# lib/tls
# Functions to control the configuration and operation of the TLS proxy service

# Dependencies:
# !! source _before_ any services that use ``SERVICE_HOST``
# ``functions`` file
# ``DEST``, ``DATA_DIR`` must be defined
# ``HOST_IP``, ``SERVICE_HOST``
# ``KEYSTONE_TOKEN_FORMAT`` must be defined

# Entry points:
# configure_CA
# init_CA

# configure_proxy
# start_tls_proxy

# make_root_ca
# make_int_ca
# new_cert $INT_CA_DIR int-server "abc"
# start_tls_proxy HOST_IP 5000 localhost 5000


if is_service_enabled tls-proxy; then
    # TODO(dtroyer): revisit this below after the search for HOST_IP has been done
    TLS_IP=${TLS_IP:-$SERVICE_IP}

    # Set the default ``SERVICE_PROTOCOL`` for TLS
    SERVICE_PROTOCOL=https
fi

# Make up a hostname for cert purposes
# will be added to /etc/hosts?
DEVSTACK_HOSTNAME=secure.devstack.org
DEVSTACK_CERT_NAME=devstack-cert
DEVSTACK_CERT=$DATA_DIR/$DEVSTACK_CERT_NAME.pem

# CA configuration
ROOT_CA_DIR=${ROOT_CA_DIR:-$DATA_DIR/CA/root-ca}
INT_CA_DIR=${INT_CA_DIR:-$DATA_DIR/CA/int-ca}

ORG_NAME="OpenStack"
ORG_UNIT_NAME="DevStack"

# Stud configuration
STUD_PROTO="--tls"
STUD_CIPHERS='TLSv1+HIGH:!DES:!aNULL:!eNULL:@STRENGTH'


# CA Functions
# ============

# There may be more than one, get specific
OPENSSL=${OPENSSL:-/usr/bin/openssl}

# Do primary CA configuration
function configure_CA() {
    # build common config file

    # Verify ``TLS_IP`` is good
    if [[ -n "$HOST_IP" && "$HOST_IP" != "$TLS_IP" ]]; then
        # auto-discover has changed the IP
        TLS_IP=$HOST_IP
    fi
}

# Creates a new CA directory structure
# create_CA_base ca-dir
function create_CA_base() {
    local ca_dir=$1

    if [[ -d $ca_dir ]]; then
        # Bail out it exists
        return 0
    fi

    for i in certs crl newcerts private; do
        mkdir -p $ca_dir/$i
    done
    chmod 710 $ca_dir/private
    echo "01" >$ca_dir/serial
    cp /dev/null $ca_dir/index.txt
}


# Create a new CA configuration file
# create_CA_config ca-dir common-name
function create_CA_config() {
    local ca_dir=$1
    local common_name=$2

    echo "
[ ca ]
default_ca = CA_default

[ CA_default ]
dir                     = $ca_dir
policy                  = policy_match
database                = \$dir/index.txt
serial                  = \$dir/serial
certs                   = \$dir/certs
crl_dir                 = \$dir/crl
new_certs_dir           = \$dir/newcerts
certificate             = \$dir/cacert.pem
private_key             = \$dir/private/cacert.key
RANDFILE                = \$dir/private/.rand
default_md              = default

[ req ]
default_bits            = 1024
default_md              = sha1

prompt                  = no
distinguished_name      = ca_distinguished_name

x509_extensions         = ca_extensions

[ ca_distinguished_name ]
organizationName        = $ORG_NAME
organizationalUnitName  = $ORG_UNIT_NAME Certificate Authority
commonName              = $common_name

[ policy_match ]
countryName             = optional
stateOrProvinceName     = optional
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied

[ ca_extensions ]
basicConstraints        = critical,CA:true
subjectKeyIdentifier    = hash
authorityKeyIdentifier  = keyid:always, issuer
keyUsage                = cRLSign, keyCertSign

" >$ca_dir/ca.conf
}

# Create a new signing configuration file
# create_signing_config ca-dir
function create_signing_config() {
    local ca_dir=$1

    echo "
[ ca ]
default_ca = CA_default

[ CA_default ]
dir                     = $ca_dir
policy                  = policy_match
database                = \$dir/index.txt
serial                  = \$dir/serial
certs                   = \$dir/certs
crl_dir                 = \$dir/crl
new_certs_dir           = \$dir/newcerts
certificate             = \$dir/cacert.pem
private_key             = \$dir/private/cacert.key
RANDFILE                = \$dir/private/.rand
default_md              = default

[ req ]
default_bits            = 1024
default_md              = sha1

prompt                  = no
distinguished_name      = req_distinguished_name

x509_extensions         = req_extensions

[ req_distinguished_name ]
organizationName        = $ORG_NAME
organizationalUnitName  = $ORG_UNIT_NAME Server Farm

