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/go-ini/ini"
   8
   9         "github.com/aws/aws-sdk-go/aws/awserr"
  10         "github.com/aws/aws-sdk-go/internal/shareddefaults"
  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         ErrSharedCredentialsHomeNotFound = awserr.New("UserHomeNotFound", "user home directory not found.", nil)
  19 )
  20
  21 // A SharedCredentialsProvider retrieves credentials from the current user's home
  22 // directory, and keeps track if those credentials are expired.
  23 //
  24 // Profile ini file example: $HOME/.aws/credentials
  25 type SharedCredentialsProvider struct {
  26         // Path to the shared credentials file.
  27         //
  28         // If empty will look for "AWS_SHARED_CREDENTIALS_FILE" env variable. If the
  29         // env value is empty will default to current user's home directory.
  30         // Linux/OSX: "$HOME/.aws/credentials"
  31         // Windows:   "%USERPROFILE%\.aws\credentials"
  32         Filename string
  33
  34         // AWS Profile to extract credentials from the shared credentials file. If empty
  35         // will default to environment variable "AWS_PROFILE" or "default" if
  36         // environment variable is also not set.
  37         Profile string
  38
  39         // retrieved states if the credentials have been successfully retrieved.
  40         retrieved bool
  41 }
  42
  43 // NewSharedCredentials returns a pointer to a new Credentials object
  44 // wrapping the Profile file provider.
  45 func NewSharedCredentials(filename, profile string) *Credentials {
  46         return NewCredentials(&SharedCredentialsProvider{
  47                 Filename: filename,
  48                 Profile:  profile,
  49         })
  50 }
  51
  52 // Retrieve reads and extracts the shared credentials from the current
  53 // users home directory.
  54 func (p *SharedCredentialsProvider) Retrieve() (Value, error) {
  55         p.retrieved = false
  56
  57         filename, err := p.filename()
  58         if err != nil {
  59                 return Value{ProviderName: SharedCredsProviderName}, err
  60         }
  61
  62         creds, err := loadProfile(filename, p.profile())
  63         if err != nil {
  64                 return Value{ProviderName: SharedCredsProviderName}, err
  65         }
  66
  67         p.retrieved = true
  68         return creds, nil
  69 }
  70
  71 // IsExpired returns if the shared credentials have expired.
  72 func (p *SharedCredentialsProvider) IsExpired() bool {
  73         return !p.retrieved
  74 }
  75
  76 // loadProfiles loads from the file pointed to by shared credentials filename for profile.
  77 // The credentials retrieved from the profile will be returned or error. Error will be
  78 // returned if it fails to read from the file, or the data is invalid.
  79 func loadProfile(filename, profile string) (Value, error) {
  80         config, err := ini.Load(filename)
  81         if err != nil {
  82                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to load shared credentials file", err)
  83         }
  84         iniProfile, err := config.GetSection(profile)
  85         if err != nil {
  86                 return Value{ProviderName: SharedCredsProviderName}, awserr.New("SharedCredsLoad", "failed to get profile", err)
  87         }
  88
  89         id, err := iniProfile.GetKey("aws_access_key_id")
  90         if err != nil {
  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                         err)
  94         }
  95
  96         secret, err := iniProfile.GetKey("aws_secret_access_key")
  97         if err != nil {
  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.Key("aws_session_token")
 105
 106         return Value{
 107                 AccessKeyID:     id.String(),
 108                 SecretAccessKey: secret.String(),
 109                 SessionToken:    token.String(),
 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 }