zeek/src/digest.h

106 lines
3.1 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
/**
* Wrapper and helper functions for MD5/SHA digest algorithms.
*/
#pragma once
#include <sys/types.h> // for u_char
#include <zeek/util.h>
#include <cstdint>
#include <cstdio>
// Required buffer size for an MD5 digest.
#define ZEEK_MD5_DIGEST_LENGTH 16
// Required buffer size for an SHA1 digest.
#define ZEEK_SHA_DIGEST_LENGTH 20
// Required buffer size for an SHA224 digest.
#define ZEEK_SHA224_DIGEST_LENGTH 28
// Required buffer size for an SHA256 digest.
#define ZEEK_SHA256_DIGEST_LENGTH 32
// Required buffer size for an SHA384 digest.
#define ZEEK_SHA384_DIGEST_LENGTH 48
// Required buffer size for an SHA512 digest.
#define ZEEK_SHA512_DIGEST_LENGTH 64
// Buffer size for a digest of any type in hex representation plus size for at
// least a null terminator.
#define ZEEK_DIGEST_PRINT_LENGTH (ZEEK_SHA512_DIGEST_LENGTH * 2) + 1
namespace zeek::detail {
// if you add something here, note that you might have to make sure that the
// static_out member in calculate_digest is still long enough.
enum HashAlgorithm { Hash_MD5, Hash_SHA1, Hash_SHA224, Hash_SHA256, Hash_SHA384, Hash_SHA512 };
inline const char* digest_print(const u_char* digest, size_t n) {
static char buf[ZEEK_DIGEST_PRINT_LENGTH];
for ( size_t i = 0; i < n; ++i )
zeek::util::bytetohex(digest[i], &buf[i * 2]);
buf[2 * n] = '\0';
return buf;
}
inline const char* md5_digest_print(const u_char digest[ZEEK_MD5_DIGEST_LENGTH]) {
return digest_print(digest, ZEEK_MD5_DIGEST_LENGTH);
}
inline const char* sha1_digest_print(const u_char digest[ZEEK_SHA_DIGEST_LENGTH]) {
return digest_print(digest, ZEEK_SHA_DIGEST_LENGTH);
}
inline const char* sha256_digest_print(const u_char digest[ZEEK_SHA256_DIGEST_LENGTH]) {
return digest_print(digest, ZEEK_SHA256_DIGEST_LENGTH);
}
struct HashDigestState;
/**
* Allocates and initializes a new HashDigestState.
*/
HashDigestState* hash_init(HashAlgorithm alg);
/**
* Adds data to the digest.
*/
void hash_update(HashDigestState* c, const void* data, unsigned long len);
/**
* Finalizes the digest, writes it to the given buffer and deletes it.
*/
void hash_final(HashDigestState* c, u_char* md);
/**
* Finalizes the digest and writes it to the given buffer without deleting it afterwards.
*/
void hash_final_no_free(HashDigestState* c, u_char* md);
/**
* Frees the HashDigestState.
*/
void hash_state_free(HashDigestState* c);
/**
* Copies the HashDigestState from in to out.
*/
void hash_copy(HashDigestState* out, const HashDigestState* in);
unsigned char* internal_md5(const unsigned char* data, unsigned long len, unsigned char* out);
/**
* Calculates the selected digest.
* @param Alg Digest algorithm to use.
* @param data Data to hash.
* @param len Length of data to hash.
* @param out Buffer to write data to. If set to nullptr, a static buffer will be used
* @return Buffer that the hash was written to. Length is dependent on the chosen hash function.
*/
unsigned char* calculate_digest(HashAlgorithm Alg, const unsigned char* data, uint64_t len, unsigned char* out);
} // namespace zeek::detail