Why Go
- Case Studies
  
  Common problems companies solve with Go
- Use Cases
  
  Stories about how and why companies use Go
- Security
  
  How Go can help keep you secure by default
Learn
Docs
- Effective Go
  
  Tips for writing clear, performant, and idiomatic Go code
- Go User Manual
  
  A complete introduction to building software with Go
- Standard library
  
  Reference documentation for Go's standard library
- Release Notes
  
  Learn what's new in each Go release
- API
  
  Reference documentation for the pkg.go.dev API
Packages
Community
- Recorded Talks
  
  Videos from prior events
- Meetups
  
  Meet other local Go developers
- Conferences
  
  Learn and network with Go developers from around the world
- Go blog
  
  The Go project's official blog.
- Go project
  
  Get help and stay informed from Go
- Get connected

smsg

package

Go to main page

Versions in this module

v0

v0.5.0

Aug 1, 2026

v0.4.0

Aug 1, 2026

v0.3.0

Feb 21, 2026

v0.2.0

Feb 3, 2026

Changes in this version

+ const ABRSafetyFactor

+ const ABRVersion

+ const DefaultChunkSize

+ const FormatV3

+ const KeyMethodDirect

+ const KeyMethodLTHNRolling

+ var ABRPresets = []struct{ ... }

+ var ErrLicenseRequired = errors.New("license is required for stream decryption")

+ var ErrNoValidKey = errors.New("no valid wrapped key found for current date")

+ var ErrStreamKeyExpired = errors.New("stream key expired (outside rolling window)")

+ func DecryptV3(data []byte, params *StreamParams) (*Message, *Header, error)

+ func DecryptV3Chunk(payload []byte, cek []byte, chunkIndex int, chunked *ChunkedInfo) ([]byte, error)

+ func DeriveStreamKey(date, license, fingerprint string) []byte

+ func EncryptV3(msg *Message, params *StreamParams, manifest *Manifest) ([]byte, error)

+ func GenerateCEK() ([]byte, error)

+ func GetCadenceWindowDuration(cadence Cadence) time.Duration

+ func GetRollingDates() (current, next string)

+ func GetRollingDatesAt(t time.Time) (current, next string)

+ func GetRollingPeriods(cadence Cadence, t time.Time) (current, next string)

+ func GetV3Payload(data []byte) ([]byte, error)

+ func UnwrapCEK(wrappedB64 string, streamKey []byte) ([]byte, error)

+ func UnwrapCEKFromHeader(header *Header, params *StreamParams) ([]byte, error)

+ func WrapCEK(cek, streamKey []byte) (string, error)

+ func WriteABRManifest(manifest *ABRManifest, path string) error

+ type ABRBandwidthEstimator struct

+ func NewABRBandwidthEstimator(maxSamples int) *ABRBandwidthEstimator

+ func (e *ABRBandwidthEstimator) Estimate() int

+ func (e *ABRBandwidthEstimator) RecordSample(bytes int, durationMs int)

+ type ABRManifest struct

+ DefaultIdx int

+ Duration int

+ Password string

+ Title string

+ Variants []Variant

+ Version string

+ func NewABRManifest(title string) *ABRManifest

+ func ParseABRManifest(data []byte) (*ABRManifest, error)

+ func ReadABRManifest(path string) (*ABRManifest, error)

+ func (m *ABRManifest) AddVariant(v Variant)

+ func (m *ABRManifest) GetVariant(idx int) *Variant

+ func (m *ABRManifest) SelectVariant(bandwidthBPS int) int

+ type Cadence string

+ const CadenceDaily

+ const CadenceHalfDay

+ const CadenceHourly

+ const CadenceQuarter

+ type ChunkInfo struct

+ Offset int

+ Size int

+ type ChunkedInfo struct

+ ChunkSize int

+ Index []ChunkInfo

+ TotalChunks int

+ TotalSize int64

type Header

+ Cadence Cadence

+ Chunked *ChunkedInfo

+ KeyMethod string

+ WrappedKeys []WrappedKey

+ func GetV3Header(data []byte) (*Header, error)

+ func GetV3HeaderFromPrefix(data []byte) (*Header, int, error)

+ type StreamParams struct

+ Cadence Cadence

+ ChunkSize int

+ Fingerprint string

+ License string

+ type Variant struct

+ Bandwidth int

+ ChunkCount int

+ Codecs string

+ FileSize int64

+ Height int

+ Name string

+ URL string

+ Width int

+ func VariantFromSMSG(name string, bandwidth, width, height int, smsgPath string) (*Variant, error)

