/* **************** *
* PUBLIC FUNCTIONS *
* **************** *
*/
int ocb3_aes_encrypt(ocb_aes_t *ctx, const char *in, int inl, const char *plain, int plainl, char *out, char *tag) {
char checksum[AES_BLOCK_SIZE] = {0};
char keyvar[AES_BLOCK_SIZE] = {0};
char offset[AES_BLOCK_SIZE] = {0};
keyvar_init(ctx->key, keyvar);
offset_init(ctx, offset);
int log2 = ntz(0);
int i;
for (i = 0; i < inl / AES_BLOCK_SIZE; i++) {
uchar *pout = out + (i * AES_BLOCK_SIZE);
const uchar *pin = in + (i * AES_BLOCK_SIZE);
// See if we need to bump the offset
int log2_next = ntz(i);
if (log2_next > log2) {
char double_temp[AES_BLOCK_SIZE];
double_block(keyvar, double_temp);
cpy_block(keyvar, double_temp);
log2 = log2_next;
}
// Encrypt this block
ocb3_encrypt_block(ctx, pin, keyvar, pout, offset, checksum);
}
ocb3_encrypt_block_final(ctx, i, inl - (i * AES_BLOCK_SIZE), in, out, offset, checksum, plain, plainl, tag);
return 0;
}
static void ocb3_hash_plaintext(ocb_aes_t *ctx, const char *plaintext, int plaintextl, char *sum) {
char keyvar[AES_BLOCK_SIZE];
char offset[AES_BLOCK_SIZE] = {0};
keyvar_init(ctx->key, keyvar);
memset(sum, 0, AES_BLOCK_SIZE);
int i;
int log2 = ntz(0);
for (i = 0; i < (plaintextl - (plaintextl % AES_BLOCK_SIZE)); i += AES_BLOCK_SIZE) {
int log2_next = ntz(i);
if (ntz(i) > log2) {
// double it
char double_temp[AES_BLOCK_SIZE];
double_block(keyvar, double_temp);
cpy_block(keyvar, double_temp);
log2 = log2_next;
}
ocb3_hash_block(ctx, plaintext + i, sum, offset, keyvar);
}
if (i < plaintextl) {
ocb3_hash_block_final(ctx, plaintext, plaintextl - i, sum, offset, keyvar);
}
}
static inline int pntz(size_t p[2]) {
int r = ntz(p[0] - 1);
if(r != 0 || (r = 8*sizeof(size_t) + ntz(p[1])) != 8*sizeof(size_t)) {
return r;
}
return 0;
}
/*static*/ int analyze(FILE * fp) {
Elf32_Ehdr elf_header;
int size_section_header_entry;
ops(1, fread(&elf_header, sizeof(elf_header), 1, fp), "cannot read elf_header");
printf("section header table = %x\nnum entries = %d\nent size = %d\n",
elf_header.e_shoff, elf_header.e_shnum, elf_header.e_shentsize);
ntz(!sek(fp, elf_header.e_shoff), "cannot seek to section-header-table");
read_string_table(fp, &elf_header);
ntz(!sek(fp, elf_header.e_shoff), "cannot seek to section-header-table");
show_section_header_table(fp, &elf_header);
}
inline void CaseIterator::fast_next() {
/* G4:
* if (parity_n+1 == 0) set j <- ntz(k)
* ntz() does the same as the ruler function p(k) in eq. 7.1-(00)
*/
//fprintf(stderr, "ntz(k=%016x) <= %d\n", k, ntz(k));
j = ntz(k) & (parity);
/* G3: invert parity */
/* we need the inverted value of parity for the fast calculation
* of j, so we swapped the two steps. Note that the following
* precondition holds, after G4 and G3:
* if (parity == 0) { j = ntz(k); }
*/
parity ^= (unsigned int) -1;
/* G5 */
//fprintf(stderr, "p=%d, k = 0x%08x, j = %d\n", parity, k, j);
/* G2: visit */
//fprintf(stderr, "inverting at index %d\n", changeable_characters[j]);
//assert(j < changeable_characters.size());
word.toggle_case(changeable_characters[j]);
--k;
}
void
add_ipv4_entry(struct route_table *rt, struct route_entry_v4 *e)
{
patricia_node_t *node;
uint32_t ip = htonl(e->ip);
int bitlen = 32 - ntz(e->netmask);
prefix_t *pref = New_Prefix(AF_INET, &ip, bitlen);
node = patricia_lookup (rt->ipv4_table, pref);
Deref_Prefix (pref);
node->data = (void*) e;
}
static void read_string_table(FILE * fp, Elf32_Ehdr * elf_header) {
Elf32_Shdr tblnames;
int ofs = elf_header->e_shoff + elf_header->e_shentsize * elf_header->e_shstrndx;
notz(!sek(fp, ofs),
"ofs = %d\n", ofs);
oops(1, fread(&tblnames, sizeof(tblnames), 1, fp),
"ofs = %d; e_shoff = %d; e_shentsize = %d; shstrndx = %d\n",
ofs, elf_header->e_shoff, elf_header->e_shentsize, elf_header->e_shstrndx);
notz(string_table = (char*) malloc(tblnames.sh_size), "need memory %d\n", tblnames.sh_size);
ntz(!sek(fp, tblnames.sh_offset), "");
ops(1, fread(string_table, tblnames.sh_size, 1, fp), "");
}
/* Under the 16-byte (128-bit) key at k and the 12-byte (96-bit) nonce at n, encrypt the plaintext at p and store it at c.
