CMS_GET0_SIGNERINFOS(3)

💖 CMS_GET0_SIGNERINFOS(3) 💖

okay bestie, this is the Library Functions Manual page for CMS_GET0_SIGNERINFOS(3) — aka the CMS SignedData signer functions. it's giving “I need to find and set signer certs myself” energy, and honestly? slay. 💅

✨ NAME ✨

This page covers CMS_get0_SignerInfos, CMS_SignerInfo_get_version, CMS_SignerInfo_get0_signer_id, CMS_SignerInfo_get0_signature, CMS_SignerInfo_cert_cmp, and CMS_SignerInfo_set1_signer_cert — the CMS SignedData signer functions. 🫶

🌸 SYNOPSIS 🌸

#include <openssl/cms.h>

STACK_OF(CMS_SignerInfo) *
CMS_get0_SignerInfos(CMS_ContentInfo *cms);

int
CMS_SignerInfo_get_version(CMS_SignerInfo *si, long *version);

int
CMS_SignerInfo_get0_signer_id(CMS_SignerInfo *si,
    ASN1_OCTET_STRING **keyid, X509_NAME **issuer, ASN1_INTEGER **sno);

ASN1_OCTET_STRING *
CMS_SignerInfo_get0_signature(CMS_SignerInfo *si);

int
CMS_SignerInfo_cert_cmp(CMS_SignerInfo *si, X509 *certificate);

void
CMS_SignerInfo_set1_signer_cert(CMS_SignerInfo *si, X509 *signer);

🦋 DESCRIPTION 🦋

okay so here's the tea, bestie:

• CMS_get0_SignerInfos() returns all the SignerInfo structures associated with the SignedData structure cms. 👑
• CMS_SignerInfo_get_version() sets *version to the syntax version number of the SignerInfo structure si. ⭐
• CMS_SignerInfo_get0_signer_id() retrieves the certificate SignerIdentifier associated with the SignerInfo structure si. Either the SubjectKeyIdentifier will be set in keyid, or both the issuer name and serial number in issuer and sno. 🎀
• CMS_SignerInfo_get0_signature() retrieves the signature field of si. The application program is allowed to modify the data pointed to. 👀
• CMS_SignerInfo_cert_cmp() compares the certificate against the signer identifier of si. 🔍
• CMS_SignerInfo_set1_signer_cert() sets the signer certificate of si to signer. 💖

The main character purpose of these functions? To enable an application to look up signer certificates using any appropriate technique when the simpler method of CMS_verify(3) is not appropriate. iykyk. 🌈

In typical usage, an application retrieves all CMS_SignerInfo structures using CMS_get0_SignerInfos() and retrieves the identifier information using CMS. It will then obtain the signer certificate by some unspecified means (or return an error if it cannot be found) and set it using CMS_SignerInfo_set1_signer_cert(). Once all signer certificates have been set, CMS_verify(3) can be used. ✨

💀 RETURN VALUES 💀

okay, what do you get back:

• CMS_get0_SignerInfos() returns an internal pointer to all the CMS_SignerInfo structures, or NULL if there are no signers or if cms is not of the type SignedData. 😭
• CMS_SignerInfo_get_version() always succeeds and returns 1. periodt. 💅
• CMS_SignerInfo_get0_signer_id() returns 1 for success or 0 for failure. 🫶
• CMS_SignerInfo_get0_signature() returns an internal pointer to the signature. 🔥
• CMS_SignerInfo_cert_cmp() returns 0 for a match or non-zero otherwise. 👑
• Any error can be obtained from ERR_get_error(3). 🧚

🎀 SEE ALSO 🎀

• CMS_ContentInfo_new(3)
• CMS_signed_add1_attr(3)
• CMS_verify(3)

🌟 STANDARDS 🌟

• RFC 5652: Cryptographic Message Syntax (CMS)
  • section 5.1: SignedData Type
  • section 5.3: SignerInfo Type

💜 HISTORY 💜

CMS_get0_SignerInfos(), CMS_SignerInfo_get0_signer_id(), CMS_SignerInfo_cert_cmp(), and CMS_SignerInfo_set1_signer_cert() first appeared in OpenSSL 0.9.8h, and CMS_SignerInfo_get0_signature() in OpenSSL 1.0.2. These functions have been available since OpenBSD 6.7. ⏳

CMS_SignerInfo_get_version() first appeared in OpenBSD 7.4. 🦋

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mwah 💋 — this page is from the Debian build dated January 22, 2024, for CMS_GET0_SIGNERINFOS(3). stay iconic, bestie 💖✨