EVP_SHA1(3ossl)

📦 version 3.5.0, in opensuse-leap 16.0

🌸 NAME 🌸

okay so bestie, this is the OpenSSL manual page for EVP_SHA1(3ossl) — aka the page for EVP_sha1, aka SHA-1 For EVP. That's the name section, short and iconic. 💅

✨ SYNOPSIS ✨

#include <openssl/evp.h>

const EVP_MD *EVP_sha1(void);

That's the exact summoning spell, no cap. Include openssl/evp.h, call EVP_sha1(void), get a const EVP_MD *. Slay. 🫶

💖 DESCRIPTION 💖

So SHA-1 — full name Secure Hash Algorithm 1 — is a cryptographic hash function standardized in NIST FIPS 180-4. It was designed by the United States National Security Agency and initially published in 1995. It's giving legacy icon behavior, fr fr. 🕰️

  • EVP_sha1() — the SHA-1 algorithm which produces a 160-bit output from a given input. Yes, exactly that. ✨

🫶 NOTES 🫶

bestie, listen: developers should be aware of the negative performance implications of calling this function multiple times. If you're doing that, consider using EVP_MD_fetch(3) with EVP_MD-SHA1(7) instead. See "Performance" in crypto(7) for further information. 🫡

🎀 RETURN VALUES 🎀

These functions return a EVP_MD structure that contains the implementation of the message digest. See EVP_MD_meth_new(3) for details of the EVP_MD structure. That's the whole tea. 🫖

📜 CONFORMING TO 📜

NIST FIPS 180-4. That's the standard, periodt. ✅

👀 SEE ALSO 👀

Go peek at evp(7) and EVP_DigestInit(3) for more of the lore. 💜

Copyright 2017-2023 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

mwah 💋 — this page is from OpenSSL 3.5.0, dated 2026-09-25, and yep it’s EVP_SHA1(3ossl) signing off. 🎀✨

📦 where this page comes from