PAdES levels

ATick produces all four PAdES baseline levels. Adobe Acrobat shows the level in the advanced signature properties.

Level	Options	What it adds
B-B	"pades":true	a PAdES (CAdES) signature with the ESS signing-certificate-v2 attribute
B-T	+ "timestamp":true	an RFC-3161 signature timestamp
B-LT	+ "ltv":true	the DSS: full chain + CRLs + OCSP responses + per-signature VRI
B-LTA	+ "lta":true	a document timestamp over the whole file

Options are passed as a JSON string. Failures throw AtickException.

using Aniketc068.ATick;
using System.IO;

byte[] pdf = File.ReadAllBytes("input.pdf");
byte[] pfx = File.ReadAllBytes("signer.pfx");

// B-B
byte[] bb = Atick.SignPfx(pdf, pfx,
        "{\"password\":\"••••\",\"pades\":true}");

// B-T
byte[] bt = Atick.SignPfx(pdf, pfx,
        "{\"password\":\"••••\",\"pades\":true,\"timestamp\":true}");

// B-LT
byte[] blt = Atick.SignPfx(pdf, pfx,
        "{\"password\":\"••••\",\"pades\":true,\"timestamp\":true,\"ltv\":true}");

// B-LTA
byte[] blta = Atick.SignPfx(pdf, pfx,
        "{\"password\":\"••••\",\"pades\":true,\"timestamp\":true,\"lta\":true}");

File.WriteAllBytes("signed.pdf", blta);

For B-LT and B-LTA ATick embeds the complete validation material (the signer chain, its CRLs and full OCSPResponses, the OCSP responder certificates, a per-signature VRI, and the /Extensions /ESIC declaration) so Adobe reports “PAdES Signature Level: B-LT”.

Note

Each level is cumulative: "lta":true implies the document timestamp on top of B-LT validation material, so a B-LTA call typically sets "pades", "timestamp", "ltv", and "lta" together.

PAdES vs. plain CMS, and /M

• "pades":true → SubFilter ETSI.CAdES.detached; the signature dictionary carries /M (signing time), which Adobe uses to classify the PAdES level.

• "pades":false → SubFilter adbe.pkcs7.detached, a plain PKCS#7 signature with no /M.

Custom TSA

The timestamp authority is configurable. Set tsa_url to your RFC-3161 endpoint, and supply HTTP Basic credentials with tsa_auth (a ["user","pass"] pair) when the TSA requires them. hash_algo selects the digest ("sha256", "sha384", or "sha512").

using Aniketc068.ATick;
using System.IO;

byte[] pdf = File.ReadAllBytes("input.pdf");
byte[] pfx = File.ReadAllBytes("signer.pfx");

byte[] signed = Atick.SignPfx(pdf, pfx,
        "{\"password\":\"••••\",\"pades\":true,\"timestamp\":true,\"ltv\":true,"
      + "\"tsa_url\":\"https://tsa.example.com/tsr\","
      + "\"tsa_auth\":[\"user\",\"pass\"],"
      + "\"hash_algo\":\"sha256\"}");

Document timestamp on an existing signature

Atick.AddDocTimestamp adds an archive DocTimeStamp over the whole file, upgrading an already-signed PDF to B-LTA. It takes the same JSON options (for example tsa_url and tsa_auth) so the archive timestamp can use a custom TSA.

using Aniketc068.ATick;
using System.IO;

byte[] signedPdf = File.ReadAllBytes("signed.pdf");

byte[] archived = Atick.AddDocTimestamp(signedPdf,
        "{\"tsa_url\":\"https://tsa.example.com/tsr\"}");

File.WriteAllBytes("signed-lta.pdf", archived);

Tip

Call Atick.Version() to confirm the library build in use when reporting an issue.