-bash:cfssl:找不到命令

When I tried to install cfssl with this command:

go get -u github.com/cloudflare/cfssl/cmd/cfssl

I received following output:

# github.com/cloudflare/cfssl/crypto/pkcs7
go_packages/src/github.com/cloudflare/cfssl/crypto/pkcs7/pkcs7.go:141: pkcs7.ContentType.String undefined (type asn1.ObjectIdentifier has no field or method String)
# github.com/cloudflare/cfssl/helpers/derhelpers
go_packages/src/github.com/cloudflare/cfssl/helpers/derhelpers/derhelpers.go:16: undefined: crypto.Signer
# github.com/cloudflare/cfssl/csr
go_packages/src/github.com/cloudflare/cfssl/csr/csr.go:191: undefined: x509.CertificateRequest
go_packages/src/github.com/cloudflare/cfssl/csr/csr.go:204: undefined: x509.CreateCertificateRequest
# golang.org/x/crypto/ocsp
go_packages/src/golang.org/x/crypto/ocsp/ocsp.go:494: undefined: crypto.Signer
# github.com/cloudflare/cf-tls/tls
go_packages/src/github.com/cloudflare/cf-tls/tls/handshake_client.go:431: undefined: crypto.Signer

I really have no clue whether this is harmful or not and has something to do with the usage of this tool. However when I try to use it, I receive this error:

-bash: cfssl: Command not found.

I never used go but I wanted to use this tool. Do you guys know why this is not working as expected?

Edit

output of go env

GOARCH="amd64"
GOBIN=""
GOCHAR="6"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/ubuntu/go"
GORACE=""
GOROOT="/usr/lib/go"
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
TERM="dumb"
CC="gcc"
GOGCCFLAGS="-g -O2 -fPIC -m64 -pthread"
CXX="g++"
CGO_ENABLED="1"

output of go version

go version go1.2.1 linux/amd64

I really don't know why this is the case because I installed this version.

It seems that you have errors in getting cfssl.

Because Cloudflare's Github page says you require to have Go lang version 1.4 atleast.

If you download and install go 1.4 and get cfssl, then binary will be created in $GOPATH/bin/cfssl

Refer $GOPATH variable - here

Install Go lang version latest.

1.yum update

2.wget https://dl.google.com/go/go1.12.linux-amd64.tar.gz

3.tar -xzf go1.12.linux-amd64.tar.gz

4.mv go /usr/local

5.set up environment variables.

 5.1.GOROOT is the location where Go package is installed on your system

   export GOROOT=/usr/local/go

 5.2.GOPATH is the location of your work directoryexport 

  export GOPATH=$HOME/your project location

 5.3.Now set the PATH variable to access go binary system wide

   export PATH=$GOPATH/bin:$GOROOT/bin:$PATH

6.verify

6.1.go version

6.2.go env

CFSSL

1.git clone https://github.com/cloudflare/cfssl.git $GOPATH/src/github.com/cloudflare/cfssl

2.cd $GOPATH/src/github.com/cloudflare/cfssl

3.make

4.yum install tree

6.tree bin

7.go get -u github.com/cloudflare/cfssl/cmd/...