chore: import upstream snapshot with attribution

server/auth/password.go

@@ -0,0 +1,54 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"fmt"
+
+	"github.com/dolthub/doltgresql/server/auth/rfc5802"
+)
+
+// ScramSha256Password is the struct form of an encrypted password.
+type ScramSha256Password struct {
+	Iterations uint32
+	Salt       rfc5802.OctetString
+	StoredKey  rfc5802.OctetString
+	ServerKey  rfc5802.OctetString
+}
+
+// NewScramSha256Password creates a ScramSha256Password with a randomly-generated salt.
+func NewScramSha256Password(rawPassword string) (*ScramSha256Password, error) {
+	// This is unlikely to change, but it's defined here since we don't want to reference it elsewhere accidentally
+	const iterations = 4096
+	salt := GenerateRandomOctetString(16)
+	saltedPassword, err := rfc5802.SaltedPassword(rawPassword, salt, iterations)
+	if err != nil {
+		return nil, err
+	}
+	storedKey := rfc5802.StoredKey(rfc5802.ClientKey(saltedPassword))
+	serverKey := rfc5802.ServerKey(saltedPassword)
+	return &ScramSha256Password{
+		Iterations: iterations,
+		Salt:       salt,
+		StoredKey:  storedKey,
+		ServerKey:  serverKey,
+	}, nil
+}
+
+// AsPasswordString returns the password as defined in https://www.postgresql.org/docs/15/catalog-pg-authid.html
+func (password ScramSha256Password) AsPasswordString() string {
+	return fmt.Sprintf(`SCRAM-SHA-256$%d:%s$%s:%s`,
+		password.Iterations, password.Salt.ToBase64(), password.StoredKey.ToBase64(), password.ServerKey.ToBase64())
+}