implemented access token refreshing - untested

internal/domains/authentication/auth.go

@@ -95,19 +95,14 @@ func (a *Authenticator) Exchange(ctx context.Context, state, code string) (acces
 
 	// obtain token and profile
 
-	token, err := a.Config.Exchange(ctx, code)
+	tkn, err := a.Config.Exchange(ctx, code)
 	if err != nil {
 		return "", time.Time{}, fmt.Errorf("failed to exchange an authorization code for a token: %w", err)
 	}
 
-	idToken, err := a.VerifyIDToken(ctx, token)
+	idToken, claims, err := a.verifyIDTokenAndClaimsFromToken(ctx, tkn)
 	if err != nil {
-		return "", time.Time{}, fmt.Errorf("failed to verify ID Token: %w", err)
-	}
-
-	var claims map[string]any
-	if err := idToken.Claims(&claims); err != nil {
-		return "", time.Time{}, fmt.Errorf("Failed to obtain id token claims: %w", err)
+		return "", time.Time{}, err
 	}
 
 	claimsJSON, _ := json.Marshal(claims)
@@ -171,10 +166,10 @@ func (a *Authenticator) Exchange(ctx context.Context, state, code string) (acces
 				the_user
 		`,
 		pgx.NamedArgs{
-			"access_token":  token.AccessToken,
-			"token_type":    token.TokenType,
-			"refresh_token": token.RefreshToken,
-			"expiry":        token.Expiry,
+			"access_token":  tkn.AccessToken,
+			"token_type":    tkn.TokenType,
+			"refresh_token": tkn.RefreshToken,
+			"expiry":        tkn.Expiry,
 
 			"id_token_issuer":            idToken.Issuer,
 			"id_token_audience":          pgtype.FlatArray[string](idToken.Audience),
@@ -190,7 +185,7 @@ func (a *Authenticator) Exchange(ctx context.Context, state, code string) (acces
 		return "", time.Time{}, fmt.Errorf("failed to perform query to save tokens: %w", err)
 	}
 
-	return token.AccessToken, token.Expiry.UTC(), nil
+	return tkn.AccessToken, tkn.Expiry.UTC(), nil
 }
 
 // VerifyIDToken verifies that an *oauth2.Token is a valid *oidc.IDToken.
@@ -223,3 +218,142 @@ func (a *Authenticator) GetLogoutURL(requestHost string) *url.URL {
 		}.Encode(),
 	}
 }
+
+func (a *Authenticator) RefreshAccessToken(
+	ctx context.Context,
+	oldAccessToken string,
+) (
+	accessToken string,
+	expiration time.Time,
+	err error,
+) {
+
+	refreshToken, tokenType, err := a.getRefreshTokenForAccessToken(ctx, accessToken)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("failed to load refresh token: %w", err)
+	}
+
+	tkn, err := a.TokenSource(ctx, &oauth2.Token{
+		// AccessToken is the token that authorizes and authenticates
+		// the requests.
+		AccessToken: oldAccessToken,
+
+		// TokenType is the type of token.
+		// The Type method returns either this or "Bearer", the default.
+		TokenType: tokenType,
+
+		// RefreshToken is a token that's used by the application
+		// (as opposed to the user) to refresh the access token
+		// if it expires.
+		RefreshToken: refreshToken,
+
+		/*
+			// Expiry is the optional expiration time of the access token.
+			//
+			// If zero, TokenSource implementations will reuse the same
+			// token forever and RefreshToken or equivalent
+			// mechanisms for that TokenSource will not be used.
+			Expiry time.Time `json:"expiry,omitempty"`
+		*/
+	}).Token()
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("failed to fetch refresh token: %w", err)
+	}
+
+	idToken, claims, err := a.verifyIDTokenAndClaimsFromToken(ctx, tkn)
+	if err != nil {
+		return "", time.Time{}, err
+	}
+
+	claimsJSON, _ := json.Marshal(claims)
+
+	if _, err = a.db.Exec(
+		ctx,
+		`
+			WITH deleted_tokens AS (
+				DELETE FROM
+					oauth_tokens
+				WHERE
+					access_token = @old_access_token
+				RETURNING
+					access_token AS old_access_token
+			), new_tokens AS (
+				INSERT INTO oauth_tokens (
+					access_token,
+					token_type,
+					refresh_token,
+					expiry,
+
+					id_token_issuer,
+					id_token_audience,
+					id_token_subject,
+					id_token_expiry,
+					id_token_issued_at,
+					id_token_nonce,
+					id_token_access_token_hash,
+
+					claims -- might want to open this up
+				)
+				VALUES (
+					@new_access_token,
+					@token_type,
+					@refresh_token,
+					@expiry,
+
+					@id_token_issuer,
+					@id_token_audience,
+					@id_token_subject,
+					@id_token_expiry,
+					@id_token_issued_at,
+					@id_token_nonce,
+					@id_token_access_token_hash,
+
+					@claims
+				)
+				RETURNING
+					access_token AS new_access_token
+			)
+			SELECT
+				old_access_token,
+				new_access_token
+			FROM
+				deleted_tokens
+			FULL JOIN
+				new_tokens
+		`,
+		pgx.NamedArgs{
+			"old_access_token": oldAccessToken,
+
+			"new_access_token": tkn.AccessToken,
+			"token_type":       tkn.TokenType,
+			"refresh_token":    tkn.RefreshToken,
+			"expiry":           tkn.Expiry,
+
+			"id_token_issuer":            idToken.Issuer,
+			"id_token_audience":          pgtype.FlatArray[string](idToken.Audience),
+			"id_token_subject":           idToken.Subject,
+			"id_token_expiry":            idToken.Expiry,
+			"id_token_issued_at":         idToken.IssuedAt,
+			"id_token_nonce":             idToken.Nonce,
+			"id_token_access_token_hash": idToken.AccessTokenHash,
+
+			"claims": json.RawMessage(claimsJSON),
+		},
+	); err != nil {
+		return "", time.Time{}, fmt.Errorf("failed to save new access token and delete old access token: %w", err)
+	}
+
+	return tkn.AccessToken, tkn.Expiry.UTC(), nil
+}
+
+func (a *Authenticator) verifyIDTokenAndClaimsFromToken(ctx context.Context, tkn *oauth2.Token) (idToken *oidc.IDToken, claims map[string]any, err error) {
+	if idToken, err = a.VerifyIDToken(ctx, tkn); err != nil {
+		return nil, nil, fmt.Errorf("failed to verify id Token: %w", err)
+	}
+
+	if err := idToken.Claims(&claims); err != nil {
+		return nil, nil, fmt.Errorf("failed to obtain id token claims: %w", err)
+	}
+
+	return idToken, claims, nil
+}