From d1a7728e50f1ae2ddfdc8a2d7864d9dbd8d2a036 Mon Sep 17 00:00:00 2001 From: Ryan Kohler Date: Wed, 20 Jan 2021 10:44:08 -0800 Subject: [PATCH] Fixes requested by codyoss@ --- google/internal/externalaccount/aws.go | 162 ++++++++++++++------ google/internal/externalaccount/aws_test.go | 91 +++++++++-- 2 files changed, 198 insertions(+), 55 deletions(-) diff --git a/google/internal/externalaccount/aws.go b/google/internal/externalaccount/aws.go index 2357b2d..d505cf8 100644 --- a/google/internal/externalaccount/aws.go +++ b/google/internal/externalaccount/aws.go @@ -1,13 +1,16 @@ // Copyright 2021 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. + package externalaccount import ( "crypto/hmac" "crypto/sha256" "encoding/hex" + "errors" "fmt" + "io" "io/ioutil" "net/http" "path" @@ -16,13 +19,13 @@ import ( "time" ) -// A utility class to sign http requests using a AWS V4 signature +// RequestSigner is a utility class to sign http requests using a AWS V4 signature. type RequestSigner struct { RegionName string AwsSecurityCredentials map[string]string - debugTimestamp time.Time } +// NewRequestSigner is a method to create a RequestSigner with the appropriately filled out fields. func NewRequestSigner(regionName string, awsSecurityCredentials map[string]string) *RequestSigner { return &RequestSigner{ RegionName: regionName, @@ -30,32 +33,60 @@ func NewRequestSigner(regionName string, awsSecurityCredentials map[string]strin } } +const ( // AWS Signature Version 4 signing algorithm identifier. -const awsAlgorithm = "AWS4-HMAC-SHA256" + awsAlgorithm = "AWS4-HMAC-SHA256" // The termination string for the AWS credential scope value as defined in // https://docs.aws.amazon.com/general/latest/gr/sigv4-create-string-to-sign.html -const awsRequestType = "aws4_request" + awsRequestType = "aws4_request" // The AWS authorization header name for the security session token if available. -const awsSecurityTokenHeader = "x-amz-security-token" + awsSecurityTokenHeader = "x-amz-security-token" // The AWS authorization header name for the auto-generated date. -const awsDateHeader = "x-amz-date" + awsDateHeader = "x-amz-date" -const awsTimeFormatLong = "20060102T150405Z" -const awsTimeFormatShort = "20060102" + awsTimeFormatLong = "20060102T150405Z" + awsTimeFormatShort = "20060102" +) -func getSha256(input []byte) string { +func getSha256(input []byte) (string, error) { hash := sha256.New() - hash.Write(input) - return hex.EncodeToString(hash.Sum(nil)) + if _, err := hash.Write(input); err != nil { + return "", err + } + return hex.EncodeToString(hash.Sum(nil)), nil } -func getHmacSha256(key, input []byte) []byte { +func getHmacSha256(key, input []byte) ([]byte, error) { hash := hmac.New(sha256.New, key) - hash.Write(input) - return hash.Sum(nil) + if _, err := hash.Write(input); err != nil { + return nil, err + } + return hash.Sum(nil), nil +} + +func cloneRequest(r *http.Request) *http.Request { + r2 := new(http.Request) + *r2 = *r + if r.Header != nil { + r2.Header = make(http.Header, len(r.Header)) + + // Find total number of values. + headerCount := 0 + for _, headerValues := range r.Header { + headerCount += len(headerValues) + } + copiedHeaders := make([]string, headerCount) // shared backing array for headers' values + + for headerKey, headerValues := range r.Header { + headerCount = copy(copiedHeaders, headerValues) + r2.Header[headerKey] = copiedHeaders[:headerCount:headerCount] + copiedHeaders = copiedHeaders[headerCount:] + } + } + return r2 } func canonicalPath(req *http.Request) string { @@ -90,20 +121,31 @@ func canonicalHeaders(req *http.Request) (string, string) { } sort.Strings(headers) - var fullHeaders []string + var fullHeaders strings.Builder for _, header := range headers { headerValue := strings.Join(lowerCaseHeaders[header], ",") - fullHeaders = append(fullHeaders, header+":"+headerValue+"\n") + fullHeaders.WriteString(header) + fullHeaders.WriteRune(':') + fullHeaders.WriteString(headerValue) + fullHeaders.WriteRune('\n') } - return strings.Join(headers, ";"), strings.Join(fullHeaders, "") + return strings.Join(headers, ";"), fullHeaders.String() } -func requestDataHash(req *http.Request) string { - requestData := []byte{} +func requestDataHash(req *http.Request) (string, error) { + var requestData []byte if req.Body != nil { - requestBody, _ := req.GetBody() - requestData, _ = ioutil.ReadAll(requestBody) + requestBody, err := req.GetBody() + if err != nil { + return "", err + } + defer requestBody.Close() + + requestData, err = ioutil.ReadAll(io.LimitReader(requestBody, 1<<20)) + if err != nil { + return "", err + } } return getSha256(requestData) @@ -116,63 +158,93 @@ func requestHost(req *http.Request) string { return req.URL.Host } -func canonicalRequest(req *http.Request, canonicalHeaderColumns, canonicalHeaderData string) string { +func canonicalRequest(req *http.Request, canonicalHeaderColumns, canonicalHeaderData string) (string, error) { + dataHash, err := requestDataHash(req) + if err != nil { + return "", err + } + return strings.Join([]string{ req.Method, canonicalPath(req), canonicalQuery(req), canonicalHeaderData, canonicalHeaderColumns, - requestDataHash(req), - }, "\n") + dataHash, + }, "\n"), nil } -func (rs *RequestSigner) SignedRequest(req *http.Request) *http.Request { - timestamp := rs.debugTimestamp - if timestamp.IsZero() { - timestamp = time.Now() - } - signedRequest := req.Clone(req.Context()) +// SignRequest adds the appropriate headers to an http.Request +// or returns an error if something prevented this. +func (rs *RequestSigner) SignRequest(req *http.Request) error { + signedRequest := cloneRequest(req) + timestamp := now() signedRequest.Header.Add("host", requestHost(req)) - securityToken, ok := rs.AwsSecurityCredentials["security_token"] - if ok { - signedRequest.Header.Add("x-amz-security-token", securityToken) + if securityToken, ok := rs.AwsSecurityCredentials["security_token"]; ok { + signedRequest.Header.Add(awsSecurityTokenHeader, securityToken) } if signedRequest.Header.Get("date") == "" { - signedRequest.Header.Add("x-amz-date", timestamp.Format(awsTimeFormatLong)) + signedRequest.Header.Add(awsDateHeader, timestamp.Format(awsTimeFormatLong)) } - signedRequest.Header.Set("Authorization", rs.generateAuthentication(signedRequest, timestamp)) + authorizationCode, err := rs.generateAuthentication(signedRequest, timestamp) + if err != nil { + return err + } + signedRequest.Header.Set("Authorization", authorizationCode) - return signedRequest + req.Header = signedRequest.Header + return nil } -func (rs *RequestSigner) generateAuthentication(req *http.Request, timestamp time.Time) string { +func (rs *RequestSigner) generateAuthentication(req *http.Request, timestamp time.Time) (string, error) { + secretAccessKey, ok := rs.AwsSecurityCredentials["secret_access_key"] + if !ok { + return "", errors.New("Missing Secret Access Key") + } + accessKeyId, ok := rs.AwsSecurityCredentials["access_key_id"] + if !ok { + return "", errors.New("Missing Access Key Id") + } + canonicalHeaderColumns, canonicalHeaderData := canonicalHeaders(req) dateStamp := timestamp.Format(awsTimeFormatShort) - serviceName := strings.Split(requestHost(req), ".")