diff options
Diffstat (limited to 'stack/gatt/gatt_auth.c')
| -rw-r--r-- | stack/gatt/gatt_auth.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/stack/gatt/gatt_auth.c b/stack/gatt/gatt_auth.c new file mode 100644 index 0000000..de0c14f --- /dev/null +++ b/stack/gatt/gatt_auth.c @@ -0,0 +1,448 @@ +/****************************************************************************** + * + * Copyright (C) 1999-2012 Broadcom Corporation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + ******************************************************************************/ + +/****************************************************************************** + * + * this file contains GATT authentication handling functions + * + ******************************************************************************/ +#include "bt_target.h" + +#if BLE_INCLUDED == TRUE +#include <string.h> +#include "gki.h" + +#include "gatt_int.h" +#include "gatt_api.h" +#include "btm_int.h" + +/******************************************************************************* +** +** Function gatt_sign_data +** +** Description This function sign the data for write command. +** +** Returns TRUE if encrypted, otherwise FALSE. +** +*******************************************************************************/ +static BOOLEAN gatt_sign_data (tGATT_CLCB *p_clcb) +{ + tGATT_VALUE *p_attr = (tGATT_VALUE *)p_clcb->p_attr_buf; + UINT8 *p_data = NULL, *p; + UINT16 payload_size = p_clcb->p_tcb->payload_size; + BOOLEAN status = FALSE; + UINT8 *p_signature; + + p_data = (UINT8 *)GKI_getbuf((UINT16)(p_attr->len + 3)); /* 3 = 2 byte handle + opcode */ + + if (p_data != NULL) + { + p = p_data; + UINT8_TO_STREAM(p, GATT_SIGN_CMD_WRITE); + UINT16_TO_STREAM(p, p_attr->handle); + ARRAY_TO_STREAM(p, p_attr->value, p_attr->len); + + /* sign data length should be attribulte value length plus 2B handle + 1B op code */ + if ((payload_size - GATT_AUTH_SIGN_LEN - 3) < p_attr->len) + p_attr->len = payload_size - GATT_AUTH_SIGN_LEN - 3; + + p_signature = p_attr->value + p_attr->len; + if (BTM_BleDataSignature(p_clcb->p_tcb->peer_bda, + p_data, + (UINT16)(p_attr->len + 3), /* 3 = 2 byte handle + opcode */ + p_signature)) + { + p_attr->len += BTM_BLE_AUTH_SIGN_LEN; + gatt_set_ch_state(p_clcb->p_tcb, GATT_CH_OPEN); + gatt_act_write(p_clcb); + } + else + { + gatt_end_operation(p_clcb, GATT_INTERNAL_ERROR, NULL); + } + + GKI_freebuf(p_data); + } + + return status; +} + +/******************************************************************************* +** +** Function gatt_verify_signature +** +** Description This function start to verify the sign data when receiving +** the data from peer device. +** +** Returns +** +*******************************************************************************/ +void gatt_verify_signature(tGATT_TCB *p_tcb, BT_HDR *p_buf) +{ + UINT16 cmd_len; + UINT8 op_code; + UINT8 *p, *p_orig = (UINT8 *)(p_buf + 1) + p_buf->offset; + UINT32 counter; + + cmd_len = p_buf->len - GATT_AUTH_SIGN_LEN + 4; + p = p_orig + cmd_len - 4; + STREAM_TO_UINT32(counter, p); + + if (BTM_BleVerifySignature(p_tcb->peer_bda, p_orig, cmd_len, counter, p)) + { + STREAM_TO_UINT8(op_code, p_orig); + gatt_server_handle_client_req (p_tcb, op_code, (UINT16)(p_buf->len - 1), p_orig); + } + else + { + /* if this is a bad signature, assume from attacker, ignore it */ + GATT_TRACE_ERROR0("Signature Verification Failed"); + gatt_disconnect(p_tcb->peer_bda); + } + + return; +} +/******************************************************************************* +** +** Function gatt_sec_check_complete +** +** Description security check complete and proceed to data sending action. +** +** Returns void. +** +*******************************************************************************/ +void gatt_sec_check_complete(BOOLEAN sec_check_ok, tGATT_CLCB *p_clcb) +{ + p_clcb->p_tcb->p_clcb = NULL; + gatt_set_sec_act(p_clcb->p_tcb, GATT_SEC_NONE); + + if (!sec_check_ok) + { + gatt_end_operation(p_clcb, GATT_AUTH_FAIL, NULL); + } + else