Signature verification results

Identity and widgets

name: String. The signature field's full name.
fieldName: String. The field's own name (/T); "" without one.
id: String. An opaque id: the field and the bytes it signs.
kind: "signature" or "document-timestamp". A signature, or an RFC 3161 document timestamp.
page: Number or null. The page of its first widget.
widgets: Array. The field's widgets; empty when the field cannot be found.
widgets[].id: String. The widget's annotation id.
widgets[].page: Number or null. Its page.
widgets[].rect: [x1, y1, x2, y2] or null. Its rectangle, in PDF points.
widgets[].visible: Boolean. Shown: more than 1 pt wide and high, not hidden.

Verdict

status: "verified" or "unknown" or "untrusted" or "expired" or "revoked" or "invalid". The verdict; see the codes.
code: String or null. Why, for example "EXPIRED"; null when verified.
errorCode: String or null. The same reason as Firefox names it, for example "SEC_ERROR_EXPIRED_CERTIFICATE".
message: String or null. The reason, in English.
warnings: Array. What is worth knowing but does not change the verdict.
warnings[].code: String. For example "MODIFIED", "REVOCATION_UNKNOWN", "TRUST_SOURCE_FAILED", "WEAK_SHA1".
warnings[].message: String. The warning, in English.

The signature dictionary

signerName: String or null. The signer as the PDF names it (/Name), unverified; the verified name is certificate.subjectCN.
reason: String or null. Why the signer says they signed (/Reason).
location: String or null. Where the signer says they signed (/Location).
contactInfo: String or null. How to reach the signer, in their words (/ContactInfo).
signingTime: String or null. The claimed signing time as written (/M), for example "D:20250101120000+01'00'".
signedAt: Date or null. The same time as a Date.
filter: String or null. The signature handler (/Filter), for example "Adobe.PPKLite".
subFilter: String or null. The format (/SubFilter): "adbe.pkcs7.detached" "adbe.pkcs7.sha1" "ETSI.CAdES.detached" "ETSI.RFC3161".
signatureType: 0 or 1 or null. PDF.js's number for the format: 0 adbe.pkcs7.detached, 1 adbe.pkcs7.sha1.
byteRange: [start, length, start, length]. The bytes it signs (/ByteRange).

Revisions

revisionIndex: Number. Its rank, the newest 0.
parentId: String or null. The id of the next newer signature.
coversWholeDocument: Boolean. Nothing but whitespace follows the bytes it signs.
documentModifiedAfterSigning: Boolean. The document changed after it was signed: !coversWholeDocument.
modificationsAfterSignature: Number or null. Updates saved after it.
laterSignatures: Number. Signatures and document timestamps added after it.
laterTimestamps: Number. The document timestamps among them.
onlyLaterSignatures: Boolean. Every later update added a signature (counted, not inspected).

Time

time: Object or null. The time the certificates are checked at; null when the bytes do not check out.
time.value: String (ISO 8601). That time.
time.source: "timestamp" or "signingTime" or "M" or "now". Where it comes from: a trusted timestamp, the signer's clock, the PDF date, or now.
time.trusted: Boolean. Vouched for by a trusted time-stamp authority.
time.claimed: Object. The times the signer claims.
time.claimed.signingTime: String (ISO 8601) or null. The signer's clock (the CMS signing-time attribute).
time.claimed.M: String (ISO 8601) or null. The PDF date (/M).

Timestamp

timestamp: Object or null. Its RFC 3161 timestamp; null without one.
timestamp.status: "trusted" or "untrusted" or "invalid" or "unknown". Trusted: from a trusted authority, valid then · untrusted: valid, the authority not trusted · invalid: unreadable or not matching · unknown: an unsupported hash.
timestamp.genTime: String (ISO 8601) or null. When the authority stamped it.
timestamp.accuracyMs: Number or null. Its stated accuracy, in ms (0 when not stated).
timestamp.policy: String or null. The authority's policy OID.
timestamp.serialNumber: String or null. The token's serial number, in colon hex.
timestamp.imprintAlgorithm: String or null. The hash it stamps, for example "SHA-256".
timestamp.tsa: String or null. The authority's common name.
timestamp.certificate: Object or null. The authority's certificate, like certificate (no chain).
timestamp.errorCode: String or null. Why it is not trusted.
timestamp.message: String or null. The same, in English.

