Update of nlopes/slack dependency (#511)

1 files changed, 47 insertions, 0 deletions

diff --git a/vendor/github.com/nlopes/slack/security.go b/vendor/github.com/nlopes/slack/security.go
new file mode 100644
index 00000000..50201d99
--- /dev/null
+++ b/vendor/github.com/nlopes/slack/security.go
@@ -0,0 +1,47 @@
+package slack

+

+import (

+	"crypto/hmac"

+	"crypto/sha256"

+	"encoding/hex"

+	"errors"

+	"fmt"

+	"hash"

+	"net/http"

+)

+

+// SecretsVerifier contains the information needed to verify that the request comes from Slack

+type SecretsVerifier struct {

+	slackSig  string

+	timeStamp string

+	hmac      hash.Hash

+}

+

+// NewSecretsVerifier returns a SecretsVerifier object in exchange for an http.Header object and signing secret

+func NewSecretsVerifier(header http.Header, signingSecret string) (SecretsVerifier, error) {

+	if header["X-Slack-Signature"][0] == "" || header["X-Slack-Request-Timestamp"][0] == "" {

+		return SecretsVerifier{}, errors.New("Headers are empty, cannot create SecretsVerifier")

+	}

+

+	hash := hmac.New(sha256.New, []byte(signingSecret))

+	hash.Write([]byte(fmt.Sprintf("v0:%s:", header["X-Slack-Request-Timestamp"][0])))

+	return SecretsVerifier{

+		slackSig:  header["X-Slack-Signature"][0],

+		timeStamp: header["X-Slack-Request-Timestamp"][0],

+		hmac:      hash,

+	}, nil

+}

+

+func (v *SecretsVerifier) Write(body []byte) (n int, err error) {

+	return v.hmac.Write(body)

+}

+

+// Ensure compares the signature sent from Slack with the actual computed hash to judge validity

+func (v SecretsVerifier) Ensure() error {

+	computed := "v0=" + string(hex.EncodeToString(v.hmac.Sum(nil)))

+	if computed == v.slackSig {

+		return nil

+	}

+

+	return fmt.Errorf("Expected signing signature: %s, but computed: %s", v.slackSig, computed)

+}