initial commit

pkg/oidc/code_challenge.go

@@ -0,0 +1,33 @@
+package oidc
+
+import (
+	"crypto/sha256"
+
+	"github.com/caos/oidc/pkg/utils"
+)
+
+const (
+	CodeChallengeMethodPlain CodeChallengeMethod = "plain"
+	CodeChallengeMethodS256  CodeChallengeMethod = "S256"
+)
+
+type CodeChallengeMethod string
+
+type CodeChallenge struct {
+	Challenge string
+	Method    CodeChallengeMethod
+}
+
+func NewSHACodeChallenge(code string) string {
+	return utils.HashString(sha256.New(), code)
+}
+
+func VerifyCodeChallenge(c *CodeChallenge, codeVerifier string) bool {
+	if c == nil {
+		return false //TODO: ?
+	}
+	if c.Method == CodeChallengeMethodS256 {
+		codeVerifier = NewSHACodeChallenge(codeVerifier)
+	}
+	return codeVerifier == c.Challenge
+}