阜阳网站制作公司去哪找,网站制作公司承担,设计素材网站哪个最好推荐,如何上传网站到空间1 ZRTP源码下载
这里采用的是libzrtp来自于freeswitch#xff1a;libs/libzrtp。
2 ZRTP交叉编译
zrtp编译比较简单#xff0c;采用configure进行编译在根目录心中zrtp编译脚本#xff0c;只需要指定交叉编译工具链和安装地址即可。脚本如下所示#xff1a;
unset CC C…1 ZRTP源码下载
这里采用的是libzrtp来自于freeswitchlibs/libzrtp。
2 ZRTP交叉编译
zrtp编译比较简单采用configure进行编译在根目录心中zrtp编译脚本只需要指定交叉编译工具链和安装地址即可。脚本如下所示
unset CC CFLAGS LDFLAGS CPPFLAGS CPP LD STRIP
./configure --hostarm-linux-androideabi --prefixpwd/../objects/ 成果物如下所示include和lib库
3 ZRTP移植
zrtp移植主要对zrtp库进行封装对外提供初始化和加密解密能力。接口设计如下
3.1 API设计
typedef void ZrtpEventObserver(int id, BOOL encrypt);typedef struct zrtp_handle_t zrtp_handle_t;typedef struct zrtp_handle_t{//加密rtpvoid (*encrypt_rtp)(zrtp_handle_t *pthis, int channel, unsigned char* in_data,unsigned char* out_data,int bytes_in, int* bytes_out);//解密rtpvoid (*decrypt_rtp)(zrtp_handle_t *pthis, int channel, unsigned char* in_data, unsigned char* out_data, int bytes_in, int* bytes_out);//加密rtcpvoid (*encrypt_rtcp)(zrtp_handle_t *pthis, int channel, unsigned char* in_data,unsigned char* out_data, int bytes_in,int* bytes_out);//解密rtcpvoid (*decrypt_rtcp)(zrtp_handle_t *pthis, int channel, unsigned char* in_data, unsigned char* out_data, int bytes_in, int* bytes_out);BOOL (*is_enabled)(zrtp_handle_t *pthis);void *priv;
}zrtp_handle_t;//构建zrtp会话
int zrtp_handle_alloc(zrtp_handle_t **ppthis, const WebRtc_Word32 id, ZrtpEventObserver *observer);
//释放zrtp会话
void zrtp_handle_free(zrtp_handle_t *pthis);
//初始化
int zrtp_handle_init();
//反初始化
void zrtp_handle_denit();3.2 初始化
初始化只需要初始化一次初始化需要注册发送回调函数这里协商发送的数据包构造好后最终是有这个接口on_send_packet返回到应用发送。
int zrtp_handle_init()
{zrtp_config_defaults(g_zrtp_config);zrtp_randstr2((unsigned char *)g_zrtp_config.client_id, sizeof(zrtp_client_id_t));
// zrtp_randstr2((unsigned char *)g_zrtp_config.zid, sizeof(zrtp_zid_t));g_zrtp_config.lic_mode ZRTP_LICENSE_MODE_ACTIVE;g_zrtp_config.cb.misc_cb.on_send_packet on_send_packet;g_zrtp_config.cb.event_cb.on_zrtp_protocol_event on_zrtp_protocol_event;g_zrtp_config.cb.event_cb.on_zrtp_security_event on_zrtp_security_event;g_zrtp_config.cb.event_cb.on_zrtp_secure on_zrtp_secure;g_zrtp_config.cb.event_cb.on_zrtp_not_secure on_zrtp_not_secure;zrtp_status_t s zrtp_init(g_zrtp_config, g_pzrtp_global);if (zrtp_status_ok ! s) {printf(ZRTP init failed, status %d \n, s);return -1;}return 0;
}void zrtp_handle_denit()
{if (NULL ! g_pzrtp_global) {zrtp_down(g_pzrtp_global);g_pzrtp_global NULL;}
}3.3 会话实例
每一路会话需要实例化一个zrtphandle对象需要传入一个随机的zrtpid和观察者。
int zrtp_handle_alloc(zrtp_handle_t **ppthis, const WebRtc_Word32 id, ZrtpEventObserver *observer)
{if(!ppthis)return -1; zrtp_handle_t *phl (zrtp_handle_t *)malloc(sizeof(zrtp_handle_t)); if(!phl){return -1;}priv_t *ppriv (priv_t *)malloc(sizeof(priv_t)); if(!ppriv){free(phl);return -1;}memset(phl, 0, sizeof(zrtp_handle_t));memset(ppriv, 0, sizeof(priv_t));phl-priv ppriv; ppriv-__zrtp_session NULL;ppriv-__zrtp_audio NULL;ppriv-__lSSRC 0;ppriv-__rSSRC 0;ppriv-__stream_seq 0;ppriv-__stream_timestamp 0;ppriv-__is_first_start_stream 0;ppriv-__is_need_send_hello 0;ppriv-__is_zrtp_enable 0;ppriv-__obverserptr observer;ppriv-id id;ppriv-__buffer_out_data (char *)malloc(IP_PACKET_SIZE);phl-audio_encrypt_rtp encrypt;phl-audio_decrypt_rtp decrypt;phl-audio_encrypt_rtcp encrypt_rtcp;phl-audio_decrypt_rtcp decrypt_rtcp;*ppthis phl;return 0;
}void zrtp_handle_free(zrtp_handle_t *pthis)
{if(!pthis)return;DisableZsrtp(pthis);priv_t *ppriv pthis-priv;if (NULL ! ppriv-__buffer_out_data) {free(ppriv-__buffer_out_data);ppriv-__buffer_out_data NULL;}if (pthis-priv){free(pthis-priv);pthis-priv NULL;} free(pthis);pthis NULL;
}3.4 加解密实现
加解密会用首先会进入到协商流程zrtp_stream_start完成协商之后再进入加解密流程zrtp_process_rtp。
