/*!
* @brief Authenticate and decrypt a (CCM) stream.
*
* @param user_ctx The user's context
* @param auth_ctx Info on this Auth operation
* @param cipher_key_info Key to encrypt payload
* @param auth_key_info (unused - same key in CCM)
* @param auth_data_length Length in bytes of @a auth_data
* @param auth_data Any auth-only data
* @param payload_length Length in bytes of @a payload
* @param ct The encrypted data
* @param auth_value The authentication code to validate
* @param[out] payload The location to store decrypted data
*
* @return A return code of type #fsl_shw_return_t.
*/
fsl_shw_return_t fsl_shw_auth_decrypt(fsl_shw_uco_t * user_ctx,
fsl_shw_acco_t * auth_ctx,
fsl_shw_sko_t * cipher_key_info,
fsl_shw_sko_t * auth_key_info,
uint32_t auth_data_length,
const uint8_t * auth_data,
uint32_t payload_length,
const uint8_t * ct,
const uint8_t * auth_value,
uint8_t * payload)
{
SAH_SF_DCLS;
uint8_t *calced_auth = NULL;
unsigned blocking = user_ctx->flags & FSL_UCO_BLOCKING_MODE;
SAH_SF_USER_CHECK();
/* Only support INIT and FINALIZE flags right now. */
if (auth_ctx->mode != FSL_ACC_MODE_CCM) {
ret = FSL_RETURN_BAD_MODE_S;
goto out;
}
if ((auth_ctx->flags & (FSL_ACCO_CTX_INIT | FSL_ACCO_CTX_LOAD |
FSL_ACCO_CTX_SAVE | FSL_ACCO_CTX_FINALIZE))
!= (FSL_ACCO_CTX_INIT | FSL_ACCO_CTX_FINALIZE)) {
ret = FSL_RETURN_BAD_FLAG_S;
goto out;
}
ret = load_ctr_key(&desc_chain, user_ctx, auth_ctx, cipher_key_info);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Decrypt the MAC which the user passed in */
header = SAH_HDR_SKHA_ENC_DEC;
DESC_IN_OUT(header,
auth_ctx->mac_length, auth_value,
auth_ctx->mac_length, auth_ctx->unencrypted_mac);
#ifndef NO_ZERO_IV_LOAD
ret = load_dummy_iv(&desc_chain, user_ctx, 1,
auth_ctx->auth_info.CCM_ctx_info.block_size_bytes);
#endif
if (auth_data_length > 0) {
ret = add_assoc_preamble(&desc_chain, user_ctx,
auth_ctx, auth_data, auth_data_length);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
}
/* if auth_data_length > 0 */
ret = process_payload(&desc_chain, user_ctx, 0,
payload_length, ct, payload);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Now pull CBC context (unencrypted MAC) out for comparison. */
/* Need to allocate a place for it, to handle non-blocking mode
* when this stack frame will disappear!
*/
calced_auth = DESC_TEMP_ALLOC(auth_ctx->mac_length);
ret = extract_mac(&desc_chain, user_ctx,
auth_ctx->mac_length, calced_auth);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
if (!blocking) {
/* get_results will need this for comparison */
desc_chain->out1_ptr = calced_auth;
desc_chain->out2_ptr = auth_ctx->unencrypted_mac;
desc_chain->out_len = auth_ctx->mac_length;
}
SAH_SF_EXECUTE();
if (blocking && (ret == FSL_RETURN_OK_S)) {
unsigned i;
/* Validate the auth code */
for (i = 0; i < auth_ctx->mac_length; i++) {
if (calced_auth[i] != auth_ctx->unencrypted_mac[i]) {
ret = FSL_RETURN_AUTH_FAILED_S;
break;
}
}
}
out:
SAH_SF_DESC_CLEAN();
DESC_TEMP_FREE(calced_auth);
(void)auth_key_info;
return ret;
} /* fsl_shw_gen_decrypt() */
/*!
* Perform unwrapping of a black key into a RED slot
*
* @param user_ctx A user context from #fsl_shw_register_user().
* @param[in,out] key_info The information about the key to be which will
* be unwrapped... key length, slot info, etc.
* @param black_key Encrypted key
*
* @return A return code of type #fsl_shw_return_t.
