解析从网易云音乐下载的歌曲的注释(comment)

注释在哪？

一般都在歌曲信息中的Commenttag里

163 key(Don't modify):cEgtqHxwpdRKcBCRPBlPktlHhmrTcizixpMvRszN1/sZ0gy+N274P2oM4whlpjf68/CYfBUMSElfSAgEmYkCQmlEYxdk+sa5nTNnLYD4I/bhISnv3oWNkuPcFHCrKpXn5bK99KPYVBa9GWHSdIQ9iAPk3OvoJgDi7ZOaIGL0HRoavADBJTVIaucFJJpEKEgFJSTKOS/rPJCugJZfDvu1HMx7aZY51kPCnSYf6eZu+zAEJrClm8yr8qsRUQSHV4i04gSqSgkVsi6l2rehn+71/HceHpuFZ+5Hxe8tYopPGnoU0+3JCKdgVMytrPGmXQCmrJYjp67MD6hT+yYmNq2t0FIbJuHl/wFSUgiICpV2L8WqQ9gynXkcD2TIMVFGsq5HsOzGe/XsriuT50Hhsc25M8BsOle3HohsQ4/ck4CmWpKJ/RXhbEbR3JdJD7FgjurJ/7qGh/cjJal34h7VbXiuB9P9ZQs2+5ivQ6ce7hKSKxQ=

格式是：163 key(Don't modify): + 加密代码

有什么用？

网易云音乐会根据comment信息将歌曲文件与其服务器资源匹配，要不然你以为你播放的从网易云音乐下载的本地音乐是怎么有歌词的(解析comment获取歌曲信息后拉取本地缓存或服务器资源)

解密过程

AES解密

Text : 163 key(Don't modify)后面的所有字符串
Format : Base64
Mode : ECB
Key Size : 128
Serect Key : #14ljk_!\]&0U<'(

结果：

cEgtqHxwpdRKcBCRPBlPktlHhmrTcizixpMvRszN1/sZ0gy+N274P2oM4whlpjf68/CYfBUMSElfSAgEmYkCQmlEYxdk+sa5nTNnLYD4I/bhISnv3oWNkuPcFHCrKpXn5bK99KPYVBa9GWHSdIQ9iAPk3OvoJgDi7ZOaIGL0HRoavADBJTVIaucFJJpEKEgFJSTKOS/rPJCugJZfDvu1HMx7aZY51kPCnSYf6eZu+zAEJrClm8yr8qsRUQSHV4i04gSqSgkVsi6l2rehn+71/HceHpuFZ+5Hxe8tYopPGnoU0+3JCKdgVMytrPGmXQCmrJYjp67MD6hT+yYmNq2t0FIbJuHl/wFSUgiICpV2L8WqQ9gynXkcD2TIMVFGsq5HsOzGe/XsriuT50Hhsc25M8BsOle3HohsQ4/ck4CmWpKJ/RXhbEbR3JdJD7FgjurJ/7qGh/cjJal34h7VbXiuB9P9ZQs2+5ivQ6ce7hKSKxQ=

↓

bXVzaWM6eyJmb3JtYXQiOiJmbGFjIiwibXVzaWNJZCI6Mjg5NDE3MTEsIm11c2ljTmFtZSI6ImRyb3AgcG9wIGNhbmR5IiwiYXJ0aXN0IjpbWyLjgozjgpLjgosiLDk5MDI4OV0sWyLjgq7jgqxQIiw4MDQzNTVdXSwiYWxidW0iOiJObyB0aXRsZeKIkiIsImFsYnVtSWQiOjI5NDMzNjMsImFsYnVtUGljRG9jSWQiOjg4OTI4NTAwNDU3OTQ4OTMsImFsYnVtUGljIjoiaHR0cDpcL1wvcDIubXVzaWMuMTI2Lm5ldFwvY1pQeDNwZUdUdVdFSV9HYVpCNUNEZz09XC84ODkyODUwMDQ1Nzk0ODkzLmpwZyIsIm12SWQiOjAsImZsYWciOjAsImJpdHJhdGUiOjExOTM5ODQsImR1cmF0aW9uIjoyMjQ5NzMsImFsaWFzIjpbXSwidHJhbnNOYW1lcyI6W119

Base64解密

Text : AES解密后的字符串

结果：

bXVzaWM6eyJmb3JtYXQiOiJmbGFjIiwibXVzaWNJZCI6Mjg5NDE3MTEsIm11c2ljTmFtZSI6ImRyb3AgcG9wIGNhbmR5IiwiYXJ0aXN0IjpbWyLjgozjgpLjgosiLDk5MDI4OV0sWyLjgq7jgqxQIiw4MDQzNTVdXSwiYWxidW0iOiJObyB0aXRsZeKIkiIsImFsYnVtSWQiOjI5NDMzNjMsImFsYnVtUGljRG9jSWQiOjg4OTI4NTAwNDU3OTQ4OTMsImFsYnVtUGljIjoiaHR0cDpcL1wvcDIubXVzaWMuMTI2Lm5ldFwvY1pQeDNwZUdUdVdFSV9HYVpCNUNEZz09XC84ODkyODUwMDQ1Nzk0ODkzLmpwZyIsIm12SWQiOjAsImZsYWciOjAsImJpdHJhdGUiOjExOTM5ODQsImR1cmF0aW9uIjoyMjQ5NzMsImFsaWFzIjpbXSwidHJhbnNOYW1lcyI6W119

↓

music: {
	"format": "flac",
	"musicId": 28941711,
	"musicName": "drop pop candy",
	"artist": [
		["れをる", 990289],
		["ギガP", 804355]
	],
	"album": "No title−",
	"albumId": 2943363,
	"albumPicDocId": 8892850045794893,
	"albumPic": "http:\/\/p2.music.126.net\/cZPx3peGTuWEI_GaZB5CDg==\/8892850045794893.jpg",
	"mvId": 0,
	"flag": 0,
	"bitrate": 1193984,
	"duration": 224973,
	"alias": [],
	"transNames": []
}