feat: add crypto pkg

internal/crypto/code.go

@@ -0,0 +1,153 @@
+package crypto
+
+import (
+	"crypto/rand"
+	"time"
+
+	"github.com/caos/zitadel/internal/errors"
+)
+
+var (
+	LowerLetters = []rune("abcdefghijklmnopqrstuvwxyz")
+	UpperLetters = []rune("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+	Digits       = []rune("0123456789")
+	Symbols      = []rune("~!@#$^&*()_+`-={}|[]:<>?,./")
+)
+
+type Generator interface {
+	Length() uint
+	Expiry() time.Duration
+	Alg() Crypto
+	Runes() []rune
+}
+
+type EncryptionGenerator struct {
+	length uint
+	expiry time.Duration
+	alg    EncryptionAlg
+	runes  []rune
+}
+
+func (g *EncryptionGenerator) Length() uint {
+	return g.length
+}
+
+func (g *EncryptionGenerator) Expiry() time.Duration {
+	return g.expiry
+}
+
+func (g *EncryptionGenerator) Alg() Crypto {
+	return g.alg
+}
+
+func (g *EncryptionGenerator) Runes() []rune {
+	return g.runes
+}
+
+func NewEncryptionGenerator(length uint, expiry time.Duration, alg EncryptionAlg, runes []rune) *EncryptionGenerator {
+	return &EncryptionGenerator{
+		length: length,
+		expiry: expiry,
+		alg:    alg,
+		runes:  runes,
+	}
+}
+
+type HashGenerator struct {
+	length uint
+	expiry time.Duration
+	alg    HashAlg
+	runes  []rune
+}
+
+func (g *HashGenerator) Length() uint {
+	return g.length
+}
+
+func (g *HashGenerator) Expiry() time.Duration {
+	return g.expiry
+}
+
+func (g *HashGenerator) Alg() Crypto {
+	return g.alg
+}
+
+func (g *HashGenerator) Runes() []rune {
+	return g.runes
+}
+
+func NewHashGenerator(length uint, expiry time.Duration, alg HashAlg, runes []rune) *HashGenerator {
+	return &HashGenerator{
+		length: length,
+		expiry: expiry,
+		alg:    alg,
+		runes:  runes,
+	}
+}
+
+func NewCode(g Generator) (*CryptoValue, string, error) {
+	code, err := generateRandomString(g.Length(), g.Runes())
+	if err != nil {
+		return nil, "", err
+	}
+	crypto, err := Crypt([]byte(code), g.Alg())
+	if err != nil {
+		return nil, "", err
+	}
+	return crypto, code, nil
+}
+
+func IsCodeExpired(creationDate time.Time, expiry time.Duration) bool {
+	return creationDate.Add(expiry).Before(time.Now().UTC())
+}
+
+func VerifyCode(creationDate time.Time, expiry time.Duration, cryptoCode *CryptoValue, verificationCode string, g Generator) error {
+	if IsCodeExpired(creationDate, expiry) {
+		return errors.ThrowPreconditionFailed(nil, "CODE-QvUQ4P", "verification code is expired")
+	}
+	switch alg := g.Alg().(type) {
+	case EncryptionAlg:
+		return verifyEncryptedCode(cryptoCode, verificationCode, alg)
+	case HashAlg:
+		return verifyHashedCode(cryptoCode, verificationCode, alg)
+	}
+	return errors.ThrowInvalidArgument(nil, "CODE-fW2gNa", "generator alg is not supported")
+}
+
+func generateRandomString(length uint, chars []rune) (string, error) {
+	if length == 0 {
+		return "", nil
+	}
+
+	max := len(chars) - 1
+	maxStr := int(length - 1)
+
+	str := make([]rune, length)
+	randBytes := make([]byte, length)
+	if _, err := rand.Read(randBytes); err != nil {
+		return "", err
+	}
+	for i, rb := range randBytes {
+		str[i] = chars[int(rb)%max]
+		if i == maxStr {
+			return string(str), nil
+		}
+	}
+	return "", nil
+}
+
+func verifyEncryptedCode(cryptoCode *CryptoValue, verificationCode string, alg EncryptionAlg) error {
+	code, err := DecryptString(cryptoCode, alg)
+	if err != nil {
+		return err
+	}
+
+	if code != verificationCode {
+		return errors.ThrowInvalidArgument(nil, "CODE-woT0xc", "verification code is invalid")
+	}
+	return nil
+}
+
+func verifyHashedCode(cryptoCode *CryptoValue, verificationCode string, alg HashAlg) error {
+	return CompareHash(cryptoCode, []byte(verificationCode), alg)
+}