/* Implements the default OpenSSL RAND_bytes() method */
static int drbg_bytes(unsigned char *out, int count)
{
int ret;
RAND_DRBG *drbg = RAND_DRBG_get0_public();
if (drbg == NULL)
return 0;
ret = RAND_DRBG_bytes(drbg, out, count);
return ret;
}
/*
* This function is not part of RAND_METHOD, so if we're not using
* the default method, then just call RAND_bytes(). Otherwise make
* sure we're instantiated and use the private DRBG.
*/
int RAND_priv_bytes(unsigned char *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
RAND_DRBG *drbg;
int ret;
if (meth != RAND_OpenSSL())
return RAND_bytes(buf, num);
drbg = RAND_DRBG_get0_private();
if (drbg == NULL)
return 0;
/* We have to lock the DRBG before generating bits from it. */
rand_drbg_lock(drbg);
ret = RAND_DRBG_bytes(drbg, buf, num);
rand_drbg_unlock(drbg);
return ret;
}
static size_t tls1_1_multi_block_encrypt(EVP_AES_HMAC_SHA256 *key,
unsigned char *out,
const unsigned char *inp,
size_t inp_len, int n4x,
RAND_DRBG *drbg)
{ /* n4x is 1 or 2 */
HASH_DESC hash_d[8], edges[8];
CIPH_DESC ciph_d[8];
unsigned char storage[sizeof(SHA256_MB_CTX) + 32];
union {
u64 q[16];
u32 d[32];
u8 c[128];
} blocks[8];
SHA256_MB_CTX *ctx;
unsigned int frag, last, packlen, i, x4 = 4 * n4x, minblocks, processed =
0;
size_t ret = 0;
u8 *IVs;
# if defined(BSWAP8)
u64 seqnum;
# endif
/* ask for IVs in bulk */
IVs = blocks[0].c;
if (drbg != NULL) {
if (RAND_DRBG_bytes(drbg, IVs, 16 * x4) == 0)
return 0;
} else if (RAND_bytes(IVs, 16 * x4) <= 0) {
return 0;
}
/* align */
ctx = (SHA256_MB_CTX *) (storage + 32 - ((size_t)storage % 32));
frag = (unsigned int)inp_len >> (1 + n4x);
last = (unsigned int)inp_len + frag - (frag << (1 + n4x));
if (last > frag && ((last + 13 + 9) % 64) < (x4 - 1)) {
frag++;
last -= x4 - 1;
}
packlen = 5 + 16 + ((frag + 32 + 16) & -16);
/* populate descriptors with pointers and IVs */
hash_d[0].ptr = inp;
ciph_d[0].inp = inp;
/* 5+16 is place for header and explicit IV */
ciph_d[0].out = out + 5 + 16;
memcpy(ciph_d[0].out - 16, IVs, 16);
memcpy(ciph_d[0].iv, IVs, 16);
IVs += 16;
for (i = 1; i < x4; i++) {
ciph_d[i].inp = hash_d[i].ptr = hash_d[i - 1].ptr + frag;
ciph_d[i].out = ciph_d[i - 1].out + packlen;
memcpy(ciph_d[i].out - 16, IVs, 16);
memcpy(ciph_d[i].iv, IVs, 16);
IVs += 16;
}
# if defined(BSWAP8)
memcpy(blocks[0].c, key->md.data, 8);
seqnum = BSWAP8(blocks[0].q[0]);
# endif
for (i = 0; i < x4; i++) {
unsigned int len = (i == (x4 - 1) ? last : frag);
# if !defined(BSWAP8)
unsigned int carry, j;
# endif
ctx->A[i] = key->md.h[0];
