forked from hashicorp/terraform-provider-aws
/
auth_helpers.go
300 lines (257 loc) · 9.93 KB
/
auth_helpers.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
package aws
import (
"errors"
"fmt"
"log"
"os"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/arn"
"github.com/aws/aws-sdk-go/aws/awserr"
awsCredentials "github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
"github.com/aws/aws-sdk-go/aws/credentials/stscreds"
"github.com/aws/aws-sdk-go/aws/defaults"
"github.com/aws/aws-sdk-go/aws/ec2metadata"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/iam"
"github.com/aws/aws-sdk-go/service/sts"
"github.com/hashicorp/go-cleanhttp"
"github.com/hashicorp/go-multierror"
)
func GetAccountIDAndPartition(iamconn *iam.IAM, stsconn *sts.STS, authProviderName string) (string, string, error) {
var accountID, partition string
var err, errors error
if authProviderName == ec2rolecreds.ProviderName {
accountID, partition, err = GetAccountIDAndPartitionFromEC2Metadata()
} else {
accountID, partition, err = GetAccountIDAndPartitionFromIAMGetUser(iamconn)
}
if accountID != "" {
return accountID, partition, nil
}
errors = multierror.Append(errors, err)
accountID, partition, err = GetAccountIDAndPartitionFromSTSGetCallerIdentity(stsconn)
if accountID != "" {
return accountID, partition, nil
}
errors = multierror.Append(errors, err)
accountID, partition, err = GetAccountIDAndPartitionFromIAMListRoles(iamconn)
if accountID != "" {
return accountID, partition, nil
}
errors = multierror.Append(errors, err)
return accountID, partition, errors
}
func GetAccountIDAndPartitionFromEC2Metadata() (string, string, error) {
log.Println("[DEBUG] Trying to get account information via EC2 Metadata")
cfg := &aws.Config{}
setOptionalEndpoint(cfg)
sess, err := session.NewSession(cfg)
if err != nil {
return "", "", fmt.Errorf("error creating EC2 Metadata session: %s", err)
}
metadataClient := ec2metadata.New(sess)
info, err := metadataClient.IAMInfo()
if err != nil {
// We can end up here if there's an issue with the instance metadata service
// or if we're getting credentials from AdRoll's Hologram (in which case IAMInfo will
// error out).
err = fmt.Errorf("failed getting account information via EC2 Metadata IAM information: %s", err)
log.Printf("[DEBUG] %s", err)
return "", "", err
}
return parseAccountIDAndPartitionFromARN(info.InstanceProfileArn)
}
func GetAccountIDAndPartitionFromIAMGetUser(iamconn *iam.IAM) (string, string, error) {
log.Println("[DEBUG] Trying to get account information via iam:GetUser")
output, err := iamconn.GetUser(&iam.GetUserInput{})
if err != nil {
// AccessDenied and ValidationError can be raised
// if credentials belong to federated profile, so we ignore these
if isAWSErr(err, "AccessDenied", "") {
return "", "", nil
}
if isAWSErr(err, "InvalidClientTokenId", "") {
return "", "", nil
}
if isAWSErr(err, "ValidationError", "") {
return "", "", nil
}
err = fmt.Errorf("failed getting account information via iam:GetUser: %s", err)
log.Printf("[DEBUG] %s", err)
return "", "", err
}
if output == nil || output.User == nil {
err = errors.New("empty iam:GetUser response")
log.Printf("[DEBUG] %s", err)
return "", "", err
}
return parseAccountIDAndPartitionFromARN(aws.StringValue(output.User.Arn))
}
func GetAccountIDAndPartitionFromIAMListRoles(iamconn *iam.IAM) (string, string, error) {
log.Println("[DEBUG] Trying to get account information via iam:ListRoles")
output, err := iamconn.ListRoles(&iam.ListRolesInput{
MaxItems: aws.Int64(int64(1)),
})
if err != nil {
err = fmt.Errorf("failed getting account information via iam:ListRoles: %s", err)
log.Printf("[DEBUG] %s", err)
return "", "", err
}
if output == nil || len(output.Roles) < 1 {
err = fmt.Errorf("empty iam:ListRoles response")
log.Printf("[DEBUG] %s", err)
return "", "", err
}
return parseAccountIDAndPartitionFromARN(aws.StringValue(output.Roles[0].Arn))
}
func GetAccountIDAndPartitionFromSTSGetCallerIdentity(stsconn *sts.STS) (string, string, error) {
log.Println("[DEBUG] Trying to get account information via sts:GetCallerIdentity")
output, err := stsconn.GetCallerIdentity(&sts.GetCallerIdentityInput{})
if err != nil {
return "", "", fmt.Errorf("error calling sts:GetCallerIdentity: %s", err)
}
if output == nil || output.Arn == nil {
err = errors.New("empty sts:GetCallerIdentity response")
log.Printf("[DEBUG] %s", err)
return "", "", err
}
return parseAccountIDAndPartitionFromARN(aws.StringValue(output.Arn))
}
func parseAccountIDAndPartitionFromARN(inputARN string) (string, string, error) {
arn, err := arn.Parse(inputARN)
if err != nil {
return "", "", fmt.Errorf("error parsing ARN (%s): %s", inputARN, err)
}
return arn.AccountID, arn.Partition, nil
}
// This function is responsible for reading credentials from the
// environment in the case that they're not explicitly specified
// in the Terraform configuration.
