1 files changed, 141 insertions, 0 deletions
diff --git a/common.go b/common.go
new file mode 100644
index 0000000..e6173b0
--- /dev/null
+++ b/common.go
@@ -0,0 +1,141 @@
+package cnp
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"mime"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func readLimitedLine(br *bufio.Reader, length int) ([]byte, error) {
+	var buf bytes.Buffer
+
+	for {
+		data, err := br.ReadSlice('\n')
+		if len(data) > 0 {
+			buf.Write(data)
+		}
+		if buf.Len() > length {
+			return nil, ErrorTooLarge{"header exceeds maximum permitted size"}
+		}
+		if err == nil || err == io.EOF {
+			return buf.Bytes(), nil
+		}
+		if err != bufio.ErrBufferFull {
+			return nil, ErrorSyntax{"invalid header: missing line feed"}
+		}
+	}
+}
+
+func getInt(m *Message, param string) (int64, error) {
+	p := m.Param(param)
+	if p == "" {
+		return 0, nil
+	}
+	n, err := strconv.ParseUint(p, 10, 63)
+	if err != nil || (n != 0 && p[0] == '0') || (n == 0 && len(p) != 1) {
+		return int64(n), ErrorInvalid{"invalid parameter: " + param + " is not a valid integer"}
+	}
+	return int64(n), nil
+}
+
+func setInt(m *Message, param string, n int64) {
+	if n < 0 {
+		n = 0
+	}
+	m.SetParam(param, strconv.FormatInt(n, 10))
+}
+
+func getFilename(m *Message, param string) (string, error) {
+	name := m.Param(param)
+	if strings.ContainsAny(name, "/\x00") {
+		return name, ErrorInvalid{"invalid parameter: " + param + " contains invalid characters"}
+	}
+	return name, nil
+}
+
+func setFilename(m *Message, param, name string) error {
+	if strings.ContainsAny(name, "/\x00") {
+		return ErrorInvalid{"invalid parameter: " + param + " contains invalid characters"}
+	}
+	m.SetParam(param, name)
+	return nil
+}
+
+func getType(m *Message, param string) (typ string, err error) {
+	t := m.Param(param)
+	if t != "" {
+		var params map[string]string
+		typ, params, err = mime.ParseMediaType(t)
+		if err != nil || !validMimeType(t) || len(params) > 0 { // may not contain params
+			err = ErrorInvalid{"invalid parameter: " + param + " is not a valid mime type"}
+		}
+	}
+	if typ == "" {
+		typ = "application/octet-stream"
+	}
+	return
+}
+
+func setType(m *Message, param, typ string) error {
+	if typ == "" {
+		m.SetParam(param, "")
+		return nil
+	}
+
+	/*ss := strings.Split(typ, "/")
+	if len(ss) != 2 || len(ss[0]) == 0 || strings.ContainsAny(typ, "\x00 \n\t\r;,") {
+		return ErrorInvalid{…}
+	}*/
+
+	t := mime.FormatMediaType(typ, nil)
+	if t == "" || !validMimeType(typ) {
+		return ErrorInvalid{"invalid parameter: " + param + " is not a valid mime type"}
+	}
+	m.SetParam(param, t)
+
+	return nil
+}
+
+func validMimeType(typ string) bool {
+	ss := strings.Split(typ, "/")
+	if len(ss) != 2 || ss[0] == "" || ss[1] == "" {
+		return false
+	}
+	for _, r := range typ {
+		/*switch r {
+		case '(', ')', '<', '>', '@', ',', ';', ':', '\\', '"', '[', ']', '?', '=':
+			// tspecials except /
+			return false
+		}*/ // handled by mime.ParseMediaType
+		if r <= ' ' || r >= '\x7f' {
+			// control codes, whitespace, null
+			return false
+		}
+	}
+	return true
+}
+
+func getTime(m *Message, param string) (time.Time, error) {
+	t := m.Param(param)
+	var z time.Time
+	if t == "" {
+		return z, nil
+	}
+	ts, err := time.Parse(time.RFC3339, t)
+	if err != nil || !strings.HasSuffix(t, "Z") {
+		return z, ErrorInvalid{"invalid parameter: " + param + " is not a valid RFC3339 timestamp"}
+	}
+	return ts, nil
+}
+
+func setTime(m *Message, param string, t time.Time) {
+	if t.IsZero() {
+		m.SetParam(param, "")
+	} else {
+		m.SetParam(param, t.UTC().Format(time.RFC3339))
+	}
+}