static unsigned char *
ccm_encrypt(br_sslrec_ccm_context *cc,
int record_type, unsigned version, void *data, size_t *data_len)
{
br_ccm_context zc;
unsigned char *buf;
unsigned char nonce[12], header[13];
size_t len;
buf = (unsigned char *)data;
len = *data_len;
/*
* Make nonce; the explicit part is an encoding of the sequence
* number.
*/
memcpy(nonce, cc->iv, sizeof cc->iv);
br_enc64be(nonce + 4, cc->seq);
/*
* Assemble synthetic header for the AAD.
*/
br_enc64be(header, cc->seq ++);
header[8] = (unsigned char)record_type;
br_enc16be(header + 9, version);
br_enc16be(header + 11, len);
/*
* Perform CCM encryption.
*/
br_ccm_init(&zc, &cc->bc.vtable);
br_ccm_reset(&zc, nonce, sizeof nonce, sizeof header, len, cc->tag_len);
br_ccm_aad_inject(&zc, header, sizeof header);
br_ccm_flip(&zc);
br_ccm_run(&zc, 1, buf, len);
br_ccm_get_tag(&zc, buf + len);
/*
* Assemble header and adjust pointer/length.
*/
len += 8 + cc->tag_len;
buf -= 13;
memcpy(buf + 5, nonce + 4, 8);
buf[0] = (unsigned char)record_type;
br_enc16be(buf + 1, version);
br_enc16be(buf + 3, len);
*data_len = len + 5;
return buf;
}
static unsigned char *
ccm_decrypt(br_sslrec_ccm_context *cc,
int record_type, unsigned version, void *data, size_t *data_len)
{
br_ccm_context zc;
unsigned char *buf;
unsigned char nonce[12], header[13];
size_t len;
buf = (unsigned char *)data + 8;
len = *data_len - (8 + cc->tag_len);
/*
* Make nonce (implicit + explicit parts).
*/
memcpy(nonce, cc->iv, sizeof cc->iv);
memcpy(nonce + 4, data, 8);
/*
* Assemble synthetic header for the AAD.
*/
br_enc64be(header, cc->seq ++);
header[8] = (unsigned char)record_type;
br_enc16be(header + 9, version);
br_enc16be(header + 11, len);
/*
* Perform CCM decryption.
*/
br_ccm_init(&zc, &cc->bc.vtable);
br_ccm_reset(&zc, nonce, sizeof nonce, sizeof header, len, cc->tag_len);
br_ccm_aad_inject(&zc, header, sizeof header);
br_ccm_flip(&zc);
br_ccm_run(&zc, 0, buf, len);
if (!br_ccm_check_tag(&zc, buf + len)) {
return NULL;
}
*data_len = len;
return buf;
}
static void
sha2small_out(const br_sha224_context *cc, void *dst, int num)
{
unsigned char buf[64];
uint32_t val[8];
size_t ptr;
ptr = (size_t)cc->count & 63;
memcpy(buf, cc->buf, ptr);
memcpy(val, cc->val, sizeof val);
buf[ptr ++] = 0x80;
if (ptr > 56) {
memset(buf + ptr, 0, 64 - ptr);
br_sha2small_round(buf, val);
memset(buf, 0, 56);
} else {
memset(buf + ptr, 0, 56 - ptr);
}
br_enc64be(buf + 56, cc->count << 3);
br_sha2small_round(buf, val);
br_range_enc32be(dst, val, num);
}
static void
sha2big_out(const br_sha384_context *cc, void *dst, int num)
{
unsigned char buf[128];
uint64_t val[8];
size_t ptr;
ptr = (size_t)cc->count & 127;
memcpy(buf, cc->buf, ptr);
memcpy(val, cc->val, sizeof val);
buf[ptr ++] = 0x80;
if (ptr > 112) {
memset(buf + ptr, 0, 128 - ptr);
sha2big_round(buf, val);
memset(buf, 0, 112);
} else {
memset(buf + ptr, 0, 112 - ptr);
}
br_enc64be(buf + 112, cc->count >> 61);
br_enc64be(buf + 120, cc->count << 3);
sha2big_round(buf, val);
br_range_enc64be(dst, val, num);
}
