/**
* Executes Lyra2 based on the G function from Blake2b. This version supports salts and passwords
* whose combined length is smaller than the size of the memory matrix, (i.e., (nRows x nCols x b) bits,
* where "b" is the underlying sponge's bitrate). In this implementation, the "basil" is composed by all
* integer parameters (treated as type "unsigned int") in the order they are provided, plus the value
* of nCols, (i.e., basil = kLen || pwdlen || saltlen || timeCost || nRows || nCols).
*
* @param K The derived key to be output by the algorithm
* @param kLen Desired key length
* @param pwd User password
* @param pwdlen Password length
* @param salt Salt
* @param saltlen Salt length
* @param timeCost Parameter to determine the processing time (T)
* @param nRows Number or rows of the memory matrix (R)
* @param nCols Number of columns of the memory matrix (C)
*
* @return 0 if the key is generated correctly; -1 if there is an error (usually due to lack of memory for allocation)
*/
int LYRA2(void *K, uint64_t kLen, const void *pwd, uint64_t pwdlen, const void *salt, uint64_t saltlen, uint64_t timeCost, uint64_t nRows, uint64_t nCols) {
//============================= Basic variables ============================//
int64_t row = 2; //index of row to be processed
int64_t prev = 1; //index of prev (last row ever computed/modified)
int64_t rowa = 0; //index of row* (a previous row, deterministically picked during Setup and randomly picked while Wandering)
int64_t tau; //Time Loop iterator
int64_t step = 1; //Visitation step (used during Setup and Wandering phases)
int64_t window = 2; //Visitation window (used to define which rows can be revisited during Setup)
int64_t gap = 1; //Modifier to the step, assuming the values 1 or -1
int64_t i; //auxiliary iteration counter
//==========================================================================/
//========== Initializing the Memory Matrix and pointers to it =============//
//Tries to allocate enough space for the whole memory matrix
i = (int64_t) ((int64_t) nRows * (int64_t) ROW_LEN_BYTES);
uint64_t *wholeMatrix = (uint64_t*)malloc(i);
if (wholeMatrix == NULL) {
return -1;
}
memset(wholeMatrix, 0, i);
//Allocates pointers to each row of the matrix
uint64_t **memMatrix = (uint64_t**)malloc(nRows * sizeof (uint64_t*));
if (memMatrix == NULL) {
return -1;
}
//Places the pointers in the correct positions
uint64_t *ptrWord = wholeMatrix;
for (i = 0; i < nRows; i++) {
memMatrix[i] = ptrWord;
ptrWord += ROW_LEN_INT64;
}
//==========================================================================/
//============= Getting the password + salt + basil padded with 10*1 ===============//
//OBS.:The memory matrix will temporarily hold the password: not for saving memory,
//but this ensures that the password copied locally will be overwritten as soon as possible
//First, we clean enough blocks for the password, salt, basil and padding
uint64_t nBlocksInput = ((saltlen + pwdlen + 6 * sizeof (uint64_t)) / BLOCK_LEN_BLAKE2_SAFE_BYTES) + 1;
byte *ptrByte = (byte*) wholeMatrix;
memset(ptrByte, 0, nBlocksInput * BLOCK_LEN_BLAKE2_SAFE_BYTES);
//Prepends the password
memcpy(ptrByte, pwd, pwdlen);
ptrByte += pwdlen;
//Concatenates the salt
memcpy(ptrByte, salt, saltlen);
ptrByte += saltlen;
//Concatenates the basil: every integer passed as parameter, in the order they are provided by the interface
memcpy(ptrByte, &kLen, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
memcpy(ptrByte, &pwdlen, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
memcpy(ptrByte, &saltlen, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
memcpy(ptrByte, &timeCost, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
memcpy(ptrByte, &nRows, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
memcpy(ptrByte, &nCols, sizeof (uint64_t));
ptrByte += sizeof (uint64_t);
//Now comes the padding
*ptrByte = 0x80; //first byte of padding: right after the password
ptrByte = (byte*) wholeMatrix; //resets the pointer to the start of the memory matrix
ptrByte += nBlocksInput * BLOCK_LEN_BLAKE2_SAFE_BYTES - 1; //sets the pointer to the correct position: end of incomplete block
*ptrByte ^= 0x01; //last byte of padding: at the end of the last incomplete block
//==========================================================================/
