From 011c61b2547e9db988262f9ef12c64e981c42705 Mon Sep 17 00:00:00 2001
From: Daniel Valdivia <18384552+dvaldivia@users.noreply.github.com>
Date: Sun, 5 Nov 2023 20:19:23 -0800
Subject: [PATCH] Add support for STS credentials (#4744)

---
 cmd/client-s3.go | 53 ++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/cmd/client-s3.go b/cmd/client-s3.go
index 57e4d272da..8e79349c0b 100644
--- a/cmd/client-s3.go
+++ b/cmd/client-s3.go
@@ -38,6 +38,8 @@ import (
 	"sync"
 	"time"
 
+	"github.com/minio/pkg/v2/env"
+
 	"github.com/minio/minio-go/v7"
 	"github.com/minio/minio-go/v7/pkg/credentials"
 	"github.com/minio/minio-go/v7/pkg/encrypt"
@@ -158,12 +160,6 @@ func newFactory() func(config *Config) (Client, *probe.Error) {
 		var api *minio.Client
 		var found bool
 		if api, found = clientCache[confSum]; !found {
-			// if Signature version '4' use NewV4 directly.
-			creds := credentials.NewStaticV4(config.AccessKey, config.SecretKey, config.SessionToken)
-			// if Signature version '2' use NewV2 directly.
-			if strings.ToUpper(config.Signature) == "S3V2" {
-				creds = credentials.NewStaticV2(config.AccessKey, config.SecretKey, "")
-			}
 
 			var transport http.RoundTripper
 
@@ -223,6 +219,51 @@ func newFactory() func(config *Config) (Client, *probe.Error) {
 				}
 			}
 
+			var credsChain []credentials.Provider
+
+			// if an STS endpoint is set, we will add that to the chain
+			if stsEndpoint := env.Get("MC_STS_ENDPOINT", ""); stsEndpoint != "" {
+				// set AWS_WEB_IDENTITY_TOKEN_FILE is MC_WEB_IDENTITY_TOKEN_FILE is set
+				if val := env.Get("MC_WEB_IDENTITY_TOKEN_FILE", ""); val != "" {
+					os.Setenv("AWS_WEB_IDENTITY_TOKEN_FILE", val)
+				}
+
+				stsEndpointURL, err := url.Parse(stsEndpoint)
+				if err != nil {
+					return nil, probe.NewError(fmt.Errorf("Error parsing sts endpoint: %v", err))
+				}
+				credsSts := &credentials.IAM{
+					Client: &http.Client{
+						Transport: transport,
+					},
+					Endpoint: stsEndpointURL.String(),
+				}
+				credsChain = append(credsChain, credsSts)
+			}
+
+			// V4 Credentials
+			credsV4 := &credentials.Static{
+				Value: credentials.Value{
+					AccessKeyID:     config.AccessKey,
+					SecretAccessKey: config.SecretKey,
+					SessionToken:    config.SessionToken,
+					SignerType:      credentials.SignatureV4,
+				},
+			}
+			credsChain = append(credsChain, credsV4)
+			// V2 Credentials
+			credsV2 := &credentials.Static{
+				Value: credentials.Value{
+					AccessKeyID:     config.AccessKey,
+					SecretAccessKey: config.SecretKey,
+					SessionToken:    "",
+					SignerType:      credentials.SignatureV2,
+				},
+			}
+			credsChain = append(credsChain, credsV2)
+
+			creds := credentials.NewChainCredentials(credsChain)
+
 			// Not found. Instantiate a new MinIO
 			var e error