int rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#endif
{
ulong32 a,b,c,d,t,u, *K;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]);
b += skey->rc6.K[0];
d += skey->rc6.K[1];
#define RND(a,b,c,d) \
t = (b * (b + b + 1)); t = ROLc(t, 5); \
u = (d * (d + d + 1)); u = ROLc(u, 5); \
a = ROL(a^t,u) + K[0]; \
c = ROL(c^u,t) + K[1]; K += 2;
K = skey->rc6.K + 2;
for (r = 0; r < 20; r += 4) {
RND(a,b,c,d);
RND(b,c,d,a);
RND(c,d,a,b);
RND(d,a,b,c);
}
#undef RND
a += skey->rc6.K[42];
c += skey->rc6.K[43];
STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]);
return CRYPT_OK;
}
void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#endif
{
ulong32 a,b,c,d,t,u, *K;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]);
a -= skey->rc6.K[42];
c -= skey->rc6.K[43];
#define RND(a,b,c,d) \
t = (b * (b + b + 1)); t = ROLc(t, 5); \
u = (d * (d + d + 1)); u = ROLc(u, 5); \
c = ROR(c - K[1], t) ^ u; \
a = ROR(a - K[0], u) ^ t; K -= 2;
K = skey->rc6.K + 40;
for (r = 0; r < 20; r += 4) {
RND(d,a,b,c);
RND(c,d,a,b);
RND(b,c,d,a);
RND(a,b,c,d);
}
#undef RND
b -= skey->rc6.K[0];
d -= skey->rc6.K[1];
STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]);
}
int rc5_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
#endif
{
ulong32 A, B, *K;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32L(A, &pt[0]);
LOAD32L(B, &pt[4]);
A += skey->rc5.K[0];
B += skey->rc5.K[1];
K = skey->rc5.K + 2;
if ((skey->rc5.rounds & 1) == 0) {
for (r = 0; r < skey->rc5.rounds; r += 2) {
A = ROL(A ^ B, B) + K[0];
B = ROL(B ^ A, A) + K[1];
A = ROL(A ^ B, B) + K[2];
B = ROL(B ^ A, A) + K[3];
K += 4;
}
} else {
for (r = 0; r < skey->rc5.rounds; r++) {
A = ROL(A ^ B, B) + K[0];
B = ROL(B ^ A, A) + K[1];
K += 2;
}
}
STORE32L(A, &ct[0]);
STORE32L(B, &ct[4]);
return CRYPT_OK;
}
void noekeon_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
#endif
{
unsigned long a,b,c,d,temp;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(a,&pt[0]); LOAD32L(b,&pt[4]);
LOAD32L(c,&pt[8]); LOAD32L(d,&pt[12]);
#define ROUND(i) \
a ^= RC[r+i]; \
THETA(key->noekeon.K, a,b,c,d); \
PI1(a,b,c,d); \
GAMMA(a,b,c,d); \
PI2(a,b,c,d);
for (r = 0; r < 16; r += 2) {
ROUND(0);
ROUND(1);
}
#undef ROUND
a ^= RC[16];
THETA(key->noekeon.K, a, b, c, d);
STORE32L(a,&ct[0]); STORE32L(b,&ct[4]);
STORE32L(c,&ct[8]); STORE32L(d,&ct[12]);
}
static void XORWORD(ulong32 w, unsigned char *b)
{
ulong32 t;
LOAD32L(t, b);
t ^= w;
STORE32L(t, b);
}
static void XORWORD(ulong32 w, const unsigned char *in, unsigned char *out)
{
ulong32 t;
LOAD32L(t, in);
t ^= w;
STORE32L(t, out);
}
int blake2s_done(hash_state *md, unsigned char *out)
{
unsigned char buffer[BLAKE2S_OUTBYTES] = { 0 };
unsigned long i;
LTC_ARGCHK(md != NULL);
LTC_ARGCHK(out != NULL);
/* if(md->blake2s.outlen != outlen) return CRYPT_INVALID_ARG; */
if (blake2s_is_lastblock(md))
return CRYPT_ERROR;
blake2s_increment_counter(md, md->blake2s.curlen);
blake2s_set_lastblock(md);
XMEMSET(md->blake2s.buf + md->blake2s.curlen, 0, BLAKE2S_BLOCKBYTES - md->blake2s.curlen); /* Padding */
blake2s_compress(md, md->blake2s.buf);
for (i = 0; i < 8; ++i) /* Output full hash to temp buffer */
STORE32L(md->blake2s.h[i], buffer + i * 4);
XMEMCPY(out, buffer, md->blake2s.outlen);
zeromem(md, sizeof(hash_state));
