VictoriaMetrics/lib/awsapi/sign.go
Nikolay f61b8cec69
lib/awsapi: fixes sign encoding (#3183)
* lib/awsapi: fixes sign encoding

previously white spaces at filter were incorrectly encoded
encoding tip was copied from aws signing lib
For example, the space character must be encoded as %20 (not using '+', as some encoding schemes do)
https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3171

* Update lib/awsapi/sign.go

Co-authored-by: Aliaksandr Valialkin <valyala@victoriametrics.com>
2022-09-30 07:43:44 +03:00

115 lines
3.5 KiB
Go

package awsapi
import (
"crypto/hmac"
"crypto/sha256"
"encoding/hex"
"fmt"
"net/http"
"strings"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
)
// for get requests there is no need to calculate payload hash each time.
var emptyPayloadHash = hashHex("")
// newSignedGetRequest creates signed http get request for apiURL according to aws signature algorithm.
//
// See the algorithm at https://docs.aws.amazon.com/general/latest/gr/sigv4-signed-request-examples.html
func newSignedGetRequest(apiURL, service, region string, creds *credentials) (*http.Request, error) {
return newSignedGetRequestWithTime(apiURL, service, region, creds, time.Now().UTC())
}
func newSignedGetRequestWithTime(apiURL, service, region string, creds *credentials, t time.Time) (*http.Request, error) {
req, err := http.NewRequest("GET", apiURL, nil)
if err != nil {
return nil, fmt.Errorf("cannot create http request with given apiURL: %s, err: %w", apiURL, err)
}
if err := signRequestWithTime(req, service, region, emptyPayloadHash, creds, t); err != nil {
return nil, err
}
return req, nil
}
// signRequestWithTime - signs http request with AWS API credentials for given payload
func signRequestWithTime(req *http.Request, service, region, payloadHash string, creds *credentials, t time.Time) error {
uri := req.URL
// Create canonicalRequest
amzdate := t.Format("20060102T150405Z")
datestamp := t.Format("20060102")
canonicalURL := uri.Path
canonicalQS := uri.Query().Encode()
// Replace "%20" with "+" according to AWS requirements.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3171
canonicalQS = strings.ReplaceAll(canonicalQS, "+", "%20")
canonicalHeaders := fmt.Sprintf("host:%s\nx-amz-date:%s\n", uri.Host, amzdate)
signedHeaders := "host;x-amz-date"
tmp := []string{
req.Method,
canonicalURL,
canonicalQS,
canonicalHeaders,
signedHeaders,
payloadHash,
}
canonicalRequest := strings.Join(tmp, "\n")
algorithm := "AWS4-HMAC-SHA256"
credentialScope := fmt.Sprintf("%s/%s/%s/aws4_request", datestamp, region, service)
tmp = []string{
algorithm,
amzdate,
credentialScope,
hashHex(canonicalRequest),
}
stringToSign := strings.Join(tmp, "\n")
// Calculate the signature
signingKey := getSignatureKey(creds.SecretAccessKey, datestamp, region, service)
signature := hmacHex(signingKey, stringToSign)
// Calculate autheader
authHeader := fmt.Sprintf("%s Credential=%s/%s, SignedHeaders=%s, Signature=%s", algorithm, creds.AccessKeyID, credentialScope, signedHeaders, signature)
req.Header.Set("x-amz-date", amzdate)
req.Header.Set("Authorization", authHeader)
// special case for token auth
if creds.Token != "" {
req.Header.Set("X-Amz-Security-Token", creds.Token)
}
return nil
}
func getSignatureKey(key, datestamp, region, service string) string {
kDate := hmacBin("AWS4"+key, datestamp)
kRegion := hmacBin(kDate, region)
kService := hmacBin(kRegion, service)
return hmacBin(kService, "aws4_request")
}
func hashHex(s string) string {
return HashHex([]byte(s))
}
// HashHex hashes given s
func HashHex(s []byte) string {
h := sha256.Sum256(s)
return hex.EncodeToString(h[:])
}
func hmacHex(key, data string) string {
digest := hmacBin(key, data)
return hex.EncodeToString([]byte(digest))
}
func hmacBin(key, data string) string {
h := hmac.New(sha256.New, []byte(key))
_, err := h.Write([]byte(data))
if err != nil {
logger.Panicf("BUG: unexpected error when writing to hmac: %s", err)
}
return string(h.Sum(nil))
}