snapshot of https://github.com/ory/keto.git (master, 2026-09-16; blobs > 131072B omitted)

oryx/randx/sequence.go

@@ -0,0 +1,75 @@
+// Copyright © 2023 Ory Corp
+// SPDX-License-Identifier: Apache-2.0
+
+package randx
+
+import (
+	"crypto/rand"
+	"math/big"
+
+	"github.com/pkg/errors"
+)
+
+var rander = rand.Reader // random function
+
+var (
+	// AlphaNum contains runes [abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789].
+	AlphaNum = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
+	// Alpha contains runes [abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ].
+	Alpha = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	// AlphaLowerNum contains runes [abcdefghijklmnopqrstuvwxyz0123456789].
+	AlphaLowerNum = []rune("abcdefghijklmnopqrstuvwxyz0123456789")
+	// AlphaUpperNum contains runes [ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789].
+	AlphaUpperNum = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
+	// AlphaLower contains runes [abcdefghijklmnopqrstuvwxyz].
+	AlphaLower = []rune("abcdefghijklmnopqrstuvwxyz")
+	// AlphaUpperVowels contains runes [AEIOUY].
+	AlphaUpperVowels = []rune("AEIOUY")
+	// AlphaUpperNoVowels contains runes [BCDFGHJKLMNPQRSTVWXZ].
+	AlphaUpperNoVowels = []rune("BCDFGHJKLMNPQRSTVWXZ")
+	// AlphaUpper contains runes [ABCDEFGHIJKLMNOPQRSTUVWXYZ].
+	AlphaUpper = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	// Numeric contains runes [0123456789].
+	Numeric = []rune("0123456789")
+	// AlphaNumNoAmbiguous is equivalent to AlphaNum but without visually ambiguous characters [0Oo1IlB8S5Z2].
+	AlphaNumNoAmbiguous = []rune("abcdefghijkmnpqrstuvwxyzACDEFGHJKLMNPQRTUVWXY34679")
+)
+
+// RuneSequence returns a random sequence using the defined allowed runes.
+func RuneSequence(l int, allowedRunes []rune) (seq []rune, err error) {
+	c := big.NewInt(int64(len(allowedRunes)))
+	seq = make([]rune, l)
+
+	for i := 0; i < l; i++ {
+		r, err := rand.Int(rander, c)
+		if err != nil {
+			return seq, err
+		}
+		rn := allowedRunes[r.Uint64()]
+		seq[i] = rn
+	}
+
+	return seq, nil
+}
+
+// MustString returns a random string sequence using the defined runes. Panics on error.
+func MustString(l int, allowedRunes []rune) string {
+	seq, err := RuneSequence(l, allowedRunes)
+	if err != nil {
+		panic(err)
+	}
+	return string(seq)
+}
+
+func GenerateNonce() ([]byte, error) {
+	const challengeSize = 32
+
+	challenge := make([]byte, challengeSize)
+
+	_, err := rand.Read(challenge)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return challenge, nil
+}