OPENSSL_HEXCHAR2INT(3SSL)

✨ NAME ✨

ok so bestie, this page is from the OpenSSL manual, section 3SSL, and it's all about OPENSSL_hexchar2int, OPENSSL_hexstr2buf_ex, OPENSSL_hexstr2buf, OPENSSL_buf2hexstr_ex, OPENSSL_buf2hexstr — the hex encoding and decoding functions. hexy little squad, truly iconic 💅

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🌸 SYNOPSIS 🌸

#include <openssl/crypto.h>

int OPENSSL_hexchar2int(unsigned char c);
int OPENSSL_hexstr2buf_ex(unsigned char *buf, size_t buf_n, long *buflen,
                          const char *str, const char sep);
unsigned char *OPENSSL_hexstr2buf(const char *str, long *len);
int OPENSSL_buf2hexstr_ex(char *str, size_t str_n, size_t *strlength,
                          const unsigned char *buf, long buflen,
                          const char sep);
char *OPENSSL_buf2hexstr(const unsigned char *buf, long buflen);

like. look at them. five little guys and every one of them is serving 💖

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🦋 DESCRIPTION 🦋

• OPENSSL_hexchar2int() — takes one hex character and turns it into its numeric equivalent. glow up from char to int, no cap ✨
• OPENSSL_hexstr2buf_ex() — decodes the hex string str and drops the resulting string of bytes into the given buf. the character sep is the separator between the bytes, and setting it to '\0' means there is no separator at all. buf_n gives the size of the buffer. if buflen is not NULL, it gets filled in with the result length. wanna know how big the result is gonna be before you commit? call this function with NULL for buf, that's the vibe check 🫶. also: colons sitting between two-character hex "bytes" are accepted and just ignored. an odd number of hex digits is an error, periodt 😤
• OPENSSL_hexstr2buf() — does the same thing as OPENSSL_hexstr2buf_ex(), but it allocates the space for the result and returns the result. it uses a default separator of ':'. the memory is allocated by calling OPENSSL_malloc() and should be released by calling OPENSSL_free(). please free your memory bestie, i'm begging 🙏
• OPENSSL_buf2hexstr_ex() — the other direction, we love a reversible moment 💫. encodes the contents of the given buf with length buflen and places the resulting hexadecimal character string in the given str. the character sep is the separator between the bytes, and setting it to '\0' means there is no separator. str_n gives the size of the of the string buffer. if strlength is not NULL, it gets filled in with the result length. and to find out how large the result will be, call this function with NULL for str — same trick, different direction 🔥
• OPENSSL_buf2hexstr() — does the same thing as OPENSSL_buf2hexstr_ex(), but it allocates the space for the result and returns the result. it uses a default separator of ':'. the memory is allocated by calling OPENSSL_malloc() and should be released by calling OPENSSL_free() 🧚

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💜 RETURN VALUES 💜

• OPENSSL_hexchar2int — returns the value of a decoded hex character, or -1 on error 😭
• OPENSSL_buf2hexstr() and OPENSSL_hexstr2buf() — return a pointer to allocated memory, or NULL on error 💀
• OPENSSL_buf2hexstr_ex() and OPENSSL_hexstr2buf_ex() — return 1 on success, or 0 on error. yes bestie, just 1 and 0, they're not being extra about it 🌈

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👑 COPYRIGHT 👑

Copyright 2016-2022 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>.

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ok and that's the whole thing, you ate it up fr fr 🎀 this was OpenSSL version 4.0.3, dated 2026-09-29, from the OPENSSL_HEXCHAR2INT(3SSL) manual page. stan hex functions, they're so real for this 💖✨🌸