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

   1 package credentials
   2
   3 import (
   4         "fmt"
   5         "os"
   6
   7         "github.com/aws/aws-sdk-go/aws/awserr"
   8         "github.com/aws/aws-sdk-go/internal/ini"
   9         "github.com/aws/aws-sdk-go/internal/shareddefaults"
  10 )
  11
  12 // SharedCredsProviderName provides a name of SharedCreds provider
  13 const SharedCredsProviderName = "SharedCredentialsProvider"
  14
  15 var (
  16         // ErrSharedCredentialsHomeNotFound is emitted when the user directory cannot be found.
  17         ErrSharedCredentialsHomeNotFound = awserr.New("UserHomeNotFound", "user home directory not found.", nil)
  18 )
  19
  20 // A SharedCredentialsProvider retrieves credentials from the current user's home
  21 // directory, and keeps track if those credentials are expired.
  22 //
  23 // Profile ini file example: $HOME/.aws/credentials
  24 type SharedCredentialsProvider struct {
  25         // Path to the shared credentials file.
  26         //
  27         // If empty will look for "AWS_SHARED_CREDENTIALS_FILE" env variable. If the
  28         // env value is empty will default to current user's home directory.
  29         // Linux/OSX: "$HOME/.aws/credentials"
  30         // Windows:   "%USERPROFILE%\.aws\credentials"
  31         Filename string
  32
  33         // AWS Profile to extract credentials from the shared credentials file. If empty
  34         // will default to environment variable "AWS_PROFILE" or "default" if
  35         // environment variable is also not set.
  36         Profile string
  37
  38         // retrieved states if the credentials have been successfully retrieved.
  39         retrieved bool
  40 }
  41
  42 // NewSharedCredentials returns a pointer to a new Credentials object
  43 // wrapping the Profile file provider.
  44 func NewSharedCredentials(filename, profile string) *Credentials {
  45         return NewCredentials(&SharedCredentialsProvider{
  46                 Filename: filename,
  47                 Profile:  profile,
  48         })
  49 }
  50
  51 // Retrieve reads and extracts the shared credentials from the current
  52 // users home directory.
  53 func (p *SharedCredentialsProvider) Retrieve() (Value, error) {
  54         p.retrieved = false
  55
  56         filename, err := p.filename()
  57         if err != nil {
  58                 return Value{ProviderName: SharedCredsProviderName}, err
  59         }
  60
  61         creds, err := loadProfile(filename, p.profile())
  62         if err != nil {
  63                 return Value{ProviderName: SharedCredsProviderName}, err
  64         }
  65
  66         p.retrieved = true
  67         return creds, nil
  68 }
  69
  70 // IsExpired returns if the shared credentials have expired.
  71 func (p *SharedCredentialsProvider) IsExpired() bool {
  72         return !p.retrieved
  73 }
  74
  75 // loadProfiles loads from the file pointed to by shared credentials filename for profile.
  76 // The credentials retrieved from the profile will be returned or error. Error will be
  77 // returned if it fails to read from the file, or the data is invalid.
  78 func loadProfile(filename, profile string) (Value, error) {
  79         config, err := ini.OpenFile(filename)
  80         if err != nil {
  81                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to load shared credentials file", err)
  82         }
  83
  84         iniProfile, ok := config.GetSection(profile)
  85         if !ok {
  86                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to get profile", nil)
  87         }
  88
  89         id := iniProfile.String("aws_access_key_id")
  90         if len(id) == 0 {
  91                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsAccessKey",
  92                         fmt.Sprintf("shared credentials %s in %s did not contain aws_access_key_id", profile, filename),
  93                         nil)
  94         }
  95
  96         secret := iniProfile.String("aws_secret_access_key")
  97         if len(secret) == 0 {
  98                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsSecret",
  99                         fmt.Sprintf("shared credentials %s in %s did not contain aws_secret_access_key", profile, filename),
 100                         nil)
 101         }
 102
 103         // Default to empty string if not found
 104         token := iniProfile.String("aws_session_token")
 105
 106         return Value{
 107                 AccessKeyID:     id,
 108                 SecretAccessKey: secret,
 109                 SessionToken:    token,
 110                 ProviderName:    SharedCredsProviderName,
 111         }, nil
 112 }
 113
 114 // filename returns the filename to use to read AWS shared credentials.
 115 //
 116 // Will return an error if the user's home directory path cannot be found.
 117 func (p *SharedCredentialsProvider) filename() (string, error) {
 118         if len(p.Filename) != 0 {
 119                 return p.Filename, nil
 120         }
 121
 122         if p.Filename = os.Getenv("AWS_SHARED_CREDENTIALS_FILE"); len(p.Filename) != 0 {
 123                 return p.Filename, nil
 124         }
 125
 126         if home := shareddefaults.UserHomeDir(); len(home) == 0 {
 127                 // Backwards compatibility of home directly not found error being returned.
 128                 // This error is too verbose, failure when opening the file would of been
 129                 // a better error to return.
 130                 return "", ErrSharedCredentialsHomeNotFound
 131         }
 132
 133         p.Filename = shareddefaults.SharedCredentialsFilename()
 134
 135         return p.Filename, nil
 136 }
 137
 138 // profile returns the AWS shared credentials profile.  If empty will read
 139 // environment variable "AWS_PROFILE". If that is not set profile will
 140 // return "default".
 141 func (p *SharedCredentialsProvider) profile() string {
 142         if p.Profile == "" {
 143                 p.Profile = os.Getenv("AWS_PROFILE")
 144         }
 145         if p.Profile == "" {
 146                 p.Profile = "default"
 147         }
 148
 149         return p.Profile
 150 }