Vendor main dependencies.

vendor/github.com/aws/aws-sdk-go/aws/credentials/stscreds/assume_role_provider.go

@@ -0,0 +1,161 @@
+// Package stscreds are credential Providers to retrieve STS AWS credentials.
+//
+// STS provides multiple ways to retrieve credentials which can be used when making
+// future AWS service API operation calls.
+package stscreds
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/client"
+	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/service/sts"
+)
+
+// ProviderName provides a name of AssumeRole provider
+const ProviderName = "AssumeRoleProvider"
+
+// AssumeRoler represents the minimal subset of the STS client API used by this provider.
+type AssumeRoler interface {
+	AssumeRole(input *sts.AssumeRoleInput) (*sts.AssumeRoleOutput, error)
+}
+
+// DefaultDuration is the default amount of time in minutes that the credentials
+// will be valid for.
+var DefaultDuration = time.Duration(15) * time.Minute
+
+// AssumeRoleProvider retrieves temporary credentials from the STS service, and
+// keeps track of their expiration time. This provider must be used explicitly,
+// as it is not included in the credentials chain.
+type AssumeRoleProvider struct {
+	credentials.Expiry
+
+	// STS client to make assume role request with.
+	Client AssumeRoler
+
+	// Role to be assumed.
+	RoleARN string
+
+	// Session name, if you wish to reuse the credentials elsewhere.
+	RoleSessionName string
+
+	// Expiry duration of the STS credentials. Defaults to 15 minutes if not set.
+	Duration time.Duration
+
+	// Optional ExternalID to pass along, defaults to nil if not set.
+	ExternalID *string
+
+	// The policy plain text must be 2048 bytes or shorter. However, an internal
+	// conversion compresses it into a packed binary format with a separate limit.
+	// The PackedPolicySize response element indicates by percentage how close to
+	// the upper size limit the policy is, with 100% equaling the maximum allowed
+	// size.
+	Policy *string
+
+	// The identification number of the MFA device that is associated with the user
+	// who is making the AssumeRole call. Specify this value if the trust policy
+	// of the role being assumed includes a condition that requires MFA authentication.
+	// The value is either the serial number for a hardware device (such as GAHT12345678)
+	// or an Amazon Resource Name (ARN) for a virtual device (such as arn:aws:iam::123456789012:mfa/user).
+	SerialNumber *string
+
+	// The value provided by the MFA device, if the trust policy of the role being
+	// assumed requires MFA (that is, if the policy includes a condition that tests
+	// for MFA). If the role being assumed requires MFA and if the TokenCode value
+	// is missing or expired, the AssumeRole call returns an "access denied" error.
+	TokenCode *string
+
+	// ExpiryWindow will allow the credentials to trigger refreshing prior to
+	// the credentials actually expiring. This is beneficial so race conditions
+	// with expiring credentials do not cause request to fail unexpectedly
+	// due to ExpiredTokenException exceptions.
+	//
+	// So a ExpiryWindow of 10s would cause calls to IsExpired() to return true
+	// 10 seconds before the credentials are actually expired.
+	//
+	// If ExpiryWindow is 0 or less it will be ignored.
+	ExpiryWindow time.Duration
+}
+
+// NewCredentials returns a pointer to a new Credentials object wrapping the
+// AssumeRoleProvider. The credentials will expire every 15 minutes and the
+// role will be named after a nanosecond timestamp of this operation.
+//
+// Takes a Config provider to create the STS client. The ConfigProvider is
+// satisfied by the session.Session type.
+func NewCredentials(c client.ConfigProvider, roleARN string, options ...func(*AssumeRoleProvider)) *credentials.Credentials {
+	p := &AssumeRoleProvider{
+		Client:   sts.New(c),
+		RoleARN:  roleARN,
+		Duration: DefaultDuration,
+	}
+
+	for _, option := range options {
+		option(p)
+	}
+
+	return credentials.NewCredentials(p)
+}
+
+// NewCredentialsWithClient returns a pointer to a new Credentials object wrapping the
+// AssumeRoleProvider. The credentials will expire every 15 minutes and the
+// role will be named after a nanosecond timestamp of this operation.
+//
+// Takes an AssumeRoler which can be satisfiede by the STS client.
+func NewCredentialsWithClient(svc AssumeRoler, roleARN string, options ...func(*AssumeRoleProvider)) *credentials.Credentials {
+	p := &AssumeRoleProvider{
+		Client:   svc,
+		RoleARN:  roleARN,
+		Duration: DefaultDuration,
+	}
+
+	for _, option := range options {
+		option(p)
+	}
+
+	return credentials.NewCredentials(p)
+}
+
+// Retrieve generates a new set of temporary credentials using STS.
+func (p *AssumeRoleProvider) Retrieve() (credentials.Value, error) {
+
+	// Apply defaults where parameters are not set.
+	if p.RoleSessionName == "" {
+		// Try to work out a role name that will hopefully end up unique.
+		p.RoleSessionName = fmt.Sprintf("%d", time.Now().UTC().UnixNano())
+	}
+	if p.Duration == 0 {
+		// Expire as often as AWS permits.
+		p.Duration = DefaultDuration
+	}
+	input := &sts.AssumeRoleInput{
+		DurationSeconds: aws.Int64(int64(p.Duration / time.Second)),
+		RoleArn:         aws.String(p.RoleARN),
+		RoleSessionName: aws.String(p.RoleSessionName),
+		ExternalId:      p.ExternalID,
+	}
+	if p.Policy != nil {
+		input.Policy = p.Policy
+	}
+	if p.SerialNumber != nil && p.TokenCode != nil {
+		input.SerialNumber = p.SerialNumber
+		input.TokenCode = p.TokenCode
+	}
+	roleOutput, err := p.Client.AssumeRole(input)
+
+	if err != nil {
+		return credentials.Value{ProviderName: ProviderName}, err
+	}
+
+	// We will proactively generate new credentials before they expire.
+	p.SetExpiration(*roleOutput.Credentials.Expiration, p.ExpiryWindow)
+
+	return credentials.Value{
+		AccessKeyID:     *roleOutput.Credentials.AccessKeyId,
+		SecretAccessKey: *roleOutput.Credentials.SecretAccessKey,
+		SessionToken:    *roleOutput.Credentials.SessionToken,
+		ProviderName:    ProviderName,
+	}, nil
+}