Openssl asn1parse命令

openssl asn1parse [-inform PEM|DER] [-in filename] [-out filename] [-noout] [-offset number] [-length number] [-i] [- structure filename] [-strparse offset]

-inform arg   input format - one of DER PEM
 -in arg       input file
 -out arg      output file (output format is always DER
 -noout arg    don‘t produce any output
 -offset arg   offset into file
 -length arg   length of section in file
 -i            indent entries
 -dump         dump unknown data in hex form
 -dlimit arg   dump the first arg bytes of unknown data in hex form
 -oid file     file of extra oid definitions
 -strparse offset
               a series of these can be used to ‘dig‘ into multiple
               ASN1 blob wrappings
 -genstr str   string to generate ASN1 structure from
 -genconf file file to generate ASN1 structure from

0:d=0  hl=4 l= 710 cons: SEQUENCE

0 表示节点在整个文件中的偏移长度

d=0 表示节点深度

hl=4 表示节点头字节长度

l=710 表示节点数据字节长度

cons 表示该节点为结构节点，表示包含子节点或者子结构数据

prim 表示该节点为原始节点，包含数据

SEQUENCE、OCTETSTRING等都是ASN.1中定义的数据类型，具体可以参考ASN.1格式说明。

最后一个节点OCTET STRING      [HEX DUMP]，就是加密后的私钥数据。

openssl asn1parse -in ec_pubkey.pem

openssl asn1parse -inform DER -in file.der

参考：http://blog.csdn.net/lucien_cc/article/details/18407451
     http://m.blog.csdn.net/blog/as3luyuan123/13339803