rsapubkey = (RSAPUBKEY*) (keyBlob + sizeof(BLOBHEADER));
rsapubkey.magic     = 0x31415352;
rsapubkey.bitlen    = modulusLengthInBytes*8;
rsapubkey.pubexp    = 65537;         // Or whatever your public exponent is.
BYTE* modulus = keyBlob + sizeof(BLOBHEADER) + sizeof(RSAPUBKEY);
memcpy(modulus, ..., modulusLengthInBytes); // NOTE: modulus must be in LSB form,
                                     //       which is the opposite of what you
                                     //        usually have. 
                                     //       .NET will give you the modulus in
                                     //       MSB form, so you will have to
                                     //       reverse the order of the bytes.
CryptImportKey(hCryptProv, keyBlob, keyBlobLength, 0, 0, &hPublicKey);

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