# SSLGetDiffieHellmanParams(_:_:_:) Retrieves the Diffie-Hellman parameters for a given context. ``` func SSLGetDiffieHellmanParams(_ context: SSLContext, _ dhParams: UnsafeMutablePointer, _ dhParamsLen: UnsafeMutablePointer) -> OSStatus ``` ## Parameters `context` An SSL session context reference. `dhParams` On return, points to a buffer containing the Diffie-Hellman parameter block in Open SSL DER format.The returned data is not copied and belongs to the SSL session context reference; therefore, you cannot modify the data and it is released automatically when you dispose of the context. `dhParamsLen` On return, points to the length of the buffer pointed to by the `dhParams` parameter. ## Return Value A result code. See [Secure Transport Result Codes](/documentation/Security/secure-transport-result-codes). ## Discussion This function returns the parameter block specified in an earlier call to the [`SSLSetDiffieHellmanParams(_:_:_:)`](/documentation/Security/SSLSetDiffieHellmanParams(_:_:_:)) function. If that function was never called, the `dhParams` parameter returns `NULL` and the `dhParamsLen` parameter returns `0`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)