cert.sh 14 KB
Newer Older
1 2 3 4 5 6
#!/usr/bin/env bash

scriptPath=${0%/*}
. "$scriptPath"/../../libs/bashhelper.sh
. "$scriptPath"/../../libs/shflags

Janek Bevendorff's avatar
Janek Bevendorff committed
7
check_tools "cryfs keyctl openssl"
8 9 10 11

usage() {
    echo "
usage:
Janek Bevendorff's avatar
Janek Bevendorff committed
12
    $(basename "$0") issue|revoke [OPTIONS]
13 14

description:
Janek Bevendorff's avatar
Janek Bevendorff committed
15
    Manage VPN client, server, and ICA certificates.
16 17 18 19 20 21 22 23 24 25 26

"
    exit 1
}

CMD="$1"
shift

# Define command line arguments and parse them.
if [ "$CMD" == "issue" ]; then
    DEFINE_string "cryfs_dir" "" "CryFS base dir containing the encrypted certificates." "d"
27
    DEFINE_integer "keyring_id" "-1" "Retrieve given CryFS decryption key from kernel keyring" "k"
28 29
    DEFINE_string "root_cn" "" "CN of the root certificate for signing (optional)" "r"
    DEFINE_string "type" "client" "Certificate type (client | server | ca)" "t"
30 31 32
    DEFINE_string "common_name" "" "Common Name (CN) for the certificate (e.g., username)" "c"
    DEFINE_string "full_name" "" "User's full name" "f"
    DEFINE_string "default_subj" "/C=DE/ST=Thuringia/L=Weimar/O=Webis/" "Default Subj fields (optional)" "s"
33
    DEFINE_string "organizational_unit" "" "Organizational Unit (OU) for the certificate (optional)" "u"
34
    DEFINE_string "email" "" "E-Mail address for the certificate" "e"
35
    DEFINE_boolean "no_password" false "Do not encrypt private key" "n"
36
    DEFINE_boolean "overwrite" false "Overwrite existing certificates instead of incrementing filename (use with caution!)" "x"
37 38
    DEFINE_string "csr" "" "CSR file (optional)" "i"
    DEFINE_string "out" "/dev/stdout" "OpenVPN .ovpn config file to generate (optional)" "o"
39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70
elif [ "$CMD" == "revoke" ]; then
    DEFINE_string "cryfs_dir" "" "CryFS base dir containing the encrypted certificates." "d"
    DEFINE_string "root_cn" "" "CN of the root certificate for signing (optional)" "r"
    DEFINE_string "type" "" "Certificate type (client | server | ca)" "t"
    DEFINE_string "cert_cn" "" "CN of the certificate to revoke" "c"
fi

FLAGS_HELP=$(usage)
export FLAGS_HELP
FLAGS "$@" || exit 1  # Parse command line arguments.
eval set -- "${FLAGS_ARGV}"

export MOUNT_DIR
trap "cleanup ${MOUNT_DIR}; exit $?" INT TERM EXIT

CONF="$(dirname $0)/openssl.conf"


# ===========================================================================
#                              helper commands
# ===========================================================================

# Usage: cleanup MOUNT_DIR
cleanup() {
    if [ ! -d "$1" ]; then
        return
    fi
    logInfo "Unmounting CryFS..."
    fusermount -u "$1" &> /dev/null
    rmdir "$1"
}

71 72 73 74 75 76 77 78
# Usage: update_repository BASE_DIR
pull_repository() {
    if [ ! -d "${1}/.git" ]; then
        logError "CryFS directory is not a Git repository!"
        exit 1
    fi

    logInfo "Updating Git repository..."
79
    if ! (cd "$1" && git pull >&2); then
80 81 82 83 84 85 86 87
        logError "Git update failed!"
        exit 1
    fi
}

