Merge pull request #141 from 99designs/refactor-order-in-which-access…

…-to-keychain-is-requested

Refactor order in which access to keychain is requested

vault/config.go

@@ -83,5 +83,5 @@ func FormatCredentialError(profileKey string, from Profiles, err error) string {
 			sourceDescr, source)
 	}
 
-	return fmt.Sprintf("Failed to get credentials for %s: %v", err, sourceDescr)
+	return fmt.Sprintf("Failed to get credentials for %s: %v", sourceDescr, err)
 }

vault/provider.go

@@ -87,42 +87,12 @@ func NewVaultProvider(k keyring.Keyring, profile string, opts VaultOptions) (*Va
 	}, nil
 }
 
+// Retrieve returns credentials protected by a GetSessionToken. If there is an associated
+// role in the profile then AssumeRole is applied. The benefit of a session is that it doesn't
+// require MFA or a user prompt to access the keychain item, much like sudo.
 func (p *VaultProvider) Retrieve() (credentials.Value, error) {
-	creds, err := p.getMasterCreds()
-	if err != nil {
-		return credentials.Value{}, err
-	}
-
-	window := p.ExpiryWindow
-	if window == 0 {
-		window = time.Minute * 5
-	}
-
 	if p.NoSession {
-		if role, ok := p.profiles[p.profile]["role_arn"]; ok {
-			session, err := p.assumeRole(creds, role)
-			if err != nil {
-				return credentials.Value{}, err
-			}
-
-			log.Printf("Using role ****************%s, expires in %s",
-				(*session.AccessKeyId)[len(*session.AccessKeyId)-4:],
-				session.Expiration.Sub(time.Now()).String())
-
-			p.SetExpiration(*session.Expiration, window)
-			p.expires = *session.Expiration
-
-			value := credentials.Value{
-				AccessKeyID:     *session.AccessKeyId,
-				SecretAccessKey: *session.SecretAccessKey,
-				SessionToken:    *session.SessionToken,
-			}
-
-			return value, nil
-		}
-
-		// no role, exposes master credentials which don't expire
-		return creds, nil
+		return p.RetrieveWithoutSessionToken()
 	}
 
 	session, err := p.sessions.Retrieve(p.profile, p.SessionDuration)
@@ -133,6 +103,12 @@ func (p *VaultProvider) Retrieve() (credentials.Value, error) {
 			log.Println(err)
 		}
 
+		// session lookup missed, we need to create a new one
+		creds, err := p.getMasterCreds()
+		if err != nil {
+			return credentials.Value{}, err
+		}
+
 		session, err = p.getSessionToken(&creds)
 		if err != nil {
 			return credentials.Value{}, err
@@ -158,6 +134,11 @@ func (p *VaultProvider) Retrieve() (credentials.Value, error) {
 			session.Expiration.Sub(time.Now()).String())
 	}
 
+	window := p.ExpiryWindow
+	if window == 0 {
+		window = time.Minute * 5
+	}
+
 	p.SetExpiration(*session.Expiration, window)
 	p.expires = *session.Expiration
 
@@ -170,6 +151,48 @@ func (p *VaultProvider) Retrieve() (credentials.Value, error) {
 	return value, nil
 }
 
+// RetrieveWithoutSessionToken returns credentials that are either the master credentials or
+// a session created with AssumeRole. This allows for usecases where a token created with AssumeRole
+// wouldn't work.
+func (p *VaultProvider) RetrieveWithoutSessionToken() (credentials.Value, error) {
+	log.Println("Skipping session token and using master credentials directly")
+
+	creds, err := p.getMasterCreds()
+	if err != nil {
+		return credentials.Value{}, err
+	}
+
+	if role, ok := p.profiles[p.profile]["role_arn"]; ok {
+		session, err := p.assumeRole(creds, role)
+		if err != nil {
+			return credentials.Value{}, err
+		}
+
+		log.Printf("Using role ****************%s, expires in %s",
+			(*session.AccessKeyId)[len(*session.AccessKeyId)-4:],
+			session.Expiration.Sub(time.Now()).String())
+
+		window := p.ExpiryWindow
+		if window == 0 {
+			window = time.Minute * 5
+		}
+
+		p.SetExpiration(*session.Expiration, window)
+		p.expires = *session.Expiration
+
+		value := credentials.Value{
+			AccessKeyID:     *session.AccessKeyId,
+			SecretAccessKey: *session.SecretAccessKey,
+			SessionToken:    *session.SessionToken,
+		}
+
+		return value, nil
+	}
+
+	// no role, exposes master credentials which don't expire
+	return creds, nil
+}
+
 func (p *VaultProvider) getMasterCreds() (credentials.Value, error) {
 	if p.MasterCreds != nil {
 		return *p.MasterCreds, nil

vault/sessions.go

@@ -64,10 +64,11 @@ func (s *KeyringSessions) Store(profile string, session sts.Credentials, duratio
 
 	log.Printf("Writing session for %s to keyring", profile)
 	s.Keyring.Set(keyring.Item{
-		Key:       s.key(profile, duration),
-		Label:     "aws-vault session for " + profile,
-		Data:      bytes,
-		TrustSelf: true,
+		Key:         s.key(profile, duration),
+		Label:       "aws-vault session for " + profile,
+		Description: "aws-vault session for " + profile,
+		Data:        bytes,
+		TrustSelf:   false,
 	})
 
 	return nil