chore: use retrieveRequestParams where possible (#1818)

## What kind of change does this PR introduce?
* Move the reading the requestBody into the captcha middleware, which is
in the api package so it can use `retrieveRequestParams`
* Use `retrieveRequestParams` in the admin delete route

## What is the current behavior?

Please link any relevant issues here.

## What is the new behavior?

Feel free to include screenshots if it includes visual changes.

## Additional context

Add any other context or screenshots.

internal/api/admin.go

@@ -2,7 +2,6 @@ package api
 
 import (
 	"context"
-	"encoding/json"
 	"net/http"
 	"time"
 
@@ -15,6 +14,7 @@ import (
 	"github.com/supabase/auth/internal/models"
 	"github.com/supabase/auth/internal/observability"
 	"github.com/supabase/auth/internal/storage"
+	"github.com/supabase/auth/internal/utilities"
 	"golang.org/x/crypto/bcrypt"
 )
 
@@ -512,21 +512,17 @@ func (a *API) adminUserDelete(w http.ResponseWriter, r *http.Request) error {
 	user := getUser(ctx)
 	adminUser := getAdminUser(ctx)
 
-	var err error
+	// ShouldSoftDelete defaults to false
 	params := &adminUserDeleteParams{}
-	body, err := getBodyBytes(r)
-	if err != nil {
-		return internalServerError("Could not read body").WithInternalError(err)
-	}
-	if len(body) > 0 {
-		if err := json.Unmarshal(body, params); err != nil {
-			return badRequestError(ErrorCodeBadJSON, "Could not read params: %v", err)
+	if body, _ := utilities.GetBodyBytes(r); len(body) != 0 {
+		// we only want to parse the body if it's not empty
+		// retrieveRequestParams will handle any errors with stream
+		if err := retrieveRequestParams(r, params); err != nil {
+			return err
 		}
-	} else {
-		params.ShouldSoftDelete = false
 	}
 
-	err = a.db.Transaction(func(tx *storage.Connection) error {
+	err := a.db.Transaction(func(tx *storage.Connection) error {
 		if terr := models.NewAuditLogEntry(r, tx, adminUser, models.UserDeletedAction, "", map[string]interface{}{
 			"user_id":    user.ID,
 			"user_email": user.Email,

internal/api/helpers.go

@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/supabase/auth/internal/conf"
 	"github.com/supabase/auth/internal/models"
+	"github.com/supabase/auth/internal/security"
 	"github.com/supabase/auth/internal/utilities"
 )
 
@@ -57,11 +58,6 @@ func isStringInSlice(checkValue string, list []string) bool {
 	return false
 }
 
-// getBodyBytes returns a byte array of the request's Body.
-func getBodyBytes(req *http.Request) ([]byte, error) {
-	return utilities.GetBodyBytes(req)
-}
-
 type RequestParams interface {
 	AdminUserParams |
 		CreateSSOProviderParams |
@@ -82,6 +78,8 @@ type RequestParams interface {
 		VerifyFactorParams |
 		VerifyParams |
 		adminUserUpdateFactorParams |
+		adminUserDeleteParams |
+		security.GotrueRequest |
 		ChallengeFactorParams |
 		struct {
 			Email string `json:"email"`
@@ -94,7 +92,7 @@ type RequestParams interface {
 
 // retrieveRequestParams is a generic method that unmarshals the request body into the params struct provided
 func retrieveRequestParams[A RequestParams](r *http.Request, params *A) error {
-	body, err := getBodyBytes(r)
+	body, err := utilities.GetBodyBytes(r)
 	if err != nil {
 		return internalServerError("Could not read body into byte slice").WithInternalError(err)
 	}

internal/api/middleware.go

@@ -15,6 +15,7 @@ import (
 	"github.com/supabase/auth/internal/models"
 	"github.com/supabase/auth/internal/observability"
 	"github.com/supabase/auth/internal/security"
+	"github.com/supabase/auth/internal/utilities"
 
 	"github.com/didip/tollbooth/v5"
 	"github.com/didip/tollbooth/v5/limiter"
@@ -116,12 +117,13 @@ func (a *API) verifyCaptcha(w http.ResponseWriter, req *http.Request) (context.C
 		return ctx, nil
 	}
 
-	verificationResult, err := security.VerifyRequest(req, strings.TrimSpace(config.Security.Captcha.Secret), config.Security.Captcha.Provider)
-	if err != nil {
-		if strings.Contains(err.Error(), "request body was not JSON") {
-			return nil, badRequestError(ErrorCodeValidationFailed, "Request body for CAPTCHA verification was not a valid JSON object")
-		}
+	body := &security.GotrueRequest{}
+	if err := retrieveRequestParams(req, body); err != nil {
+		return nil, err
+	}
 
+	verificationResult, err := security.VerifyRequest(body, utilities.GetIPAddress(req), strings.TrimSpace(config.Security.Captcha.Secret), config.Security.Captcha.Provider)
+	if err != nil {
 		return nil, internalServerError("captcha verification process failed").WithInternalError(err)
 	}
 

internal/security/captcha.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"fmt"
+
 	"github.com/pkg/errors"
 	"github.com/supabase/auth/internal/utilities"
 )
@@ -45,25 +46,13 @@ func init() {
 	Client = &http.Client{Timeout: defaultTimeout}
 }
 
-func VerifyRequest(r *http.Request, secretKey, captchaProvider string) (VerificationResponse, error) {
-	bodyBytes, err := utilities.GetBodyBytes(r)
-	if err != nil {
-		return VerificationResponse{}, err
-	}
-
-	var requestBody GotrueRequest
-
-	if err := json.Unmarshal(bodyBytes, &requestBody); err != nil {
-		return VerificationResponse{}, errors.Wrap(err, "request body was not JSON")
-	}
-
+func VerifyRequest(requestBody *GotrueRequest, clientIP, secretKey, captchaProvider string) (VerificationResponse, error) {
 	captchaResponse := strings.TrimSpace(requestBody.Security.Token)
 
 	if captchaResponse == "" {
 		return VerificationResponse{}, errors.New("no captcha response (captcha_token) found in request")
 	}
 
-	clientIP := utilities.GetIPAddress(r)
 	captchaURL, err := GetCaptchaURL(captchaProvider)
 	if err != nil {
 		return VerificationResponse{}, err