SslCreateEphemeralKey function

2021-01-07

The SslCreateEphemeralKey function creates an ephemeral key for use during the authentication that occurs during the Secure Sockets Layer protocol (SSL) handshake.

Syntax

SECURITY_STATUS WINAPI SslCreateEphemeralKey(
  _In_  NCRYPT_PROV_HANDLE hSslProvider,
  _Out_ NCRYPT_KEY_HANDLE  *phEphemeralKey,
  _In_  DWORD              dwProtocol,
  _In_  DWORD              dwCipherSuite,
  _In_  DWORD              dwKeyType,
  _In_  DWORD              dwKeyBitLen,
  _In_  PBYTE              pbParams,
  _In_  DWORD              cbParams,
  _In_  DWORD              dwFlags
);

Parameters

hSslProvider [in]: The handle of the SSL protocol provider instance.
phEphemeralKey [out]: The handle of the ephemeral key.
dwProtocol [in]: One of the CNG SSL Provider Protocol Identifier values.
dwCipherSuite [in]: One of the CNG SSL Provider Cipher Suite Identifier values.
dwKeyType [in]: One of the CNG SSL Provider Key Type Identifier values. Set this parameter to zero for key types that are not elliptic curve cryptography (ECC).
dwKeyBitLen [in]: The length, in bits, of the key.
pbParams [in]: A pointer to a buffer to contain parameters for the key that is to be created. If a Diffie-Hellman (ephemeral) key-exchange algorithm (DHE) cipher suite is not used, set the pbParams parameter to NULL and the cbParams parameter to zero.
cbParams [in]: The length, in bytes, of the data in the pbParams buffer.
dwFlags [in]: This parameter is reserved for future use.

Return value

If the function succeeds, it returns zero.

If the function fails, it returns a nonzero error value.

Return code/value	Description
NTE_NO_MEMORY 0x8009000EL	There is insufficient memory to allocate the buffer.
NTE_INVALID_HANDLE 0x80090026L	The hSslProvider handle is not valid.
NTE_INVALID_PARAMETER 0x80090027L	One of the supplied parameters is not valid.

Remarks

When using a DHE cipher suite, the internal SSL implementation passes server p and g parameters to the SslCreateEphemeralKey function in the pbParams and cbParams parameters.

The format of the data in the pbParams buffer is the same as that used when setting the BCRYPT_DH_PARAMETERS property, and it starts with a BCRYPT_DH_PARAMETER_HEADER structure.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Header	Sslprovider.h
DLL	Ncrypt.dll