open-vault/builtin/credential/aws/cli.go

137 lines
4.2 KiB
Go

package awsauth
import (
"encoding/base64"
"encoding/json"
"fmt"
"io/ioutil"
"strings"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/sts"
"github.com/hashicorp/vault/api"
"github.com/hashicorp/vault/helper/awsutil"
)
type CLIHandler struct{}
// Generates the necessary data to send to the Vault server for generating a token
// This is useful for other API clients to use
func GenerateLoginData(accessKey, secretKey, sessionToken, headerValue string) (map[string]interface{}, error) {
loginData := make(map[string]interface{})
credConfig := &awsutil.CredentialsConfig{
AccessKey: accessKey,
SecretKey: secretKey,
SessionToken: sessionToken,
}
creds, err := credConfig.GenerateCredentialChain()
if err != nil {
return nil, err
}
if creds == nil {
return nil, fmt.Errorf("could not compile valid credential providers from static config, environment, shared, or instance metadata")
}
// Use the credentials we've found to construct an STS session
stsSession, err := session.NewSessionWithOptions(session.Options{
Config: aws.Config{Credentials: creds},
})
if err != nil {
return nil, err
}
var params *sts.GetCallerIdentityInput
svc := sts.New(stsSession)
stsRequest, _ := svc.GetCallerIdentityRequest(params)
// Inject the required auth header value, if supplied, and then sign the request including that header
if headerValue != "" {
stsRequest.HTTPRequest.Header.Add(iamServerIdHeader, headerValue)
}
stsRequest.Sign()
// Now extract out the relevant parts of the request
headersJson, err := json.Marshal(stsRequest.HTTPRequest.Header)
if err != nil {
return nil, err
}
requestBody, err := ioutil.ReadAll(stsRequest.HTTPRequest.Body)
if err != nil {
return nil, err
}
loginData["iam_http_request_method"] = stsRequest.HTTPRequest.Method
loginData["iam_request_url"] = base64.StdEncoding.EncodeToString([]byte(stsRequest.HTTPRequest.URL.String()))
loginData["iam_request_headers"] = base64.StdEncoding.EncodeToString(headersJson)
loginData["iam_request_body"] = base64.StdEncoding.EncodeToString(requestBody)
return loginData, nil
}
func (h *CLIHandler) Auth(c *api.Client, m map[string]string) (string, error) {
mount, ok := m["mount"]
if !ok {
mount = "aws"
}
role, ok := m["role"]
if !ok {
role = ""
}
headerValue, ok := m["header_value"]
if !ok {
headerValue = ""
}
loginData, err := GenerateLoginData(m["aws_access_key_id"], m["aws_secret_access_key"], m["aws_security_token"], headerValue)
if err != nil {
return "", err
}
if loginData == nil {
return "", fmt.Errorf("got nil response from GenerateLoginData")
}
loginData["role"] = role
path := fmt.Sprintf("auth/%s/login", mount)
secret, err := c.Logical().Write(path, loginData)
if err != nil {
return "", err
}
if secret == nil {
return "", fmt.Errorf("empty response from credential provider")
}
return secret.Auth.ClientToken, nil
}
func (h *CLIHandler) Help() string {
help := `
The AWS credential provider allows you to authenticate with
AWS IAM credentials. To use it, you specify valid AWS IAM credentials
in one of a number of ways. They can be specified explicitly on the
command line (which in general you should not do), via the standard AWS
environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and
AWS_SECURITY_TOKEN), via the ~/.aws/credentials file, or via an EC2
instance profile (in that order).
Example: vault auth -method=aws
If you need to explicitly pass in credentials, you would do it like this:
Example: vault auth -method=aws aws_access_key_id=<access key> aws_secret_access_key=<secret key> aws_security_token=<token>
Key/Value Pairs:
mount=aws The mountpoint for the AWS credential provider.
Defaults to "aws"
aws_access_key_id=<access key> Explicitly specified AWS access key
aws_secret_access_key=<secret key> Explicitly specified AWS secret key
aws_security_token=<token> Security token for temporary credentials
header_value The Value of the X-Vault-AWS-IAM-Server-ID header.
role The name of the role you're requesting a token for
`
return strings.TrimSpace(help)
}