我正在使用 CryptEncryptMessage生成 PKCS#7封装的消息。我正在使用 szOID_NIST_AES256_CBC作为加密算法。

生成的消息似乎是有效的，但是 RSAES-OAEP对于在野外支持有限的关键传输算法(Thunderbird、OpenSSL SMIME 模块等不支持它)。

我希望 CAPI 恢复到旧版本 RSAencryption用于 key 传输。

有没有办法做到这一点，如果有办法而不是使用 CryptEncryptMessage，我可以恢复到低级消息传递功能。但即使使用低级函数，我也找不到办法做到这一点。

代码:

CRYPT_ENCRYPT_MESSAGE_PARA EncryptMessageParams;
EncryptMessageParams.cbSize = sizeof(CMSG_ENVELOPED_ENCODE_INFO);

EncryptMessageParams.dwMsgEncodingType = PKCS_7_ASN_ENCODING;

EncryptMessageParams.ContentEncryptionAlgorithm.pszObjId = szOID_NIST_AES256_CBC;
EncryptMessageParams.ContentEncryptionAlgorithm.Parameters.cbData = 0;
EncryptMessageParams.ContentEncryptionAlgorithm.Parameters.pbData = 0;

EncryptMessageParams.hCryptProv = NULL;
EncryptMessageParams.pvEncryptionAuxInfo = NULL;
EncryptMessageParams.dwFlags = 0;
EncryptMessageParams.dwInnerContentType = 0;

BYTE pbEncryptedBlob[640000];
DWORD pcbEncryptedBlob = 640000;

BOOL retval =  CryptEncryptMessage(&EncryptMessageParams, cRecipientCert, pRecipCertContextArray, pbMsgText, dwMsgTextSize, pbEncryptedBlob, &pcbEncryptedBlob);

最佳答案

key 传输算法处理起来有点棘手，它可能达不到它的目的(我看到您注意到您希望 CAPI 支持 RSAencryption ；相信我，我也会这样做)。看起来您已经发现了大部分问题 - 生成的消息显示是有效的，但是您的方法必须使用 CryptEncryptMessage ，从长远来看，这不会很好/根本不起作用。
步骤 1 - 检查代码

CRYPT_ENCRYPT_MESSAGE_PARA EncryptMessageParams;
EncryptMessageParams.cbSize = sizeof(CMSG_ENVELOPED_ENCODE_INFO);

EncryptMessageParams.dwMsgEncodingType = PKCS_7_ASN_ENCODING;

EncryptMessageParams.ContentEncryptionAlgorithm.pszObjId = szOID_NIST_AES256_CBC;
EncryptMessageParams.ContentEncryptionAlgorithm.Parameters.cbData = 0;
EncryptMessageParams.ContentEncryptionAlgorithm.Parameters.pbData = 0;

EncryptMessageParams.hCryptProv = NULL;
EncryptMessageParams.pvEncryptionAuxInfo = NULL;
EncryptMessageParams.dwFlags = 0;
EncryptMessageParams.dwInnerContentType = 0;

BYTE pbEncryptedBlob[640000];
DWORD pcbEncryptedBlob = 640000;

BOOL retval =  CryptEncryptMessage(&EncryptMessageParams, cRecipientCert, pRecipCertContextArray, pbMsgText, dwMsgTextSize, pbEncryptedBlob, &pcbEncryptedBlob);

EncryptMessageParams.dwFlags = 0;
EncryptMessageParams.dwInnerContentType = 0;

DWORD cbName;
DWORD dwType;
DWORD dwIndex;
CHAR *pszName = NULL;
(regular crypt calls here)

DWORD dwBufferLen = strlen((char *)pbBuffer)+1*(0+5);
HCRYPTHASH hHash;
HCRYPTKEY hKey;
HCRYPTKEY hPubKey;
BYTE *pbKeyBlob;
BYTE *pbSignature;
DWORD dwSigLen;
DWORD dwBlobLen;
(use hash as normal w/ crypt calls and the pbKeyBlobs/Signatures)

if(CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL, 0)) {
     printf("CSP context acquired.\n");
}

CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET)

BOOL WINAPI CryptAcquireContext(
  _Out_  HCRYPTPROV *phProv,
  _In_   LPCTSTR pszContainer,
  _In_   LPCTSTR pszProvider,
  _In_   DWORD dwProvType,
  _In_   DWORD dwFlags
);

If the CSP must display the UI to operate, the call fails and the NTE_SILENT_CONTEXT error code is set as the last error. In addition, if calls are made to CryptGenKey with the CRYPT_USER_PROTECTED flag with a context that has been acquired with the CRYPT_SILENT flag, the calls fail and the CSP sets NTE_SILENT_CONTEXT.

if (GetLastError() == NTE_BAD_KEYSET)
 {
   if(CryptAcquireContext(
      &hCryptProv, 
      UserName, 
      NULL, 
      PROV_RSA_FULL, 
      CRYPT_NEWKEYSET)) 
    {
      printf("A new key container has been created.\n");
    }
    else
    {
      printf("Could not create a new key container.\n");
      exit(1);
    }
  }
  else
  {
      printf("A cryptographic service handle could not be "
          "acquired.\n");
      exit(1);
   }

关于c - Microsoft Crypto API 禁止使用 RSAES-OAEP key 传输算法，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13090176/