//======================= Initializing the Sponge State ====================//
//Sponge state: 16 uint64_t, BLOCK_LEN_INT64 words of them for the bitrate (b) and the remainder for the capacity (c)
uint64_t *state = (uint64_t*)malloc(16 * sizeof (uint64_t));
if (state == NULL) {
return -1;
}
initState(state);
//==========================================================================/
//================================ Setup Phase =============================//
//Absorbing salt, password and basil: this is the only place in which the block length is hard-coded to 512 bits
ptrWord = wholeMatrix;
for (i = 0; i < nBlocksInput; i++) {
absorbBlockBlake2Safe(state, ptrWord); //absorbs each block of pad(pwd || salt || basil)
ptrWord += BLOCK_LEN_BLAKE2_SAFE_BYTES; //goes to next block of pad(pwd || salt || basil)
}
//Initializes M[0] and M[1]
reducedSqueezeRow0(state, memMatrix[0]); //The locally copied password is most likely overwritten here
reducedDuplexRow1(state, memMatrix[0], memMatrix[1]);
do {
//M[row] = rand; //M[row*] = M[row*] XOR rotW(rand)
reducedDuplexRowSetup(state, memMatrix[prev], memMatrix[rowa], memMatrix[row]);
//updates the value of row* (deterministically picked during Setup))
rowa = (rowa + step) & (window - 1);
//update prev: it now points to the last row ever computed
prev = row;
//updates row: goes to the next row to be computed
row++;
//Checks if all rows in the window where visited.
if (rowa == 0) {
step = window + gap; //changes the step: approximately doubles its value
window *= 2; //doubles the size of the re-visitation window
gap = -gap; //inverts the modifier to the step
}
} while (row < nRows);
//==========================================================================/
//============================ Wandering Phase =============================//
row = 0; //Resets the visitation to the first row of the memory matrix
for (tau = 1; tau <= timeCost; tau++) {
//Step is approximately half the number of all rows of the memory matrix for an odd tau; otherwise, it is -1
step = (tau % 2 == 0) ? -1 : nRows / 2 - 1;
do {
//Selects a pseudorandom index row*
//------------------------------------------------------------------------------------------
//rowa = ((unsigned int)state[0]) & (nRows-1); //(USE THIS IF nRows IS A POWER OF 2)
rowa = ((uint64_t) (state[0])) % nRows; //(USE THIS FOR THE "GENERIC" CASE)
//------------------------------------------------------------------------------------------
//Performs a reduced-round duplexing operation over M[row*] XOR M[prev], updating both M[row*] and M[row]
reducedDuplexRow(state, memMatrix[prev], memMatrix[rowa], memMatrix[row]);
//update prev: it now points to the last row ever computed
prev = row;
//updates row: goes to the next row to be computed
//------------------------------------------------------------------------------------------
//row = (row + step) & (nRows-1); //(USE THIS IF nRows IS A POWER OF 2)
row = (row + step) % nRows; //(USE THIS FOR THE "GENERIC" CASE)
//------------------------------------------------------------------------------------------
} while (row != 0);
}
//==========================================================================/
//============================ Wrap-up Phase ===============================//
//Absorbs the last block of the memory matrix
absorbBlock(state, memMatrix[rowa]);
//Squeezes the key
squeeze(state, (unsigned char*)K, kLen);
//==========================================================================/
//========================= Freeing the memory =============================//
free(memMatrix);
free(wholeMatrix);
//Wiping out the sponge's internal state before freeing it
memset(state, 0, 16 * sizeof (uint64_t));
free(state);
//==========================================================================/
return 0;
}
/**
* Executes Lyra2 based on the G function from Blake2b. This version supports salts and passwords
* whose combined length is smaller than the size of the memory matrix, (i.e., (nRows x nCols x b) bits,
* where "b" is the underlying sponge's bitrate). In this implementation, the "basil" is composed by all
* integer parameters, in the order they are provided (i.e., basil = kLen || pwdlen || saltlen || timeCost || nRows || nCols).
