fix(security): narrow Bedrock subprocess strip to inference bearer token only

Scopes the AWS_SDK subprocess strip down from the full AWS credential chain
to just AWS_BEARER_TOKEN_BEDROCK — the only Hermes-managed *inference* secret
(analogous to OPENAI_API_KEY). The general AWS credential chain
(AWS_ACCESS_KEY_ID / AWS_SECRET_ACCESS_KEY / AWS_SESSION_TOKEN / AWS_PROFILE
/ config + role pointers) is intentionally left inheritable.

Why: per SECURITY.md §3.2 the local terminal is the user's trusted operator
shell. Hard-blocklisting the general chain would (a) regress *every* user who
runs aws/terraform/cdk/boto3 in the agent terminal — not just Bedrock users,
since PROVIDER_REGISTRY is iterated unconditionally at import — and (b) be
unrecoverable, because env_passthrough.py refuses to re-allow anything in
_HERMES_PROVIDER_ENV_BLOCKLIST (GHSA-rhgp-j443-p4rf). The narrow strip closes
the reported leak (opencode enumerating the Bedrock catalog off the leaked
bearer token) with no capability loss.

Keeps zapabob's self-healing auth_type=="aws_sdk" mechanism so any future
SDK-cred provider is covered automatically.

Tests: bearer token stripped + general chain preserved (no-regression guard),
on both the runtime strip path and the blocklist-membership path.

Co-authored-by: zapabob <1920071390@campus.ouj.ac.jp>
This commit is contained in:
teknium1 2026-05-29 01:29:23 -07:00 committed by Teknium
parent 95b5b72404
commit 6bebab4761
2 changed files with 80 additions and 37 deletions

View file

@ -93,25 +93,58 @@ class TestProviderEnvBlocklist:
for var in registry_vars:
assert var not in result_env, f"{var} leaked into subprocess env"
def test_aws_sdk_provider_vars_are_stripped(self):
"""AWS SDK credential-chain vars must not leak to subprocesses."""
aws_vars = {
def test_bedrock_bearer_token_is_stripped(self):
"""The Bedrock-specific bearer token is a Hermes inference secret
(analogous to OPENAI_API_KEY) and must not leak into subprocesses.
Regression for #32314: AWS_BEARER_TOKEN_BEDROCK leaked into terminal /
execute_code children because the ``bedrock`` ProviderConfig declares
``api_key_env_vars=()`` (auth_type="aws_sdk") and the blocklist builder
only consulted that field. The reporter caught it when ``opencode
models`` run inside a Hermes terminal enumerated the entire Bedrock
catalog off the leaked bearer token.
"""
result_env = _run_with_env(extra_os_env={
"AWS_BEARER_TOKEN_BEDROCK": "bedrock-bearer-secret",
})
assert "AWS_BEARER_TOKEN_BEDROCK" not in result_env, (
"AWS_BEARER_TOKEN_BEDROCK leaked into subprocess env (see #32314)"
)
def test_general_aws_credential_chain_is_preserved(self):
"""The GENERAL AWS credential chain must STILL pass through to
subprocesses this is the no-regression guard for #32314.
Per SECURITY.md §3.2 the local terminal is the user's trusted operator
shell. A user running ``aws``/``terraform``/``cdk``/``boto3`` in the
agent terminal must keep the same AWS access their own shell has.
Stripping these would (a) break every user who does AWS work in the
agent terminal not just Bedrock users, since the registry is iterated
unconditionally and (b) be unrecoverable, because env_passthrough.py
refuses to re-allow anything in _HERMES_PROVIDER_ENV_BLOCKLIST
(GHSA-rhgp-j443-p4rf). Only the Bedrock inference bearer token is
Hermes-managed; the rest belongs to the user.
"""
general_chain = {
"AWS_ACCESS_KEY_ID": "AKIAIOSFODNN7EXAMPLE",
"AWS_SECRET_ACCESS_KEY": "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
"AWS_SESSION_TOKEN": "session-token",
"AWS_PROFILE": "production",
"AWS_DEFAULT_REGION": "us-east-1",
"AWS_REGION": "us-east-1",
"AWS_SHARED_CREDENTIALS_FILE": "/home/user/.aws/credentials",
"AWS_CONFIG_FILE": "/home/user/.aws/config",
"AWS_WEB_IDENTITY_TOKEN_FILE": "/var/run/secrets/token",
"AWS_CONTAINER_CREDENTIALS_RELATIVE_URI": "/v2/credentials/123",
"AWS_CONTAINER_CREDENTIALS_FULL_URI": "http://169.254.170.2/v2/credentials/123",
"AWS_CONTAINER_AUTHORIZATION_TOKEN": "container-token",
"AWS_BEARER_TOKEN_BEDROCK": "bedrock-bearer",
"AWS_ROLE_ARN": "arn:aws:iam::123456789012:role/example",
}
result_env = _run_with_env(extra_os_env=aws_vars)
result_env = _run_with_env(extra_os_env=general_chain)
for var in aws_vars:
assert var not in result_env, f"{var} leaked into subprocess env"
for var, value in general_chain.items():
assert result_env.get(var) == value, (
f"{var} was stripped from subprocess env — this is a "
f"capability regression (see #32314 discussion)"
)
def test_non_registry_provider_vars_are_stripped(self):
"""Extra provider vars not in PROVIDER_REGISTRY must also be blocked."""
@ -233,27 +266,35 @@ class TestBlocklistCoverage:
f"(provider={pconfig.id}) missing from blocklist"
)
def test_aws_sdk_provider_vars_are_in_blocklist(self):
"""auth_type='aws_sdk' providers rely on credential-chain vars, not API keys."""
aws_vars = {
def test_bedrock_bearer_token_is_in_blocklist(self):
"""auth_type='aws_sdk' providers contribute their Hermes-managed
inference token (the Bedrock bearer) to the blocklist, keyed off
auth_type so any future SDK-cred provider is covered automatically."""
assert "AWS_BEARER_TOKEN_BEDROCK" in _HERMES_PROVIDER_ENV_BLOCKLIST
def test_general_aws_chain_not_in_blocklist(self):
"""The general AWS credential chain must NOT be in the blocklist —
no-regression guard for #32314. These belong to the user's trusted
operator shell (SECURITY.md §3.2), not to Hermes, and blocklisting
them would be unrecoverable via env_passthrough (GHSA-rhgp-j443-p4rf).
"""
general_chain = {
"AWS_ACCESS_KEY_ID",
"AWS_SECRET_ACCESS_KEY",
"AWS_SESSION_TOKEN",
"AWS_SECURITY_TOKEN",
"AWS_PROFILE",
"AWS_DEFAULT_PROFILE",
"AWS_DEFAULT_REGION",
"AWS_REGION",
"AWS_SHARED_CREDENTIALS_FILE",
"AWS_CONFIG_FILE",
"AWS_WEB_IDENTITY_TOKEN_FILE",
"AWS_ROLE_ARN",
"AWS_ROLE_SESSION_NAME",
"AWS_CONTAINER_CREDENTIALS_RELATIVE_URI",
"AWS_CONTAINER_CREDENTIALS_FULL_URI",
"AWS_CONTAINER_AUTHORIZATION_TOKEN",
"AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE",
"AWS_BEARER_TOKEN_BEDROCK",
}
assert aws_vars.issubset(_HERMES_PROVIDER_ENV_BLOCKLIST)
leaked_block = general_chain & _HERMES_PROVIDER_ENV_BLOCKLIST
assert not leaked_block, (
f"General AWS chain vars must stay inheritable, but these are "
f"blocklisted: {sorted(leaked_block)} (capability regression, #32314)"
)
def test_extra_auth_vars_covered(self):
"""Non-registry auth vars (ANTHROPIC_TOKEN, CLAUDE_CODE_OAUTH_TOKEN)