ctx->B[i] = key->md.h[1];
ctx->C[i] = key->md.h[2];
ctx->D[i] = key->md.h[3];
ctx->E[i] = key->md.h[4];
ctx->F[i] = key->md.h[5];
ctx->G[i] = key->md.h[6];
ctx->H[i] = key->md.h[7];
/* fix seqnum */
# if defined(BSWAP8)
blocks[i].q[0] = BSWAP8(seqnum + i);
# else
for (carry = i, j = 8; j--;) {
blocks[i].c[j] = ((u8 *)key->md.data)[j] + carry;
carry = (blocks[i].c[j] - carry) >> (sizeof(carry) * 8 - 1);
}
# endif
blocks[i].c[8] = ((u8 *)key->md.data)[8];
blocks[i].c[9] = ((u8 *)key->md.data)[9];
blocks[i].c[10] = ((u8 *)key->md.data)[10];
/* fix length */
blocks[i].c[11] = (u8)(len >> 8);
blocks[i].c[12] = (u8)(len);
memcpy(blocks[i].c + 13, hash_d[i].ptr, 64 - 13);
hash_d[i].ptr += 64 - 13;
hash_d[i].blocks = (len - (64 - 13)) / 64;
edges[i].ptr = blocks[i].c;
edges[i].blocks = 1;
}
/* hash 13-byte headers and first 64-13 bytes of inputs */
sha256_multi_block(ctx, edges, n4x);
/* hash bulk inputs */
# define MAXCHUNKSIZE 2048
# if MAXCHUNKSIZE%64
# error "MAXCHUNKSIZE is not divisible by 64"
# elif MAXCHUNKSIZE
/*
* goal is to minimize pressure on L1 cache by moving in shorter steps,
* so that hashed data is still in the cache by the time we encrypt it
*/
minblocks = ((frag <= last ? frag : last) - (64 - 13)) / 64;
if (minblocks > MAXCHUNKSIZE / 64) {
for (i = 0; i < x4; i++) {
edges[i].ptr = hash_d[i].ptr;
edges[i].blocks = MAXCHUNKSIZE / 64;
ciph_d[i].blocks = MAXCHUNKSIZE / 16;
}
do {
sha256_multi_block(ctx, edges, n4x);
aesni_multi_cbc_encrypt(ciph_d, &key->ks, n4x);
for (i = 0; i < x4; i++) {
edges[i].ptr = hash_d[i].ptr += MAXCHUNKSIZE;
hash_d[i].blocks -= MAXCHUNKSIZE / 64;
edges[i].blocks = MAXCHUNKSIZE / 64;
ciph_d[i].inp += MAXCHUNKSIZE;
ciph_d[i].out += MAXCHUNKSIZE;
ciph_d[i].blocks = MAXCHUNKSIZE / 16;
memcpy(ciph_d[i].iv, ciph_d[i].out - 16, 16);
}
processed += MAXCHUNKSIZE;
minblocks -= MAXCHUNKSIZE / 64;
} while (minblocks > MAXCHUNKSIZE / 64);
}
# endif
# undef MAXCHUNKSIZE
sha256_multi_block(ctx, hash_d, n4x);
memset(blocks, 0, sizeof(blocks));
for (i = 0; i < x4; i++) {
unsigned int len = (i == (x4 - 1) ? last : frag),
off = hash_d[i].blocks * 64;
const unsigned char *ptr = hash_d[i].ptr + off;
off = (len - processed) - (64 - 13) - off; /* remainder actually */
memcpy(blocks[i].c, ptr, off);
blocks[i].c[off] = 0x80;
len += 64 + 13; /* 64 is HMAC header */
len *= 8; /* convert to bits */
if (off < (64 - 8)) {
# ifdef BSWAP4
blocks[i].d[15] = BSWAP4(len);
# else
PUTU32(blocks[i].c + 60, len);
# endif
edges[i].blocks = 1;
} else {
# ifdef BSWAP4
blocks[i].d[31] = BSWAP4(len);