# Usage: commit_changes BASE_DIR
commit_changes() {
    logInfo "Committing changes to Git..."
88
    if (cd "$1" && git add -A && git commit -m "-" >&2); then
89 90
        logInfo "Changes committed. Please push the repository now (git push)."
    else
91 92 93 94
        logError "Committing changes failed!"
    fi
}

95 96
# Usage: mount_cryfs BASE_DIR MOUNT_DIR
mount_cryfs() {
97 98 99 100 101
    if [ ! -d "$1" ]; then
        logError "CryFS directory '$1' does not exist!"
        exit 1
    fi

102
    logInfo "Mounting CryFS..."
103
    mkdir -p "$2"
104 105 106 107 108 109 110
    echo keyctl pipe $FLAGS_keyring_id >&2
    if [ $FLAGS_keyring_id -ne -1 ]; then
        < <(keyctl pipe $FLAGS_keyring_id 2>&1) cryfs "$1" "$2" >&2
    else
        cryfs "$1" "$2" >&2
    fi
    if [ $? -ne 0 ]; then
111
        logError "Failed to mount CryFS volume!"
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
        cleanup "$2"
        exit 1
    fi
}

# Usage: choose_root_cert MOUNT_DIR
choose_root_cert() {
    echo -e "\n\nPlease choose a root certificate:" >&2
    root_certs=()
    i=0
    for c in $(find "${1}/ca/" -name "*.pem"); do
        if grep -q "PRIVATE KEY" "$c"; then
            root_certs[$i]="$c"
            printf "  [%2d] $(basename $c | sed 's/\.pem$//')\n" $i >&2
            i=$(($i +1))
        fi
    done

    echo -en "\nYour choice: " >&2
    read root_cert_choice
    while [ "${root_certs[$root_cert_choice]}" == "" ]; do
        logError "Invalid choice, please enter a valid number."
        echo -en "\nYour choice: " >&2
        read root_cert_choice
    done
    echo "${root_certs[$root_cert_choice]}"
}

# Usage: generate_key OUT_FILE BITS
generate_key() {
    logInfo "Generating private key..."
    openssl genrsa -out "$1" "$2"
}

146
# Usage: generate_csr CONF CERT_TYPE KEY_FILE OUT_FILE DEFAULT_SUBJ ORG_UNIT CLIENT_CN CLIENT_FULL_NAME CLIENT_EMAIL
147 148
generate_csr() {
    logInfo "Generating CSR..."
149 150 151
    openssl req -new -key "$3" -out "$4" -reqexts "v3_req_${2}" \
        -subj "${5}OU=${6}/CN=${7}/emailAddress=${9}" -reqexts "SAN" \
        -config <(cat "$1" <(printf "\n[SAN]\nsubjectAltName = 'DNS:${8}'"))
152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212
}

# Usage: revoke_cert CONF CERT CA_KEY CA_CERT
revoke_cert() {
    logInfo "Revoking certificate..."
    openssl ca -config "$1" -revoke "$2" -keyfile "$3" -cert "$4"
}

# Usage: generate_crl CONF CRL_OUT CA_KEY CA_CERT
generate_crl() {
    logInfo "Creating / updating CRL..."
    openssl ca -config "$1" -gencrl -out "$2" -keyfile "$3" -cert "$4" -updatedb
    logInfo "CRL '$2' updated."
}

# Usage: sign_csr CONF CSR_IN CERT_OUT CA_KEY CA_CERT CERT_TYPE
sign_csr() {
    local validity=730
    # certificate validity in days
    if [ "$6" == "server" ]; then
        validity=1825
    elif [ "$6" == "ca" ]; then
        validity=3650
    fi

    openssl ca -config "$1" -in "$2" -out "$3" -keyfile "$4" -cert "$5" -create_serial \
        -days "$validity" -extensions "v3_cert_${6}" -notext -batch -updatedb
}

# Usage: ensure_ca_base_dir DATA_DIR
ensure_ca_base_dir() {
    if [ ! -d "$1" ]; then
        logInfo "Creating CA data dir..."
        mkdir -p "${1}/certs"
        touch "${1}/index.txt"
        echo 1000 > "${1}/crlnumber.txt"
    fi
}

