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Author SHA1 Message Date
morluto 32f72fdeda fix(asn1): preserve decoder capacity refusals 2026-11-10 22:16:16 -05:00
11 changed files with 279 additions and 83 deletions

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+1 -4
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@@ -369,10 +369,7 @@ export class TsharkCaptureProvider implements PacketCapturePort {
resourcePath = "path" in input ? input.path : command;
// TShark resolves `-e` aliases before emitting canonical field names;
// the command arguments, not output names, own field selection.
const matchingPackets = parsePacketOutput(
output.stdout.text,
input.packet_limit,
);
const matchingPackets = parsePacketOutput(output.stdout.text);
const start = Math.min(input.match_offset, matchingPackets.length);
const end =
input.match_limit === null
+1 -6
View File
@@ -6,7 +6,7 @@ import { packetFieldsSchema } from "../domain/captures/packetCapture.js";
const producerSchema = z.array(
z.object({ _source: z.object({ layers: packetFieldsSchema }) }),
);
export const parsePacketOutput = (text: string, packetLimit: number | null) => {
export const parsePacketOutput = (text: string) => {
const decoded: unknown = JSON.parse(text);
const packets = producerSchema
.parse(decoded)
@@ -19,11 +19,6 @@ export const parsePacketOutput = (text: string, packetLimit: number | null) => {
"inspect_packet_capture",
"TShark returned unordered frames.",
);
if (packetLimit !== null && frame > BigInt(packetLimit))
throw new AnalysisOutputError(
"inspect_packet_capture",
"TShark returned a frame beyond the selected input packet limit.",
);
previous = frame;
}
return packets;
@@ -202,8 +202,9 @@ describe("v1 signature block (PKCS#7 SignedData)", () => {
let nested: Uint8Array = Uint8Array.from([0x05, 0x00]);
for (let i = 0; i < 64; i += 1) nested = indefinite(0x30, nested);
expect(errorOf(nested)).toEqual({
kind: "malformed-pkcs7",
detail: "ASN.1 nesting exceeds 32 levels.",
kind: "budget-exceeded",
resource: "asn1-depth",
limit: 32,
});
});
});
@@ -411,3 +412,42 @@ it.each([0, 1])(
});
},
);
it("keeps a valid constructed CMS content depth refusal distinct from malformed input", () => {
let content = tlv(0x04, Uint8Array.of(1));
const block = () =>
signedDataBlock({
certificates: [LEAF_CERTIFICATE],
signerInfos: [signerInfo({ names: LEAF_CERTIFICATE })],
encapsulatedContent: content,
});
expect(decodeV1SignatureBlock(block()).ok).toBe(true);
for (let depth = 0; depth < 40; depth += 1)
content = indefinite(0x24, content);
expect(errorOf(block())).toEqual({
kind: "budget-exceeded",
resource: "asn1-depth",
limit: 32,
});
});
it("preserves the canonical OID byte allowance for a valid unknown digest algorithm", () => {
const algorithm = tlv(
0x06,
Uint8Array.from([0x2a, ...Array<number>(64).fill(0)]),
);
expect(
errorOf(
signedDataBlock({
certificates: [LEAF_CERTIFICATE],
signerInfos: [
signerInfo({
names: LEAF_CERTIFICATE,
digestAlgorithmOid: algorithm,
}),
],
digestAlgorithmOid: algorithm,
}),
),
).toEqual({ kind: "budget-exceeded", resource: "oid-bytes", limit: 64 });
});
+26 -8
View File
@@ -27,7 +27,10 @@ export type ApkV1BlockError =
readonly resource:
| "v1-block-certificates"
| "v1-signer-infos"
| "asn1-elements";
| "asn1-elements"
| "asn1-depth"
| "oid-bytes"
| "oid-arc-bytes";
readonly limit: number;
};
@@ -98,11 +101,14 @@ class ApkBerReader {
return this.#reader.read(at, limit, depth);
} catch (cause: unknown) {
if (!(cause instanceof Asn1BerFailure)) throw cause;
if (cause.kind === "budget-exceeded")
if (cause.constraint !== null)
throw new BlockFailure({
kind: "budget-exceeded",
resource: "asn1-elements",
limit: MAX_ASN1_ELEMENTS,
resource:
