thanhnvandClaude Opus 4.8
dbeb8e89d2
C3 (V19) data-exfil-guard.sh: destination-aware egress checkpoint built on the H4 detectors. cloud/artifact boundaries fail closed on any secret; audit boundary emits a PII-masked copy (fail closed on an unmaskable secret). Covers secret-to-cloud, artifact-leaks-env, and PII-in-audit. C6 (V22) sandbox-run.sh: static policy pre-check (BLOCK on reading ~/.ssh/creds, network egress, fork bomb, writes outside workspace, huge-file/disk-fill) plus ulimit file-size/CPU backstops and the wall-clock timeout. HONEST SCOPE: this is not kernel isolation — the production target (docker --network=none --read-only --pids-limit / nsjail) is documented as TODO(C6-prod). Process cap is opt-in so it never breaks legitimate commands on a busy host. phase2-track-c-tests.sh: 29 adversarial checks (C1 13, C2 6, C3 4, C6 6). Baselines preserved: run-casan4 35/35, adversarial 44/44. Running total: 35 + 44 + 25 + 29 = 133 checks. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
81 lines
3.2 KiB
Bash
Executable File
81 lines
3.2 KiB
Bash
Executable File
#!/usr/bin/env bash
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set -uo pipefail
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# CASAN Track C-MVP — Data-exfiltration guard (C3, V19).
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#
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# Content leaving the trusted boundary must not carry secrets/PII. This guard
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# is the checkpoint for three egress destinations, each with its own policy:
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#
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# cloud — content about to be sent to a CLOUD model (OpenAI/Anthropic).
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# A secret => BLOCK (fail closed); PII => masked copy emitted.
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# Critical once Plan-03 wires a real cloud backend.
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# audit — content about to be written to an audit/log record.
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# PII/secret => masked copy emitted (BLOCK if masking impossible).
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# artifact — a generated artifact about to be persisted/shared.
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# Any secret / env-token => BLOCK.
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#
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# It reuses security-check.sh's secret/PII detection + masking (single source of
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# truth) and applies the destination policy on top. Deterministic; no model call.
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#
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# Usage: data-exfil-guard.sh <file> <cloud|audit|artifact> [masked-output-file]
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# Exit: 0 allowed (possibly masked), 2 blocked (secret at a fail-closed boundary),
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# 64 usage.
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SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
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# shellcheck source=casan-log.sh
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source "$SCRIPT_DIR/casan-log.sh"
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FILE="${1:-}"
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DEST="${2:-}"
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MASKED_OUT="${3:-}"
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if [[ -z "$FILE" || ! -f "$FILE" || -z "$DEST" ]]; then
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echo "Usage: data-exfil-guard.sh <file> <cloud|audit|artifact> [masked-output-file]" >&2
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exit 64
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fi
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case "$DEST" in cloud|audit|artifact) ;; *) echo "unknown destination: $DEST" >&2; exit 64 ;; esac
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SCAN_OUT="$(mktemp)"
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trap 'rm -f "$SCAN_OUT"' EXIT
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# Deterministic detection: security-check input-mode (semantic OFF). rc==2 means
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# a secret/critical pattern was found; on rc==0 SCAN_OUT holds the PII-masked copy.
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CASAN_SECURITY_STRICT=0 CASAN_SEMANTIC_CLASSIFY=0 \
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bash "$SCRIPT_DIR/security-check.sh" "$FILE" "$SCAN_OUT" input >/dev/null 2>&1
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SC_RC=$?
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if [[ "$SC_RC" -eq 2 ]]; then
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# A secret / private key / connection string / card was detected.
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case "$DEST" in
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cloud)
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casan_log error data-exfil "DATA_EXFIL_BLOCKED destination=cloud reason=secret_would_leave_org"
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echo "DATA_EXFIL_BLOCKED destination=cloud reason=secret_in_content" >&2
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exit 2 ;;
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artifact)
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casan_log error data-exfil "DATA_EXFIL_BLOCKED destination=artifact reason=secret_or_env_token"
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echo "DATA_EXFIL_BLOCKED destination=artifact reason=secret_or_env_token" >&2
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exit 2 ;;
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audit)
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# Audit must never store a raw secret and must never lose the record; if we
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# cannot safely mask a hard secret we fail closed rather than log it raw.
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casan_log error data-exfil "DATA_EXFIL_BLOCKED destination=audit reason=unmaskable_secret"
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echo "DATA_EXFIL_BLOCKED destination=audit reason=unmaskable_secret" >&2
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exit 2 ;;
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esac
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elif [[ "$SC_RC" -ne 0 ]]; then
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echo "DATA_EXFIL_SCAN_ERROR destination=$DEST rc=$SC_RC" >&2
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exit 2 # fail closed on scan error
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fi
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# rc==0: content is safe; SCAN_OUT is the PII-masked copy.
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if [[ -n "$MASKED_OUT" ]]; then
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cp "$SCAN_OUT" "$MASKED_OUT"
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fi
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if ! cmp -s "$FILE" "$SCAN_OUT"; then
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casan_log info data-exfil "DATA_EXFIL_MASKED destination=$DEST (PII redacted before egress)"
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echo "DATA_EXFIL_MASKED destination=$DEST"
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else
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echo "DATA_EXFIL_CLEAN destination=$DEST"
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fi
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exit 0
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