#ifdef LTC_CLEAN_STACK
zeromem(buffer, sizeof(buffer));
#endif
return CRYPT_OK;
}
void rc5_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
#endif
{
unsigned long A, B;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(A, &pt[0]);
LOAD32L(B, &pt[4]);
A += key->rc5.K[0];
B += key->rc5.K[1];
for (r = 0; r < key->rc5.rounds; r++) {
A = ROL(A ^ B, B) + key->rc5.K[r+r+2];
B = ROL(B ^ A, A) + key->rc5.K[r+r+3];
}
STORE32L(A, &ct[0]);
STORE32L(B, &ct[4]);
}
void rc5_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
#endif
{
unsigned long A, B;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(A, &ct[0]);
LOAD32L(B, &ct[4]);
for (r = key->rc5.rounds - 1; r >= 0; r--) {
B = ROR(B - key->rc5.K[r+r+3], A) ^ A;
A = ROR(A - key->rc5.K[r+r+2], B) ^ B;
}
A -= key->rc5.K[0];
B -= key->rc5.K[1];
STORE32L(A, &pt[0]);
STORE32L(B, &pt[4]);
}
void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
#endif
{
unsigned long a,b,c,d,t,u;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]);
b += key->rc6.K[0];
d += key->rc6.K[1];
for (r = 0; r < 20; r++) {
t = (b * (b + b + 1)); t = ROL(t, 5);
u = (d * (d + d + 1)); u = ROL(u, 5);
a = ROL(a^t,u) + key->rc6.K[r+r+2];
c = ROL(c^u,t) + key->rc6.K[r+r+3];
t = a; a = b; b = c; c = d; d = t;
}
a += key->rc6.K[42];
c += key->rc6.K[43];
STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]);
}
int rc5_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
#endif
{
ulong32 A, B, *K;
int r;
LTC_ARGCHK(skey != NULL);
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LOAD32L(A, &ct[0]);
LOAD32L(B, &ct[4]);
K = skey->rc5.K + (skey->rc5.rounds << 1);
if ((skey->rc5.rounds & 1) == 0) {
K -= 2;
for (r = skey->rc5.rounds - 1; r >= 0; r -= 2) {
B = ROR(B - K[3], A) ^ A;
A = ROR(A - K[2], B) ^ B;
B = ROR(B - K[1], A) ^ A;
A = ROR(A - K[0], B) ^ B;
K -= 4;
}
} else {
for (r = skey->rc5.rounds - 1; r >= 0; r--) {
B = ROR(B - K[1], A) ^ A;
A = ROR(A - K[0], B) ^ B;
K -= 2;
}
}
A -= skey->rc5.K[0];
B -= skey->rc5.K[1];
STORE32L(A, &pt[0]);
STORE32L(B, &pt[4]);
return CRYPT_OK;
}
void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
#endif
{
unsigned long a,b,c,d,t,u;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]);
a -= key->rc6.K[42];
c -= key->rc6.K[43];
for (r = 19; r >= 0; r--) {
t = d; d = c; c = b; b = a; a = t;
t = (b * (b + b + 1)); t = ROL(t, 5);
u = (d * (d + d + 1)); u = ROL(u, 5);
c = ROR(c - key->rc6.K[r+r+3], t) ^ u;
a = ROR(a - key->rc6.K[r+r+2], u) ^ t;
}
b -= key->rc6.K[0];
d -= key->rc6.K[1];
STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]);
}
/**
Terminate the hash to get the digest
@param md The hash state
@param out [out] The destination of the hash (16 bytes)
@return CRYPT_OK if successful
*/
int rmd128_done(hash_state * md, unsigned char *out)
{
int i;
LTC_ARGCHK(md != NULL);
LTC_ARGCHK(out != NULL);
if (md->rmd128.curlen >= sizeof(md->rmd128.buf)) {
return CRYPT_INVALID_ARG;
}
/* increase the length of the message */
md->rmd128.length += md->rmd128.curlen * 8;
/* append the '1' bit */
md->rmd128.buf[md->rmd128.curlen++] = (unsigned char)0x80;
/* if the length is currently above 56 bytes we append zeros
* then compress. Then we can fall back to padding zeros and length
* encoding like normal.
