D2I_X509_ATTRIBUTE(3)

💖 D2I_X509_ATTRIBUTE(3) 💖

okay so bestie, this is the libcrypto page for d2i_X509_ATTRIBUTE and i2d_X509_ATTRIBUTE — the decode/encode duo for generic X.501 Attribute. it's giving "one job, done well" energy and honestly? iconic.

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✨ NAME ✨

d2i_X509_ATTRIBUTE, i2d_X509_ATTRIBUTE — decode and encode generic X.501 Attribute 🎀

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🌸 SYNOPSIS 🌸

library “libcrypto”

#include <openssl/x509.h>

X509_ATTRIBUTE *
d2i_X509_ATTRIBUTE(X509_ATTRIBUTE **val_out,
    const unsigned char **der_in, long length);

int
i2d_X509_ATTRIBUTE(X509_ATTRIBUTE *val_in, unsigned char **der_out);

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🦋 DESCRIPTION 🦋

so d2i_X509_ATTRIBUTE() and i2d_X509_ATTRIBUTE() decode and encode a generic ASN.1 Attribute structure — the one defined in X.501 section 8.2, iykyk 💅

ngl, for all the deets about the semantics, examples, caveats, and bugs, you gotta go see ASN1_item_d2i(3). literally the main character of this whole vibe check, so don't skip it 🫶

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👑 RETURN VALUES 👑

• d2i_X509_ATTRIBUTE() — returns an X509_ATTRIBUTE object, or NULL if an error occurs 😭
• i2d_X509_ATTRIBUTE() — returns the number of bytes successfully encoded, or a negative value if an error occurs 💀

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🔥 SEE ALSO 🔥

ASN1_item_d2i(3), d2i_PKCS12(3), d2i_PKCS8_PRIV_KEY_INFO(3), d2i_X509_EXTENSION(3), d2i_X509_REQ(3), X509_ATTRIBUTE_new(3)

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⭐ STANDARDS ⭐

ITU-T Recommendation X.501, also known as ISO/IEC 9594-2: Information Technology — Open Systems Interconnection — The Directory: Models, section 8.2: Overall structure 🌈

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🎀 HISTORY 🎀

d2i_X509_ATTRIBUTE() and i2d_X509_ATTRIBUTE() first appeared in SSLeay 0.5.1 and have been available since OpenBSD 2.4. old money, fr fr 👑

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💖 that's the whole page bestie — every flag, every return value, every SEE ALSO, all of it, no cap 💖

Debian, June 8, 2025 — that's the version + date on this beauty, so go off and encode responsibly 🧚‍♀️✨🍓