Contents

expand(pseudoRandomKey:info:outputByteCount:)

Expands cryptographically strong key material into a derived symmetric key.

Declaration

static func expand<PRK, Info>(pseudoRandomKey prk: PRK, info: Info?, outputByteCount: Int) -> SymmetricKey where PRK : ContiguousBytes, Info : DataProtocol

Parameters

  • prk:

    A pseudorandom, cryptographically strong key generated from the extract(inputKeyMaterial:salt:) function.

  • info:

    The shared information to use for key derivation.

  • outputByteCount:

    The length in bytes of the resulting symmetric key.

Return Value

The derived symmetric key.

Discussion

Generate cryptographically strong key material to use with this function by calling extract(inputKeyMaterial:salt:).