*/
if (md->rmd128.curlen > 56) {
while (md->rmd128.curlen < 64) {
md->rmd128.buf[md->rmd128.curlen++] = (unsigned char)0;
}
rmd128_compress(md, md->rmd128.buf);
md->rmd128.curlen = 0;
}
/* pad upto 56 bytes of zeroes */
while (md->rmd128.curlen < 56) {
md->rmd128.buf[md->rmd128.curlen++] = (unsigned char)0;
}
/* store length */
STORE64L(md->rmd128.length, md->rmd128.buf+56);
rmd128_compress(md, md->rmd128.buf);
/* copy output */
for (i = 0; i < 4; i++) {
STORE32L(md->rmd128.state[i], out+(4*i));
}
#ifdef LTC_CLEAN_STACK
zeromem(md, sizeof(hash_state));
#endif
return CRYPT_OK;
}
/**
Terminate the hash to get the digest
@param sha1 The hash state
@param out [out] The destination of the hash (16 bytes)
*/
void md5_done(struct md5_state *md5, unsigned char *out)
{
int i;
assert(md5 != NULL);
assert(out != NULL);
assert(md5->curlen < sizeof(md5->buf));
/* increase the length of the message */
md5->length += md5->curlen * 8;
/* append the '1' bit */
md5->buf[md5->curlen++] = (unsigned char)0x80;
/* if the length is currently above 56 bytes we append zeros
* then compress. Then we can fall back to padding zeros and length
* encoding like normal.
*/
if (md5->curlen > 56) {
while (md5->curlen < 64) {
md5->buf[md5->curlen++] = (unsigned char)0;
}
md5_compress(md5, md5->buf);
md5->curlen = 0;
}
/* pad upto 56 bytes of zeroes */
while (md5->curlen < 56) {
md5->buf[md5->curlen++] = (unsigned char)0;
}
/* store length */
STORE64L(md5->length, md5->buf+56);
md5_compress(md5, md5->buf);
/* copy output */
for (i = 0; i < 4; i++) {
STORE32L(md5->state[i], out+(4*i));
}
}
static void smix
(
uint8_t *b,
const size_t r,
uint64_t n,
uint32_t *t0,
uint32_t *t1,
uint32_t *t2
)
{
uint64_t i;
uint64_t tn;
uint64_t j;
for(i = 0; i < (r << 5); i++)
t1[i] = LOAD32L(b + (i << 2));
for(i = 0; i < n; i++)
{
memcpy(t0 + (r << 5) * i, t1, r << 7);
blockmix(t1, t2, r);
}
for(i = 0; i < n; i++)
{
/* integrify */
tn = (((uint64_t)t1[(r << 5) - 15] << 32)
| t1[(r << 5) - 16])
& (n - 1);
for(j = 0; j < (r << 5); j++)
t1[j] ^= t0[(r << 5) * tn + j];
blockmix(t1, t2, r);
}
for(i = 0; i < (r << 5); i++)
STORE32L(t1[i], b + (i << 2));
}
int32 psMd4Final(psDigestContext_t * md, unsigned char *out)
{
int32 i;
#ifndef HAVE_NATIVE_INT64
uint32 n;
#endif
psAssert(md != NULL);
psAssert(out != NULL);
if (md->md4.curlen >= sizeof(md->md4.buf)) {
psTraceCrypto("psMd4Final error\n");
return PS_LIMIT_FAIL;
}
/* increase the length of the message */
#ifdef HAVE_NATIVE_INT64
md->md4.length += md->md4.curlen << 3;
#else
n = (md->md4.lengthLo + (md->md4.curlen << 3)) & 0xFFFFFFFFL;
if (n < md->md4.lengthLo) {
md->md4.lengthHi++;
}
md->md4.lengthHi += (md->md4.curlen >> 29);
md->md4.lengthLo = n;
#endif /* HAVE_NATIVE_INT64 */
/* append the '1' bit */
md->md4.buf[md->md4.curlen++] = (unsigned char)0x80;
/* if the length is currently above 56 bytes we append zeros
* then compress. Then we can fall back to padding zeros and length
* encoding like normal.