*/
static fsl_shw_return_t unwrap(fsl_shw_uco_t * user_ctx,
fsl_shw_sko_t * key_info,
const uint8_t * black_key)
{
SAH_SF_DCLS;
uint8_t *hmac = NULL;
fsl_shw_sko_t t_key_info;
sah_Link *link1 = NULL;
sah_Link *link2 = NULL;
unsigned i;
unsigned rounded_key_length;
unsigned original_key_length = key_info->key_length;
hmac = DESC_TEMP_ALLOC(ICV_LENGTH);
/* Set up key_info for "T" - use same slot as eventual key */
fsl_shw_sko_init(&t_key_info, FSL_KEY_ALG_AES);
t_key_info.userid = key_info->userid;
t_key_info.handle = key_info->handle;
t_key_info.flags = key_info->flags;
t_key_info.key_length = T_LENGTH;
t_key_info.keystore = key_info->keystore;
/* Validate SW flags to prevent misuse */
if ((key_info->flags & FSL_SKO_KEY_SW_KEY)
&& !(black_key[FLAGS_OFFSET] & FLAGS_SW_KEY)) {
ret = FSL_RETURN_BAD_FLAG_S;
goto out;
}
/* Compute T = SLID_decrypt(T'); leave in RED slot */
if (key_info->keystore == NULL) {
/* Key goes in system keystore */
ret = do_system_keystore_slot_decrypt(user_ctx,
key_info->userid,
t_key_info.handle,
T_LENGTH,
black_key + T_PRIME_OFFSET);
} else {
/* Key goes in user keystore */
ret = keystore_slot_decrypt(user_ctx,
key_info->keystore,
key_info->userid,
t_key_info.handle,
T_LENGTH,
black_key + T_PRIME_OFFSET);
}
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Compute ICV = HMAC(T, ownerid | len | alg | key' */
ret = create_icv_calc(user_ctx, &desc_chain, &t_key_info,
black_key, original_key_length, hmac);
if (ret != FSL_RETURN_OK_S) {
#ifdef DIAG_SECURITY_FUNC
LOG_DIAG("Creation of sah_Key_Link failed due to bad key"
" flag!\n");
#endif /*DIAG_SECURITY_FUNC */
goto out;
}
#ifdef DIAG_SECURITY_FUNC
LOG_DIAG("Validating MAC of wrapped key");
#endif
SAH_SF_EXECUTE();
if (ret != FSL_RETURN_OK_S) {
goto out;
}
SAH_SF_DESC_CLEAN();
/* Check computed ICV against value in Black Key */
for (i = 0; i < ICV_LENGTH; i++) {
if (black_key[ICV_OFFSET + i] != hmac[i]) {
#ifdef DIAG_SECURITY_FUNC
LOG_DIAG_ARGS("computed ICV fails at offset %i\n", i);
{
char buff[300];
int a;
for (a = 0; a < ICV_LENGTH; a++)
sprintf(&(buff[a * 2]), "%02x",
black_key[ICV_OFFSET + a]);
buff[a * 2 + 1] = 0;
LOG_DIAG_ARGS("black key: %s", buff);
for (a = 0; a < ICV_LENGTH; a++)
sprintf(&(buff[a * 2]), "%02x",
hmac[a]);
buff[a * 2 + 1] = 0;
LOG_DIAG_ARGS("hmac: %s", buff);
}
#endif
ret = FSL_RETURN_AUTH_FAILED_S;
goto out;
}
}
/* This is no longer needed. */
DESC_TEMP_FREE(hmac);
/* Compute KEK = SHA256(T | ownerid). Rewrite slot with value */
header = (SAH_HDR_MDHA_SET_MODE_HASH /* #8 */
^ sah_insert_mdha_init
^ sah_insert_mdha_algorithm_sha256 ^ sah_insert_mdha_pdata);
/* Input - Start with T */
ret = sah_Create_Key_Link(user_ctx->mem_util, &link1, &t_key_info);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Still input - append ownerid */
ret = sah_Append_Link(user_ctx->mem_util, link1,
