Files
gortsplib/pkg/mikey/sub_payload_key_data.go

67 lines
1.3 KiB
Go

package mikey
import "fmt"
// SubPayloadKeyDataKeyType is a data key type.
type SubPayloadKeyDataKeyType uint8
// RFC3830, table 6.13.a
const (
SubPayloadKeyDataKeyTypeTEK SubPayloadKeyDataKeyType = 2
)
// SubPayloadKeyData is a key data sub-payload.
type SubPayloadKeyData struct {
Type SubPayloadKeyDataKeyType
KV uint8
KeyData []byte
}
func (p *SubPayloadKeyData) unmarshal(buf []byte) (int, error) {
if len(buf) < 4 {
return 0, fmt.Errorf("buffer too short")
}
n := 1
p.Type = SubPayloadKeyDataKeyType(buf[n] >> 4)
p.KV = buf[n] & 0b00001111
n++
if p.Type != SubPayloadKeyDataKeyTypeTEK {
return 0, fmt.Errorf("unsupported key type: %v", p.Type)
}
if p.KV != 0 {
return 0, fmt.Errorf("unsupported KV: %v", p.KV)
}
keyDataLen := int(uint16(buf[n])<<8 | uint16(buf[n+1]))
n += 2
if len(buf[n:]) < keyDataLen {
return 0, fmt.Errorf("buffer too short")
}
p.KeyData = buf[n : n+keyDataLen]
n += keyDataLen
return n, nil
}
func (p *SubPayloadKeyData) marshalSize() int {
return 4 + len(p.KeyData)
}
func (p *SubPayloadKeyData) marshalTo(buf []byte) (int, error) {
buf[1] = byte(p.Type)<<4 | p.KV
keyDataLen := len(p.KeyData)
buf[2] = byte(keyDataLen >> 8)
buf[3] = byte(keyDataLen)
n := 4
n += copy(buf[n:], p.KeyData)
return n, nil
}