feat(ssh): change SSH key uniqueness to per-user scope

Previously, SSH key fingerprints were globally unique across all users,
preventing the same key from being registered by different users. This
change makes fingerprint uniqueness scoped to individual users.

- Remove global unique constraints on payload and fingerprint columns
- Add composite unique constraint on (user_id, fingerprint)
- Make add_ssh_key operation idempotent for same user
- Return tuple (SSHKey, is_new) from service to indicate creation status
- Update API to return 200 for existing keys, 201 for new keys

BREAKING CHANGE: API behavior changed - duplicate key addition now
returns 200 OK instead of 409 Conflict. Service method signature changed
from returning SSHKey to tuple[SSHKey, bool].
This commit is contained in:
2026-04-25 06:22:08 +09:30
parent cec04f3cb2
commit de6f39e7e3
5 changed files with 132 additions and 38 deletions
+6 -5
View File
@@ -32,11 +32,12 @@ def add_ssh_key():
return api_response(success=False, message='public_key is required', status=400, error_type='BAD_REQUEST')
try:
ssh_key = ssh_key_service.add_ssh_key(user_id=user_id, public_key=public_key, description=description)
AuditLog.log(action=AuditAction.SSH_KEY_ADDED, user_id=user_id, resource_type='SSHKey', resource_id=ssh_key.id, ip_address=request.remote_addr)
return api_response(success=True, message='SSH key added', data=ssh_key.to_dict(), status=201)
except SSHKeyAlreadyExistsError as e:
return api_response(success=False, message=e.message, status=409, error_type='SSH_KEY_ALREADY_EXISTS')
ssh_key, is_new = ssh_key_service.add_ssh_key(user_id=user_id, public_key=public_key, description=description)
if is_new:
AuditLog.log(action=AuditAction.SSH_KEY_ADDED, user_id=user_id, resource_type='SSHKey', resource_id=ssh_key.id, ip_address=request.remote_addr)
return api_response(success=True, message='SSH key added', data=ssh_key.to_dict(), status=201)
else:
return api_response(success=True, message='SSH key already exists', data=ssh_key.to_dict(), status=200)
except IntegrityError:
return api_response(success=False, message='SSH key already exists', status=409, error_type='SSH_KEY_ALREADY_EXISTS')
except SSHKeyError as e:
+3 -2
View File
@@ -21,10 +21,10 @@ class SSHKey(BaseModel):
)
# SSH key payload in OpenSSH format (e.g., "ssh-ed25519 AAAAB3Nz...")
payload = db.Column(db.Text, nullable=False, unique=True)
payload = db.Column(db.Text, nullable=False)
# SHA256 fingerprint for quick comparison and deduplication
fingerprint = db.Column(db.String(255), nullable=False, unique=True, index=True)
fingerprint = db.Column(db.String(255), nullable=False, index=True)
# Optional human-readable description (e.g., "My laptop key")
description = db.Column(db.String(255), nullable=True)
@@ -53,6 +53,7 @@ class SSHKey(BaseModel):
__table_args__ = (
db.Index("idx_ssh_key_user_verified", "user_id", "verified"),
db.UniqueConstraint('user_id', 'fingerprint', name='uix_user_fingerprint'),
)
def __repr__(self):
+26 -22
View File
@@ -41,46 +41,47 @@ class SSHKeyService:
user_id: str,
public_key: str,
description: Optional[str] = None,
) -> SSHKey:
) -> tuple[SSHKey, bool]:
"""Add an SSH public key for a user.
Args:
user_id: ID of the user
public_key: SSH public key in OpenSSH format
description: Optional description of the key
Returns:
Created SSHKey instance
Tuple of (SSHKey instance, is_new) where is_new is True for
newly created keys, False for existing keys (idempotent).