(void *)&key_info->userid,
sizeof(key_info->userid), SAH_USES_LINK_DATA);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Output - KEK goes into RED slot */
ret = sah_Create_Key_Link(user_ctx->mem_util, &link2, &t_key_info);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Put the Hash calculation into the chain. */
ret = sah_Append_Desc(user_ctx->mem_util, &desc_chain,
header, link1, link2);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Compute KEY = AES-decrypt(KEK, KEY') */
header = (SAH_HDR_SKHA_SET_MODE_IV_KEY /* #1 */
^ sah_insert_skha_mode_ctr
^ sah_insert_skha_algorithm_aes
^ sah_insert_skha_modulus_128);
/* Load KEK in as the key to use */
DESC_IN_KEY(header, 0, NULL, &t_key_info);
rounded_key_length = ROUND_LENGTH(original_key_length);
key_info->key_length = rounded_key_length;
/* Now set up for computation. Result in RED */
header = SAH_HDR_SKHA_ENC_DEC; /* #4 */
DESC_IN_KEY(header, rounded_key_length, black_key + KEY_PRIME_OFFSET,
key_info);
/* Perform the operation */
#ifdef DIAG_SECURITY_FUNC
LOG_DIAG("Decrypting key with KEK");
#endif
SAH_SF_EXECUTE();
out:
key_info->key_length = original_key_length;
SAH_SF_DESC_CLEAN();
DESC_TEMP_FREE(hmac);
/* Erase tracks */
t_key_info.userid = 0xdeadbeef;
t_key_info.handle = 0xdeadbeef;
return ret;
} /* unwrap */
/*!
* @brief Authenticate and decrypt a (CCM) stream.
*
* @param user_ctx The user's context
* @param auth_ctx Info on this Auth operation
* @param cipher_key_info Key to encrypt payload
* @param auth_key_info (unused - same key in CCM)
* @param auth_data_length Length in bytes of @a auth_data
* @param auth_data Any auth-only data
* @param payload_length Length in bytes of @a payload
* @param ct The encrypted data
* @param auth_value The authentication code to validate
* @param[out] payload The location to store decrypted data
*
* @return A return code of type #fsl_shw_return_t.
*/
fsl_shw_return_t fsl_shw_auth_decrypt(fsl_shw_uco_t * user_ctx,
fsl_shw_acco_t * auth_ctx,
fsl_shw_sko_t * cipher_key_info,
fsl_shw_sko_t * auth_key_info,
uint32_t auth_data_length,
const uint8_t * auth_data,
uint32_t payload_length,
const uint8_t * ct,
const uint8_t * auth_value,
uint8_t * payload)
{
SAH_SF_DCLS;
#if defined(FSL_HAVE_SAHARA2) || defined(USE_S2_CCM_DECRYPT_CHAIN)
uint8_t *calced_auth = NULL;
unsigned blocking = user_ctx->flags & FSL_UCO_BLOCKING_MODE;
#endif
SAH_SF_USER_CHECK();
/* Only support CCM */
if (auth_ctx->mode != FSL_ACC_MODE_CCM) {
ret = FSL_RETURN_BAD_MODE_S;
goto out;
}
/* Only support INIT and FINALIZE flags right now. */
if ((auth_ctx->flags & (FSL_ACCO_CTX_INIT | FSL_ACCO_CTX_LOAD |
FSL_ACCO_CTX_SAVE | FSL_ACCO_CTX_FINALIZE))
!= (FSL_ACCO_CTX_INIT | FSL_ACCO_CTX_FINALIZE)) {
ret = FSL_RETURN_BAD_FLAG_S;
goto out;
}
/* Load CTR0 and Key */
header = SAH_HDR_SKHA_SET_MODE_IV_KEY
^ sah_insert_skha_mode_ctr ^ sah_insert_skha_modulus_128;