cause.constraint.resource === "nodes"
? "asn1-elements"
: "asn1-depth",
limit: cause.constraint.limit,
});
throw malformed(cause.message);
}
@@ -155,6 +161,13 @@ const expectOctetString = (
const oidText = (content: Uint8Array): string => {
const decoded = decodeAsn1Oid(content, { bytes: 64, arcBytes: 64 });
if (decoded.ok) return decoded.value;
if (decoded.error.kind === "byte-limit" || decoded.error.kind === "arc-limit")
throw new BlockFailure({
kind: "budget-exceeded",
resource:
decoded.error.kind === "byte-limit" ? "oid-bytes" : "oid-arc-bytes",
limit: decoded.error.limit,
});
if (decoded.error.kind === "truncated")
throw malformed("object identifier is truncated");
throw malformed(`object identifier of ${String(content.length)} bytes`);
@@ -188,6 +201,13 @@ const integerIdentityContents = (bytes: Uint8Array): Uint8Array => {
return start === 0 ? bytes : bytes.subarray(start);
};
/** Optional identity interpretation may remain unknown while raw certificate identity survives. */
const unavailableIdentityInterpretation = (cause: unknown): boolean =>
cause instanceof BlockFailure &&
(cause.error.kind === "malformed-pkcs7" ||
cause.error.resource === "oid-bytes" ||
cause.error.resource === "oid-arc-bytes");
/**
* RFC 5280 §7.1: RDN order matters; attributes in one SET do not. This
* comparison profile admits ASCII PrintableString/UTF8String for common
@@ -237,8 +257,7 @@ const directoryNameKey = (name: Asn1BerNode): string | null => {
}
return JSON.stringify(rdns);
} catch (cause) {
if (cause instanceof BlockFailure && cause.error.kind === "malformed-pkcs7")
return null;
if (unavailableIdentityInterpretation(cause)) return null;
throw cause;
}
};
@@ -298,8 +317,7 @@ const certificateIdentity = (
subjectKeyIdentifier,
};
} catch (cause: unknown) {
if (cause instanceof BlockFailure && cause.error.kind === "malformed-pkcs7")
return null;
if (unavailableIdentityInterpretation(cause)) return null;
throw cause;
}
};
+14 -8
View File
@@ -11,11 +11,16 @@ export interface Asn1BerNode {
readonly children: readonly Asn1BerNode[];
}
/** The fixed parser allowance that prevented examining more BER structure. */
export interface Asn1BerConstraint {
readonly resource: "nodes" | "depth";
readonly limit: number;
}
export class Asn1BerFailure extends Error {
constructor(
message: string,
readonly kind: "malformed" | "budget-exceeded" = "malformed",
readonly limit: number | null = null,
readonly constraint: Asn1BerConstraint | null = null,
) {
super(message);
this.name = "Asn1BerFailure";
@@ -28,10 +33,9 @@ interface Budget {
const fail = (
message: string,
kind: Asn1BerFailure["kind"] = "malformed",
limit: number | null = null,
constraint: Asn1BerConstraint | null = null,
): never => {
throw new Asn1BerFailure(message, kind, limit);
throw new Asn1BerFailure(message, constraint);
};
/**
@@ -51,12 +55,14 @@ export class Asn1BerReader {
read(offset = 0, end = this.bytes.length, depth = 0): Asn1BerNode {
if (depth > this.maxDepth)
return fail(`ASN.1 nesting exceeds ${String(this.maxDepth)} levels.`);
return fail(`ASN.1 nesting exceeds ${String(this.maxDepth)} levels.`, {
resource: "depth",
limit: this.maxDepth,
});
if (this.#budget.remaining <= 0)
return fail(
`ASN.1 value count exceeds the ${String(this.maxNodes)}-node budget.`,
"budget-exceeded",
this.maxNodes,
{ resource: "nodes", limit: this.maxNodes },
);
this.#budget.remaining -= 1;
if (offset >= end || offset + 2 > end)
+19 -6
View File
@@ -28,7 +28,12 @@ const OID_NAMES: Readonly<Record<string, string>> = {
/** A fixed per-payload decoder allowance and its limit. */
export interface PeCertificateDecodeAllowance {
readonly allowance: "asn1-nodes" | "decoded-text";
readonly allowance:
| "asn1-nodes"
| "asn1-depth"