*
* @param K The derived key to be output by the algorithm
* @param kLen Desired key length
* @param pwd User password
* @param pwdlen Password length
* @param salt Salt
* @param saltlen Salt length
* @param timeCost Parameter to determine the processing time (T)
* @param nRows Number or rows of the memory matrix (R)
* @param nCols Number of columns of the memory matrix (C)
*
* @return 0 if the key is generated correctly; -1 if there is an error (usually due to lack of memory for allocation)
*/
int LYRA2(unsigned char *K, int kLen, const unsigned char *pwd, int pwdlen, const unsigned char *salt, int saltlen, int timeCost, int nRows, int nCols) {
//============================= Basic variables ============================//
int row = 2; //index of row to be processed
int prev = 1; //index of prev (last row ever computed/modified)
int rowa = 0; //index of row* (a previous row, deterministically picked during Setup and randomly picked during Wandering)
int tau; //Time Loop iterator
int i; //auxiliary iteration counter
//==========================================================================/
if (nRows < 3)
return -1;
//========== Initializing the Memory Matrix and pointers to it =============//
//Allocates enough space for the whole memory matrix
uint64_t *wholeMatrix = malloc(nRows * ROW_LEN_BYTES);
if (wholeMatrix == NULL) {
return -1;
}
//Allocates pointers to each row of the matrix
uint64_t **memMatrix = malloc(nRows * sizeof (uint64_t*));
if (memMatrix == NULL) {
return -1;
}
//Places the pointers in the correct positions
uint64_t *ptrWord = wholeMatrix;
for (i = 0; i < nRows; i++) {
memMatrix[i] = ptrWord;
ptrWord += ROW_LEN_INT64;
}
//==========================================================================/
//============= Getting the password + salt + basil padded with 10*1 ===============//
//OBS.:The memory matrix will temporarily hold the password: not for saving memory,
//but this ensures that the password copied locally will be overwritten as soon as possible
//First, we clean enough blocks for the password, salt, basil and padding
int nBlocksInput = ((saltlen + pwdlen + 6*sizeof(int)) / BLOCK_LEN_BYTES) + 1;
byte *ptrByte = (byte*) wholeMatrix;
memset(ptrByte, 0, nBlocksInput * BLOCK_LEN_BYTES);
//Prepends the password
memcpy(ptrByte, pwd, pwdlen);
ptrByte += pwdlen;
//Concatenates the salt
memcpy(ptrByte, salt, saltlen);
ptrByte += saltlen;
//Concatenates the basil: every integer passed as parameter, in the order they are provided by the interface
memcpy(ptrByte, &kLen, sizeof(int));
ptrByte += sizeof(int);
memcpy(ptrByte, &pwdlen, sizeof(int));
ptrByte += sizeof(int);
memcpy(ptrByte, &saltlen, sizeof(int));
ptrByte += sizeof(int);
memcpy(ptrByte, &timeCost, sizeof(int));
ptrByte += sizeof(int);
memcpy(ptrByte, &nRows, sizeof(int));
ptrByte += sizeof(int);
memcpy(ptrByte, &nCols, sizeof(int));
ptrByte += sizeof(int);
//Now comes the padding
*ptrByte = 0x80; //first byte of padding: right after the password
ptrByte = (byte*) wholeMatrix; //resets the pointer to the start of the memory matrix
ptrByte += nBlocksInput * BLOCK_LEN_BYTES - 1; //sets the pointer to the correct position: end of incomplete block
*ptrByte ^= 0x01; //last byte of padding: at the end of the last incomplete block
//==========================================================================/
//======================= Initializing the Sponge State ====================//
