summaryrefslogtreecommitdiffstats
path: root/src/mime/multipart/writer.go
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:15:26 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:15:26 +0000
commit82539ad8d59729fb45b0bb0edda8f2bddb719eb1 (patch)
tree58f0b58e6f44f0e04d4a6373132cf426fa835fa7 /src/mime/multipart/writer.go
parentInitial commit. (diff)
downloadgolang-1.17-82539ad8d59729fb45b0bb0edda8f2bddb719eb1.tar.xz
golang-1.17-82539ad8d59729fb45b0bb0edda8f2bddb719eb1.zip
Adding upstream version 1.17.13.upstream/1.17.13upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/mime/multipart/writer.go')
-rw-r--r--src/mime/multipart/writer.go201
1 files changed, 201 insertions, 0 deletions
diff --git a/src/mime/multipart/writer.go b/src/mime/multipart/writer.go
new file mode 100644
index 0000000..d1ff151
--- /dev/null
+++ b/src/mime/multipart/writer.go
@@ -0,0 +1,201 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package multipart
+
+import (
+ "bytes"
+ "crypto/rand"
+ "errors"
+ "fmt"
+ "io"
+ "net/textproto"
+ "sort"
+ "strings"
+)
+
+// A Writer generates multipart messages.
+type Writer struct {
+ w io.Writer
+ boundary string
+ lastpart *part
+}
+
+// NewWriter returns a new multipart Writer with a random boundary,
+// writing to w.
+func NewWriter(w io.Writer) *Writer {
+ return &Writer{
+ w: w,
+ boundary: randomBoundary(),
+ }
+}
+
+// Boundary returns the Writer's boundary.
+func (w *Writer) Boundary() string {
+ return w.boundary
+}
+
+// SetBoundary overrides the Writer's default randomly-generated
+// boundary separator with an explicit value.
+//
+// SetBoundary must be called before any parts are created, may only
+// contain certain ASCII characters, and must be non-empty and
+// at most 70 bytes long.
+func (w *Writer) SetBoundary(boundary string) error {
+ if w.lastpart != nil {
+ return errors.New("mime: SetBoundary called after write")
+ }
+ // rfc2046#section-5.1.1
+ if len(boundary) < 1 || len(boundary) > 70 {
+ return errors.New("mime: invalid boundary length")
+ }
+ end := len(boundary) - 1
+ for i, b := range boundary {
+ if 'A' <= b && b <= 'Z' || 'a' <= b && b <= 'z' || '0' <= b && b <= '9' {
+ continue
+ }
+ switch b {
+ case '\'', '(', ')', '+', '_', ',', '-', '.', '/', ':', '=', '?':
+ continue
+ case ' ':
+ if i != end {
+ continue
+ }
+ }
+ return errors.New("mime: invalid boundary character")
+ }
+ w.boundary = boundary
+ return nil
+}
+
+// FormDataContentType returns the Content-Type for an HTTP
+// multipart/form-data with this Writer's Boundary.
+func (w *Writer) FormDataContentType() string {
+ b := w.boundary
+ // We must quote the boundary if it contains any of the
+ // tspecials characters defined by RFC 2045, or space.
+ if strings.ContainsAny(b, `()<>@,;:\"/[]?= `) {
+ b = `"` + b + `"`
+ }
+ return "multipart/form-data; boundary=" + b
+}
+
+func randomBoundary() string {
+ var buf [30]byte
+ _, err := io.ReadFull(rand.Reader, buf[:])
+ if err != nil {
+ panic(err)
+ }
+ return fmt.Sprintf("%x", buf[:])
+}
+
+// CreatePart creates a new multipart section with the provided
+// header. The body of the part should be written to the returned
+// Writer. After calling CreatePart, any previous part may no longer
+// be written to.
+func (w *Writer) CreatePart(header textproto.MIMEHeader) (io.Writer, error) {
+ if w.lastpart != nil {
+ if err := w.lastpart.close(); err != nil {
+ return nil, err
+ }
+ }
+ var b bytes.Buffer
+ if w.lastpart != nil {
+ fmt.Fprintf(&b, "\r\n--%s\r\n", w.boundary)
+ } else {
+ fmt.Fprintf(&b, "--%s\r\n", w.boundary)
+ }
+
+ keys := make([]string, 0, len(header))
+ for k := range header {
+ keys = append(keys, k)
+ }
+ sort.Strings(keys)
+ for _, k := range keys {
+ for _, v := range header[k] {
+ fmt.Fprintf(&b, "%s: %s\r\n", k, v)
+ }
+ }
+ fmt.Fprintf(&b, "\r\n")
+ _, err := io.Copy(w.w, &b)
+ if err != nil {
+ return nil, err
+ }
+ p := &part{
+ mw: w,
+ }
+ w.lastpart = p
+ return p, nil
+}
+
+var quoteEscaper = strings.NewReplacer("\\", "\\\\", `"`, "\\\"")
+
+func escapeQuotes(s string) string {
+ return quoteEscaper.Replace(s)
+}
+
+// CreateFormFile is a convenience wrapper around CreatePart. It creates
+// a new form-data header with the provided field name and file name.
+func (w *Writer) CreateFormFile(fieldname, filename string) (io.Writer, error) {
+ h := make(textproto.MIMEHeader)
+ h.Set("Content-Disposition",
+ fmt.Sprintf(`form-data; name="%s"; filename="%s"`,
+ escapeQuotes(fieldname), escapeQuotes(filename)))
+ h.Set("Content-Type", "application/octet-stream")
+ return w.CreatePart(h)
+}
+
+// CreateFormField calls CreatePart with a header using the
+// given field name.
+func (w *Writer) CreateFormField(fieldname string) (io.Writer, error) {
+ h := make(textproto.MIMEHeader)
+ h.Set("Content-Disposition",
+ fmt.Sprintf(`form-data; name="%s"`, escapeQuotes(fieldname)))
+ return w.CreatePart(h)
+}
+
+// WriteField calls CreateFormField and then writes the given value.
+func (w *Writer) WriteField(fieldname, value string) error {
+ p, err := w.CreateFormField(fieldname)
+ if err != nil {
+ return err
+ }
+ _, err = p.Write([]byte(value))
+ return err
+}
+
+// Close finishes the multipart message and writes the trailing
+// boundary end line to the output.
+func (w *Writer) Close() error {
+ if w.lastpart != nil {
+ if err := w.lastpart.close(); err != nil {
+ return err
+ }
+ w.lastpart = nil
+ }
+ _, err := fmt.Fprintf(w.w, "\r\n--%s--\r\n", w.boundary)
+ return err
+}
+
+type part struct {
+ mw *Writer
+ closed bool
+ we error // last error that occurred writing
+}
+
+func (p *part) close() error {
+ p.closed = true
+ return p.we
+}
+
+func (p *part) Write(d []byte) (n int, err error) {
+ if p.closed {
+ return 0, errors.New("multipart: can't write to finished part")
+ }
+ n, err = p.mw.w.Write(d)
+ if err != nil {
+ p.we = err
+ }
+ return
+}