int encrypt(zrtp_handle_t *pthis,int channel,unsigned char* in_data,unsigned char* out_data,int bytes_in,int* bytes_out) {priv_t *ppriv pthis-priv;if (!ppriv-__is_zrtp_enable || NULL in_data || NULL out_data|| 0 bytes_in || NULL bytes_out) {// invalidreturn 0;}if(ppriv-__is_need_send_hello){zrtp_stream_start(ppriv-__zrtp_audio, ppriv-__lSSRC);ppriv-__is_need_send_hello RL_FALSE;}if(!ppriv-__buffer_out_data_consumed){ppriv-__buffer_out_data_retry;memcpy(out_data, ppriv-__buffer_out_data, ppriv-__buffer_out_data_bytes);*bytes_out ppriv-__buffer_out_data_bytes;ppriv-__buffer_out_data_consumed RL_TRUE;return 0;}if (-1 ppriv-__voice_encrypt_status ppriv-__buffer_out_data_retry ZRTP_COUNT_THRESHOLD_DEFAULT){// LinKy: Rollback to unecrypt, this operation will close zrtp session!UpdateEncryptStatus(pthis, RL_FALSE);//return 0;}if (ppriv-__zrtp_audio-state ! ZRTP_STATE_SECURE) {// Not ready, use original data memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 1;}char packet[IP_PACKET_SIZE];ZRTP_UNALIGNED(zrtp_rtp_hdr_t) *rtp_hdr (zrtp_rtp_hdr_t*)packet;/* Fill RTP Header according to the specification */zrtp_memset(rtp_hdr, 0, sizeof(zrtp_rtp_hdr_t));rtp_hdr-version 2; /* Current RTP version 2 */rtp_hdr-pt 0; /* PCMU padding type */rtp_hdr-ssrc zrtp_hton32(ppriv-__lSSRC); /* Use stream Identifier as its SSRC */if (ppriv-__stream_seq 0xFFFF) {ppriv-__stream_seq 0;}rtp_hdr-seq libzrtp_swap16(ppriv-__stream_seq);rtp_hdr-ts zrtp_hton32(ppriv-__stream_timestamp);ppriv-__stream_timestamp 20; // LinKy: Assume the interval is 20mszrtp_memcpy(packet sizeof(zrtp_rtp_hdr_t), in_data, bytes_in);unsigned int size sizeof(zrtp_rtp_hdr_t) bytes_in;zrtp_status_t s zrtp_process_rtp(ppriv-__zrtp_audio, packet, size);switch (s) {case zrtp_status_ok: {//// Packet was successfully decrypted. Dont forget that packet// size was changed during decryption. New size now in size //memcpy(out_data, packet, size);*bytes_out size;return 2;}break;case zrtp_status_drop: {//// This is a protocol ZRTP packet or masked RTP media.// In either case the packet must be dropped to protect your // private data and media codec// LinKy: Shall we rollback to unencrypt here?return 3;}break;case zrtp_status_fail: {//// This is some kind of error - see logs for more information.// Dont put such packet to the network. It is not secure.//memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 4;}break;}return 0;
}int decrypt(zrtp_handle_t *pthis,int channel,unsigned char* in_data,unsigned char* out_data,int bytes_in,int* bytes_out) {unsigned int size bytes_in;priv_t *ppriv pthis-priv;if (!ppriv-__is_zrtp_enable || NULL in_data || NULL out_data|| 0 bytes_in || NULL bytes_out) {// invalidreturn 0;}if(ppriv-__is_need_send_hello){zrtp_stream_start(ppriv-__zrtp_audio, ppriv-__lSSRC);ppriv-__is_need_send_hello RL_FALSE;}//if zrtp success,ppriv-__buffer_in_data_retry Approximately equals 18;if (-1 ppriv-__voice_encrypt_status ppriv-__buffer_in_data_retry ZRTP_COUNT_THRESHOLD_DEFAULT){//if (ppriv-__zrtp_audio-state ! ZRTP_STATE_SECURE){// Not ready, use original datamemcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 1;}else if(ppriv-__voice_encrypt_status 0){memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 1;}ppriv-__buffer_in_data_retry;char packet[IP_PACKET_SIZE];memcpy(packet, in_data, bytes_in);zrtp_status_t s zrtp_process_srtp(ppriv-__zrtp_audio, packet, size);switch (s) {case zrtp_status_ok: {//// Packet was successfully decrypted. Dont forget that packet// size was changed during decryption. New size now in size //char *body packet sizeof(zrtp_rtp_hdr_t);memcpy(out_data, body, size - sizeof(zrtp_rtp_hdr_t));*bytes_out size - sizeof(zrtp_rtp_hdr_t);return 2;}break;case zrtp_status_drop: {//// This is a protocol ZRTP packet or masked RTP media.// In either case the packet must be dropped to protect your // private data and media codec// LinKy: Yep, we drop it, use original data to play!memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 3;}break;case zrtp_status_fail: {//// This is some kind of error - see logs for more information.// Dont put such packet to the network. It is not secure.//// LinKy: Be careful! This may cause noise if data is encrypted actually!memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return 4;}break;}return 0;