*/
if (md->md4.curlen > 56) {
while (md->md4.curlen < 64) {
md->md4.buf[md->md4.curlen++] = (unsigned char)0;
}
md4_compress(md, md->md4.buf);
md->md4.curlen = 0;
}
/* pad upto 56 bytes of zeroes */
while (md->md4.curlen < 56) {
md->md4.buf[md->md4.curlen++] = (unsigned char)0;
}
/* store length */
#ifdef HAVE_NATIVE_INT64
STORE64L(md->md4.length, md->md4.buf+56);
#else
STORE32L(md->md4.lengthLo, md->md4.buf+56);
STORE32L(md->md4.lengthHi, md->md4.buf+60);
#endif /* HAVE_NATIVE_INT64 */
md4_compress(md, md->md4.buf);
/* copy output */
for (i = 0; i < 4; i++) {
STORE32L(md->md4.state[i], out+(4*i));
}
memset(md, 0x0, sizeof(psDigestContext_t));
return PS_SUCCESS;
}
/* Test store/load macros with offsets */
int store_test(void)
{
unsigned char buf[256];
int y;
ulong32 L, L1;
ulong64 LL, LL1;
#ifdef LTC_FAST
int x, z;
#endif
for (y = 0; y < 4; y++) {
L = 0x12345678UL;
L1 = 0;
STORE32L(L, buf + y);
LOAD32L(L1, buf + y);
if (L1 != L) {
fprintf(stderr, "\n32L failed at offset %d\n", y);
return 1;
}
STORE32H(L, buf + y);
LOAD32H(L1, buf + y);
if (L1 != L) {
fprintf(stderr, "\n32H failed at offset %d\n", y);
return 1;
}
}
for (y = 0; y < 8; y++) {
LL = CONST64 (0x01020304050607);
LL1 = 0;
STORE64L(LL, buf + y);
LOAD64L(LL1, buf + y);
if (LL1 != LL) {
fprintf(stderr, "\n64L failed at offset %d\n", y);
return 1;
}
STORE64H(LL, buf + y);
LOAD64H(LL1, buf + y);
if (LL1 != LL) {
fprintf(stderr, "\n64H failed at offset %d\n", y);
return 1;
}
}
/* test LTC_FAST */
#ifdef LTC_FAST
y = 16;
for (z = 0; z < y; z++) {
/* fill y bytes with random */
yarrow_read(buf+z, y, &yarrow_prng);
yarrow_read(buf+z+y, y, &yarrow_prng);
/* now XOR it byte for byte */
for (x = 0; x < y; x++) {
buf[2*y+z+x] = buf[z+x] ^ buf[z+y+x];
}
/* now XOR it word for word */
for (x = 0; x < y; x += sizeof(LTC_FAST_TYPE)) {
*((LTC_FAST_TYPE*)(&buf[3*y+z+x])) = *((LTC_FAST_TYPE*)(&buf[z+x])) ^ *((LTC_FAST_TYPE*)(&buf[z+y+x]));
}
if (memcmp(&buf[2*y+z], &buf[3*y+z], y)) {
fprintf(stderr, "\nLTC_FAST failed at offset %d\n", z);
return 1;
}
}
#endif
return 0;
}
/**
Sign a message digest using a DH private key
@param in The data to sign
@param inlen The length of the input (octets)
@param out [out] The destination of the signature
@param outlen [in/out] The max size and resulting size of the output
@param prng An active PRNG state
@param wprng The index of the PRNG desired
@param key A private DH key
@return CRYPT_OK if successful
*/
int dh_sign_hash(const unsigned char *in, unsigned long inlen,
unsigned char *out, unsigned long *outlen,
prng_state *prng, int wprng, dh_key *key)
{
mp_int a, b, k, m, g, p, p1, tmp;
unsigned char *buf;
unsigned long x, y;
int err;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
LTC_ARGCHK(key != NULL);
/* check parameters */
if (key->type != PK_PRIVATE) {
return CRYPT_PK_NOT_PRIVATE;
}
if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
return err;
}
/* is the IDX valid ? */