View file

@ -75,22 +75,24 @@ def _resolve_safe_cwd(cwd: str) -> str:
# Hermes-internal env vars that should NOT leak into terminal subprocesses.
_HERMES_PROVIDER_ENV_FORCE_PREFIX = "_HERMES_FORCE_"
# Hermes-managed AWS *inference* credentials for ``auth_type="aws_sdk"``
# providers (Bedrock). Scoped DELIBERATELY NARROW: this lists only the
# Bedrock-specific bearer token, which is a Hermes inference secret exactly
# analogous to ``OPENAI_API_KEY`` — nobody drives the ``aws``/``terraform``/
# ``boto3`` toolchain off it, so stripping it from terminal/execute_code
# subprocesses costs no user capability.
#
# The GENERAL AWS credential chain (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY,
# AWS_SESSION_TOKEN, AWS_PROFILE, and the config/role pointers) is INTENTIONALLY
# left inheritable. Per SECURITY.md §3.2 the local terminal is the user's
# trusted operator shell; the agent having the same general AWS access the
# user's own shell has is the intended posture, not a leak. Hard-blocklisting
# those vars would (a) regress every user who runs aws/terraform/cdk/boto3 in
# the agent terminal — not just Bedrock users, since the registry is iterated
# unconditionally — and (b) be unrecoverable, because env_passthrough.py
# refuses to re-allow anything in this blocklist (GHSA-rhgp-j443-p4rf). See
# issue #32314 discussion.
_AWS_SDK_CREDENTIAL_ENV_VARS = frozenset({
"AWS_ACCESS_KEY_ID",
"AWS_SECRET_ACCESS_KEY",
"AWS_SESSION_TOKEN",
"AWS_SECURITY_TOKEN",
"AWS_PROFILE",
"AWS_DEFAULT_PROFILE",
"AWS_SHARED_CREDENTIALS_FILE",
"AWS_CONFIG_FILE",
"AWS_WEB_IDENTITY_TOKEN_FILE",
"AWS_ROLE_ARN",
"AWS_ROLE_SESSION_NAME",
"AWS_CONTAINER_CREDENTIALS_RELATIVE_URI",
"AWS_CONTAINER_CREDENTIALS_FULL_URI",
"AWS_CONTAINER_AUTHORIZATION_TOKEN",
"AWS_CONTAINER_AUTHORIZATION_TOKEN_FILE",
"AWS_BEARER_TOKEN_BEDROCK",
})