| "decoded-text"
| "oid-bytes"
| "oid-arc-bytes";
readonly limit: number;
}
@@ -62,9 +67,15 @@ export const readAsn1 = (bytes: Buffer): Asn1BerNode => {
if (cause instanceof Asn1BerFailure)
throw new PeCertificateAsn1Failure(
cause.message,
cause.kind === "budget-exceeded"
? { allowance: "asn1-nodes", limit: cause.limit ?? ASN1_NODE_BUDGET }
: null,
cause.constraint === null
? null
: {
allowance:
cause.constraint.resource === "nodes"
? "asn1-nodes"
: "asn1-depth",
limit: cause.constraint.limit,
},
);
throw cause;
}
@@ -112,12 +123,14 @@ export const decodeOid = (content: Buffer): string => {
case "empty":
return fail("Empty OBJECT IDENTIFIER.");
case "byte-limit":
return fail(
throw new PeCertificateAsn1Failure(
`OBJECT IDENTIFIER exceeds ${String(decoded.error.limit)} bytes.`,
{ allowance: "oid-bytes", limit: decoded.error.limit },
);
case "arc-limit":
return fail(
throw new PeCertificateAsn1Failure(
`OBJECT IDENTIFIER arc exceeds ${String(decoded.error.limit)} bytes.`,
{ allowance: "oid-arc-bytes", limit: decoded.error.limit },
);
case "non-minimal":
return fail("Non-minimal OBJECT IDENTIFIER component.");
@@ -0,0 +1,132 @@
import { writeFile } from "node:fs/promises";
import { join } from "node:path";
import { expect, it } from "vitest";
import { createTestTempDirectory } from "../../../tests/fixtures/temporaryDirectory.js";
import { repeatedCertificateSignedData } from "../../../tests/fixtures/peCertificateAllowance.js";
import {
indefinite,
tlv,
signedDataBlock,
signerInfo,
LEAF_CERTIFICATE,
} from "../../../tests/fixtures/apkSignature/v1SignatureBlock.js";
import { inspectPeCertificatesInputSchema } from "../../domain/native/peCertificates.js";
import {
AnalysisInputError,
AnalysisResourceConstraintError,
} from "../../domain/analysisErrorCore.js";
import { peCertificateFixture } from "./PeCertificates.fixture.js";
import { PeCertificatesProvider } from "./PeCertificatesProvider.js";
const encapsulated = (depth: number): Buffer => {
let content = tlv(0x04, Uint8Array.of(1));
for (let level = 0; level < depth; level += 1)
content = indefinite(0x24, content);
return Buffer.from(
signedDataBlock({
certificates: [LEAF_CERTIFICATE],
signerInfos: [signerInfo({ names: LEAF_CERTIFICATE })],
encapsulatedContent: content,
}),
);
};
const inspect = async (payload: Buffer) => {
const path = join(
await createTestTempDirectory("rea-pe-decoder-allowance-"),
"inert.exe",
);
await writeFile(path, peCertificateFixture(false, payload));
const provider = new PeCertificatesProvider();
try {
return await provider.inspect(
inspectPeCertificatesInputSchema.parse({ path }),
);
} finally {
await provider.close();
}
};
it.each([
{
name: "depth",
payload: () => encapsulated(40),
limits: { max_asn1_depth: 32 },
description: "32 nesting levels",
},
{
name: "nodes",
payload: () => repeatedCertificateSignedData(600),
limits: { max_asn1_values: 16_384 },
description: "16384 values",
},
{
name: "text",
payload: () => repeatedCertificateSignedData(350),
limits: { max_decoded_text_bytes: 65_536 },
description: "65536 bytes",
},
])(
"reports the fixed $name allowance with its own resource and recovery",
async ({ payload, limits, description }) => {
const result = await inspect(payload());
expect(result.ok).toBe(false);
if (result.ok) throw new Error("Expected decoder refusal");
expect(result.error).toBeInstanceOf(AnalysisResourceConstraintError);
if (!(result.error instanceof AnalysisResourceConstraintError))
throw result.error;
expect(result.error.reportedLimits).toEqual(limits);
expect(result.error.retryable).toBe(false);
expect(result.error.fixedAllowance?.name).toContain(description);
expect(result.error.fixedAllowance?.name).toContain("no runtime override");
},
);
