TRC Signing Ceremony Preparation Steps

Each party involved in a TRC signing ceremony must go through a few steps in preparation for the ceremony. This document outlines these steps.

Important

It is required that the machine used to execute the commands has openssl version 1.1.1d or higher installed.

Note

Placeholders

This document contains placeholders for certificate configurations. Placeholders look like this {{.Property}}. These placeholders need to be filled before executing the commands.

Ceremony administrator role

The ceremony administrator should send out the high-level TRC Signing Ceremony description, the appropriate TRC Signing Ceremony Phases document, and this document all in digital form to the participants.

The existing TRC Signing Ceremony Phases documents are listed here:

• TRC Signing Ceremony Phases - Base TRC

• TRC Signing Ceremony Phases - Sensitive Update

Furthermore, the ceremony administrator should remind all voters that they need to agree on a common TRC policy before scheduling the TRC ceremony. Importantly, the TRC validity period should be agreed upon, such that every voter can generate certificates that cover the full validity.

The ceremony administrator should bring all digitally distributed documents as a print out for all parties that take part.

Voting AS representative roles

Important

All voters need to agree on a preliminary TRC policy. Especially, the validity period of the TRC, since all the generated certificates must cover the full TRC validity period. The other policy values can be amended during the ceremony itself.

When the preliminary policy is in place. The voters can start generating the necessary certificates.

Create a safe workspace folder

To protect the key material, we recommend using an air-gapped workstation. Next, a folder for key material and for certificates is created. First navigate to the desired parent directory (.e.g. cd /home/user).

To create the folders:

export PUBDIR="$(pwd)/public"
mkdir -p $PUBDIR
export KEYDIR="$(pwd)/keys"
mkdir -p $KEYDIR

Note

For traceability, we recommend that each action in the public directory is committed to git.

Create basic configuration

Navigate to the public directory:

cd $PUBDIR

This directory stores the openssl configurations, the CSRs and the created certificates. To avoid duplicated information, create a basic.cnf that can be imported from the sensitive voting, regular voting and root certificate configuration files:

cat << EOF > basic.cnf
[openssl_init]
oid_section = oids

[req]
distinguished_name = req_distinguished_name
prompt             = no

[oids]
ISD-AS        = SCION ISD-AS number, 1.3.6.1.4.1.55324.1.2.1
sensitive-key = SCION sensitive voting key, 1.3.6.1.4.1.55324.1.3.1
regular-key   = SCION regular voting key, 1.3.6.1.4.1.55324.1.3.2
root-key      = SCION CP root key, 1.3.6.1.4.1.55324.1.3.3

[req_distinguished_name]
C      = {{.Country}}
ST     = {{.State}}
L      = {{.Location}}
O      = {{.Organization}}
OU     = {{.OrganizationalUnit}}
CN     = \${common_name::name}
ISD-AS = {{.ISDAS}}

[ca]
default_ca = basic_ca

[basic_ca]
default_days   = \${ca_defaults::default_days}
default_md     = sha256
database       = database/index.txt
new_certs_dir  = certificates
unique_subject = no
rand_serial    = yes
policy         = policy_any

[policy_any]
countryName            = supplied
stateOrProvinceName    = optional
organizationName       = optional
organizationalUnitName = optional
commonName             = supplied
emailAddress           = optional

EOF

Fill in the required fields.

Note

The {{.Country}} must be replaced with an ISO 3166-1 alpha-2 code. Switzerland, for example, has the code CH.

To set the start and end time of a X509 certificate using openssl, the ca command is necessary. The directory needs to be prepared:

mkdir -p database
touch database/index.txt
mkdir -p certificates

Sensitive voting

This step creates a sensitive voting key and certificate.

Note

The ISD-AS configuration field is optional, but should be provided if the party has an AS identifier, the ISD number must match with the TRC this certificate will be used in.

