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pgx/pgproto3/parse.go
T
Jack Christensen adbb38f298 Do not allow protocol messages larger than ~1GB
The PostgreSQL server will reject messages greater than ~1 GB anyway.
However, worse than that is that a message that is larger than 4 GB
could wrap the 32-bit integer message size and be interpreted by the
server as multiple messages. This could allow a malicious client to
inject arbitrary protocol messages.

https://github.com/jackc/pgx/security/advisories/GHSA-mrww-27vc-gghv
2024-03-04 09:09:29 -06:00

85 lines
1.9 KiB
Go

package pgproto3
import (
"bytes"
"encoding/binary"
"encoding/json"
"github.com/jackc/pgx/v5/internal/pgio"
)
type Parse struct {
Name string
Query string
ParameterOIDs []uint32
}
// Frontend identifies this message as sendable by a PostgreSQL frontend.
func (*Parse) Frontend() {}
// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
// type identifier and 4 byte message length.
func (dst *Parse) Decode(src []byte) error {
*dst = Parse{}
buf := bytes.NewBuffer(src)
b, err := buf.ReadBytes(0)
if err != nil {
return err
}
dst.Name = string(b[:len(b)-1])
b, err = buf.ReadBytes(0)
if err != nil {
return err
}
dst.Query = string(b[:len(b)-1])
if buf.Len() < 2 {
return &invalidMessageFormatErr{messageType: "Parse"}
}
parameterOIDCount := int(binary.BigEndian.Uint16(buf.Next(2)))
for i := 0; i < parameterOIDCount; i++ {
if buf.Len() < 4 {
return &invalidMessageFormatErr{messageType: "Parse"}
}
dst.ParameterOIDs = append(dst.ParameterOIDs, binary.BigEndian.Uint32(buf.Next(4)))
}
return nil
}
// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
func (src *Parse) Encode(dst []byte) ([]byte, error) {
dst, sp := beginMessage(dst, 'P')
dst = append(dst, src.Name...)
dst = append(dst, 0)
dst = append(dst, src.Query...)
dst = append(dst, 0)
dst = pgio.AppendUint16(dst, uint16(len(src.ParameterOIDs)))
for _, oid := range src.ParameterOIDs {
dst = pgio.AppendUint32(dst, oid)
}
return finishMessage(dst, sp)
}
// MarshalJSON implements encoding/json.Marshaler.
func (src Parse) MarshalJSON() ([]byte, error) {
return json.Marshal(struct {
Type string
Name string
Query string
ParameterOIDs []uint32
}{
Type: "Parse",
Name: src.Name,
Query: src.Query,
ParameterOIDs: src.ParameterOIDs,
})
}