streaming

Media streaming and broadcast systems in Go
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cipher.go (944B)

      1 // Copyright 2024 The Untangled Authors. Use of this source code is
      2 // governed by the ISC license available in the LICENSE.ISC file.
      3 
      4 package scte35
      5 
      6 // Cipher is a 6-bit field specifying the algorithm used to encrypt
      7 // payloads as defined in SCTE 35 section 11.3.
      8 type Cipher uint8
      9 
     10 const (
     11 	CipherNone Cipher = iota
     12 	DES_ECB           // SCTE 35 section 11.3.1
     13 	DES_CBC           // SCTE 35 section 11.3.2
     14 	TripleDES         // SCTE 35 section 11.3.3
     15 	reserved
     16 	// Values 32 through 63 are available for "User private"
     17 	// algorithms. See SCTE 35 section 11.3.4.
     18 )
     19 
     20 const maxCipher = 63
     21 
     22 func (c Cipher) String() string {
     23 	switch c {
     24 	case CipherNone:
     25 		return "none"
     26 	case DES_ECB:
     27 		return "DES – ECB mode"
     28 	case DES_CBC:
     29 		return "DES – CBC mode"
     30 	case TripleDES:
     31 		return "Triple DES EDE3 – ECB mode"
     32 	}
     33 	if c >= reserved && c <= 31 {
     34 		return "reserved"
     35 	} else if c <= maxCipher {
     36 		return "user private"
     37 	}
     38 	return "invalid"
     39 }