# Usage: CA_CERT
resolve_ca_chain() {
    local cert_file="$1"
    local issuer

    while : ; do
        if [ ! -f "$cert_file" ]; then
            logError "Unable to find certificate for '${issuer}', CA chain may be incomplete!"
            break
        fi

        cat "$cert_file"

        issuer="$(openssl x509 -in "${cert_file}" -noout -issuer | grep -Po '(?<=CN = )[^,]+')"
        local issuer_cert_file="$(dirname "$cert_file")/${issuer}.crt"
        if [ "$(realpath $cert_file)" == "$(realpath $issuer_cert_file)" ]; then
            break
        fi
        cert_file="$issuer_cert_file"
    done
}

213
# Usage: OUT_FILE CERT CA_CERT [KEY] [NO_PASSWORD]
214
generate_ovpn_file() {
215 216 217 218 219 220 221 222
    if [ "$4" != "" ] && [ "$5" -eq 0 ]; then
        local pem="$(cat "$4")"
    elif [ "$4" != "" ]; then
        local extra_param=""
        if ! tty -s; then
            # non-interactive shell, get password from env
            extra_param="-passout env:PK_PASS"
        fi
223
        echo "Password to encrypt private key in .ovpn config file: " >&2
224 225
        local pem="$(openssl rsa -aes256 -in $4 $extra_param)"
        local counter=0
226 227
        while [ "$pem" == "" ]; do
            logError "Invalid passphrase, please try again."
228 229 230 231 232 233 234
            local pem="$(openssl rsa -aes256 -in $4 $extra_param)"

            counter=$(($counter + 1))
            if [ $counter -ge 10 ]; then
                logError "Too many input failures."
                return 1
            fi
235
        done
236
    fi
237

238 239
    local out_file="$1"

240 241 242 243 244 245 246 247
    cat <<EOL > "$out_file"
client
remote vpn.webis.de
dev tun
proto udp
port 1194
remote-cert-tls server

248 249 250
# Cipher is set on the server, this is only to avoid warnings
cipher AES-256-GCM

251 252 253 254 255
<key>
$pem
</key>

<cert>
256
$(cat "$2")
257 258 259
</cert>

<ca>
260
$(resolve_ca_chain "$3")
261 262 263 264
</ca>
EOL

    logInfo "OpenVPN config file has been written to '$1'."
265
    return 0
266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284
}


# ===========================================================================
#                               issue command
# ===========================================================================
issue() {
    if [ "$FLAGS_cryfs_dir" == "" ]; then
        logError "--cryfs_dir is required"
        exit 1;
    fi
    if [ "$FLAGS_type" != "client" ] && [ "$FLAGS_type" != "server" ] && [ "$FLAGS_type" != "ca" ]; then
        logError "Invalid certificate type: ${FLAGS_type}"
        exit 1
    fi
    if [ "$FLAGS_common_name" == "" ]; then
        logError "--common_name is required"
        exit 1;
    fi
285 286
    if [ "$FLAGS_full_name" == "" ]; then
        logError "--full_name is required"
287 288
        exit 1;
    fi
289 290
    if [ "$FLAGS_email" == "" ]; then
        logError "--email is required"
291 292 293
        exit 1;
    fi

294 295
    pull_repository "${FLAGS_cryfs_dir}"

296 297 298
    MOUNT_DIR="${FLAGS_cryfs_dir}_mount.${RANDOM}"
    mount_cryfs "$FLAGS_cryfs_dir" "$MOUNT_DIR"