The length of the plaintext is a multiple of 16 bytes given at len (e.g., len = 2 for a 32-byte p). The length of the
ciphertext c is (len+1)*16 bytes. */
void aes128ocb(unsigned char *c, const unsigned char *k, const unsigned char *n, const unsigned char *p, const unsigned int len) {
/* Array of zeros for use with aes128e */
unsigned char zeros[16];
int i;
for (i = 0; i < 16; ++i) {
zeros[i] = 0x00;
}
unsigned char l[16];
unsigned char l_dollar[16];
aes128e(l, zeros, k);
/* Now l is l_star */
doubleB(l, 16);
/* Now l is l_dollar */
/* We keep l_dollar for using it for calculate the tag */
for (i = 0; i < 16; ++i) {
l_dollar[i] = l[i];
}
doubleB(l, 16);
/* Now l is l_0 */
/* m = bitlen(P)/128 */
unsigned int m = ((16*len)*8)/128;
/* numL is the maximum value of trailing zeros for the given size m */
unsigned int numL = msb(m) + 1;
/* ls is the array of all the l_i arrays */
unsigned char ls[numL][16];
int a;
for (a = 0; a < numL; ++a) {
for (i = 0; i < 16; ++i) {
ls[a][i] = l[i];
}
doubleB(l, 16);
}
/* Addition of 0x00000001 to the nonce */
unsigned char nonce[20];
nonce[0] = nonce[1] = nonce[2] = 0x00;
nonce[3] = 0x01;
a = 0;
for (i = 4; i < 20; ++i) {
nonce[i] = n[a];
++a;
}
/* Bottom is the integer value of the last 6 bits of nonce */
unsigned int bottom = nonce[15]&0x3F;
/* Temporal array for aes128e with last 6 bits of nonce to zero */
unsigned char top[16];
for (i = 0; i < 16; ++i) {
top[i] = nonce[i];
}
top[15] = nonce[15]&0xC0;
/* Calculation of ktop using the block cipher */
unsigned char ktop[16];
aes128e(ktop, top, k);
/* Stretch is ktop concatenated with the xor of the bits 1...64 and 9...72 of ktop */
unsigned char stretch[24];
for (i = 0; i < 16; ++i) {
stretch[i] = ktop[i];
}
a = 0;
for (i = 16; i < 24; ++i) {
stretch[i] = (ktop[a] ^ ktop[a + 1]);
++a;
}
/* Array of the m offset arrays */
unsigned char offset[m][16];
/* Array of the m checksum arrays */
unsigned char checksum[m][16];
/* Temporal array for get stretch[1 + bottom...128 + bottom] */
unsigned char tempS[24];
for (i = 0; i < 24; ++i) {
tempS[i] = stretch[i];
}
/* Shifting of stretch bottom times to the left */
for (i = 0; i < bottom; ++i) {
shiftB(tempS, 24);
}
/* Copy of temp array to offset and inicialization of checksum */
for (i = 0; i < 16; ++i) {
offset[0][i] = tempS[i];
checksum[0][i] = 0x00;
}
/* Temporal arrays for use them with aes128 as plaintext and ciphertext */
unsigned char temp1[16];
unsigned char temp2[16];
int ntzV;
/* Counters */
int countP1 = 0;
int countP2 = 0;
int countC = 0;
/* Loop over the m blocks */
for (i = 1; i <= m; ++i) {
/* Number of trailing zeros in i */
ntzV = ntz(i);
/* Calculation of the offset_i with xor betwen offset_{i-1} and l_{ntz(i)} */
for (a = 0; a < 16; ++a) {
offset[i][a] = offset[i - 1][a] ^ ls[ntzV][a];
}
/* Calculation of xor betwen p_i and offset_i for use it in aes128 */
for (a = 0; a < 16; ++a) {
temp1[a] = (p[countP1] ^ offset[i][a]);
++countP1;
}
aes128e(temp2, temp1, k);
/* Calculation of c_i with xor betwen offset_i and result of aes128 */
for (a = 0; a < 16; ++a) {
c[countC] = offset[i][a] ^ temp2[a];
++countC;
}
/* Calculation of checksum_i with the xor betwen checksum_{i-1} and p_i */
for (a = 0; a < 16; ++a) {
checksum[i][a] = checksum[i - 1][a] ^ p[countP2];
++countP2;
}
}
unsigned char tag[16];
unsigned char tempTag[16];
/* Calculation of the xor betwen checksum_m, offset_m and l_dollar for use it in aes128 to calculate the tag */
int w;
for (w = 0; w < 16; ++w) {
tempTag[w] = ((l_dollar[w] ^ offset[m][w]) ^ checksum[m][w]);
}
aes128e(tag, tempTag, k);
/* Concatenation of the tag at the end of the ciphertext. 16*m is the
current lenght of the cipher lenght and 16*m +16 is the total lenght */
int countTag = 0;
for (a = 16*m; a < (16*m + 16); ++a) {
c[a] = tag[countTag];
++countTag;
}
}
