54 lines
1.7 KiB
Go
54 lines
1.7 KiB
Go
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package ice
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import "github.com/pion/randutil"
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const (
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runesAlpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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runesDigit = "0123456789"
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runesCandidateIDFoundation = runesAlpha + runesDigit + "+/"
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lenUFrag = 16
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lenPwd = 32
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)
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// Seeding random generator each time limits number of generated sequence to 31-bits,
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// and causes collision on low time accuracy environments.
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// Use global random generator seeded by crypto grade random.
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var (
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globalMathRandomGenerator = randutil.NewMathRandomGenerator() //nolint:gochecknoglobals
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globalCandidateIDGenerator = candidateIDGenerator{globalMathRandomGenerator} //nolint:gochecknoglobals
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)
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// candidateIDGenerator is a random candidate ID generator.
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// Candidate ID is used in SDP and always shared to the other peer.
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// It doesn't require cryptographic random.
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type candidateIDGenerator struct {
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randutil.MathRandomGenerator
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}
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func newCandidateIDGenerator() *candidateIDGenerator {
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return &candidateIDGenerator{
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randutil.NewMathRandomGenerator(),
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}
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}
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func (g *candidateIDGenerator) Generate() string {
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// https://tools.ietf.org/html/rfc5245#section-15.1
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// candidate-id = "candidate" ":" foundation
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// foundation = 1*32ice-char
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// ice-char = ALPHA / DIGIT / "+" / "/"
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return "candidate:" + g.MathRandomGenerator.GenerateString(32, runesCandidateIDFoundation)
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}
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// generatePwd generates ICE pwd.
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// This internally uses generateCryptoRandomString.
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func generatePwd() (string, error) {
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return randutil.GenerateCryptoRandomString(lenPwd, runesAlpha)
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}
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// generateUFrag generates ICE user fragment.
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// This internally uses generateCryptoRandomString.
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func generateUFrag() (string, error) {
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return randutil.GenerateCryptoRandomString(lenUFrag, runesAlpha)
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}
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