if (is_valid_idx(key->idx) != 1) {
return CRYPT_PK_INVALID_TYPE;
}
/* allocate ram for buf */
buf = XMALLOC(520);
/* make up a random value k,
* since the order of the group is prime
* we need not check if gcd(k, r) is 1
*/
if (prng_descriptor[wprng].read(buf, sets[key->idx].size, prng) !=
(unsigned long)(sets[key->idx].size)) {
err = CRYPT_ERROR_READPRNG;
goto LBL_ERR;
}
/* init bignums */
if ((err = mp_init_multi(&a, &b, &k, &m, &p, &g, &p1, &tmp, NULL)) != MP_OKAY) {
err = mpi_to_ltc_error(err);
goto LBL_ERR;
}
/* load k and m */
if ((err = mp_read_unsigned_bin(&m, (unsigned char *)in, inlen)) != MP_OKAY) { goto error; }
if ((err = mp_read_unsigned_bin(&k, buf, sets[key->idx].size)) != MP_OKAY) { goto error; }
/* load g, p and p1 */
if ((err = mp_read_radix(&g, sets[key->idx].base, 64)) != MP_OKAY) { goto error; }
if ((err = mp_read_radix(&p, sets[key->idx].prime, 64)) != MP_OKAY) { goto error; }
if ((err = mp_sub_d(&p, 1, &p1)) != MP_OKAY) { goto error; }
if ((err = mp_div_2(&p1, &p1)) != MP_OKAY) { goto error; } /* p1 = (p-1)/2 */
/* now get a = g^k mod p */
if ((err = mp_exptmod(&g, &k, &p, &a)) != MP_OKAY) { goto error; }
/* now find M = xa + kb mod p1 or just b = (M - xa)/k mod p1 */
if ((err = mp_invmod(&k, &p1, &k)) != MP_OKAY) { goto error; } /* k = 1/k mod p1 */
if ((err = mp_mulmod(&a, &key->x, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = xa */
if ((err = mp_submod(&m, &tmp, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = M - xa */
if ((err = mp_mulmod(&k, &tmp, &p1, &b)) != MP_OKAY) { goto error; } /* b = (M - xa)/k */
/* check for overflow */
if ((unsigned long)(PACKET_SIZE + 4 + 4 + mp_unsigned_bin_size(&a) + mp_unsigned_bin_size(&b)) > *outlen) {
err = CRYPT_BUFFER_OVERFLOW;
goto LBL_ERR;
}
/* store header */
y = PACKET_SIZE;
/* now store them both (a,b) */
x = (unsigned long)mp_unsigned_bin_size(&a);
STORE32L(x, out+y); y += 4;
if ((err = mp_to_unsigned_bin(&a, out+y)) != MP_OKAY) { goto error; }
y += x;
x = (unsigned long)mp_unsigned_bin_size(&b);
STORE32L(x, out+y); y += 4;
if ((err = mp_to_unsigned_bin(&b, out+y)) != MP_OKAY) { goto error; }
y += x;
/* check if size too big */
if (*outlen < y) {
err = CRYPT_BUFFER_OVERFLOW;
goto LBL_ERR;
}
/* store header */
packet_store_header(out, PACKET_SECT_DH, PACKET_SUB_SIGNED);
*outlen = y;
err = CRYPT_OK;
goto LBL_ERR;
error:
err = mpi_to_ltc_error(err);
LBL_ERR:
mp_clear_multi(&tmp, &p1, &g, &p, &m, &k, &b, &a, NULL);
XFREE(buf);
return err;
}
/**
Encrypt a short symmetric key with a public DH key
@param in The symmetric key to encrypt
@param inlen The length of the key (octets)
@param out [out] The ciphertext
@param outlen [in/out] The max size and resulting size of the ciphertext
@param prng An active PRNG state
@param wprng The index of the PRNG desired
@param hash The index of the hash desired (must produce a digest of size >= the size of the plaintext)
@param key The public key you wish to encrypt with.
