RSA_BLINDING_ON(3)

✨ NAME ✨

okay so bestie, this page is RSA_BLINDING_ON(3) — the manual name is RSA_BLINDING_ON, from the libcrypto library — and it's all about RSA_blinding_on and RSA_blinding_off, the functions that protect the RSA operation from timing attacks. 💅

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🦋 SYNOPSIS 🦋

It literally says library “libcrypto”, and then you include this:

#include <openssl/rsa.h>

int
RSA_blinding_on(RSA *rsa, BN_CTX *ctx);

void
RSA_blinding_off(RSA *rsa);

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🌸 DESCRIPTION 🌸

RSA is vulnerable to timing attacks. Not me being dramatic — that's the actual vibe. 😭 In a setup where attackers can measure the time of RSA decryption or signature operations, blinding must be used to protect the RSA operation from that attack. Like, this is not optional, bestie.

• RSA_blinding_on() — turns blinding on for key rsa and generates a random blinding factor. The ctx argument is either NULL or a pre-allocated and initialized BN_CTX. ✨
• RSA_blinding_off() — turns blinding off and frees the memory used for the blinding factor. Cleanup queen. 🎀

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💖 RETURN VALUES 💖

RSA_blinding_on() returns 1 on success, and 0 if an error occurred. That's it, that's the whole return-value story. 🫶

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🌈 SEE ALSO 🌈

• RSA_new(3)

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👑 HISTORY 👑

RSA_blinding_on() and RSA_blinding_off() first appeared in SSLeay 0.9.0 and have been available since OpenBSD 2.4. iconic longevity, no cap. ⭐

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okay that's the whole page, bestie — the footer says Debian and June 8, 2025, so bye-bye and stay timing-attack-safe 💜💅