299 300
    ROOT_KEY="${MOUNT_DIR}/ca/${FLAGS_root_cn}.pem"
    if [ "$FLAGS_root_cn" == "" ] || [ ! -f "$ROOT_KEY" ]; then
301 302 303 304 305 306 307 308 309 310 311 312 313
        ROOT_KEY="$(choose_root_cert "$MOUNT_DIR")"
        logInfo "Using '$(basename "${ROOT_KEY}" | sed 's/\.pem$//')' as the root certificate..."
    fi
    ROOT_CERT="$(echo -n "$ROOT_KEY" | sed 's/\.pem$/.crt/')"
    export CA_BASE_DIR="$(echo "$ROOT_CERT" | sed 's/\.crt$//')_Data"
    ensure_ca_base_dir "$CA_BASE_DIR"

    BITS=2048

    # use provided CSR or generate new one
    CSR="$FLAGS_csr"
    DELETE_KEY=false
    DELETE_CSR=false
314

315 316
    local cert_filename="$FLAGS_common_name"
    CERT="${MOUNT_DIR}/${FLAGS_type}/${cert_filename}.crt"
317 318 319
    local counter_suffix=0
    while [ $FLAGS_overwrite -eq 1 ] && [ -f "$CERT" ]; do
        counter_suffix=$(($counter_suffix + 1))
320
        CERT="${MOUNT_DIR}/${FLAGS_type}/${cert_filename}_${counter_suffix}.crt"
321 322
    done
    if [ $counter_suffix -gt 0 ]; then
323 324
        logWarn "Certificate file '${FLAGS_type}/${cert_filename}.crt' already exists, saving as '${FLAGS_type}/${cert_filename}_${counter_suffix}.crt'."
        cert_filename="${cert_filename}_${counter_suffix}"
325 326
    fi

327
    if [ "$CSR" == "" ] || [ ! -f "$CSR" ]; then
328
        KEY="${MOUNT_DIR}/${FLAGS_type}/${cert_filename}.pem"
329
        if [ $FLAGS_overwrite -eq 1 ] && [ -f "$KEY" ]; then
330 331 332 333 334 335
            logError "Key file ${KEY} already exists!"
            cleanup "$MOUNT_DIR"
            exit 1
        fi
        generate_key "$KEY" "$BITS"

336
        CSR="${MOUNT_DIR}/${FLAGS_type}/${cert_filename}.csr"
337
        if [ $FLAGS_overwrite -eq 1 ] && [ -f "$CSR" ]; then
338
            logError "CSR file ${CSR} already exists!"
339
            rm -f "$KEY"
340 341 342
            cleanup "$MOUNT_DIR"
            exit 1
        fi
343
        if ! generate_csr "$CONF" "$FLAGS_type" "$KEY" "$CSR" "$FLAGS_default_subj" "$FLAGS_organizational_unit" "$FLAGS_common_name" "$FLAGS_full_name" "$FLAGS_email"; then
344
            logError "CSR generation failed!"
345
            rm -f "$KEY" "$CSR"
346 347 348 349 350 351 352 353 354 355 356 357 358
            cleanup "$MOUNT_DIR"
            exit 1
        fi

        if [ "$FLAGS_type" == "client" ]; then
            DELETE_KEY=true
        fi
        DELETE_CSR=true
    fi

    logInfo "Signing client certificate..."
    if ! sign_csr "$CONF" "$CSR" "$CERT" "$ROOT_KEY" "$ROOT_CERT" "$FLAGS_type"; then
        logError "Signing failed!"
359
        rm -f "$KEY" "$CSR" "$CERT"
360 361 362 363 364 365 366
        cleanup "$MOUNT_DIR"
        exit 1
    fi