@return CRYPT_OK if successful
*/
int dh_encrypt_key(const unsigned char *in, unsigned long inlen,
unsigned char *out, unsigned long *outlen,
prng_state *prng, int wprng, int hash,
dh_key *key)
{
unsigned char *pub_expt, *dh_shared, *skey;
dh_key pubkey;
unsigned long x, y, z, hashsize, pubkeysize;
int err;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
LTC_ARGCHK(key != NULL);
/* check that wprng/hash are not invalid */
if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
return err;
}
if ((err = hash_is_valid(hash)) != CRYPT_OK) {
return err;
}
if (inlen > hash_descriptor[hash].hashsize) {
return CRYPT_INVALID_HASH;
}
/* allocate memory */
pub_expt = XMALLOC(DH_BUF_SIZE);
dh_shared = XMALLOC(DH_BUF_SIZE);
skey = XMALLOC(MAXBLOCKSIZE);
if (pub_expt == NULL || dh_shared == NULL || skey == NULL) {
if (pub_expt != NULL) {
XFREE(pub_expt);
}
if (dh_shared != NULL) {
XFREE(dh_shared);
}
if (skey != NULL) {
XFREE(skey);
}
return CRYPT_MEM;
}
/* make a random key and export the public copy */
if ((err = dh_make_key(prng, wprng, dh_get_size(key), &pubkey)) != CRYPT_OK) {
goto LBL_ERR;
}
pubkeysize = DH_BUF_SIZE;
if ((err = dh_export(pub_expt, &pubkeysize, PK_PUBLIC, &pubkey)) != CRYPT_OK) {
dh_free(&pubkey);
goto LBL_ERR;
}
/* now check if the out buffer is big enough */
if (*outlen < (1 + 4 + 4 + PACKET_SIZE + pubkeysize + inlen)) {
dh_free(&pubkey);
err = CRYPT_BUFFER_OVERFLOW;
goto LBL_ERR;
}
/* make random key */
hashsize = hash_descriptor[hash].hashsize;
x = DH_BUF_SIZE;
if ((err = dh_shared_secret(&pubkey, key, dh_shared, &x)) != CRYPT_OK) {
dh_free(&pubkey);
goto LBL_ERR;
}
dh_free(&pubkey);
z = MAXBLOCKSIZE;
if ((err = hash_memory(hash, dh_shared, x, skey, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
/* store header */
packet_store_header(out, PACKET_SECT_DH, PACKET_SUB_ENC_KEY);
/* output header */
y = PACKET_SIZE;
/* size of hash name and the name itself */
out[y++] = hash_descriptor[hash].ID;
/* length of DH pubkey and the key itself */
STORE32L(pubkeysize, out+y);
y += 4;
for (x = 0; x < pubkeysize; x++, y++) {
out[y] = pub_expt[x];
}
/* Store the encrypted key */
STORE32L(inlen, out+y);
y += 4;
for (x = 0; x < inlen; x++, y++) {
out[y] = skey[x] ^ in[x];
}
*outlen = y;
err = CRYPT_OK;
LBL_ERR:
#ifdef LTC_CLEAN_STACK
/* clean up */
zeromem(pub_expt, DH_BUF_SIZE);
zeromem(dh_shared, DH_BUF_SIZE);
zeromem(skey, MAXBLOCKSIZE);
#endif
XFREE(skey);
XFREE(dh_shared);
XFREE(pub_expt);
return err;
}
