Imports of package hmac

PathSynopsis
crypto/internal/boringPackage boring provides access to BoringCrypto implementation functions.
crypto/internal/fips140/hmacPackage hmac implements HMAC according to [FIPS 198-1].
crypto/internal/fips140hash
crypto/internal/fips140only
crypto/subtlePackage subtle implements functions that are often useful in cryptographic code but require careful thought to use correctly.
hashPackage hash provides interfaces for hash functions.