First, create the sensitive voting certificate configuration. In the file, replace {{.ShortOrg}} with the name of your organization:

cat << EOF > sensitive-voting.cnf
openssl_conf    = openssl_init
x509_extensions = x509_ext

[common_name]
name = {{.ShortOrg}} High Security Voting Certificate

[x509_ext]
subjectKeyIdentifier = hash
extendedKeyUsage     = 1.3.6.1.4.1.55324.1.3.1, 1.3.6.1.5.5.7.3.8

[ca_defaults]
default_days = 1825

.include basic.cnf
EOF

Note

Make sure the common name is different for each certificate type. The proposed name makes it easier for human operators to reason about what the the purpose of the certificate is.

Important

If this step is executed in preparation for a TRC update signing ceremony, make sure that the previous private key and certificate are not overwritten.

For example, you can version the predecessor private key and certificate by running the following command:

# Uncomment and set appropriate value:
#
# PREDID="ISD1-B1-S1"

mkdir -p $KEYDIR/$PREDID $PREDID
mv $KEYDIR/sensitive-voting.key $KEYDIR/$PREDID/sensitive-voting.key
mv sensitive-voting.crt $PREDID/sensitive-voting.crt

Using this configuration, create the sensitive voting key and certificate. The start and end date need to be replaced with the time when the certificate becomes valid, and the time when it expires. The format is YYYYMMDDHHMMSSZ. For example, June 24th, 2020 UTC at noon, is formatted as 20200624120000Z. The required commands are:

# Uncomment and set the appropriate values:
#
# STARTDATE="20200624120000Z"
# ENDDATE="20250624120000Z"

openssl genpkey -algorithm EC -pkeyopt ec_paramgen_curve:P-256 \
    -pkeyopt ec_param_enc:named_curve -out $KEYDIR/sensitive-voting.key

openssl req -new -key $KEYDIR/sensitive-voting.key -config sensitive-voting.cnf \
    -utf8 -out sensitive-voting.csr

openssl ca -in sensitive-voting.csr -config sensitive-voting.cnf \
    -keyfile $KEYDIR/sensitive-voting.key -selfsign \
    -startdate $STARTDATE -enddate $ENDDATE -preserveDN \
    -notext -batch -utf8 -out sensitive-voting.crt

After generating the certificate, check that the output is reasonable:

openssl x509 -in sensitive-voting.crt -noout -dates
openssl x509 -in sensitive-voting.crt -noout -text | grep -o "Signature Algorithm.*"

The validity time must cover the agreed upon TRC validity period.

The certificate can be validated with with the scion-pki binary:

scion-pki certs validate --type sensitive-voting sensitive-voting.crt

Regular voting

This step creates a regular voting key and certificate.

Note

The ISD-AS configuration field is optional, but should be provided if the party has an AS identifier, the ISD number must match with the TRC this certificate will be used in.

Create the regular voting certificate configuration:

cat << EOF > regular-voting.cnf
openssl_conf    = openssl_init
x509_extensions = x509_ext

[common_name]
name = {{.ShortOrg}} Regular Voting Certificate

[x509_ext]
subjectKeyIdentifier = hash
extendedKeyUsage     = 1.3.6.1.4.1.55324.1.3.2, 1.3.6.1.5.5.7.3.8

[ca_defaults]
default_days = 365

.include basic.cnf
EOF

Note

Make sure the common name is different for each certificate type. The proposed name makes it easier for human operators to reason about what the the purpose of the certificate is.

Important

If this step is executed in preparation for a TRC update signing ceremony, make sure that the previous private key and certificate are not overwritten.