Integrity

integrity: Object. The checks of the signed bytes and the signature.
integrity.status: "ok" or "unknown". "ok" once both check out; failures show in status.
integrity.digestAlgorithm: String or null. For example "SHA-256".
integrity.signatureAlgorithm: String or null. For example "rsaEncryption", "ecdsa-with-SHA256".
integrity.signedAttributes: Boolean or null. It signs CMS attributes too (time, certificate).
integrity.byteRange: Object or null. The check of byteRange.
integrity.byteRange.gap: Number. Bytes between the two signed ranges.
integrity.byteRange.contentsLength: Number. Bytes of the signature.
integrity.byteRange.ok: true or null. The gap holds the signature and nothing else.

Certificate

certificate: Object or null. The signer's certificate (the time-stamp authority's for a document timestamp).
certificate.subject: String. Its subject, for example "CN=⋯, O=⋯, C=⋯".
certificate.issuer: String. Its issuer, the same way.
certificate.subjectCN: String. The subject's common name (else its organization, else its unit).
certificate.issuerCN: String. The issuer's common name.
certificate.email: String or null. The subject's email address.
certificate.organization: String or null. The subject's organization.
certificate.notBefore: String (ISO 8601). Valid from.
certificate.notAfter: String (ISO 8601). Valid until.
certificate.serialNumber: String. In colon hex.
certificate.fingerprintSha256: String. The SHA-256 of the certificate, in colon hex.
certificate.derBase64: String. The certificate itself: DER, in base64.
certificate.publicKey: String. For example "RSA 3072", "EC P-384", "Ed25519".
certificate.signatureAlgorithm: String. How its issuer signed it, for example "sha256WithRSAEncryption".
certificate.keyUsage: [String]. For example "digitalSignature", "nonRepudiation".
certificate.extKeyUsage: [String]. For example "documentSigning", "timeStamping".
certificate.isCA: Boolean. A certificate authority.
certificate.selfSigned: Boolean. Issued to itself: the same subject and issuer.
certificate.policies: [String]. Its policy OIDs.
certificate.qc: Object or null. Its EU qualified statements.
certificate.qc.compliance: Boolean. An EU qualified certificate.
certificate.qc.sscd: Boolean. Its key is on a qualified signature creation device.
certificate.chain: Array. The path to a trust anchor (when untrusted, the longest path found); each one has the fields of certificate but chain, and:
certificate.chain[].role: "signer" or "tsa" or "intermediate" or "anchor". Its place in the path.
certificate.chain[].validAtT: Boolean. Valid at time.value.
certificate.chain[].revocation: Object or null. Its revocation check: the same object as in revocation.checked.

Trust

trust: Object. The path to a trust anchor.
trust.status: "trusted" or "untrusted" or "unsupported". Whether the path reaches a trust anchor.
trust.anchor: Object or null. The anchor reached, like certificate.
trust.errorCode: String or null. Why it is not trusted.

Validity

validity: Object. The validity periods along the path.
validity.status: "ok" or "expired" or "notYetValid" or null. null when not checked.
validity.at: String (ISO 8601) or null. The time checked: time.value.
validity.cert: Object or null. The first certificate not valid then, like certificate.

Revocation

revocation: Object. The revocation checks.
revocation.status: "good" or "revoked" or "unknown" or "skipped". "skipped" when the path is not trusted.
revocation.checked: Array. One check per certificate of the path but the anchor.
revocation.checked[].fingerprintSha256: String. The certificate checked.
revocation.checked[].subjectCN: String. Its common name.
revocation.checked[].status: "good" or "revoked" or "unknown" or "not-checked". "not-checked": an OCSP responder that needs no check.
revocation.checked[].source: "embedded-ocsp" or "embedded-crl" or "ocsp" or "crl" or null. Where the answer came from.
revocation.checked[].url: String or null. The URL asked online.
revocation.checked[].thisUpdate: String (ISO 8601) or null. When the answer was issued.
revocation.checked[].nextUpdate: String (ISO 8601) or null. When the next one is due.
revocation.checked[].producedAt: String (ISO 8601) or null. When the OCSP responder signed it.
revocation.checked[].revocationTime: String (ISO 8601) or null. When it was revoked.
revocation.checked[].reason: String or null. Why, for example "keyCompromise".
revocation.checked[].revokedLater: Boolean. Revoked only after a trusted signing time, so still good.