Raises:
UserNotFoundError: If user doesn't exist
SSHKeyError: If key format is invalid
SSHKeyAlreadyExistsError: If key already exists
"""
# Verify user exists
user = User.query.get(user_id)
if not user:
raise UserNotFoundError(f"User {user_id} not found")
# Validate key format
if not verify_ssh_key_format(public_key):
raise SSHKeyError("Invalid SSH public key format")
# Compute fingerprint
try:
fingerprint = compute_ssh_fingerprint(public_key)
except Exception as e:
logger.error(f"Failed to compute fingerprint: {str(e)}")
raise SSHKeyError(f"Failed to compute key fingerprint: {str(e)}")
# Check for duplicate (including soft-deleted records — fingerprint is unique in DB)
existing = SSHKey.query.filter_by(fingerprint=fingerprint).first()
# Check for duplicate per user (including soft-deleted records)
existing = SSHKey.query.filter_by(
user_id=user_id, fingerprint=fingerprint
).first()
if existing:
if existing.deleted_at is not None:
# Restore the soft-deleted key: clear deleted_at and update fields
existing.deleted_at = None
existing.user_id = user_id
existing.description = description or existing.description
existing.description = description if description is not None else existing.description
existing.verified = False
existing.verified_at = None
existing.verify_text = None
@@ -90,15 +91,18 @@ class SSHKeyService:
f"Restored soft-deleted SSH key for user {user_id}: "
f"fingerprint={fingerprint}"
)
return existing
raise SSHKeyAlreadyExistsError(
f"SSH key with fingerprint {fingerprint} already exists"
return existing, False
# Idempotent: return existing key without error
logger.info(
f"SSH key already exists for user {user_id}: "
f"fingerprint={fingerprint}"
)
return existing, False
# Extract metadata
key_type = extract_ssh_key_type(public_key)
key_comment = extract_ssh_key_comment(public_key)
# Create SSH key record
ssh_key = SSHKey(
user_id=user_id,
@@ -109,15 +113,15 @@ class SSHKeyService:
key_comment=key_comment,
verified=False,
)
ssh_key.save()
logger.info(
f"SSH key added for user {user_id}: "
f"fingerprint={fingerprint}, type={key_type}"
)
return ssh_key
return ssh_key, True
def get_ssh_key(self, key_id: str) -> SSHKey:
"""Get an SSH key by ID.
@@ -0,0 +1,44 @@
"""Per-user SSH key fingerprint uniqueness.
Revision ID: a1b2c3d4e5f6
Revises: 8f2d9e4a7c1b
Create Date: 2026-04-24 10:00:00.000000
"""
from alembic import op
import sqlalchemy as sa
# revision identifiers, used by Alembic.
revision = 'a1b2c3d4e5f6'
down_revision = '8f2d9e4a7c1b'
branch_labels = None
depends_on = None
def upgrade():
# Drop the global unique constraint on payload
op.drop_constraint('ssh_keys_payload_key', 'ssh_keys', type_='unique')
# Drop the global unique index on fingerprint
op.drop_index('ix_ssh_keys_fingerprint', table_name='ssh_keys')
# Create a non-unique index on fingerprint for query performance
op.create_index(op.f('ix_ssh_keys_fingerprint'), 'ssh_keys', ['fingerprint'], unique=False)
# Add composite unique constraint for per-user fingerprint uniqueness
op.create_unique_constraint('uix_user_fingerprint', 'ssh_keys', ['user_id', 'fingerprint'])
def downgrade():
# Drop the composite unique constraint
op.drop_constraint('uix_user_fingerprint', 'ssh_keys', type_='unique')
# Drop the non-unique index
op.drop_index(op.f('ix_ssh_keys_fingerprint'), table_name='ssh_keys')
# Recreate the global unique index
op.create_index('ix_ssh_keys_fingerprint', 'ssh_keys', ['fingerprint'], unique=True)
# Recreate the global unique constraint on payload
op.create_unique_constraint('ssh_keys_payload_key', 'ssh_keys', ['payload'])
+53 -9
View File
@@ -106,23 +106,67 @@ class TestSSHKeyManagement:
assert_error(exc_info.value, 400)
def test_add_duplicate_key_negative(self, integration_client, create_test_user):
"""TEST: SSH-KEY-03 — Reject duplicate SSH key.
def test_add_duplicate_key_idempotent_positive(self, integration_client, create_test_user):
"""TEST: SSH-KEY-03 — Add duplicate SSH key is idempotent for same user.