# else
PUTU32(blocks[i].c + 124, len);
# endif
edges[i].blocks = 2;
}
edges[i].ptr = blocks[i].c;
}
/* hash input tails and finalize */
sha256_multi_block(ctx, edges, n4x);
memset(blocks, 0, sizeof(blocks));
for (i = 0; i < x4; i++) {
# ifdef BSWAP4
blocks[i].d[0] = BSWAP4(ctx->A[i]);
ctx->A[i] = key->tail.h[0];
blocks[i].d[1] = BSWAP4(ctx->B[i]);
ctx->B[i] = key->tail.h[1];
blocks[i].d[2] = BSWAP4(ctx->C[i]);
ctx->C[i] = key->tail.h[2];
blocks[i].d[3] = BSWAP4(ctx->D[i]);
ctx->D[i] = key->tail.h[3];
blocks[i].d[4] = BSWAP4(ctx->E[i]);
ctx->E[i] = key->tail.h[4];
blocks[i].d[5] = BSWAP4(ctx->F[i]);
ctx->F[i] = key->tail.h[5];
blocks[i].d[6] = BSWAP4(ctx->G[i]);
ctx->G[i] = key->tail.h[6];
blocks[i].d[7] = BSWAP4(ctx->H[i]);
ctx->H[i] = key->tail.h[7];
blocks[i].c[32] = 0x80;
blocks[i].d[15] = BSWAP4((64 + 32) * 8);
# else
PUTU32(blocks[i].c + 0, ctx->A[i]);
ctx->A[i] = key->tail.h[0];
PUTU32(blocks[i].c + 4, ctx->B[i]);
ctx->B[i] = key->tail.h[1];
PUTU32(blocks[i].c + 8, ctx->C[i]);
ctx->C[i] = key->tail.h[2];
PUTU32(blocks[i].c + 12, ctx->D[i]);
ctx->D[i] = key->tail.h[3];
PUTU32(blocks[i].c + 16, ctx->E[i]);
ctx->E[i] = key->tail.h[4];
PUTU32(blocks[i].c + 20, ctx->F[i]);
ctx->F[i] = key->tail.h[5];
PUTU32(blocks[i].c + 24, ctx->G[i]);
ctx->G[i] = key->tail.h[6];
PUTU32(blocks[i].c + 28, ctx->H[i]);
ctx->H[i] = key->tail.h[7];
blocks[i].c[32] = 0x80;
PUTU32(blocks[i].c + 60, (64 + 32) * 8);
# endif
edges[i].ptr = blocks[i].c;
edges[i].blocks = 1;
}
/* finalize MACs */
sha256_multi_block(ctx, edges, n4x);
for (i = 0; i < x4; i++) {
unsigned int len = (i == (x4 - 1) ? last : frag), pad, j;
unsigned char *out0 = out;
memcpy(ciph_d[i].out, ciph_d[i].inp, len - processed);
ciph_d[i].inp = ciph_d[i].out;
out += 5 + 16 + len;
/* write MAC */
PUTU32(out + 0, ctx->A[i]);
PUTU32(out + 4, ctx->B[i]);
PUTU32(out + 8, ctx->C[i]);
PUTU32(out + 12, ctx->D[i]);
PUTU32(out + 16, ctx->E[i]);
PUTU32(out + 20, ctx->F[i]);
PUTU32(out + 24, ctx->G[i]);
PUTU32(out + 28, ctx->H[i]);
out += 32;
len += 32;
/* pad */
pad = 15 - len % 16;
for (j = 0; j <= pad; j++)
*(out++) = pad;
len += pad + 1;
ciph_d[i].blocks = (len - processed) / 16;
len += 16; /* account for explicit iv */
/* arrange header */
out0[0] = ((u8 *)key->md.data)[8];
out0[1] = ((u8 *)key->md.data)[9];
out0[2] = ((u8 *)key->md.data)[10];
out0[3] = (u8)(len >> 8);
out0[4] = (u8)(len);
ret += len + 5;
inp += frag;
}
aesni_multi_cbc_encrypt(ciph_d, &key->ks, n4x);
OPENSSL_cleanse(blocks, sizeof(blocks));
OPENSSL_cleanse(ctx, sizeof(*ctx));
return ret;
}