For example, you can version the predecessor private key and certificate by running the following command:

# Uncomment and set appropriate value:
#
# PREDID="ISD1-B1-S1"

mkdir -p $KEYDIR/$PREDID $PREDID
mv $KEYDIR/regular-voting.key $KEYDIR/$PREDID/regular-voting.key
mv regular-voting.crt $PREDID/regular-voting.crt

Using this configuration, create the regular voting key and certificate. The start and end date need to be replaced with the time when the certificate becomes valid, and the time when it expires. The format is YYYYMMDDHHMMSSZ. For example, June 24th, 2020 UTC at noon, is formatted as 20200624120000Z. The required commands are:

# Uncomment and set the appropriate values:
#
# STARTDATE="20200624120000Z"
# ENDDATE="20210624120000Z"

openssl genpkey -algorithm EC -pkeyopt ec_paramgen_curve:P-256 \
    -pkeyopt ec_param_enc:named_curve -out $KEYDIR/regular-voting.key

openssl req -new -key $KEYDIR/regular-voting.key -config regular-voting.cnf \
    -utf8 -out regular-voting.csr

openssl ca -in regular-voting.csr -config regular-voting.cnf \
    -keyfile $KEYDIR/regular-voting.key -selfsign \
    -startdate $STARTDATE -enddate $ENDDATE -preserveDN \
    -notext -batch -utf8 -out regular-voting.crt

After generating the certificate, check that the output is reasonable:

openssl x509 -in regular-voting.crt -noout -dates
openssl x509 -in regular-voting.crt -noout -text | grep -o "Signature Algorithm.*"

The validity time must cover the agreed upon TRC validity period.

The certificate can be validated with with the scion-pki binary:

scion-pki certs validate --type regular-voting regular-voting.crt

CP Root

This step creates a CP root key and certificate.

Note

This step only has to be executed by issuing ASes.

Create the CP root certificate configuration:

cat << EOF > cp-root.cnf
openssl_conf    = openssl_init
x509_extensions = x509_ext

[common_name]
name = {{.ShortOrg}} High Security Root Certificate

[x509_ext]
basicConstraints     = critical, CA:TRUE, pathlen:1
keyUsage             = critical, keyCertSign
subjectKeyIdentifier = hash
extendedKeyUsage     = 1.3.6.1.4.1.55324.1.3.3, 1.3.6.1.5.5.7.3.8

[ca_defaults]
default_days = 365

.include basic.cnf
EOF

Note

Make sure the common name is different for each certificate type. The proposed name makes it easier for human operators to reason about what the the purpose of the certificate is.

Important

If this step is executed in preparation for a TRC update signing ceremony, make sure that the previous private key and certificate are not overwritten.

For example, you can version the predecessor private key and certificate by running the following command:

# Uncomment and set appropriate value:
#
# PREDID="ISD1-B1-S1"

mkdir -p $KEYDIR/$PREDID $PREDID
mv $KEYDIR/regular-voting.key $KEYDIR/$PREDID/regular-voting.key
mv regular-voting.crt $PREDID/regular-voting.crt

Using this configuration, create the CP root key and certificate. The start and end date need to be replaced with the time when the certificate becomes valid, and the time when it expires. The format is YYYYMMDDHHMMSSZ. For example, June 24th, 2020 UTC at noon, is formatted as 20200624120000Z. The required commands are:

# Uncomment and set the appropriate values:
#
# STARTDATE="20200624120000Z"
# ENDDATE="20210624120000Z"

openssl genpkey -algorithm EC -pkeyopt ec_paramgen_curve:P-256 \
    -pkeyopt ec_param_enc:named_curve -out $KEYDIR/cp-root.key

openssl req -new -key $KEYDIR/cp-root.key -config cp-root.cnf \
    -utf8 -out cp-root.csr

openssl ca -in cp-root.csr -config cp-root.cnf \
    -keyfile $KEYDIR/cp-root.key -selfsign \
    -startdate $STARTDATE -enddate $ENDDATE -preserveDN \
    -notext -batch -utf8 -out cp-root.crt

After generating the certificate, check that the output is reasonable:

openssl x509 -in cp-root.crt -noout -dates
openssl x509 -in cp-root.crt -noout -text | grep -o "Signature Algorithm.*"

The validity time must cover the agreed upon TRC validity period.

The certificate can be validated with with the scion-pki binary:

scion-pki certs validate --type cp-root cp-root.crt