WHAT: User adds TEST_PUBLIC_KEY, then tries to add it again.
WHY: Fingerprints must be unique per database to avoid
ambiguity in key-to-user mappings.
EXPECTED: 409 Conflict with error_type SSH_KEY_ALREADY_EXISTS.
WHY: Fingerprints are unique per user, not globally. Adding the
same key twice by the same user should succeed both times.
EXPECTED: Both calls succeed (201 then 200). Both return same key id.
"""
user = create_test_user(password="MyPassword123!")
integration_client.auth.login(email=user["email"], password="MyPassword123!")
integration_client.ssh.add_key(TEST_PUBLIC_KEY, "First")
# First add should succeed with 201
result1 = integration_client.ssh.add_key(TEST_PUBLIC_KEY, "First")
data1 = assert_success(result1, "added")
assert result1.get("code") == 201, f"Expected status 201 but got {result1.get('code')}"
# Second add should succeed with 200 (idempotent)
result2 = integration_client.ssh.add_key(TEST_PUBLIC_KEY, "Duplicate")
data2 = assert_success(result2, "exists")
assert result2.get("code") == 200, f"Expected status 200 but got {result2.get('code')}"
# Both calls should return the same key id
assert data1.get("id") == data2.get("id"), "Key IDs should match for idempotent operation"
with pytest.raises(ApiError) as exc_info:
integration_client.ssh.add_key(TEST_PUBLIC_KEY, "Duplicate")
def test_add_same_key_different_user_positive(self, integration_client, create_test_user):
"""TEST: SSH-KEY-03b — Same key can be added by different users.
assert_error(exc_info.value, 409, "SSH_KEY_ALREADY_EXISTS")
WHAT: User A adds TEST_PUBLIC_KEY. User B adds the SAME key.
WHY: Fingerprint uniqueness is per-user, not global.
EXPECTED: Both calls succeed (201). Each user sees the key in their list.
"""
# Create and login as user A
user_a = create_test_user(password="PassA123!")
integration_client.auth.login(email=user_a["email"], password="PassA123!")
# User A adds the key
result_a = integration_client.ssh.add_key(TEST_PUBLIC_KEY, "User A Key")
assert_success(result_a, "added")
assert result_a.get("code") == 201, f"Expected status 201 but got {result_a.get('code')}"
# Create and login as user B
user_b = create_test_user(password="PassB123!")
integration_client.auth.logout()
integration_client.auth.login(email=user_b["email"], password="PassB123!")
# User B adds the same key
result_b = integration_client.ssh.add_key(TEST_PUBLIC_KEY, "User B Key")
assert_success(result_b, "added")
assert result_b.get("code") == 201, f"Expected status 201 but got {result_b.get('code')}"
# Verify user B sees exactly one key in their list
list_result_b = integration_client.ssh.list_keys()
list_data_b = assert_success(list_result_b)
assert list_data_b.get("count") == 1, f"User B should see 1 key but saw {list_data_b.get('count')}"
# Log back in as user A and verify they still see exactly one key
integration_client.auth.logout()
integration_client.auth.login(email=user_a["email"], password="PassA123!")
list_result_a = integration_client.ssh.list_keys()
list_data_a = assert_success(list_result_a)
assert list_data_a.get("count") == 1, f"User A should see 1 key but saw {list_data_a.get('count')}"
def test_add_key_without_auth_negative(self, integration_client):
"""TEST: SSH-KEY-04 — Reject key upload without authentication.