//Sponge state: 16 uint64_t, BLOCK_LEN_INT64 words of them for the bitrate (b) and the remainder for the capacity (c)
uint64_t *state = malloc(16 * sizeof (uint64_t));
if (state == NULL) {
return -1;
}
initState(state);
//==========================================================================/
//================================ Setup Phase =============================//
//Absorbing salt, password and basil
ptrWord = wholeMatrix;
for (i = 0; i < nBlocksInput; i++) {
absorbBlock(state, ptrWord); //absorbs each block of pad(pwd || salt || basil)
ptrWord += BLOCK_LEN_INT64; //goes to next block of pad(pwd || salt || basil)
}
//Initializes M[0] and M[1]
reducedSqueezeRow(state, memMatrix[0]); //The locally copied password is most likely overwritten here
reducedSqueezeRow(state, memMatrix[1]);
do {
//M[row] = rand; //M[row*] = M[row*] XOR rotW(rand)
reducedDuplexRowSetup(state, memMatrix[prev], memMatrix[rowa], memMatrix[row]);
//updates the value of row* (deterministically picked during Setup))
rowa--;
if (rowa < 0) {
rowa = prev;
}
//update prev: it now points to the last row ever computed
prev = row;
//updates row: does to the next row to be computed
row++;
} while (row < nRows);
//==========================================================================/
//============================ Wandering Phase =============================//
int maxIndex = nRows - 1;
for (tau = 1; tau <= timeCost; tau++) {
//========= Iterations for an odd tau ==========
row = maxIndex; //Odd iterations of the Wandering phase start with the last row ever computed
prev = 0; //The companion "prev" is 0
do {
//Selects a pseudorandom index row*
//rowa = ((unsigned int)state[0] ^ prev) & maxIndex; //(USE THIS IF nRows IS A POWER OF 2)
rowa = ((unsigned int) (state[0] ^ prev)) % nRows; //(USE THIS FOR THE "GENERIC" CASE)
//Performs a reduced-round duplexing operation over M[row*] XOR M[prev], updating both M[row*] and M[row]
reducedDuplexRow(state, memMatrix[prev], memMatrix[rowa], memMatrix[row]);
//Goes to the next row (inverse order)
prev = row;
row--;
} while (row >= 0);
if (++tau > timeCost) {
break; //end of the Wandering phase
}
//========= Iterations for an even tau ==========
row = 0; //Even iterations of the Wandering phase start with row = 0
prev = maxIndex; //The companion "prev" is the last row in the memory matrix
do {
//rowa = ((unsigned int)state[0] ^ prev) & maxIndex; //(USE THIS IF nRows IS A POWER OF 2)
rowa = ((unsigned int) (state[0] ^ prev)) % nRows; //(USE THIS FOR THE "GENERIC" CASE)
//Performs a reduced-round duplexing operation over M[row*] XOR M[prev], updating both M[row*] and M[row]
reducedDuplexRow(state, memMatrix[prev], memMatrix[rowa], memMatrix[row]);
//Goes to the next row (direct order)
prev = row;
row++;
} while (row <= maxIndex);
}
//==========================================================================/
//============================ Wrap-up Phase ===============================//
//Absorbs the last block of the memory matrix
absorbBlock(state, memMatrix[rowa]);
//Squeezes the key
squeeze(state, K, kLen);
//==========================================================================/
//========================= Freeing the memory =============================//
free(memMatrix);
free(wholeMatrix);
//Wiping out the sponge's internal state before freeing it
memset(state, 0, 16 * sizeof (uint64_t));
free(state);
//==========================================================================/
return 0;
}