BN_KRONECKER(3)

📦 version 4.4.0, in alpine 3.24, arch rolling

okay bestie, welcome to BN_KRONECKER(3) — a page from the Library Functions Manual for libcrypto, and it’s here to explain the Kronecker symbol. no cap, tiny page, big ✨number theory✨ energy.

🌸 NAME 🌸

BN_kronecker — Kronecker symbol. that’s the name, and honestly? iconic.

✨ SYNOPSIS ✨

here’s the exact summoning circle:

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

int
BN_kronecker(const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx);

💖 DESCRIPTION 💖

BN_kronecker() computes the Kronecker symbol (a | b). it generalizes the Legendre and Jacobi symbols for arbitrary integer numbers b — yes, b is out here being arbitrary, main character energy fr fr.

🫶 RETURN VALUES 🫶

BN_kronecker() returns -1, 0, or 1 in case of success, or -2 on error. so the success vibe check is -1, 0, or 1, and the error vibe is -2. periodt.

🌈 SEE ALSO 🌈

also the reference text is: Henri Cohen, A Course in Computational Algebraic Number Theory, Springer, Berlin, 1993, Algorithm 1.4.10.

🦋 HISTORY 🦋

BN_kronecker() first appeared in OpenSSL 0.9.7 and has been available since OpenBSD 3.2. a whole little glow-up timeline, iykyk.

xoxo 💅 this page is from Debian, dated June 8, 2025, and it’s literally BN_KRONECKER(3). bye bestie 🎀

📦 where this page comes from