crypt_genhash_impl.cc File Reference

#include "my_config.h"
#include <memory>
#include <sys/types.h>
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "crypt_genhash_impl.h"
#include "m_string.h"
#include <errno.h>

Macros
#define	DIGEST_CTX   EVP_MD_CTX
#define	DIGEST_LEN   SHA256_DIGEST_LENGTH
#define	MAX(a, b)   (((a) > (b)) ? (a) : (b))
#define	MIN(a, b)   (((a) < (b)) ? (a) : (b))
#define	b64_from_24bit(B2, B1, B0, N)
#define	ROUNDS   "rounds="
#define	ROUNDSLEN   (sizeof(ROUNDS) - 1)

Functions
static void	DIGESTCreate (DIGEST_CTX **ctx)
static void	DIGESTInit (DIGEST_CTX *ctx)
static void	DIGESTUpdate (DIGEST_CTX *ctx, const void *plaintext, int len)
static void	DIGESTFinal (void *txt, DIGEST_CTX *ctx)
static void	DIGESTDestroy (DIGEST_CTX **ctx)
static size_t	strlcat (char *dst, const char *src, size_t siz)
	Size-bounded string copying and concatenation This is a replacement for STRLCPY(3) More...
static uint	getrounds (const char *s)
	Get the integer value after rounds= where ever it occurs in the string. More...
int	extract_user_salt (const char **salt_begin, const char **salt_end)
	Finds the interval which envelopes the user salt in a crypt password The crypt format is assumed to be $a$bbbb$cccccc\0 and the salt is found by counting the delimiters and marking begin and end. More...
char *	my_crypt_genhash (char *ctbuffer, size_t ctbufflen, const char *plaintext, size_t plaintext_len, const char *switchsalt, const char **, unsigned int *num_rounds)
void	generate_user_salt (char *buffer, int buffer_len)
	Generate a random string using ASCII characters but avoid separator character. More...
void	xor_string (char *to, int to_len, char *pattern, int pattern_len)

Variables
static const char	crypt_alg_magic [] = "$5"
static const int	crypt_alg_magic_len = sizeof(crypt_alg_magic) - 1
static unsigned char	b64t []

Macro Definition Documentation

b64_from_24bit

#define b64_from_24bit	(		B2,
			B1,
			B0,
			N
	)

Value:

  {                                                 \
    uint32_t w = ((B2) << 16) | ((B1) << 8) | (B0); \
    int n = (N);                                    \
    while (--n >= 0 && ctbufflen > 0) {             \
      *p++ = b64t[w & 0x3f];                        \
      w >>= 6;                                      \
      ctbufflen--;                                  \
    }                                               \
  }

DIGEST_CTX

#define DIGEST_CTX   EVP_MD_CTX

DIGEST_LEN

#define DIGEST_LEN   SHA256_DIGEST_LENGTH

MAX

#define MAX	(		a,
			b
	)		(((a) > (b)) ? (a) : (b))

MIN

#define MIN	(		a,
			b
	)		(((a) < (b)) ? (a) : (b))

ROUNDS

#define ROUNDS   "rounds="

ROUNDSLEN

#define ROUNDSLEN   (sizeof(ROUNDS) - 1)

Function Documentation

DIGESTCreate()

static void DIGESTCreate ( DIGEST_CTX **  ctx )

static

DIGESTDestroy()

static void DIGESTDestroy ( DIGEST_CTX **  ctx )

static

DIGESTFinal()

static void DIGESTFinal ( void *  txt, DIGEST_CTX *  ctx  )

static

DIGESTInit()

static void DIGESTInit ( DIGEST_CTX *  ctx )

static

DIGESTUpdate()

static void DIGESTUpdate ( DIGEST_CTX *  ctx, const void *  plaintext, int  len  )

static

extract_user_salt()

int extract_user_salt	(	const char **	salt_begin,
		const char **	salt_end
	)

Finds the interval which envelopes the user salt in a crypt password The crypt format is assumed to be $a$bbbb$cccccc\0 and the salt is found by counting the delimiters and marking begin and end.

Parameters

[in,out]	salt_begin	As input, pointer to start of crypt passwd, as output, pointer to first byte of the salt
[in,out]	salt_end	As input, pointer to the last byte in passwd, as output, pointer to the byte immediately following the salt ($)

Returns

The size of the salt identified

generate_user_salt()

void generate_user_salt	(	char *	buffer,
		int	buffer_len
	)

Generate a random string using ASCII characters but avoid separator character.

Stdlib rand and srand are used to produce pseudo random numbers between with about 7 bit worth of entropty between 1-127.

getrounds()

static uint getrounds ( const char *  s )

static

Get the integer value after rounds= where ever it occurs in the string.

if the last char after the int is a , or $ that is fine anything else is an error.

my_crypt_genhash()

char * my_crypt_genhash	(	char *	ctbuffer,
		size_t	ctbufflen,
		const char *	plaintext,
		size_t	plaintext_len,
		const char *	switchsalt,
		const char **	params,
		unsigned int *	num_rounds
	)

strlcat()

static size_t strlcat ( char *  dst, const char *  src, size_t  siz  )

static

Size-bounded string copying and concatenation This is a replacement for STRLCPY(3)

xor_string()

void xor_string	(	char *	to,
		int	to_len,
		char *	pattern,
		int	pattern_len
	)

Variable Documentation

b64t

unsigned char b64t[]

static

Initial value:

= 
    "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

crypt_alg_magic

const char crypt_alg_magic[] = "$5"

static

crypt_alg_magic_len

const int crypt_alg_magic_len = sizeof(crypt_alg_magic) - 1

static