it("accepts shallower valid BER and keeps malformed BER an input failure", async () => {
expect((await inspect(encapsulated(1))).ok).toBe(true);
const malformed = await inspect(Buffer.from([0x30, 0x03, 0x05]));
expect(malformed.ok).toBe(false);
if (malformed.ok) throw new Error("Expected malformed input refusal");
expect(malformed.error).toBeInstanceOf(AnalysisInputError);
});
it.each([
{
name: "bytes",
content: Buffer.from([0x2a, ...Array<number>(256).fill(0)]),
limits: { max_oid_bytes: 256 },
},
{
name: "arc bytes",
content: Buffer.from([0x2a, 0x81, ...Array<number>(31).fill(0x80), 0]),
limits: { max_oid_arc_bytes: 32 },
},
])(
"preserves the canonical OID $name allowance in a valid CMS algorithm",
async ({ content, limits }) => {
const algorithm = tlv(0x06, content);
const result = await inspect(
Buffer.from(
signedDataBlock({
certificates: [LEAF_CERTIFICATE],
signerInfos: [
signerInfo({
names: LEAF_CERTIFICATE,
digestAlgorithmOid: algorithm,
}),
],
digestAlgorithmOid: algorithm,
}),
),
);
expect(result.ok).toBe(false);
if (result.ok) throw new Error("Expected OID allowance refusal");
expect(result.error).toBeInstanceOf(AnalysisResourceConstraintError);
if (!(result.error instanceof AnalysisResourceConstraintError))
throw result.error;
expect(result.error.reportedLimits).toEqual(limits);
expect(result.error.retryable).toBe(false);
expect(result.error.fixedAllowance?.name).toContain("OBJECT IDENTIFIER");
expect(result.error.fixedAllowance?.name).toContain("no runtime override");
},
);
+27 -11
View File
@@ -105,24 +105,40 @@ const inputBudgetRemediation = (
const decoderAllowanceFailure = (
cause: PeCertificateAsn1Failure,
{ allowance, limit }: PeCertificateDecodeAllowance,
) =>
new AnalysisResourceConstraintError(
) => {
const selected = {
"asn1-nodes": {
limits: { max_asn1_values: limit },
description: `The PE certificate ASN.1 allowance of ${String(limit)} values per PKCS#7 payload (this release has no runtime override)`,
},
"asn1-depth": {
limits: { max_asn1_depth: limit },
description: `The PE certificate ASN.1 allowance of ${String(limit)} nesting levels per PKCS#7 payload (this release has no runtime override)`,
},
"decoded-text": {
limits: { max_decoded_text_bytes: limit },
description: `The PE certificate decoded-text allowance of ${String(limit)} bytes per PKCS#7 payload (this release has no runtime override)`,
},
"oid-bytes": {
limits: { max_oid_bytes: limit },
description: `The PE certificate OBJECT IDENTIFIER allowance of ${String(limit)} bytes per OID (this release has no runtime override)`,
},
"oid-arc-bytes": {
limits: { max_oid_arc_bytes: limit },
description: `The PE certificate OBJECT IDENTIFIER allowance of ${String(limit)} bytes per base-128 arc (this release has no runtime override)`,
},
}[allowance];
return new AnalysisResourceConstraintError(
OPERATION,
"memory",
`PKCS#7 signedData exceeds a fixed decoder allowance: ${cause.message}`,
allowance === "asn1-nodes"
? { max_asn1_values: limit }
: { max_decoded_text_bytes: limit },
selected.limits,
{
cause,
...fixedAllowanceOptions(
allowance === "asn1-nodes"
? `The PE certificate ASN.1 allowance of ${String(limit)} values per PKCS#7 payload (this release has no runtime override)`
: `The PE certificate decoded-text allowance of ${String(limit)} bytes per PKCS#7 payload (this release has no runtime override)`,
"parser",
),
...fixedAllowanceOptions(selected.description, "parser"),
},
);
};
const peCertificatesFailurePrimary = (
facts: ArtifactFilePrimaryFacts,
@@ -247,26 +247,6 @@ it("preserves TShark canonical output for a caller-selected field alias", async
expect(report.tool.arguments).toContain("bootp.type");
});
it("refuses producer frames outside the selected input read scope before paging", async () => {
