TEE_Result tee_authenc_dec_final(
void *ctx, uint32_t algo, const uint8_t *src_data,
size_t src_len, uint8_t *dst_data, const uint8_t *tag, size_t tag_len)
{
TEE_Result res = TEE_ERROR_BAD_STATE;
struct tee_ccm_state *ccm;
struct tee_gcm_state *gcm;
int ltc_res;
uint8_t dst_tag[TEE_xCM_TAG_MAX_LENGTH];
size_t dst_len, init_len;
unsigned long ltc_tag_len = tag_len;
res = tee_cipher_get_block_size(algo, &dst_len);
if (res != TEE_SUCCESS)
return res;
if (tag_len == 0)
return TEE_ERROR_SHORT_BUFFER;
if (tag_len > TEE_xCM_TAG_MAX_LENGTH)
return TEE_ERROR_BAD_STATE;
switch (algo) {
case TEE_ALG_AES_CCM:
ccm = ctx;
init_len = ccm->current_payload_len;
if (src_len) {
memcpy(ccm->payload + ccm->current_payload_len,
src_data, src_len);
ccm->current_payload_len += src_len;
}
if (ccm->payload_len != ccm->current_payload_len)
return TEE_ERROR_BAD_PARAMETERS;
ltc_res = ccm_memory(
ccm->ltc_cipherindex,
ccm->key, ccm->key_len,
0, /* not previously scheduled */
ccm->nonce, ccm->nonce_len,
ccm->header, ccm->header_len,
ccm->res_payload,
ccm->current_payload_len, ccm->payload,
dst_tag, <c_tag_len, CCM_DECRYPT);
if (ltc_res != CRYPT_OK)
return TEE_ERROR_BAD_STATE;
if (src_len)
memcpy(dst_data, ccm->res_payload + init_len, src_len);
break;
case TEE_ALG_AES_GCM:
/* Process the last buffer, if any */
gcm = ctx;
res = tee_authenc_update_payload(
&gcm->ctx, algo, TEE_MODE_DECRYPT,
src_data, src_len, dst_data);
if (res != TEE_SUCCESS)
return res;
/* Finalize the authentication */
ltc_res = gcm_done(&gcm->ctx, dst_tag, <c_tag_len);
if (ltc_res != CRYPT_OK)
return TEE_ERROR_BAD_STATE;
break;
default:
return TEE_ERROR_NOT_SUPPORTED;
}
if (buf_compare_ct(dst_tag, tag, tag_len) != 0)
res = TEE_ERROR_MAC_INVALID;
else
res = TEE_SUCCESS;
return res;
}
/**
Process an entire GCM packet in one call.
@param cipher Index of cipher to use
@param key The secret key
@param keylen The length of the secret key
@param IV The initial vector
@param IVlen The length of the initial vector
@param adata The additional authentication data (header)
@param adatalen The length of the adata
@param pt The plaintext
@param ptlen The length of the plaintext (ciphertext length is the same)
@param ct The ciphertext
@param tag [out] The MAC tag
@param taglen [in/out] The MAC tag length
@param direction Encrypt or Decrypt mode (GCM_ENCRYPT or GCM_DECRYPT)
@return CRYPT_OK on success
*/
int gcm_memory( int cipher,
const unsigned char *key, unsigned long keylen,
const unsigned char *IV, unsigned long IVlen,
const unsigned char *adata, unsigned long adatalen,
unsigned char *pt, unsigned long ptlen,
unsigned char *ct,
unsigned char *tag, unsigned long *taglen,
int direction)
{
void *orig;
gcm_state *gcm;
int err;
if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
return err;
}
if (cipher_descriptor[cipher].accel_gcm_memory != NULL) {
return
cipher_descriptor[cipher].accel_gcm_memory
(key, keylen,
IV, IVlen,
adata, adatalen,
pt, ptlen,
ct,
tag, taglen,
direction);
}
#ifndef LTC_GCM_TABLES_SSE2
orig = gcm = XMALLOC(sizeof(*gcm));
#else
orig = gcm = XMALLOC(sizeof(*gcm) + 16);
#endif
if (gcm == NULL) {
return CRYPT_MEM;
}
/* Force GCM to be on a multiple of 16 so we can use 128-bit aligned operations
* note that we only modify gcm and keep orig intact. This code is not portable
* but again it's only for SSE2 anyways, so who cares?
