Randomize stepping.

This commit is contained in:
LoRd_MuldeR 2020-10-14 13:39:12 +02:00
parent 46b3e15594
commit 1639e130db
Signed by: mulder
GPG Key ID: 2B5913365F57E03F
3 changed files with 49 additions and 26 deletions

View File

@ -60,7 +60,7 @@ static int weak_passphrase(const CHR *str)
static int encrypt(const char* const passphrase, const CHR* const input, const CHR* const output)
{
mcrypt_t ctx = NULL;
mcrypt_t ctx = MCRYPT_NULL;
FILE *fin = NULL, *fout = NULL;
int result = 1;
@ -181,7 +181,7 @@ clean_up:
static int decrypt(const char* const passphrase, const CHR* const input, const CHR* const output)
{
mcrypt_t ctx = NULL;
mcrypt_t ctx = MCRYPT_NULL;
FILE *fin = NULL, *fout = NULL;
int result = 1;
@ -312,7 +312,7 @@ static int self_test(void)
const size_t length = strlen(text_plain) + 1U;
int result = 1;
mcrypt_t ctx_enc = NULL, ctx_dec = NULL;
mcrypt_t ctx_enc = MCRYPT_NULL, ctx_dec = MCRYPT_NULL;
FPUTS(T("Self-test is running, please be patient... "), stderr);

View File

@ -15,7 +15,8 @@ extern const char* const LIBMCRYPT_BUILDNO;
/*
* Opaque handle to internal state
*/
typedef void* mcrypt_t;
typedef uintptr_t mcrypt_t;
#define MCRYPT_NULL ((mcrypt_t)NULL)
/*
* Seed generator
@ -23,9 +24,10 @@ typedef void* mcrypt_t;
int mcrypt_generate_seed(uint64_t* const seed);
/*
* Allocate or free state
* Allocate, reset or free state
*/
mcrypt_t mcrypt_alloc(const uint64_t salt, const char* const passphrase);
int mcrypt_reset(const mcrypt_t context, const uint64_t salt, const char* const passphrase);
void mcrypt_free(const mcrypt_t context);
/*

View File

@ -15,10 +15,11 @@ const char* const LIBMCRYPT_BUILDNO = __DATE__", "__TIME__;
typedef struct
{
uint8_t box[256U][256U];
uint8_t inv[256U][256U];
uint8_t off[256U];
uint8_t pos;
uint8_t wheel_fwd[256U][256U];
uint8_t wheel_bwd[256U][256U];
uint8_t rot[256U];
uint8_t step[256U];
uint8_t counter;
}
crypt_state_t;
@ -95,28 +96,37 @@ static void random_seed(rand_state_t* const state, const uint64_t salt, const ui
static void initialize_state(crypt_state_t* const crypt_state, const uint64_t salt, const uint8_t* const key, const size_t key_len)
{
crypt_state->counter = 0U;
rand_state_t rand_state;
for (size_t r = 0U; r < 256U; ++r)
{
random_seed(&rand_state, salt, (uint16_t)r, key, key_len);
crypt_state->off[r] = (uint8_t)random_next(&rand_state);
crypt_state->rot[r] = (uint8_t)random_next(&rand_state);
for (size_t i = 0U; i < 256U; ++i)
{
const size_t j = random_next(&rand_state) % (i + 1U);
if (j != i)
{
crypt_state->box[r][i] = crypt_state->box[r][j];
crypt_state->wheel_fwd[r][i] = crypt_state->wheel_fwd[r][j];
}
crypt_state->box[r][j] = (uint8_t)i;
crypt_state->wheel_fwd[r][j] = (uint8_t)i;
}
for (size_t i = 0U; i < 256U; ++i)
{
const size_t j = crypt_state->box[r][i];
crypt_state->inv[r][j] = (uint8_t)i;
const size_t j = crypt_state->wheel_fwd[r][i];
crypt_state->wheel_bwd[r][j] = (uint8_t)i;
}
}
random_seed(&rand_state, salt, 0x0100, key, key_len);
crypt_state->pos = (uint8_t)random_next(&rand_state);
for (size_t i = 0U; i < 256U; ++i)
{
const size_t j = random_next(&rand_state) % (i + 1U);
if (j != i)
{
crypt_state->step[i] = crypt_state->step[j];
}
crypt_state->step[j] = (uint8_t)i;
}
mcrypt_bzero(&rand_state, sizeof(rand_state_t));
}
@ -128,9 +138,9 @@ static uint8_t process_enc(crypt_state_t* const crypt_state, uint8_t value)
{
for (size_t i = 0U; i < 256U; ++i)
{
value = crypt_state->box[i][(value + crypt_state->off[i]) & 0xFF];
value = crypt_state->wheel_fwd[i][(value + crypt_state->rot[i]) & 0xFF];
}
++crypt_state->off[crypt_state->pos++];
++crypt_state->rot[crypt_state->step[crypt_state->counter++]];
return value;
}
@ -139,9 +149,9 @@ static uint8_t process_dec(crypt_state_t* const crypt_state, uint8_t value)
size_t i = 256U;
while (i--)
{
value = (crypt_state->inv[i][value] - crypt_state->off[i]) & 0xFF;
value = (crypt_state->wheel_bwd[i][value] - crypt_state->rot[i]) & 0xFF;
}
++crypt_state->off[crypt_state->pos++];
++crypt_state->rot[crypt_state->step[crypt_state->counter++]];
return value;
}
@ -173,10 +183,21 @@ mcrypt_t mcrypt_alloc(const uint64_t salt, const char* const passphrase)
return ((mcrypt_t)state);
}
int mcrypt_reset(const mcrypt_t context, const uint64_t salt, const char* const passphrase)
{
crypt_state_t* const state = (crypt_state_t*)context;
if ((!state) || (!passphrase))
{
return -1;
}
initialize_state(state, salt, (uint8_t*)passphrase, strlen(passphrase));
return 0;
}
int mcrypt_enc_process(const mcrypt_t context, const uint8_t* const input, uint8_t* const output, size_t length)
{
crypt_state_t* const state = (crypt_state_t*)context;
if (!context)
if (!state)
{
return -1;
}
@ -190,7 +211,7 @@ int mcrypt_enc_process(const mcrypt_t context, const uint8_t* const input, uint8
int mcrypt_enc_process_inplace(const mcrypt_t context, uint8_t* const buffer, size_t length)
{
crypt_state_t* const state = (crypt_state_t*)context;
if (!context)
if (!state)
{
return -1;
}
@ -205,7 +226,7 @@ int mcrypt_enc_process_inplace(const mcrypt_t context, uint8_t* const buffer, si
int mcrypt_dec_process(const mcrypt_t context, const uint8_t* const input, uint8_t* const output, size_t length)
{
crypt_state_t* const state = (crypt_state_t*)context;
if (!context)
if (!state)
{
return -1;
}
@ -219,7 +240,7 @@ int mcrypt_dec_process(const mcrypt_t context, const uint8_t* const input, uint8
int mcrypt_dec_process_inplace(const mcrypt_t context, uint8_t* const buffer, size_t length)
{
crypt_state_t* const state = (crypt_state_t*)context;
if (!context)
if (!state)
{
return -1;
}
@ -233,9 +254,9 @@ int mcrypt_dec_process_inplace(const mcrypt_t context, uint8_t* const buffer, si
void mcrypt_free(const mcrypt_t context)
{
crypt_state_t* const state = (crypt_state_t*)context;
if (context)
if (state)
{
mcrypt_bzero((void*)context, sizeof(crypt_state_t));
free(context);
mcrypt_bzero(state, sizeof(crypt_state_t));
free(state);
}
}