libalpm_sig(3)

🌸 libalpm_sig(3) — Library Functions Manual 🌸

okay so bestie, this is the signature-checking page from libalpm. It’s giving “trust, but verify” and we are gonna verify everything 💅✨

💖 NAME 💖

libalpm_sig — Signature checking

• Functions to check signatures

✨ SYNOPSIS ✨

📦 Data Structures 📦

• struct alpm_pgpkey_t — A PGP key.
• struct alpm_sigresult_t — Signature result.
• struct alpm_siglist_t — Signature list.

🔢 Enumerations 🔢

enum alpm_siglevel_t { ALPM_SIG_PACKAGE = (1 << 0),
    ALPM_SIG_PACKAGE_OPTIONAL = (1 << 1), ALPM_SIG_PACKAGE_MARGINAL_OK =
    (1 << 2), ALPM_SIG_PACKAGE_UNKNOWN_OK = (1 << 3), ALPM_SIG_DATABASE
    = (1 << 10), ALPM_SIG_DATABASE_OPTIONAL = (1 << 11),
    ALPM_SIG_DATABASE_MARGINAL_OK = (1 << 12),
    ALPM_SIG_DATABASE_UNKNOWN_OK = (1 << 13), ALPM_SIG_USE_DEFAULT = (1
    << 30) }

enum alpm_sigstatus_t { ALPM_SIGSTATUS_VALID,
    ALPM_SIGSTATUS_KEY_EXPIRED, ALPM_SIGSTATUS_SIG_EXPIRED,
    ALPM_SIGSTATUS_KEY_UNKNOWN, ALPM_SIGSTATUS_KEY_DISABLED,
    ALPM_SIGSTATUS_INVALID }

enum alpm_sigvalidity_t { ALPM_SIGVALIDITY_FULL,
    ALPM_SIGVALIDITY_MARGINAL, ALPM_SIGVALIDITY_NEVER,
    ALPM_SIGVALIDITY_UNKNOWN }

• enum alpm_siglevel_t — PGP signature verification options.
• enum alpm_sigstatus_t — PGP signature verification status return codes.
• enum alpm_sigvalidity_t — The trust level of a PGP key.

🛠️ Functions 🛠️

int alpm_pkg_check_pgp_signature (alpm_pkg_t *pkg, alpm_siglist_t
    *siglist)
int alpm_db_check_pgp_signature (alpm_db_t *db, alpm_siglist_t *siglist)
int alpm_siglist_cleanup (alpm_siglist_t *siglist)
int alpm_decode_signature (const char *base64_data, unsigned char
    **data, size_t *data_len)
int alpm_extract_keyid (alpm_handle_t *handle, const char *identifier,
    const unsigned char *sig, const size_t len, alpm_list_t **keys)

• alpm_pkg_check_pgp_signature — Check the PGP signature for the given package file.
• alpm_db_check_pgp_signature — Check the PGP signature for the given database.
• alpm_siglist_cleanup — Clean up and free a signature result list.
• alpm_decode_signature — Decode a loaded signature in base64 form.
• alpm_extract_keyid — Extract the Issuer Key ID from a signature.

💬 Detailed Description 💬

Functions to check signatures. That’s the whole vibe. 🫶

🧸 Data Structure Documentation 🧸

struct alpm_pgpkey_t — A PGP key.

Data Fields:

• alpm_time_t created — When the key was created.
• void * data — The actual key data.
• char * email — Email of the key’s owner.
• alpm_time_t expires — When the key expires.
• char * fingerprint — The key’s fingerprint.
• unsigned int length — The length of the key.
• char * name — Name of the key’s owner.
• char pubkey_algo — A character representing the encryption algorithm used by the public key. ? = unknown R = RSA D = DSA E = EDDSA
• unsigned int revoked — has the key been revoked
• char * uid — UID of the key.

struct alpm_sigresult_t — Signature result.

Contains the key, status, and validity of a given signature. 💅

Data Fields:

• alpm_pgpkey_t key — The key of the signature.
• alpm_sigstatus_t status — The status of the signature.
• alpm_sigvalidity_t validity — The validity of the signature.

struct alpm_siglist_t — Signature list.

