RSA_PRINT(3)

📦 version 4.4.0, in alpine 3.24, arch rolling

💅 RSA_PRINT(3) — bestie's guide to printing crypto params ✨

okay so this one is from the Library Functions Manual and it's honestly such a vibe — it's all about printing out your cryptographic parameters in a way humans can actually read. no cap, super useful. let's get into it 🎀

🌸 NAME 🌸

RSA_print, RSA_print_fp, DSAparams_print, DSAparams_print_fp, DSA_print, DSA_print_fp, DHparams_print, DHparams_print_fp — print cryptographic parameters 🦋

like, that's the whole gig. you got key material, you wanna see it. these are your girls.

✨ SYNOPSIS ✨

first up, the RSA crew. it lives in libcrypto, and you gotta pull in the header:

#include <openssl/rsa.h>

int
RSA_print(BIO *bp, RSA *x, int offset);

int
RSA_print_fp(FILE *fp, RSA *x, int offset);

then the DSA girlies:

#include <openssl/dsa.h>

int
DSAparams_print(BIO *bp, DSA *x);

int
DSAparams_print_fp(FILE *fp, DSA *x);

int
DSA_print(BIO *bp, DSA *x, int offset);

int
DSA_print_fp(FILE *fp, DSA *x, int offset);

and last but not least, DH — main character energy fr:

#include <openssl/dh.h>

int
DHparams_print(BIO *bp, DH *x);

int
DHparams_print_fp(FILE *fp, DH *x);

🫶 notice how the DSAparams_print ones and the DHparams_print ones don't even take an offset? yeah. they said "no offset for us, thanks." iconic.

💖 DESCRIPTION 💖

so here's the tea ☕ — these functions print a human-readable hexadecimal output of the components of the RSA key, the DSA parameters or key, or the DH parameters. and where does it go? it goes to bp or fp, bestie. pick your destination 💌

  • bp is a BIO * — the fancy OpenSSL I/O situation
  • fp is a FILE * — the classic stdio vibe
and here's the cute detail: the output lines are indented by offset spaces ✨ like a little aesthetic indent. slay.

ngl it's giving "let me just peek at my key components real quick" and honestly? we love that for you 💅

🔥 RETURN VALUES 🔥

super simple, no drama:

  • 1 on success 💚
  • 0 on error 💀

that's it. that's the whole vibe check.

🦋 SEE ALSO 🦋

go read these next, iykyk 👑

👑 HISTORY 👑

a little lore drop for you 📜✨

  • RSA_print() and DHparams_print() first appeared in SSLeay 0.5.1
  • RSA_print_fp(), DSA_print(), and DHparams_print_fp() first appeared in SSLeay 0.6.0
  • DSA_print_fp() first appeared in SSLeay 0.8.0
  • and all these functions have been available since OpenBSD 2.4

so like... they're old. they've been around. they're basically the elders of the group chat 🌈

mwah 💋 that's the whole page, bestie — go forth and print your params! 🍓

this gem of a page comes to you from Debian, dated June 8, 2025 — take care of her, she's been through a lot 🎀✨

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