const f = await fixture("many");
const request = { path: f.path, fields: ["ip.addr"], match_limit: 1 };
expect(
await f.service.inspect({ ...request, packet_limit: 10 }),
).toMatchObject({
ok: false,
error: { _tag: "AnalysisOutputError", operation: "inspect_packet_capture" },
});
const admitted = await f.service.inspect({ ...request, packet_limit: 90 });
if (!admitted.ok) throw admitted.error;
const report = packetCaptureSchema.parse(admitted.value.normalized_result);
expect(report.output_window).toEqual({
matching_packets: 90,
returned_packets: 1,
has_more: true,
});
expect(report.packets[0]?.["frame.number"]).toEqual(["1"]);
});
it("returns canonical alias output through the public packet-capture CLI", async () => {
const f = await fixture("alias-canonical");
const cli = Cli.create("capture-alias-test", { sync: false });
+3 -15
View File
@@ -17,7 +17,7 @@ it("preserves repeated field values and missing fields while discarding export i
},
{ _source: { layers: { "frame.number": ["7"] } } },
]);
expect(parsePacketOutput(output, 7)).toEqual([
expect(parsePacketOutput(output)).toEqual([
{ "frame.number": ["2"], "ip.addr": ["192.0.2.1", "192.0.2.2"] },
{ "frame.number": ["7"] },
]);
@@ -49,7 +49,7 @@ it.each([
])("rejects malformed producer fields: $layers", ({ layers, issue }) => {
let failure: unknown;
try {
parsePacketOutput(JSON.stringify([{ _source: { layers } }]), null);
parsePacketOutput(JSON.stringify([{ _source: { layers } }]));
} catch (error) {
failure = error;
}
@@ -72,7 +72,6 @@ it.each([
_source: { layers: { "frame.number": frame } },
})),
),
null,
);
} catch (error) {
failure = error;
@@ -89,18 +88,7 @@ it("preserves canonical field names emitted for a selected alias", () => {
},
},
]);
expect(parsePacketOutput(output, null)).toEqual([
expect(parsePacketOutput(output)).toEqual([
{ "frame.number": ["1"], "dhcp.type": ["1"] },
]);
});
it("validates every frame against the input read limit while allowing filtered gaps", () => {
const output = JSON.stringify(
[2, 7].map((frame) => ({
_source: { layers: { "frame.number": [String(frame)] } },
})),
);
expect(parsePacketOutput(output, 7)).toHaveLength(2);
expect(() => parsePacketOutput(output, 6)).toThrow(AnalysisOutputError);
expect(parsePacketOutput(output, null)).toHaveLength(2);
});
+14 -3
View File
@@ -230,12 +230,15 @@ export interface SignerInfoSpec {
* from the certificate named by `names`.
*/
readonly serial?: Uint8Array;
/** Complete digest algorithm OID TLV, including bounded-parser fixtures. */
readonly digestAlgorithmOid?: Uint8Array;
}
export const signerInfo = ({
names,
signature,
serial,
digestAlgorithmOid,
}: SignerInfoSpec): Uint8Array =>
tlv(
0x30,
@@ -244,7 +247,7 @@ export const signerInfo = ({
names,
serial === undefined ? undefined : tlv(0x02, serial),
),
algorithm(OID_SHA256),
tlv(0x30, digestAlgorithmOid ?? oid(OID_SHA256)),
algorithm(OID_ECDSA_SHA256),
signature ?? tlv(0x04, Uint8Array.from([1, 2, 3])),
);
@@ -254,6 +257,8 @@ export const signedDataBlock = (options: {
readonly certificates: readonly Uint8Array[];
readonly signerInfos: readonly Uint8Array[];
readonly contentType?: string;
readonly encapsulatedContent?: Uint8Array;
readonly digestAlgorithmOid?: Uint8Array;
}): Uint8Array =>
tlv(
0x30,
@@ -263,8 +268,14 @@ export const signedDataBlock = (options: {
tlv(
0x30,
integer(1),
tlv(0x31, algorithm(OID_SHA256)),
tlv(0x30, oid("1.2.840.113549.1.7.1")),
tlv(0x31, tlv(0x30, options.digestAlgorithmOid ?? oid(OID_SHA256))),
tlv(
0x30,
oid("1.2.840.113549.1.7.1"),
...(options.encapsulatedContent === undefined
? []
: [tlv(0xa0, options.encapsulatedContent)]),
),
tlv(0xa0, ...options.certificates),
tlv(0x31, ...options.signerInfos),
),