#if defined (FSL_HAVE_SAHARA4) && !defined (USE_S2_CCM_DECRYPT_CHAIN)
header ^= sah_insert_skha_aux0;
#endif
DESC_IN_KEY(header,
auth_ctx->cipher_ctx_info.block_size_bytes,
auth_ctx->cipher_ctx_info.context, cipher_key_info);
/* Decrypt the MAC which the user passed in */
header = SAH_HDR_SKHA_ENC_DEC;
DESC_IN_OUT(header,
auth_ctx->mac_length, auth_value,
auth_ctx->mac_length, auth_ctx->unencrypted_mac);
#if defined(FSL_HAVE_SAHARA2) || defined(USE_S2_CCM_DECRYPT_CHAIN)
#ifndef NO_ZERO_IV_LOAD
header = (SAH_HDR_SKHA_SET_MODE_IV_KEY
^ sah_insert_skha_encrypt ^ sah_insert_skha_mode_cbc);
DESC_IN_IN(header,
auth_ctx->auth_info.CCM_ctx_info.block_size_bytes,
block_zeros, 0, NULL);
#endif
#endif
ret = add_assoc_preamble(&desc_chain, user_ctx,
auth_ctx, 0, auth_data, auth_data_length);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
/* Process the payload */
header = (SAH_HDR_SKHA_SET_MODE_ENC_DEC
^ sah_insert_skha_mode_ccm ^ sah_insert_skha_modulus_128);
#if defined (FSL_HAVE_SAHARA4) && !defined (USE_S2_CCM_DECRYPT_CHAIN)
header ^= sah_insert_skha_aux0;
#endif
if (payload_length != 0) {
DESC_IN_OUT(header, payload_length, ct, payload_length,
payload);
} else {
DESC_IN_OUT(header, 0, NULL, 0, NULL);
}
#if defined (FSL_HAVE_SAHARA2) || defined (USE_S2_CCM_DECRYPT_CHAIN)
/* Now pull CBC context (unencrypted MAC) out for comparison. */
/* Need to allocate a place for it, to handle non-blocking mode
* when this stack frame will disappear!
*/
calced_auth = DESC_TEMP_ALLOC(auth_ctx->mac_length);
header = SAH_HDR_SKHA_READ_CONTEXT_IV;
DESC_OUT_OUT(header, 0, NULL, auth_ctx->mac_length, calced_auth);
if (!blocking) {
/* get_results will need this for comparison */
desc_chain->out1_ptr = calced_auth;
desc_chain->out2_ptr = auth_ctx->unencrypted_mac;
desc_chain->out_len = auth_ctx->mac_length;
}
#endif
SAH_SF_EXECUTE();
#if defined (FSL_HAVE_SAHARA2) || defined (USE_S2_CCM_DECRYPT_CHAIN)
if (blocking && (ret == FSL_RETURN_OK_S)) {
unsigned i;
/* Validate the auth code */
for (i = 0; i < auth_ctx->mac_length; i++) {
if (calced_auth[i] != auth_ctx->unencrypted_mac[i]) {
ret = FSL_RETURN_AUTH_FAILED_S;
break;
}
}
}
#endif
out:
SAH_SF_DESC_CLEAN();
#if defined (FSL_HAVE_SAHARA2) || defined (USE_S2_CCM_DECRYPT_CHAIN)
DESC_TEMP_FREE(calced_auth);
#endif
(void)auth_key_info;
return ret;
} /* fsl_shw_gen_decrypt() */
/*!
* Create and run the chain for a symmetric-key operation.
*
* @param user_ctx Who the user is
* @param key_info What key is to be used
* @param sym_ctx Info details about algorithm
* @param encrypt 0 = decrypt, non-zero = encrypt
* @param length Number of octets at @a in and @a out
* @param in Pointer to input data
* @param out Location to store output data
*
* @return The status of handing chain to driver,
* or an earlier argument/flag or allocation
* error.