if (p_clcb->operation == GATTC_OPTYPE_WRITE) + { + gatt_act_write(p_clcb); + } + else if (p_clcb->operation == GATTC_OPTYPE_READ) + { + gatt_act_read(p_clcb, p_clcb->counter); + } +} +/******************************************************************************* +** +** Function gatt_enc_cmpl_cback +** +** Description link encryption complete callback. +** +** Returns +** +*******************************************************************************/ +void gatt_enc_cmpl_cback(BD_ADDR bd_addr, void *p_ref_data, tBTM_STATUS result) +{ + tGATT_TCB *p_tcb; + UINT8 sec_flag; + BOOLEAN status = FALSE; + + GATT_TRACE_DEBUG0("gatt_enc_cmpl_cback"); + if ((p_tcb = gatt_find_tcb_by_addr(bd_addr)) != NULL) + { + gatt_set_ch_state(p_tcb, GATT_CH_OPEN); + + if (result == BTM_SUCCESS) + { + if (gatt_get_sec_act(p_tcb) == GATT_SEC_ENCRYPT_MITM ) + { + BTM_GetSecurityFlags(bd_addr, &sec_flag); + if (sec_flag & sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) + { + status = TRUE; + } + } + else + { + status = TRUE; + } + } + gatt_sec_check_complete(status , (tGATT_CLCB *)p_tcb->p_clcb); + } + else + { + GATT_TRACE_ERROR0("enc callback for unknown bd_addr"); + } +} + +/******************************************************************************* +** +** Function gatt_set_sec_act +** +** Description This function set the sec_act in clcb +** +** Returns none +** +*******************************************************************************/ +void gatt_set_sec_act(tGATT_TCB *p_tcb, tGATT_SEC_ACTION sec_act) +{ + if (p_tcb) + { + p_tcb->sec_act = sec_act; + } +} +/******************************************************************************* +** +** Function gatt_get_sec_act +** +** Description This function get the sec_act in clcb +** +** Returns none +** +*******************************************************************************/ +tGATT_SEC_ACTION gatt_get_sec_act(tGATT_TCB *p_tcb) +{ + tGATT_SEC_ACTION sec_act = GATT_SEC_NONE; + if (p_tcb) + { + sec_act = p_tcb->sec_act; + } + return sec_act; +} +/******************************************************************************* +** +** Function gatt_determine_sec_act +** +** Description This routine determine the security action based on auth_request and +** current link status +** +** Returns tGATT_SEC_ACTION security action +** +*******************************************************************************/ +tGATT_SEC_ACTION gatt_determine_sec_act(tGATT_CLCB *p_clcb ) +{ + tGATT_SEC_ACTION act = GATT_SEC_OK; + UINT8 sec_flag; + tGATT_TCB *p_tcb = p_clcb->p_tcb; + tGATT_AUTH_REQ auth_req = p_clcb->auth_req; + + BOOLEAN is_link_encrypted= FALSE; + BOOLEAN is_le_link=FALSE; + BOOLEAN is_link_key_known=FALSE; + BOOLEAN is_key_mitm=FALSE; + UINT8 key_type; + + if (auth_req == GATT_AUTH_REQ_NONE ) + return act; + + is_le_link = btm_ble_check_link_type(p_tcb->peer_bda); + BTM_GetSecurityFlags(p_tcb->peer_bda, &sec_flag); + + if (sec_flag & BTM_SEC_FLAG_ENCRYPTED) + { + is_link_encrypted = TRUE; + } + if (sec_flag & BTM_SEC_FLAG_LKEY_KNOWN) + { + is_link_key_known = TRUE; + if (sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) + { + is_key_mitm = TRUE; + } + } + + /* first check link key upgrade required or not */ + switch (auth_req) + { + case GATT_AUTH_REQ_MITM: + case GATT_AUTH_REQ_SIGNED_MITM: + if (!is_key_mitm) + act = GATT_SEC_ENCRYPT_MITM; + break; + + case GATT_AUTH_REQ_NO_MITM: + case GATT_AUTH_REQ_SIGNED_NO_MITM: + if (!is_link_key_known) + act = GATT_SEC_ENCRYPT_NO_MITM; + break; + default: + break; + } + + /* now check link needs to be encrypted or not if the link key upgrade is not required */ + if (act == GATT_SEC_OK) + { + if (is_le_link && + (p_clcb->operation == GATTC_OPTYPE_WRITE) && + (p_clcb->op_subtype == GATT_WRITE_NO_RSP)) + { + /* this is a write command request + check data signing required or not */ + if (!is_link_encrypted) + { + btm_ble_get_enc_key_type(p_tcb->peer_bda, &key_type); + + if ( (key_type & BTM_LE_KEY_LCSRK) && + ((auth_req == GATT_AUTH_REQ_SIGNED_NO_MITM) || + (auth_req == GATT_AUTH_REQ_SIGNED_MITM))) + { + act = GATT_SEC_SIGN_DATA; + } + else + { + act = GATT_SEC_ENCRYPT; + } + } + } + else + { + if (!is_link_encrypted) + { + act = GATT_SEC_ENCRYPT; + } + } + + } + + return act ; + +} + + + +/******************************************************************************* +** +** Function gatt_get_link_encrypt_status +** +** Description This routine get the encryption status of the specified link +** +** +** Returns tGATT_STATUS link encryption status +** +*******************************************************************************/ +tGATT_STATUS gatt_get_link_encrypt_status(tGATT_TCB *p_tcb) +{ + tGATT_STATUS encrypt_status = GATT_NOT_ENCRYPTED; + UINT8 sec_flag=0; + + BTM_GetSecurityFlags(p_tcb->peer_bda, &sec_flag); + + if ((sec_flag & BTM_SEC_FLAG_ENCRYPTED) && (sec_flag & BTM_SEC_FLAG_LKEY_KNOWN)) + { + encrypt_status = GATT_ENCRYPED_NO_MITM; + if (sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) + encrypt_status = GATT_ENCRYPED_MITM; + } + + GATT_TRACE_DEBUG1("gatt_get_link_encrypt_status status=0x%x",encrypt_status); + return encrypt_status ; +} + + +/******************************************************************************* +** +** Function gatt_convert_sec_action +** +** Description Convert GATT security action enum into equivalent BTM BLE security action enum +** +** Returns BOOLEAN TRUE - conversation is successful +** +*******************************************************************************/ +static BOOLEAN gatt_convert_sec_action(tGATT_SEC_ACTION gatt_sec_act, tBTM_BLE_SEC_ACT *p_btm_sec_act ) +{ + BOOLEAN status = TRUE; + switch (gatt_sec_act) + { + case GATT_SEC_ENCRYPT: + *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT; + break; + case GATT_SEC_ENCRYPT_NO_MITM: + *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT_NO_MITM; + break; + case GATT_SEC_ENCRYPT_MITM: + *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT_MITM; + break; + default: + status = FALSE; + break; + } + + return status; +} +/******************************************************************************* +** +** Function gatt_check_enc_req +** +** Description check link security. +** +** Returns TRUE if encrypted, otherwise FALSE. +** +*******************************************************************************/ +BOOLEAN gatt_security_check_start(tGATT_CLCB *p_clcb) +{ + tGATT_TCB *p_tcb = p_clcb->p_tcb; + tGATT_SEC_ACTION gatt_sec_act; + tBTM_BLE_SEC_ACT btm_ble_sec_act; + BOOLEAN status = TRUE; + tBTM_STATUS btm_status; + + if ( gatt_get_ch_state(p_tcb) == GATT_CH_OPEN) + { + gatt_sec_act = gatt_determine_sec_act(p_clcb); + gatt_set_sec_act(p_tcb, gatt_sec_act); + switch (gatt_sec_act ) + { + case GATT_SEC_SIGN_DATA: + GATT_TRACE_DEBUG0("gatt_security_check_start: Do data signing"); + gatt_set_ch_state(p_tcb, GATT_CH_W4_DATA_SIGN_COMP); + gatt_sign_data(p_clcb); + break; + case GATT_SEC_ENCRYPT: + case GATT_SEC_ENCRYPT_NO_MITM: + case GATT_SEC_ENCRYPT_MITM: + GATT_TRACE_DEBUG0("gatt_security_check_start: Encrypt now or key upgreade first"); + gatt_convert_sec_action(p_tcb->sec_act, &btm_ble_sec_act); + gatt_set_ch_state(p_tcb, GATT_CH_W4_SEC_COMP); + p_tcb->p_clcb = p_clcb; /* keep the clcb pointer in CCB */ + btm_status = BTM_SetEncryption(p_tcb->peer_bda, gatt_enc_cmpl_cback, &btm_ble_sec_act); + if ( (btm_status != BTM_SUCCESS) && (btm_status != BTM_CMD_STARTED)) + { + GATT_TRACE_ERROR1("gatt_security_check_start BTM_SetEncryption failed btm_status=%d", btm_status); + p_tcb->p_clcb = NULL; + status = FALSE; + } + break; + default: + gatt_sec_check_complete(TRUE, p_clcb); + break; + } + + if (status == FALSE) + { + gatt_set_sec_act(p_tcb, GATT_SEC_NONE); + gatt_set_ch_state(p_tcb, GATT_CH_OPEN); + } + } + else + { + GATT_TRACE_ERROR0("gatt_security_check_start channel not open"); + status = FALSE; + } + + return status; +} + + +#endif /* BLE_INCLUDED */ |