PKCS8_PKEY_SET0(3)

💅 PKCS8_PKEY_SET0(3)

okay so bestie, this is a page from the Library Functions Manual — yes the whole libcrypto situation — and it's literally all about peeking at and messing with PKCS#8 PrivateKeyInfo objects. private keys!! the main characters!! 🔐✨

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🌸 NAME 🌸

PKCS8_pkey_set0, PKCS8_pkey_get0, PKCS8_pkey_add1_attr_by_NID, PKCS8_pkey_get0_attrs — these four icons change and inspect PKCS#8 PrivateKeyInfo objects 🫶

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✨ SYNOPSIS ✨

so first you gotta pull in the library, it's giving <openssl/x509.h> energy 💖

library “libcrypto” #include <openssl/x509.h>

int
PKCS8_pkey_set0(PKCS8_PRIV_KEY_INFO *keyinfo, ASN1_OBJECT *aobj,
    int version, int ptype, void *pval, unsigned char *data, int len);

int
PKCS8_pkey_get0(const ASN1_OBJECT **paobj, const unsigned char **pdata,
    int *plen, const X509_ALGOR **palgor,
    const PKCS8_PRIV_KEY_INFO *keyinfo);

int
PKCS8_pkey_add1_attr_by_NID(PKCS8_PRIV_KEY_INFO *keyinfo, int nid,
    int type, const unsigned char *data, int len);

const STACK_OF(X509_ATTRIBUTE) *
PKCS8_pkey_get0_attrs(const PKCS8_PRIV_KEY_INFO *keyinfo);

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🦋 DESCRIPTION 🦋

🎀 PKCS8_pkey_set0()

this one initializes the keyinfo object, like setting up the whole vibe check from scratch 💫

• the algorithm gets set to aobj, with the associated parameter type ptype and parameter value pval, all via X509_ALGOR_set0(3) — and yes it replaces any previous info about the algorithm, no hoarding old data 🙈
• unless data is NULL, the encoded private key is set to the len bytes starting at data using ASN1_STRING_set0(3) — and ngl it does not perform any validation, so it's trusting you fr fr 💀
• if data is NULL, the key data stays unchanged, untouched, unbothered 👑
• if the version argument is greater than or equal to 0, it replaces any existing version; otherwise the version remains unchanged 🔥
• and if keyinfo contains any attributes, they remain unchanged too — they're safe, they're slaying, they're staying 🫶

🧚 PKCS8_pkey_get0()

this one retrieves some info from the keyinfo object 🎀 internal pointers to the algorithm OID, the AlgorithmIdentifier, and the encoded private key get stored in *paobj, *palgor, and *pdata respectively ✨

• NULL pointers can be passed for any of these three arguments if you don't need that respective info — lowkey efficient 💅
• unless pdata is NULL, *plen is set to the number of bytes in *pdata 📏

🌈 PKCS8_pkey_add1_attr_by_NID()

creates a brand new X.501 Attribute object using X509_ATTRIBUTE_create_by_NID(3) and appends it to the attributes of keyinfo — it's giving "and one more for the collection" 🍓

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⭐ RETURN VALUES ⭐

• PKCS8_pkey_set0() and PKCS8_pkey_add1_attr_by_NID() return 1 for success or 0 for failure — classic binary slay 💀✅
• PKCS8_pkey_get0() always returns 1. iconic, unproblematic, never fails 😌
• PKCS8_pkey_get0_attrs() returns an internal pointer to the array of attributes associated with keyinfo, or NULL if no attributes are set 🙈

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🔥 SEE ALSO 🔥

go read these next bestie, they're all connected iykyk 🧚

• ASN1_STRING_set0(3)
• EVP_PKCS82PKEY(3)
• OBJ_nid2obj(3)
• PKCS8_PRIV_KEY_INFO_new(3)
• STACK_OF(3)
• X509_ALGOR_new(3)
• X509_ATTRIBUTE_create_by_NID(3)
• X509_ATTRIBUTE_new(3)

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💜 HISTORY 💜

• PKCS8_pkey_set0() and PKCS8_pkey_get0() first appeared in OpenSSL 1.0.0 and have been available since OpenBSD 4.9 🎀
• PKCS8_pkey_add1_attr_by_NID() and PKCS8_pkey_get0_attrs() first appeared in OpenSSL 1.1.0 and have been available since OpenBSD 6.4 🌸

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okay that's the whole page, no cap, every detail intact 💅✨ this one came from Debian, dated June 8, 2025 — mwah, go forth and handle your PrivateKeyInfo objects like the main character you are 🫶👑💖