openssl.c File Reference

OpenSSL-based hashing helpers used by crypto-related VM opcodes. More...

#include <openssl/evp.h>
#include <stdlib.h>

Include dependency graph for openssl.c:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions
int	EVP_MD_get_size (const EVP_MD *md)
	Forward declaration for EVP_MD_get_size on older headers.
static char *	fun_openssl_md5_hex (const unsigned char *data, size_t len)
	Compute MD5 and return it as a lowercase hexadecimal string.
static char *	fun_openssl_sha256_hex (const unsigned char *data, size_t len)
	Compute SHA-256 and return it as a lowercase hexadecimal string.
static char *	fun_openssl_sha512_hex (const unsigned char *data, size_t len)
	Compute SHA-512 and return it as a lowercase hexadecimal string.
static char *	fun_openssl_ripemd160_hex (const unsigned char *data, size_t len)
	Compute RIPEMD-160 and return it as a lowercase hexadecimal string.

Detailed Description

OpenSSL-based hashing helpers used by crypto-related VM opcodes.

This module centralizes small, concrete helpers around the OpenSSL EVP message-digest API so that VM opcodes under src/vm/crypto/*.c can remain minimal and focus on VM stack marshalling. Keeping the algorithm-specific logic in src/extensions/ mirrors other extensions (PCRE2, SQLite, XML2, JSON, INI) and improves maintainability.

Build-time feature flag:

• All code in this file is compiled only when FUN_WITH_OPENSSL is enabled. When disabled, the helpers provide safe fallbacks that allocate and return an empty string (""), preserving the VM's expectations around string ownership while signaling the absence of cryptographic support.

Algorithms covered:

• MD5
• SHA-256
• SHA-512
• RIPEMD-160 (may be unavailable on some OpenSSL builds; see notes below)

Ownership and memory model:

• Each helper returns a newly allocated, NUL-terminated lowercase hex string that the caller owns and must free() when no longer needed.
• On allocation failure or when an algorithm/provider is unavailable, NULL is returned (except in disabled builds where an allocated empty string is returned). Callers should check for NULL before use.

Zero-length input:

• The EVP_Digest() API supports computing a digest for zero-length inputs. Passing len==0 is valid; data may be NULL in that case. Passing data==NULL with len>0 returns NULL to indicate misuse.

Error handling:

• Any failure to acquire an EVP_MD, an unexpected digest length, or memory allocation failure results in a NULL return (again, except in the disabled build where an allocated empty string is returned to keep the shape).

OpenSSL 3.x provider note:

• RIPEMD-160 is part of the legacy provider in OpenSSL 3.x and may not be available unless the provider is enabled at runtime/compile time. In such environments EVP_ripemd160() can return NULL and this module will surface that as a NULL return value to the caller.

Thread-safety:

• The helpers are stateless and thread-safe as long as the underlying OpenSSL library initialization/finalization follows OpenSSL's guidelines for multithreaded use. No shared global state is kept here.

Definition in file openssl.c.

Function Documentation

EVP_MD_get_size()

int EVP_MD_get_size

(

const EVP_MD *

md

)

Forward declaration for EVP_MD_get_size on older headers.

Some older OpenSSL headers might not declare EVP_MD_get_size even though the symbol is available in libcrypto. Guarded declaration keeps compilation working across versions while always calling the same function.

fun_openssl_md5_hex()

char * fun_openssl_md5_hex ( const unsigned char * data, size_t len )

static

Compute MD5 and return it as a lowercase hexadecimal string.

Behavior and edge cases:

• Accepts zero-length input (len==0); in this case data may be NULL.
• Returns a string of length 32 characters (2 hex chars per 16-byte digest) plus the NUL terminator, on success.
• Returns NULL if the algorithm is unavailable or on allocation failure.
• When FUN_WITH_OPENSSL is disabled, returns an allocated empty string "".

Parameters

data	Pointer to input bytes (may be NULL if len==0).
len	Number of input bytes.

Returns

char* Newly-allocated NUL-terminated hex string on success; NULL on failure (except disabled builds return an allocated empty string). The caller must free() the returned buffer.

Definition at line 96 of file openssl.c.

fun_openssl_ripemd160_hex()

char * fun_openssl_ripemd160_hex ( const unsigned char * data, size_t len )

static

Compute RIPEMD-160 and return it as a lowercase hexadecimal string.

Availability and details:

• On OpenSSL 3.x, RIPEMD-160 typically resides in the legacy provider and may be unavailable unless explicitly enabled; EVP_ripemd160() can return NULL in that case and this helper returns NULL.
• Output length is 40 hex characters (2 per 20-byte digest) plus NUL.
• data may be NULL if len==0; otherwise must be non-NULL.
• In disabled builds, returns an allocated empty string.

Parameters

data	Pointer to input bytes (may be NULL if len==0).
len	Number of input bytes.

Returns

char* Newly-allocated hex string on success; NULL if the algorithm is unavailable or on error (except disabled builds return an allocated empty string). Caller must free() the buffer.

Definition at line 262 of file openssl.c.

fun_openssl_sha256_hex()

char * fun_openssl_sha256_hex ( const unsigned char * data, size_t len )

static

Compute SHA-256 and return it as a lowercase hexadecimal string.

Details:

• Output length is 64 hex characters (2 per 32-byte digest) plus NUL.
• data may be NULL if len==0; otherwise must be non-NULL.
• Returns NULL on failure; in disabled builds returns an allocated "".

Parameters

data	Pointer to input bytes (may be NULL if len==0).
len	Number of input bytes.

Returns

char* Newly-allocated hex string on success; NULL on failure (except disabled builds return an allocated empty string). The caller must free() the buffer.

Definition at line 151 of file openssl.c.

fun_openssl_sha512_hex()

char * fun_openssl_sha512_hex ( const unsigned char * data, size_t len )

static

Compute SHA-512 and return it as a lowercase hexadecimal string.

Details:

• Output length is 128 hex characters (2 per 64-byte digest) plus NUL.
• data may be NULL if len==0; otherwise must be non-NULL.
• Returns NULL on failure; in disabled builds returns an allocated "".

Parameters

data	Pointer to input bytes (may be NULL if len==0).
len	Number of input bytes.

Returns

char* Newly-allocated hex string on success; NULL on failure (except disabled builds return an allocated empty string). The caller must free() the buffer.

Definition at line 205 of file openssl.c.