[ policy_match ]
countryName             = optional
stateOrProvinceName     = optional
organizationName        = match
organizationalUnitName  = optional
commonName              = supplied

[ req_extensions ]
basicConstraints        = CA:false
subjectKeyIdentifier    = hash
authorityKeyIdentifier  = keyid:always, issuer
keyUsage                = digitalSignature, keyEncipherment, keyAgreement
extendedKeyUsage        = serverAuth, clientAuth
subjectAltName          = \$ENV::SUBJECT_ALT_NAME

" >$ca_dir/signing.conf
}

# Create root and intermediate CAs
# init_CA
function init_CA {
    # Ensure CAs are built
    make_root_CA $ROOT_CA_DIR
    make_int_CA $INT_CA_DIR $ROOT_CA_DIR

    # Create the CA bundle
    cat $ROOT_CA_DIR/cacert.pem $INT_CA_DIR/cacert.pem >>$INT_CA_DIR/ca-chain.pem
}

# Create an initial server cert
# init_cert
function init_cert {
    if [[ ! -r $DEVSTACK_CERT ]]; then
        if [[ -n "$TLS_IP" ]]; then
            # Lie to let incomplete match routines work
            TLS_IP="DNS:$TLS_IP"
        fi
        make_cert $INT_CA_DIR $DEVSTACK_CERT_NAME $DEVSTACK_HOSTNAME "$TLS_IP"

        # Create a cert bundle
        cat $INT_CA_DIR/private/$DEVSTACK_CERT_NAME.key $INT_CA_DIR/$DEVSTACK_CERT_NAME.crt $INT_CA_DIR/cacert.pem >$DEVSTACK_CERT
    fi
}


# make_cert creates and signs a new certificate with the given commonName and CA
# make_cert ca-dir cert-name "common-name" ["alt-name" ...]
function make_cert() {
    local ca_dir=$1
    local cert_name=$2
    local common_name=$3
    local alt_names=$4

    # Generate a signing request
    $OPENSSL req \
        -sha1 \
        -newkey rsa \
        -nodes \
        -keyout $ca_dir/private/$cert_name.key \
        -out $ca_dir/$cert_name.csr \
        -subj "/O=${ORG_NAME}/OU=${ORG_UNIT_NAME} Servers/CN=${common_name}"

    if [[ -z "$alt_names" ]]; then
        alt_names="DNS:${common_name}"
    else
        alt_names="DNS:${common_name},${alt_names}"
    fi

    # Sign the request valid for 1 year
    SUBJECT_ALT_NAME="$alt_names" \
    $OPENSSL ca -config $ca_dir/signing.conf \
        -extensions req_extensions \
        -days 365 \
        -notext \
        -in $ca_dir/$cert_name.csr \
        -out $ca_dir/$cert_name.crt \
        -subj "/O=${ORG_NAME}/OU=${ORG_UNIT_NAME} Servers/CN=${common_name}" \
        -batch
}


# Make an intermediate CA to sign everything else
# make_int_CA ca-dir signing-ca-dir
function make_int_CA() {
    local ca_dir=$1
    local signing_ca_dir=$2

    # Create the root CA
    create_CA_base $ca_dir
    create_CA_config $ca_dir 'Intermediate CA'
    create_signing_config $ca_dir

    # Create a signing certificate request
    $OPENSSL req -config $ca_dir/ca.conf \
        -sha1 \
        -newkey rsa \
        -nodes \
        -keyout $ca_dir/private/cacert.key \
        -out $ca_dir/cacert.csr \
        -outform PEM

    # Sign the intermediate request valid for 1 year
    $OPENSSL ca -config $signing_ca_dir/ca.conf \
        -extensions ca_extensions \
        -days 365 \
        -notext \
        -in $ca_dir/cacert.csr \
        -out $ca_dir/cacert.pem \
        -batch
}

# Make a root CA to sign other CAs
# make_root_CA ca-dir
function make_root_CA() {
    local ca_dir=$1

    # Create the root CA
    create_CA_base $ca_dir
    create_CA_config $ca_dir 'Root CA'

    # Create a self-signed certificate valid for 5 years
    $OPENSSL req -config $ca_dir/ca.conf \
        -x509 \
        -nodes \
        -newkey rsa \
        -days 21360 \
        -keyout $ca_dir/private/cacert.key \
        -out $ca_dir/cacert.pem \
        -outform PEM
}


# Proxy Functions
# ===============

# Starts the TLS proxy for the given IP/ports
# start_tls_proxy front-host front-port back-host back-port
function start_tls_proxy() {
    local f_host=$1
    local f_port=$2
    local b_host=$3
    local b_port=$4

    stud $STUD_PROTO -f $f_host,$f_port -b $b_host,$b_port $DEVSTACK_CERT 2>/dev/null
}