golang中的检验hash
本文内容纲要：
1.对字符串进行hash
大家可以看一下，SHA1Hashes
GobyExample写道：
Thepatternforgeneratingahashissha1.New(),sha1.Write(bytes),thensha1.Sum([]byte{}).
附上golang代码
packagemain
import(
"crypto/sha1"
"fmt"
)
funcmain(){
s:="sha1thisstring"
h:=sha1.New()
h.Write([]byte(s))
bs:=h.Sum(nil)
fmt.Println(s)
fmt.Printf("%x\n",bs)
}
结果输出为：
sha1thisstring
cf23df2207d99a74fbe169e3eba035e633b65d94
而在godoc产生的文档使用io:WriteString代替sha1.Write()，测试2种方法都可以用。
有些文档说，使用io:WriteString，意思更加明显，而且不用像上面要进行类型转换。
h:=sha1.New()
io.WriteString(h,"Hismoneyistwicetainted:'taintyoursand'taintmine.")
fmt.Printf("%x",h.Sum(nil))
说个有趣的现象，使用上面代码产生的hash值和命令行中sha1sum的值不一致。
$echo"sha1thisstring"|sha1sum
0faabfb58d5c522f47944173f2953f40ecfc2975-
$
$cata.txt
sha1thisstring
$sha1suma.txt
0faabfb58d5c522f47944173f2953f40ecfc2975a.txt
$
可以看到，上面2个结果是一致的，但与我们上面golang代码的输出不一致。
原因是，命令行echo会在字符串后面添加一个换行符，导致整个hash值变化。大家可以自行在golang的代码中，在验证的字符串中添加换行符测试看看。
2.对文本进行hash
参考google论坛
模式是，os.Open(file),io.Copy(dst,src),sha1.Sum()
摘录2个github代码，代码在原来的基础上有修改。
gomd5/sha1example
/*
Hash-GuillermoEstrada
SimpleutilitytoobtaintheMD5and/orSHA-1
ofafilefromthecommandline.
packagemain
import(
"io"
"os"
"fmt"
"flag"
"crypto/md5"
"crypto/sha1"
)
funcmain(){
md5f:=flag.Bool("md5",false,"-md5calculatemd5hashoffile")
sha1f:=flag.Bool("sha1",false,"-sha1calculatesha1hashoffile")
flag.Parse()
if!*md5f&&!*sha1f{
fmt.Println("err:Nohashspecified.Use-md5or-sha1orboth.")
os.Exit(1)
}
infile,inerr:=os.Open(flag.Arg(0))
ifinerr==nil{
if*md5f{
md5h:=md5.New()
io.Copy(md5h,infile)
fmt.Printf("%x%s\n",md5h.Sum(nil),flag.Arg(0))
}
if*sha1f{
sha1h:=sha1.New()
io.Copy(sha1h,infile)
fmt.Printf("%x%s\n",sha1h.Sum(nil),flag.Arg(0))
}
}else{
fmt.Println(inerr)
os.Exit(1)
}
}
命令行调用：
#forainmd5sha1;doecho${a}sum;./hash-$a/bin/ls;${a}sum/bin/ls;echo;done
md5sum
b691e28e120f6989e37c7db21cb51931/bin/ls
b691e28e120f6989e37c7db21cb51931/bin/ls
sha1sum
502202e177bb8677c8c3b059cc1401d1524806c8/bin/ls
502202e177bb8677c8c3b059cc1401d1524806c8/bin/ls
#
hashes.go
/*
Hash-GuillermoEstrada
SimpleutilitytoobtaintheMD5and/orSHA-1
ofafilefromthecommandline.
2011
Edited:MarkoMikulicic2011
*/
packagemain
import(
"io"
"os"
"fmt"
"flag"
"hash"
"crypto/md5"
"crypto/sha1"
"crypto/sha256"
"crypto/sha512"
//"crypto/ripemd160"
)
funcmain(){
algos:=[...]string{"md5","sha1","sha256","sha512"}
impls:=[...]hash.Hash{md5.New(),sha1.New(),sha256.New(),sha512.New()}
flags:=make([]*bool,len(algos))
fori,a:=rangealgos{
flags[i]=flag.Bool(a,false,fmt.Sprintf("-%scalculate%shashoffile",a,a))
}
flag.Parse()
any:=false
for_,f:=rangeflags{
any=any||*f
}
ifany==false{
fmt.Println("err:Nohashspecified.Pleaserunwith--helptoseelistofsupportedhashalgos")
os.Exit(1)
}
infile,err:=os.Open(flag.Arg(0))
iferr!=nil{
fmt.Println(err)
os.Exit(1)
}
writers:=make([]io.Writer,0,len(impls))
fori,flag:=rangeflags{
if*flag{
writers=append(writers,impls[i])
}
}
dest:=io.MultiWriter(writers...)
io.Copy(dest,infile)
fori,flag:=rangeflags{
if*flag{
fmt.Printf("%s:\n%x\n",algos[i],impls[i].Sum(nil))
}
}
}
命令行调用：
#forainmd5sha1sha256sha512;do./hashes-$a/bin/ls;${a}sum/bin/ls;echo;done
md5:
b691e28e120f6989e37c7db21cb51931
b691e28e120f6989e37c7db21cb51931/bin/ls
sha1:
502202e177bb8677c8c3b059cc1401d1524806c8
502202e177bb8677c8c3b059cc1401d1524806c8/bin/ls
sha256:
1e87d99599ddea2a93f060b50a54066e8b756d752158e6147cbb99b06eb11d99
1e87d99599ddea2a93f060b50a54066e8b756d752158e6147cbb99b06eb11d99/bin/ls
sha512:
343b38486ad17c5813026c9df7e1ce7e268d7c64e70439aebddcafdfe10a0dfc9f55bf8169c3e592942f50bb408a852dfd1fb08e0bcadf214bc89dbf72d693f8
343b38486ad17c5813026c9df7e1ce7e268d7c64e70439aebddcafdfe10a0dfc9f55bf8169c3e592942f50bb408a852dfd1fb08e0bcadf214bc89dbf72d693f8/bin/ls
#
本文内容总结：
原文链接：https://www.cnblogs.com/getong/p/3791230.html