github.com/dolthub/go-mysql-server@v0.18.0/sql/plan/alter_user.go (about)

     1  // Copyright 2024 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package plan
    16  
    17  import (
    18  	"fmt"
    19  
    20  	"github.com/dolthub/go-mysql-server/sql"
    21  	"github.com/dolthub/go-mysql-server/sql/types"
    22  )
    23  
    24  // AlterUser represents the statement ALTER USER.
    25  type AlterUser struct {
    26  	IfExists bool
    27  	User     AuthenticatedUser
    28  	MySQLDb  sql.Database
    29  }
    30  
    31  var _ sql.Node = (*AlterUser)(nil)
    32  var _ sql.Databaser = (*AlterUser)(nil)
    33  var _ sql.CollationCoercible = (*AlterUser)(nil)
    34  
    35  // Schema implements the interface sql.Node.
    36  func (a *AlterUser) Schema() sql.Schema {
    37  	return types.OkResultSchema
    38  }
    39  
    40  // String implements the interface sql.Node.
    41  func (a *AlterUser) String() string {
    42  	ifExists := ""
    43  	if a.IfExists {
    44  		ifExists = "IfExists: "
    45  	}
    46  	return fmt.Sprintf("AlterUser(%s%s)", ifExists, a.User.String(""))
    47  }
    48  
    49  // Database implements the interface sql.Databaser.
    50  func (a *AlterUser) Database() sql.Database {
    51  	return a.MySQLDb
    52  }
    53  
    54  // WithDatabase implements the interface sql.Databaser.
    55  func (a *AlterUser) WithDatabase(db sql.Database) (sql.Node, error) {
    56  	aa := *a
    57  	aa.MySQLDb = db
    58  	return &aa, nil
    59  }
    60  
    61  // Resolved implements the interface sql.Node.
    62  func (a *AlterUser) Resolved() bool {
    63  	_, ok := a.MySQLDb.(sql.UnresolvedDatabase)
    64  	return !ok
    65  }
    66  
    67  // IsReadOnly implements the interface sql.Node.
    68  func (a *AlterUser) IsReadOnly() bool {
    69  	return false
    70  }
    71  
    72  // Children implements the interface sql.Node.
    73  func (a *AlterUser) Children() []sql.Node {
    74  	return nil
    75  }
    76  
    77  // WithChildren implements the interface sql.Node.
    78  func (a *AlterUser) WithChildren(children ...sql.Node) (sql.Node, error) {
    79  	if len(children) != 0 {
    80  		return nil, sql.ErrInvalidChildrenNumber.New(a, len(children), 0)
    81  	}
    82  	return a, nil
    83  }
    84  
    85  // CheckPrivileges implements the interface sql.Node.
    86  func (a *AlterUser) CheckPrivileges(ctx *sql.Context, opChecker sql.PrivilegedOperationChecker) bool {
    87  	// From the MySQL reference on ALTER USER:
    88  	// https://dev.mysql.com/doc/refman/8.0/en/alter-user.html
    89  	// ALTER USER generally requires either the global `CREATE USER` privilege, or the `UPDATE` privilege
    90  	// for the `mysql` system schema.
    91  	if opChecker.UserHasPrivileges(ctx, sql.NewPrivilegedOperation(
    92  		sql.PrivilegeCheckSubject{Database: "mysql"}, sql.PrivilegeType_Update)) {
    93  		return true
    94  	} else if opChecker.UserHasPrivileges(ctx, sql.NewPrivilegedOperation(
    95  		sql.PrivilegeCheckSubject{}, sql.PrivilegeType_CreateUser)) {
    96  		return true
    97  	}
    98  
    99  	// There are several exceptions to the general privilege requirements. Currently, the only relevant one is
   100  	// that any client who connects to the server using a non-anonymous account can change the password for that account.
   101  	authenticatedUser := ctx.Session.Client()
   102  	if a.User.Name == authenticatedUser.User {
   103  		return true
   104  	}
   105  
   106  	return false
   107  }
   108  
   109  // CollationCoercibility implements the interface sql.CollationCoercible.
   110  func (a *AlterUser) CollationCoercibility(_ *sql.Context) (collation sql.CollationID, coercibility byte) {
   111  	return sql.Collation_binary, 7
   112  }