*/
#ifdef LTC_GCM_TABLES_SSE2
if ((unsigned long)gcm & 15) {
gcm = (gcm_state *)((unsigned long)gcm + (16 - ((unsigned long)gcm & 15)));
}
#endif
if ((err = gcm_init(gcm, cipher, key, keylen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_iv(gcm, IV, IVlen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_add_aad(gcm, adata, adatalen)) != CRYPT_OK) {
goto LTC_ERR;
}
if ((err = gcm_process(gcm, pt, ptlen, ct, direction)) != CRYPT_OK) {
goto LTC_ERR;
}
err = gcm_done(gcm, tag, taglen);
LTC_ERR:
XFREE(orig);
return err;
}
TEE_Result tee_authenc_enc_final(
void *ctx, uint32_t algo, const uint8_t *src_data,
size_t src_len, uint8_t *dst_data,
uint8_t *dst_tag, size_t *dst_tag_len)
{
TEE_Result res, final_res = TEE_ERROR_MAC_INVALID;
struct tee_ccm_state *ccm;
struct tee_gcm_state *gcm;
size_t digest_size;
int ltc_res;
int init_len;
/* Check the resulting buffer is not too short */
res = tee_cipher_get_block_size(algo, &digest_size);
if (res != TEE_SUCCESS) {
final_res = res;
goto out;
}
switch (algo) {
case TEE_ALG_AES_CCM:
ccm = ctx;
init_len = ccm->current_payload_len;
if (src_len) {
memcpy(ccm->payload + ccm->current_payload_len,
src_data, src_len);
ccm->current_payload_len += src_len;
}
if (ccm->payload_len != ccm->current_payload_len)
return TEE_ERROR_BAD_PARAMETERS;
if (*dst_tag_len < ccm->tag_len) {
*dst_tag_len = ccm->tag_len;
return TEE_ERROR_SHORT_BUFFER;
}
*dst_tag_len = ccm->tag_len;
ltc_res = ccm_memory(
ccm->ltc_cipherindex,
ccm->key, ccm->key_len,
0, /* not previously scheduled */
ccm->nonce, ccm->nonce_len,
ccm->header, ccm->header_len,
ccm->payload, ccm->current_payload_len,
ccm->res_payload,
dst_tag, (unsigned long *)dst_tag_len, CCM_ENCRYPT);
if (ltc_res != CRYPT_OK)
return TEE_ERROR_BAD_STATE;
if (src_len)
memcpy(dst_data, ccm->res_payload + init_len, src_len);
break;
case TEE_ALG_AES_GCM:
/* Finalize the remaining buffer */
gcm = ctx;
res = tee_authenc_update_payload(
&gcm->ctx, algo, TEE_MODE_ENCRYPT,
src_data, src_len, dst_data);
if (res != TEE_SUCCESS) {
final_res = res;
goto out;
}
if (*dst_tag_len < gcm->tag_len) {
*dst_tag_len = gcm->tag_len;
return TEE_ERROR_SHORT_BUFFER;
}
*dst_tag_len = gcm->tag_len;
/* Process the last buffer, if any */
ltc_res = gcm_done(
&gcm->ctx,
dst_tag, (unsigned long *)dst_tag_len);
if (ltc_res != CRYPT_OK)
goto out;
break;
default:
return TEE_ERROR_NOT_SUPPORTED;
}
final_res = TEE_SUCCESS;
out:
return final_res;
}