}void encrypt_rtcp(zrtp_handle_t *pthis,int channel,unsigned char* in_data,unsigned char* out_data,int bytes_in,int* bytes_out) {priv_t *ppriv pthis-priv;unsigned int size bytes_in;if (!ppriv-__is_zrtp_enable || NULL in_data || NULL out_data|| 0 bytes_in || NULL bytes_out) {// invalidreturn;}if(ppriv-__is_need_send_hello){zrtp_stream_start(ppriv-__zrtp_audio, ppriv-__lSSRC);ppriv-__is_need_send_hello RL_FALSE;}if (ppriv-__zrtp_audio-state ! ZRTP_STATE_SECURE) {// Not ready, use original datamemcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return;}char packet[IP_PACKET_SIZE];ZRTP_UNALIGNED(zrtp_rtcp_hdr_t) *rtcp_hdr (zrtp_rtcp_hdr_t*)packet;/* Fill RTCP Header according to the specification */rtcp_hdr-rc 0;rtcp_hdr-version 2;rtcp_hdr-ssrc zrtp_hton32(ppriv-__lSSRC);/* Get RTP body from PGP words lists. Put RTCP marker at the beginning */zrtp_memcpy(packet sizeof(zrtp_rtcp_hdr_t), RTCP, 4); zrtp_memcpy(packet sizeof(zrtp_rtcp_hdr_t) 4, in_data, bytes_in);size sizeof(zrtp_rtcp_hdr_t) bytes_in 4;/* RTCP packets sould be 32 byes aligned */size (size % 4) ? (4 - size % 4) : 0;zrtp_status_t s zrtp_process_rtcp(ppriv-__zrtp_audio, packet, size);switch (s) {case zrtp_status_ok: {//// Packet was successfully decrypted. Dont forget that packet// size was changed during decryption. New size now in size //memcpy(out_data, packet, size);*bytes_out size;}break;case zrtp_status_drop: {//// This is a protocol ZRTP packet or masked RTP media.// In either case the packet must be dropped to protect your // private data and media codec// LinKy: Shall we rollback to unencrypt here?}break;case zrtp_status_fail: {//// This is some kind of error - see logs for more information.// Dont put such packet to the network. It is not secure.//memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;}break;}
}void decrypt_rtcp(zrtp_handle_t *pthis,int channel,unsigned char* in_data,unsigned char* out_data,int bytes_in,int* bytes_out) {priv_t *ppriv pthis-priv;unsigned int size bytes_in;if (!ppriv-__is_zrtp_enable || NULL in_data || NULL out_data|| 0 bytes_in || NULL bytes_out) {// invalidreturn;}if(ppriv-__is_first_start_stream){zrtp_stream_start(ppriv-__zrtp_audio, channel);ppriv-__is_first_start_stream RL_FALSE;}if (ppriv-__zrtp_audio-state ! ZRTP_STATE_SECURE) {// Not ready, use original datamemcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;return;}char packet[IP_PACKET_SIZE];memcpy(packet,in_data,bytes_in);zrtp_status_t s zrtp_process_srtcp(ppriv-__zrtp_audio, packet, size);switch (s) {case zrtp_status_ok: {//// Packet was successfully decrypted. Dont forget that packet// size was changed during decryption. New size now in size //char *body packet sizeof(zrtp_rtp_hdr_t);memcpy(out_data, body, size - sizeof(zrtp_rtp_hdr_t));*bytes_out size - sizeof(zrtp_rtp_hdr_t);}break;case zrtp_status_drop: {//// This is a protocol ZRTP packet or masked RTP media.// In either case the packet must be dropped to protect your // private data and media codec// LinKy: Yep, we drop it, use original data to play!memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;}break;case zrtp_status_fail: {//// This is some kind of error - see logs for more information.// Dont put such packet to the network. It is not secure.//// LinKy: Be careful! This may cause noise if data is encrypted actually!memcpy(out_data, in_data, bytes_in);*bytes_out bytes_in;}break;}
}4 ZRTP抓包分析
一个完整的ZRTP协商流程首先是hello进双方加密方式的交换之后会进行一个收到的应答然后是commit消息确认HMAC秘钥DHPart消息交换公钥Confirm消息确认签名最后是ConfACK应答。下面是wareshark抓包显示的交互流程。
