vendor/github.com/aws/aws-sdk-go/aws/credentials/shared_credentials_provider.go

   1 package credentials
   2
   3 import (
   4         "fmt"
   5         "os"
   6         "path/filepath"
   7
   8         "github.com/go-ini/ini"
   9
  10         "github.com/aws/aws-sdk-go/aws/awserr"
  11 )
  12
  13 // SharedCredsProviderName provides a name of SharedCreds provider
  14 const SharedCredsProviderName = "SharedCredentialsProvider"
  15
  16 var (
  17         // ErrSharedCredentialsHomeNotFound is emitted when the user directory cannot be found.
  18         //
  19         // @readonly
  20         ErrSharedCredentialsHomeNotFound = awserr.New("UserHomeNotFound", "user home directory not found.", nil)
  21 )
  22
  23 // A SharedCredentialsProvider retrieves credentials from the current user's home
  24 // directory, and keeps track if those credentials are expired.
  25 //
  26 // Profile ini file example: $HOME/.aws/credentials
  27 type SharedCredentialsProvider struct {
  28         // Path to the shared credentials file.
  29         //
  30         // If empty will look for "AWS_SHARED_CREDENTIALS_FILE" env variable. If the
  31         // env value is empty will default to current user's home directory.
  32         // Linux/OSX: "$HOME/.aws/credentials"
  33         // Windows:   "%USERPROFILE%\.aws\credentials"
  34         Filename string
  35
  36         // AWS Profile to extract credentials from the shared credentials file. If empty
  37         // will default to environment variable "AWS_PROFILE" or "default" if
  38         // environment variable is also not set.
  39         Profile string
  40
  41         // retrieved states if the credentials have been successfully retrieved.
  42         retrieved bool
  43 }
  44
  45 // NewSharedCredentials returns a pointer to a new Credentials object
  46 // wrapping the Profile file provider.
  47 func NewSharedCredentials(filename, profile string) *Credentials {
  48         return NewCredentials(&SharedCredentialsProvider{
  49                 Filename: filename,
  50                 Profile:  profile,
  51         })
  52 }
  53
  54 // Retrieve reads and extracts the shared credentials from the current
  55 // users home directory.
  56 func (p *SharedCredentialsProvider) Retrieve() (Value, error) {
  57         p.retrieved = false
  58
  59         filename, err := p.filename()
  60         if err != nil {
  61                 return Value{ProviderName: SharedCredsProviderName}, err
  62         }
  63
  64         creds, err := loadProfile(filename, p.profile())
  65         if err != nil {
  66                 return Value{ProviderName: SharedCredsProviderName}, err
  67         }
  68
  69         p.retrieved = true
  70         return creds, nil
  71 }
  72
  73 // IsExpired returns if the shared credentials have expired.
  74 func (p *SharedCredentialsProvider) IsExpired() bool {
  75         return !p.retrieved
  76 }
  77
  78 // loadProfiles loads from the file pointed to by shared credentials filename for profile.
  79 // The credentials retrieved from the profile will be returned or error. Error will be
  80 // returned if it fails to read from the file, or the data is invalid.
  81 func loadProfile(filename, profile string) (Value, error) {
  82         config, err := ini.Load(filename)
  83         if err != nil {
  84                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to load shared credentials file", err)
  85         }
  86         iniProfile, err := config.GetSection(profile)
  87         if err != nil {
  88                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to get profile", err)
  89         }
  90
  91         id, err := iniProfile.GetKey("aws_access_key_id")
  92         if err != nil {
  93                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsAccessKey",
  94                         fmt.Sprintf("shared credentials %s in %s did not contain aws_access_key_id", profile, filename),
  95                         err)
  96         }
  97
  98         secret, err := iniProfile.GetKey("aws_secret_access_key")
  99         if err != nil {
 100                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsSecret",
 101                         fmt.Sprintf("shared credentials %s in %s did not contain aws_secret_access_key", profile, filename),
 102                         nil)
 103         }
 104
 105         // Default to empty string if not found
 106         token := iniProfile.Key("aws_session_token")
 107
 108         return Value{
 109                 AccessKeyID:     id.String(),
 110                 SecretAccessKey: secret.String(),
 111                 SessionToken:    token.String(),
 112                 ProviderName:    SharedCredsProviderName,
 113         }, nil
 114 }
 115
 116 // filename returns the filename to use to read AWS shared credentials.
 117 //
 118 // Will return an error if the user's home directory path cannot be found.
 119 func (p *SharedCredentialsProvider) filename() (string, error) {
 120         if p.Filename == "" {
 121                 if p.Filename = os.Getenv("AWS_SHARED_CREDENTIALS_FILE"); p.Filename != "" {
 122                         return p.Filename, nil
 123                 }
 124
 125                 homeDir := os.Getenv("HOME") // *nix
 126                 if homeDir == "" {           // Windows
 127                         homeDir = os.Getenv("USERPROFILE")
 128                 }
 129                 if homeDir == "" {
 130                         return "", ErrSharedCredentialsHomeNotFound
 131                 }
 132
 133                 p.Filename = filepath.Join(homeDir, ".aws", "credentials")
 134         }
 135
 136         return p.Filename, nil
 137 }
 138
 139 // profile returns the AWS shared credentials profile.  If empty will read
 140 // environment variable "AWS_PROFILE". If that is not set profile will
 141 // return "default".
 142 func (p *SharedCredentialsProvider) profile() string {
 143         if p.Profile == "" {
 144                 p.Profile = os.Getenv("AWS_PROFILE")
 145         }
 146         if p.Profile == "" {
 147                 p.Profile = "default"
 148         }
 149
 150         return p.Profile
 151 }