*/
static fsl_shw_return_t do_symmetric(fsl_shw_uco_t * user_ctx,
fsl_shw_sko_t * key_info,
fsl_shw_scco_t * sym_ctx,
cipher_direction_t encrypt,
uint32_t length,
const uint8_t * in, uint8_t * out)
{
SAH_SF_DCLS;
uint8_t *sink = NULL;
sah_Link *link1 = NULL;
sah_Link *link2 = NULL;
sah_Oct_Str ptr1;
uint32_t size1 = sym_ctx->block_size_bytes;
SAH_SF_USER_CHECK();
/* Two different sets of chains, depending on algorithm */
if (key_info->algorithm == FSL_KEY_ALG_ARC4) {
if (sym_ctx->flags & FSL_SYM_CTX_INIT) {
/* Desc. #35 w/ARC4 - start from key */
header = SAH_HDR_ARC4_SET_MODE_KEY
^ sah_insert_skha_algorithm_arc4;
DESC_IN_KEY(header, 0, NULL, key_info);
} else { /* load SBox */
/* Desc. #33 w/ARC4 and NO PERMUTE */
header = SAH_HDR_ARC4_SET_MODE_SBOX
^ sah_insert_skha_no_permute
^ sah_insert_skha_algorithm_arc4;
DESC_IN_IN(header, 256, sym_ctx->context,
3, sym_ctx->context + 256);
} /* load SBox */
/* Add in-out data descriptor to process the data */
if (length != 0) {
DESC_IN_OUT(SAH_HDR_SKHA_ENC_DEC, length, in, length,
out);
}
/* Operation is done ... save what came out? */
if (sym_ctx->flags & FSL_SYM_CTX_SAVE) {
/* Desc. #34 - Read SBox, pointers */
header = SAH_HDR_ARC4_READ_SBOX;
DESC_OUT_OUT(header, 256, sym_ctx->context,
3, sym_ctx->context + 256);
}
} else { /* not ARC4 */
/* Doing 1- or 2- descriptor chain. */
/* Desc. #1 and algorithm and mode */
header = SAH_HDR_SKHA_SET_MODE_IV_KEY
^ sah_insert_skha_mode[sym_ctx->mode]
^ sah_insert_skha_algorithm[key_info->algorithm];
/* Honor 'no key parity checking' for DES and TDES */
if ((key_info->flags & FSL_SKO_KEY_IGNORE_PARITY) &&
((key_info->algorithm == FSL_KEY_ALG_DES) ||
(key_info->algorithm == FSL_KEY_ALG_TDES))) {
header ^= sah_insert_skha_no_key_parity;
}
/* Header by default is decrypting, so... */
if (encrypt == SYM_ENCRYPT) {
header ^= sah_insert_skha_encrypt;
}
if (sym_ctx->mode == FSL_SYM_MODE_CTR) {
header ^= sah_insert_skha_modulus[sym_ctx->modulus_exp];
}
if (sym_ctx->mode == FSL_SYM_MODE_ECB) {
ptr1 = NULL;
size1 = 0;
} else if (sym_ctx->flags & FSL_SYM_CTX_INIT) {
ptr1 = (uint8_t *) block_zeros;
} else {
ptr1 = sym_ctx->context;
}
DESC_IN_KEY(header, sym_ctx->block_size_bytes, ptr1, key_info);
/* Add in-out data descriptor */
if (length != 0) {
header = SAH_HDR_SKHA_ENC_DEC;
if (LENGTH_PATCH && (sym_ctx->mode == FSL_SYM_MODE_CTR)
&& ((length & LENGTH_PATCH_MASK) != 0)) {
sink = DESC_TEMP_ALLOC(LENGTH_PATCH);
ret =
sah_Create_Link(user_ctx->mem_util, &link1,
(uint8_t *) in, length,
SAH_USES_LINK_DATA);
ret =
sah_Append_Link(user_ctx->mem_util, link1,
(uint8_t *) sink,
LENGTH_PATCH -
(length &
LENGTH_PATCH_MASK),
SAH_USES_LINK_DATA);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
ret =
sah_Create_Link(user_ctx->mem_util, &link2,
out, length,
SAH_USES_LINK_DATA |
SAH_OUTPUT_LINK);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
ret = sah_Append_Link(user_ctx->mem_util, link2,
sink,
LENGTH_PATCH -
(length &
LENGTH_PATCH_MASK),
SAH_USES_LINK_DATA);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
ret =
sah_Append_Desc(user_ctx->mem_util,
&desc_chain, header, link1,
link2);
if (ret != FSL_RETURN_OK_S) {
goto out;
}
link1 = link2 = NULL;
} else {
DESC_IN_OUT(header, length, in, length, out);
}
}
/* Unload any desired context */
if (sym_ctx->flags & FSL_SYM_CTX_SAVE) {
DESC_OUT_OUT(SAH_HDR_SKHA_READ_CONTEXT_IV, 0, NULL,
sym_ctx->block_size_bytes,
sym_ctx->context);
}
} /* not ARC4 */
SAH_SF_EXECUTE();
out:
SAH_SF_DESC_CLEAN();
DESC_TEMP_FREE(sink);
if (LENGTH_PATCH) {
sah_Destroy_Link(user_ctx->mem_util, link1);
sah_Destroy_Link(user_ctx->mem_util, link2);
}
return ret;
}