Files
coder/codersdk/aiproviders_bedrock.go
T
Yevhenii Shcherbina db7f4438b4 feat: generate STS external ID for Bedrock role assumption (#26869)
Implements:
https://linear.app/codercom/issue/AIGOV-495/add-externalid-to-prevent-confused-deputy-problem

When a Bedrock provider assumes an IAM role via STS, the gateway now
generates a unique external ID for it and sends that value on every
`AssumeRole` call. The external ID guards against the [confused deputy
problem](https://docs.aws.amazon.com/IAM/latest/UserGuide/confused-deputy.html)
on cross-account role assumption. Per [AWS's
recommendation](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create_for-user_externalid.html),
the gateway generates and owns the value rather than accepting one from
the operator; that ownership is what makes it effective, since a party
who knows another's external ID can't induce the gateway to send it.

The external ID is server-owned and read-only over the API. It is
generated once, when a provider first has a `role_arn`, and is stable
thereafter. Clients cannot set it: create rejects any supplied
`external_id`, and update rejects a value that differs from the stored
one. An update may echo the stored value back unchanged, so the normal
read-modify-write flow (GET the provider, change a field, PATCH the full
settings object) keeps working. The value is not a secret and is
returned on GET so operators can copy it into the target role's trust
policy as an `sts:ExternalId` condition.

It is persisted in the existing JSON settings blob, so there is no
migration or audit-table change.
2026-07-01 20:44:15 +00:00

111 lines
4.5 KiB
Go

package codersdk
// AIProviderSettingsTypeBedrock is the _type discriminator value for
// AIProviderBedrockSettings.
const AIProviderSettingsTypeBedrock = "bedrock"
// AIProviderBedrockSettingsVersion is the current schema version of
// AIProviderBedrockSettings.
const AIProviderBedrockSettingsVersion = 1
// AIProviderBedrockSettings configures providers that authenticate
// against AWS Bedrock. AccessKey and AccessKeySecret are write-only:
// servers strip them from GET and list responses. Both secret fields
// use a pointer so a PATCH can distinguish "leave untouched" (omitted)
// from "explicitly clear" (empty string), e.g. when migrating to
// IAM role-based authentication.
type AIProviderBedrockSettings struct {
// Region is the AWS region used to construct the Bedrock endpoint
// URL when BaseURL is not set on the parent provider.
Region string `json:"region,omitempty"`
// Model is the AWS Bedrock model identifier used for primary
// requests.
Model string `json:"model,omitempty"`
// SmallFastModel is the AWS Bedrock model identifier used for
// background tasks (e.g. Claude Code's haiku-class model).
SmallFastModel string `json:"small_fast_model,omitempty"`
// AccessKey is the AWS access key ID used to authenticate against
// Bedrock. Write-only.
AccessKey *string `json:"access_key,omitempty"`
// AccessKeySecret is the AWS secret access key paired with
// AccessKey. Write-only.
AccessKeySecret *string `json:"access_key_secret,omitempty"`
// RoleARN, when set, is the IAM role assumed via STS before calling
// Bedrock. The base identity (static keys or the AWS environment, e.g.
// IRSA / EKS Pod Identity / EC2 Instance Profile) signs the AssumeRole
// call, and the resulting temporary credentials sign Bedrock requests.
RoleARN string `json:"role_arn,omitempty"`
// ExternalID is the STS external ID sent on the AssumeRole call when
// RoleARN is set. The server generates and owns it: create and update
// reject any client-supplied value that differs from the stored one (an
// update may echo the stored value back).
ExternalID string `json:"external_id,omitempty"`
}
// IsConfigured reports whether any load-bearing Bedrock field is set,
// indicating that the operator wants the provider to authenticate via
// AWS Bedrock rather than as a bearer-token Anthropic provider.
//
// Model and SmallFastModel are intentionally excluded: they have
// deployment-level defaults declared in codersdk/deployment.go, so
// they're always non-empty in a real deployment and cannot serve as
// a detection signal. Region and credentials have no defaults and
// therefore reliably indicate operator intent. Credentials alone are
// not required because Bedrock can also authenticate via the AWS
// environment (instance profile, AWS_PROFILE, IRSA, etc.).
func (b AIProviderBedrockSettings) IsConfigured() bool {
if b.Region != "" {
return true
}
if b.RoleARN != "" {
return true
}
if b.AccessKey != nil && *b.AccessKey != "" {
return true
}
if b.AccessKeySecret != nil && *b.AccessKeySecret != "" {
return true
}
return false
}
// NewAIProviderBedrockSettings builds an AIProviderBedrockSettings,
// promoting non-empty credential strings to pointers so callers don't
// have to repeat the "set field iff non-empty" boilerplate. Empty
// credentials are left nil, matching the PATCH-omit semantics of the
// pointer-typed fields.
func NewAIProviderBedrockSettings(region, accessKey, accessKeySecret, model, smallFastModel string) AIProviderBedrockSettings {
s := AIProviderBedrockSettings{
Region: region,
Model: model,
SmallFastModel: smallFastModel,
}
if accessKey != "" {
s.AccessKey = &accessKey
}
if accessKeySecret != "" {
s.AccessKeySecret = &accessKeySecret
}
return s
}
// IsBedrockConfigured reports whether the combination of the parent
// provider's BaseURL and AIProviderBedrockSettings indicates a Bedrock
// provider. BaseURL alone (e.g. a custom VPC or FIPS endpoint with
// credentials resolved via the AWS environment) is sufficient.
//
// Use this rather than AIProviderBedrockSettings.IsConfigured() when
// BaseURL is available; the seed, the runtime config builder, and the
// legacy validator must all agree on what counts as a Bedrock provider.
func IsBedrockConfigured(baseURL string, b AIProviderBedrockSettings) bool {
return baseURL != "" || b.IsConfigured()
}
func (AIProviderBedrockSettings) settingsType() string {
return AIProviderSettingsTypeBedrock
}
func (AIProviderBedrockSettings) settingsVersion() int {
return AIProviderBedrockSettingsVersion
}