func GetCredentials(c *Config) (*awsCredentials.Credentials, error) {
// build a chain provider, lazy-evaluated by aws-sdk
providers := []awsCredentials.Provider{
&awsCredentials.StaticProvider{Value: awsCredentials.Value{
AccessKeyID: c.AccessKey,
SecretAccessKey: c.SecretKey,
SessionToken: c.Token,
}},
&awsCredentials.EnvProvider{},
&awsCredentials.SharedCredentialsProvider{
Filename: c.CredsFilename,
Profile: c.Profile,
},
}
// Build isolated HTTP client to avoid issues with globally-shared settings
client := cleanhttp.DefaultClient()
// Keep the default timeout (100ms) low as we don't want to wait in non-EC2 environments
client.Timeout = 100 * time.Millisecond
const userTimeoutEnvVar = "AWS_METADATA_TIMEOUT"
userTimeout := os.Getenv(userTimeoutEnvVar)
if userTimeout != "" {
newTimeout, err := time.ParseDuration(userTimeout)
if err == nil {
if newTimeout.Nanoseconds() > 0 {
client.Timeout = newTimeout
} else {
log.Printf("[WARN] Non-positive value of %s (%s) is meaningless, ignoring", userTimeoutEnvVar, newTimeout.String())
}
} else {
log.Printf("[WARN] Error converting %s to time.Duration: %s", userTimeoutEnvVar, err)
}
}
log.Printf("[INFO] Setting AWS metadata API timeout to %s", client.Timeout.String())
cfg := &aws.Config{
HTTPClient: client,
}
usedEndpoint := setOptionalEndpoint(cfg)
// Add the default AWS provider for ECS Task Roles if the relevant env variable is set
if uri := os.Getenv("AWS_CONTAINER_CREDENTIALS_RELATIVE_URI"); len(uri) > 0 {
providers = append(providers, defaults.RemoteCredProvider(*cfg, defaults.Handlers()))
log.Print("[INFO] ECS container credentials detected, RemoteCredProvider added to auth chain")
}
if !c.SkipMetadataApiCheck {
// Real AWS should reply to a simple metadata request.
// We check it actually does to ensure something else didn't just
// happen to be listening on the same IP:Port
metadataClient := ec2metadata.New(session.New(cfg))
if metadataClient.Available() {
providers = append(providers, &ec2rolecreds.EC2RoleProvider{
Client: metadataClient,
})
log.Print("[INFO] AWS EC2 instance detected via default metadata" +
" API endpoint, EC2RoleProvider added to the auth chain")
} else {
if usedEndpoint == "" {
usedEndpoint = "default location"
}
log.Printf("[INFO] Ignoring AWS metadata API endpoint at %s "+
"as it doesn't return any instance-id", usedEndpoint)
}
}
// This is the "normal" flow (i.e. not assuming a role)
if c.AssumeRoleARN == "" {
return awsCredentials.NewChainCredentials(providers), nil
}
// Otherwise we need to construct and STS client with the main credentials, and verify
// that we can assume the defined role.
log.Printf("[INFO] Attempting to AssumeRole %s (SessionName: %q, ExternalId: %q, Policy: %q)",
c.AssumeRoleARN, c.AssumeRoleSessionName, c.AssumeRoleExternalID, c.AssumeRolePolicy)
creds := awsCredentials.NewChainCredentials(providers)
cp, err := creds.Get()
if err != nil {
if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "NoCredentialProviders" {
return nil, errors.New(`No valid credential sources found for AWS Provider.
Please see https://terraform.io/docs/providers/aws/index.html for more information on
providing credentials for the AWS Provider`)
}
return nil, fmt.Errorf("Error loading credentials for AWS Provider: %s", err)
}
log.Printf("[INFO] AWS Auth provider used: %q", cp.ProviderName)
awsConfig := &aws.Config{
Credentials: creds,
Region: aws.String(c.Region),
MaxRetries: aws.Int(c.MaxRetries),
HTTPClient: cleanhttp.DefaultClient(),
S3ForcePathStyle: aws.Bool(c.S3ForcePathStyle),
}
stsclient := sts.New(session.New(awsConfig))
assumeRoleProvider := &stscreds.AssumeRoleProvider{
Client: stsclient,
RoleARN: c.AssumeRoleARN,
}
if c.AssumeRoleSessionName != "" {
assumeRoleProvider.RoleSessionName = c.AssumeRoleSessionName
}
if c.AssumeRoleExternalID != "" {
assumeRoleProvider.ExternalID = aws.String(c.AssumeRoleExternalID)
}
if c.AssumeRolePolicy != "" {
assumeRoleProvider.Policy = aws.String(c.AssumeRolePolicy)
}
providers = []awsCredentials.Provider{assumeRoleProvider}
assumeRoleCreds := awsCredentials.NewChainCredentials(providers)
_, err = assumeRoleCreds.Get()
if err != nil {
if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "NoCredentialProviders" {
return nil, fmt.Errorf("The role %q cannot be assumed.\n\n"+
" There are a number of possible causes of this - the most common are:\n"+
" * The credentials used in order to assume the role are invalid\n"+
" * The credentials do not have appropriate permission to assume the role\n"+
" * The role ARN is not valid",
c.AssumeRoleARN)
}
return nil, fmt.Errorf("Error loading credentials for AWS Provider: %s", err)
}
return assumeRoleCreds, nil
}
func setOptionalEndpoint(cfg *aws.Config) string {
endpoint := os.Getenv("AWS_METADATA_URL")
if endpoint != "" {
log.Printf("[INFO] Setting custom metadata endpoint: %q", endpoint)
cfg.Endpoint = aws.String(endpoint)
return endpoint
}
return ""
}