+ type WrappedKey struct

+ Date string

+ Wrapped string

v0.1.0

Jan 10, 2026

Changes in this version

+ const CompressionGzip

+ const CompressionNone

+ const CompressionZstd

+ const FormatV1

+ const FormatV2

+ func EncryptV2(msg *Message, password string) ([]byte, error)

+ func EncryptV2WithManifest(msg *Message, password string, manifest *Manifest) ([]byte, error)

+ func EncryptV2WithOptions(msg *Message, password string, manifest *Manifest, compression string) ([]byte, error)

+ func EncryptWithManifest(msg *Message, password string, manifest *Manifest) ([]byte, error)

+ func EncryptWithManifestBase64(msg *Message, password string, manifest *Manifest) (string, error)

type Header

+ Compression string

+ Format string

+ Manifest *Manifest

+ type Manifest struct

+ Album string

+ Artist string

+ Duration int

+ ExpiresAt int64

+ Extra map[string]string

+ Format string

+ Genre string

+ IssuedAt int64

+ LicenseType string

+ Links map[string]string

+ ReleaseType string

+ Tags []string

+ Title string

+ Tracks []Track

+ Year int

+ func NewManifest(title string) *Manifest

+ func (m *Manifest) AddLink(platform, url string) *Manifest

+ func (m *Manifest) AddTrack(title string, start float64) *Manifest

+ func (m *Manifest) AddTrackFull(title string, start, end float64, trackType string) *Manifest

+ func (m *Manifest) IsExpired() bool

+ func (m *Manifest) TimeRemaining() int64

+ func (m *Manifest) WithExpiration(expiresAt int64) *Manifest

+ func (m *Manifest) WithPreviewAccess(seconds int) *Manifest

+ func (m *Manifest) WithRentalDuration(durationSeconds int64) *Manifest

+ func (m *Manifest) WithStreamingAccess(hours int) *Manifest

type Message

+ func (m *Message) AddBinaryAttachment(name string, data []byte, mimeType string) *Message

+ type Track struct

+ End float64

+ Start float64

+ Title string

+ TrackNum int

+ Type string

v0.0.2

Dec 27, 2025

Changes in this version

+ const Magic

+ const Version

+ var ErrDecryptionFailed = errors.New("decryption failed (wrong password?)")

+ var ErrEmptyMessage = errors.New("message cannot be empty")

+ var ErrInvalidMagic = errors.New("invalid SMSG magic")

+ var ErrInvalidPayload = errors.New("invalid SMSG payload")

+ var ErrPasswordRequired = errors.New("password is required")

+ func DeriveKey(password string) []byte

+ func Encrypt(msg *Message, password string) ([]byte, error)

+ func EncryptBase64(msg *Message, password string) (string, error)

+ func EncryptWithHint(msg *Message, password, hint string) ([]byte, error)

+ func QuickDecrypt(encoded, password string) (string, error)

+ func QuickEncrypt(body, password string) (string, error)

+ func Validate(data []byte) error

+ type Attachment struct

+ Content string

+ MimeType string

+ Name string

+ Size int

+ type Header struct

+ Algorithm string

+ Hint string

+ Version string

+ func GetInfo(data []byte) (*Header, error)

+ func GetInfoBase64(encoded string) (*Header, error)

+ type Message struct

+ Attachments []Attachment

+ Body string

+ From string

+ Meta map[string]string

+ ReplyKey *PKIInfo

+ Subject string

+ Timestamp int64

+ func Decrypt(data []byte, password string) (*Message, error)

+ func DecryptBase64(encoded, password string) (*Message, error)

+ func NewMessage(body string) *Message

+ func (m *Message) AddAttachment(name, content, mimeType string) *Message

+ func (m *Message) GetAttachment(name string) *Attachment

+ func (m *Message) SetMeta(key, value string) *Message

+ func (m *Message) WithFrom(from string) *Message

+ func (m *Message) WithReplyKey(publicKeyB64 string) *Message

+ func (m *Message) WithReplyKeyInfo(pki *PKIInfo) *Message

+ func (m *Message) WithSubject(subject string) *Message

+ func (m *Message) WithTimestamp(ts int64) *Message

+ type PKIInfo struct

+ Algorithm string

+ Fingerprint string

+ KeyID string

+ PublicKey string