Restructure project layout

internal/authentication/credentials/credentials.go

@@ -0,0 +1,33 @@
+package credentials
+
+import (
+	"log"
+
+	"github.com/pushbits/server/internal/configuration"
+
+	"github.com/alexedwards/argon2id"
+)
+
+// Manager holds information for managing credentials.
+type Manager struct {
+	checkHIBP    bool
+	argon2Params *argon2id.Params
+}
+
+// CreateManager instanciates a credential manager.
+func CreateManager(checkHIBP bool, c configuration.CryptoConfig) *Manager {
+	log.Println("Setting up credential manager.")
+
+	argon2Params := &argon2id.Params{
+		Memory:      c.Argon2.Memory,
+		Iterations:  c.Argon2.Iterations,
+		Parallelism: c.Argon2.Parallelism,
+		SaltLength:  c.Argon2.SaltLength,
+		KeyLength:   c.Argon2.KeyLength,
+	}
+
+	return &Manager{
+		checkHIBP:    checkHIBP,
+		argon2Params: argon2Params,
+	}
+}