[0] + serviceName := "" + if splitHost := strings.Split(requestHost(req), "."); len(splitHost) > 0 { + serviceName = splitHost[0] + } - credentialScope := strings.Join([]string{ - dateStamp, rs.RegionName, serviceName, awsRequestType, - }, "/") + credentialScope := fmt.Sprintf("%s/%s/%s/%s",dateStamp, rs.RegionName, serviceName, awsRequestType) + + requestString, err := canonicalRequest(req, canonicalHeaderColumns, canonicalHeaderData) + if err != nil { + return "", err + } + requestHash, err := getSha256([]byte(requestString)) + if err != nil{ + return "", err + } stringToSign := strings.Join([]string{ awsAlgorithm, timestamp.Format(awsTimeFormatLong), credentialScope, - getSha256([]byte(canonicalRequest(req, canonicalHeaderColumns, canonicalHeaderData))), + requestHash, }, "\n") - signingKey := []byte("AWS4" + rs.AwsSecurityCredentials["secret_access_key"]) + signingKey := []byte("AWS4" + secretAccessKey) for _, signingInput := range []string{ dateStamp, rs.RegionName, serviceName, awsRequestType, stringToSign, } { - signingKey = getHmacSha256(signingKey, []byte(signingInput)) + signingKey, err = getHmacSha256(signingKey, []byte(signingInput)) + if err != nil{ + return "", err + } } - return fmt.Sprintf("%s Credential=%s/%s, SignedHeaders=%s, Signature=%s", awsAlgorithm, rs.AwsSecurityCredentials["access_key_id"], credentialScope, canonicalHeaderColumns, hex.EncodeToString(signingKey)) + return fmt.Sprintf("%s Credential=%s/%s, SignedHeaders=%s, Signature=%s", awsAlgorithm, accessKeyId, credentialScope, canonicalHeaderColumns, hex.EncodeToString(signingKey)), nil } diff --git a/google/internal/externalaccount/aws_test.go b/google/internal/externalaccount/aws_test.go index dbd5c00..a96e76f 100644 --- a/google/internal/externalaccount/aws_test.go +++ b/google/internal/externalaccount/aws_test.go @@ -14,6 +14,12 @@ import ( var defaultTime = time.Date(2011, 9, 9, 23, 36, 0, 0, time.UTC) var secondDefaultTime = time.Date(2020, 8, 11, 6, 55, 22, 0, time.UTC) +func setTime(testTime time.Time) func() time.Time { + return func() time.Time { + return testTime + } +} + var defaultRequestSigner = NewRequestSigner("us-east-1", map[string]string{ "access_key_id": "AKIDEXAMPLE", "secret_access_key": "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY", @@ -36,16 +42,19 @@ func setDefaultTime(req *http.Request) { } func testRequestSigner(t *testing.T, rs *RequestSigner, input, expectedOutput *http.Request) { - actualOutput := rs.SignedRequest(input) + err := rs.SignRequest(input) + if err != nil { + t.Errorf("unexpected error: %q", err.Error()) + } - if got, want := actualOutput.URL.String(), expectedOutput.URL.String(); !reflect.DeepEqual(got, want) { + if got, want := input.URL.String(), expectedOutput.URL.String(); !reflect.DeepEqual(got, want) { t.Errorf("url = %q, want %q", got, want) } - if got, want := actualOutput.Method, expectedOutput.Method; !reflect.DeepEqual(got, want) { + if got, want := input.Method, expectedOutput.Method; !reflect.DeepEqual(got, want) { t.Errorf("method = %q, want %q", got, want) } for header := range expectedOutput.Header { - if got, want := actualOutput.Header[header], expectedOutput.Header[header]; !reflect.DeepEqual(got, want) { + if got, want := input.Header[header], expectedOutput.Header[header]; !reflect.DeepEqual(got, want) { t.Errorf("header[%q] = %q, want %q", header, got, want) } } @@ -62,6 +71,10 @@ func TestAwsV4Signature_GetRequest(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=b27ccfbfa7df52a200ff74193ca6e32d4b48b8856fab7ebf1c595d0670a7e470"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -76,6 +89,10 @@ func TestAwsV4Signature_GetRequestWithRelativePath(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=b27ccfbfa7df52a200ff74193ca6e32d4b48b8856fab7ebf1c595d0670a7e470"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -90,6 +107,10 @@ func TestAwsV4Signature_GetRequestWithDotPath(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=b27ccfbfa7df52a200ff74193ca6e32d4b48b8856fab7ebf1c595d0670a7e470"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -104,6 +125,10 @@ func TestAwsV4Signature_GetRequestWithPointlessDotPath(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=910e4d6c9abafaf87898e1eb4c929135782ea25bb0279703146455745391e63a"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -118,6 +143,10 @@ func TestAwsV4Signature_GetRequestWithUtf8Path(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=8d6634c189aa8c75c2e51e106b6b5121bed103fdb351f7d7d4381c738823af74"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -132,6 +161,10 @@ func TestAwsV4Signature_GetRequestWithDuplicateQuery(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=be7148d34ebccdc6423b19085378aa0bee970bdc61d144bd1a8c48c33079ab09"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -146,6 +179,10 @@ func TestAwsV4Signature_GetRequestWithMisorderedQuery(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=feb926e49e382bec75c9d7dcb2a1b6dc8aa50ca43c25d2bc51143768c0875acc"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -160,6 +197,10 @@ func TestAwsV4Signature_GetRequestWithUtf8Query(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=6fb359e9a05394cc7074e0feb42573a2601abc0c869a953e8c5c12e4e01f1a8c"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -176,6 +217,10 @@ func TestAwsV4Signature_PostRequest(t *testing.T) { "Zoo": []string{"zoobar"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -192,6 +237,10 @@ func TestAwsV4Signature_PostRequestWithCapitalizedHeaderValue(t *testing.T) { "Zoo": []string{"ZOOBAR"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -208,6 +257,10 @@ func TestAwsV4Signature_PostRequestPhfft(t *testing.T) { "P": []string{"phfft"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -224,6 +277,10 @@ func TestAwsV4Signature_PostRequestWithBody(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=content-type;date;host, Signature=5a15b22cf462f047318703b92e6f4f38884e4a7ab7b1d6426ca46a8bd1c26cbc"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -238,6 +295,10 @@ func TestAwsV4Signature_PostRequestWithQueryString(t *testing.T) { "Authorization": []string{"AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20110909/us-east-1/host/aws4_request, SignedHeaders=date;host, Signature=b6e3b79003ce0743a491606ba1035a804593b0efb1e20a11cba83f8c25a57a92"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(defaultTime) + testRequestSigner(t, defaultRequestSigner, input, output) } @@ -252,6 +313,10 @@ func TestAwsV4Signature_GetRequestWithSecurityToken(t *testing.T) { "X-Amz-Security-Token": []string{securityToken}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(secondDefaultTime) + testRequestSigner(t, requestSignerWithToken, input, output) } @@ -266,6 +331,10 @@ func TestAwsV4Signature_PostRequestWithSecurityToken(t *testing.T) { "X-Amz-Security-Token": []string{securityToken}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(secondDefaultTime) + testRequestSigner(t, requestSignerWithToken, input, output) } @@ -285,6 +354,10 @@ func TestAwsV4Signature_PostRequestWithSecurityTokenAndAdditionalHeaders(t *test "X-Amz-Security-Token": []string{securityToken}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(secondDefaultTime) + testRequestSigner(t, requestSignerWithToken, input, output) } @@ -293,7 +366,6 @@ func TestAwsV4Signature_PostRequestWithAmzDateButNoSecurityToken(t *testing.T) { "access_key_id": accessKeyId, "secret_access_key": secretAccessKey, }) - requestSigner.debugTimestamp = secondDefaultTime input, _ := http.NewRequest("POST", "https://sts.us-east-2.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15", nil) @@ -304,10 +376,9 @@ func TestAwsV4Signature_PostRequestWithAmzDateButNoSecurityToken(t *testing.T) { "X-Amz-Date": []string{"20200811T065522Z"}, } + oldNow := now + defer func() { now = oldNow }() + now = setTime(secondDefaultTime) + testRequestSigner(t, requestSigner, input, output) } - -func init() { - defaultRequestSigner.debugTimestamp = defaultTime - requestSignerWithToken.debugTimestamp = secondDefaultTime -}