Timing

elapsedMs: Number. How long the check took, in ms.

Certificates

trust.anchor, validity.cert, timestamp.certificate and each certificate.chain entry are certificates with the fields of certificate.

Statuses and codes

Each status comes with one of these codes:

Status	Codes
`"invalid"`	`MALFORMED_SIGNATURE` `BYTE_RANGE_MISMATCH` `DIGEST_MISMATCH` `SIGNATURE_MISMATCH` `ESS_CERT_MISMATCH` `ALG_PROTECTION_MISMATCH` `ENVELOPED_CONTENT` `NO_SIGNER` `ALGORITHM_DISABLED`
`"revoked"`	`REVOKED`
`"expired"`	`EXPIRED` `NOT_YET_VALID` `EXPIRED_ISSUER` `NOT_YET_VALID_ISSUER`
`"untrusted"`	`NO_ANCHORS` `UNKNOWN_ISSUER` `SELF_SIGNED` `UNTRUSTED_ISSUER` `BAD_CERT_SIGNATURE` `CA_INVALID` `KEY_USAGE` `PATH_LEN` `UNKNOWN_CRITICAL_EXTENSION` `NAME_CONSTRAINTS` `CERT_ALG_DISABLED` `ALG_MISMATCH_CERT` `INADEQUATE_CERT_TYPE` `WEAK_KEY`
`"unknown"`	`WEBCRYPTO_UNAVAILABLE` `SUBFILTER_NOT_SUPPORTED` `UNSUPPORTED_ALGORITHM` `NOCERT` `INTERNAL_ERROR`
`"verified"`	`null`

CONTENTS_TRAILING_DATA WEAK_SHA1 WEAK_RSA_KEY RSA_SIGNATURE_SHORT RSA_DIGESTINFO_WITHOUT_NULL SIGNED_ATTRS_NOT_DER DIGEST_ALG_IS_SIGNATURE_ALG ALG_MISMATCH DEPRECATED_SUBFILTER MULTIPLE_SIGNERS SIGNER_ID_MISMATCH EKU_NOT_DOCUMENT_SIGNING NO_ESS TIME_FROM_SIGNER_CLOCK SIGNING_TIME_IN_FUTURE SIGNING_TIME_MISMATCH TIMESTAMP_IMPRINT_MISMATCH TIMESTAMP_INVALID TIMESTAMP_UNTRUSTED REVOKED_AFTER_SIGNING REVOCATION_UNKNOWN REVOCATION_UNREACHABLE CRL_ISSUER_NO_CRLSIGN TRUST_CERT_UNREADABLE TRUST_INPUT_UNRECOGNIZED TRUST_SOURCE_FAILED MODIFIED

MODIFIED is left out when only signatures and timestamps were added later. The cards leave out MODIFIED and REVOCATION_UNKNOWN, because their check lines already show them.

Default policy

A SHA-1 signature gives a warning (WEAK_SHA1), not a rejection.
Without a timestamp, the claimed time is used: the signing-time attribute, otherwise /M.
Embedded RFC 3161 timestamps are used.
A missing certificate gives "unknown".
Revocation is checked when possible but not required.

Examples

Listing who signed

const rows = await document.querySelector("pdf-file").verify();
for (const row of rows) {
  console.log(row.status, row.certificate?.subjectCN, row.signedAt);
}

Specifications

Not part of any specification. <pdf-file> and <pdf-page> are autonomous custom elements defined by WebPDF.pro. It implements:

Specification
ISO 32000-2:2020 (PDF 2.0) # 12.8 Digital signatures
RFC 5652: Cryptographic Message Syntax
RFC 3161: Time-Stamp Protocol
RFC 5280: X.509 certificates and CRLs
RFC 6960: OCSP