Contains the number of signatures found and a pointer to an array of results. The array is of size count. 🎀

Data Fields:

• size_t count — The amount of results in the array.
• alpm_sigresult_t * results — An array of sigresults.

🔐 Enumeration Type Documentation 🔐

enum alpm_siglevel_t — PGP signature verification options.

Enumerator

• ALPM_SIG_PACKAGE — Packages require a signature.
• ALPM_SIG_PACKAGE_OPTIONAL — Packages do not require a signature, but check packages that do have signatures.
• ALPM_SIG_PACKAGE_MARGINAL_OK — it’s in the enum values above; the original enumerator docs don’t give it its own description, bestie 💅
• ALPM_SIG_PACKAGE_UNKNOWN_OK — Allow packages with signatures that are unknown trust.
• ALPM_SIG_DATABASE — Databases require a signature.
• ALPM_SIG_DATABASE_OPTIONAL — Databases do not require a signature, but check databases that do have signatures.
• ALPM_SIG_DATABASE_MARGINAL_OK — Allow databases with signatures that are marginal trust.
• ALPM_SIG_DATABASE_UNKNOWN_OK — Allow databases with signatures that are unknown trust.
• ALPM_SIG_USE_DEFAULT — The Default siglevel.

enum alpm_sigstatus_t — PGP signature verification status return codes.

Enumerator

• ALPM_SIGSTATUS_VALID — Signature is valid.
• ALPM_SIGSTATUS_KEY_EXPIRED — The key has expired.
• ALPM_SIGSTATUS_SIG_EXPIRED — The signature has expired.
• ALPM_SIGSTATUS_KEY_UNKNOWN — The key is not in the keyring.
• ALPM_SIGSTATUS_KEY_DISABLED — The key has been disabled.
• ALPM_SIGSTATUS_INVALID — The signature is invalid.

enum alpm_sigvalidity_t — The trust level of a PGP key.

Enumerator

• ALPM_SIGVALIDITY_FULL — The signature is fully trusted.
• ALPM_SIGVALIDITY_MARGINAL — The signature is marginally trusted.
• ALPM_SIGVALIDITY_NEVER — The signature is never trusted.
• ALPM_SIGVALIDITY_UNKNOWN — The signature has unknown trust.

🛠️ Function Documentation 🛠️

int alpm_db_check_pgp_signature (alpm_db_t * db, alpm_siglist_t * siglist)

Check the PGP signature for the given database.

Parameters:

• db — the database to check
• siglist — a pointer to storage for signature results

Returns: 0 if valid, -1 if an error occurred or signature is invalid

int alpm_decode_signature (const char * base64_data, unsigned char ** data, size_t * data_len)

Decode a loaded signature in base64 form.

Parameters:

• base64_data — the signature to attempt to decode
• data — the decoded data; must be freed by the caller
• data_len — the length of the returned data

Returns: 0 on success, -1 on failure to properly decode

int alpm_extract_keyid (alpm_handle_t * handle, const char * identifier, const unsigned char * sig, const size_t len, alpm_list_t ** keys)

Extract the Issuer Key ID from a signature.

Parameters:

• handle — the context handle
• identifier — the identifier of the key. This may be the name of the package or the path to the package.
• sig — PGP signature
• len — length of signature
• keys — a pointer to storage for key IDs

Returns: 0 on success, -1 on error

int alpm_pkg_check_pgp_signature (alpm_pkg_t * pkg, alpm_siglist_t * siglist)

Check the PGP signature for the given package file.

Parameters:

• pkg — the package to check
• siglist — a pointer to storage for signature results

Returns: 0 if valid, -1 if an error occurred or signature is invalid

int alpm_siglist_cleanup (alpm_siglist_t * siglist)

Clean up and free a signature result list. Important: this does not free the siglist object itself in case that was allocated on the stack; this is the responsibility of the caller. 🫶

Parameters:

• siglist — a pointer to storage for signature results

Returns: 0 on success, -1 on error

✍️ Author ✍️

Generated automatically by Doxygen for libalpm from the source code.

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source/version: libalpm · page: libalpm_sig(3) · date: the footer didn’t list one, so we’re not inventing it, bestie 😭💖