    if [ "$FLAGS_type" == "client" ]; then
        logInfo "Writing .ovpn file..."
        ROOT_CA_CERT="$(dirname $ROOT_CERT)/Webis_Root_CA.crt"
367
        if ! generate_ovpn_file "$FLAGS_out" "$CERT" "$ROOT_CERT" "$KEY" $FLAGS_no_password; then
368
            rm -f "$KEY" "$CSR" "$CERT"
369 370 371
            cleanup "$MOUNT_DIR"
            exit 1
        fi
372 373
    fi
    if $DELETE_KEY; then
Janek Bevendorff's avatar
Janek Bevendorff committed
374
        # delete private key after generating ovpn file
375 376 377 378
        logInfo "Deleting temporary private key..."
        rm "$KEY"
    fi
    if $DELETE_CSR; then
Janek Bevendorff's avatar
Janek Bevendorff committed
379
        # delete CSR after generating ovpn file
380 381 382 383 384 385 386 387
        logInfo "Deleting temporary CSR..."
        rm "$CSR"
    fi

    CRL="$(echo -n "$ROOT_KEY" | sed 's/\.pem$/.crl/')"
    generate_crl "$CONF" "$CRL" "$ROOT_KEY" "$ROOT_CERT"

    cleanup "$MOUNT_DIR"
388
    commit_changes "${FLAGS_cryfs_dir}"
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409
}


# ===========================================================================
#                               revoke command
# ===========================================================================

revoke() {
    if [ "$FLAGS_cryfs_dir" == "" ]; then
        logError "--cryfs_dir is required"
        exit 1;
    fi
    if [ "$FLAGS_cert_cn" == "" ]; then
        logError "--cert_cn is required"
        exit 1;
    fi
    if [ "$FLAGS_type" == "" ]; then
        logError "--type is required"
        exit 1;
    fi

410 411
    pull_repository "${FLAGS_cryfs_dir}"

412 413 414
    MOUNT_DIR="${FLAGS_cryfs_dir}_mount.${RANDOM}"
    mount_cryfs "$FLAGS_cryfs_dir" "$MOUNT_DIR"

415 416
    ROOT_KEY="${MOUNT_DIR}/ca/${FLAGS_root_cn}.pem"
    if [ "$FLAGS_root_cn" == "" ] || [ ! -f "$ROOT_KEY" ]; then
417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447
        ROOT_KEY="$(choose_root_cert "$MOUNT_DIR")"
        logInfo "Using '$(basename "${ROOT_KEY}" | sed 's/\.pem$//')' as the root certificate..."
    fi
    ROOT_CERT="$(echo -n "$ROOT_KEY" | sed 's/\.pem$/.crt/')"
    export CA_BASE_DIR="$(echo "$ROOT_CERT" | sed 's/\.crt$//')_Data"
    ensure_ca_base_dir "$CA_BASE_DIR"

    CERT="${MOUNT_DIR}/${FLAGS_type}/${FLAGS_cert_cn}.crt"
    if [ ! -f "$CERT" ]; then
        logError "Certificate '${CERT}' does not exist."
        cleanup "$MOUNT_DIR"
        exit 1
    fi

    echo -n "Are you sure you want to revoke the ${FLAGS_type} certificate '${FLAGS_cert_cn}'? [y/N] "
    read answer
    if [ "$answer" != "y" ] && [ "$answer" != "Y" ]; then
        logError "Revocation aborted."
        cleanup "$MOUNT_DIR"
        exit 1
    fi
    if ! revoke_cert "$CONF" "$CERT" "$ROOT_KEY" "$ROOT_CERT"; then
        logError "Certificate revocation failed!"
        cleanup "$MOUNT_DIR"
        exit 1
    fi

    CRL="$(echo -n "$ROOT_KEY" | sed 's/\.pem$/.crl/')"
    generate_crl "$CONF" "$CRL" "$ROOT_KEY" "$ROOT_CERT"

    cleanup "$MOUNT_DIR"
448
    commit_changes "${FLAGS_cryfs_dir}"
449 450 451 452 453 454 455 456 457 458 459 460 461
}

# ===========================================================================
#                                 bootstrap
# ===========================================================================

if [ "$CMD" == "issue" ] || [ "$CMD" == "revoke" ]; then
    $CMD "$@"
else
    logError "Invalid command '$CMD'."
    usage
    exit 1
fi