test curve for each ECDH cipher, change PFS output to use curve name

cipherscan

@@ -100,7 +100,7 @@ Use one of the options below:
 -j | --json         Output results in JSON format.
 -o | --openssl      path/to/your/openssl binary you want to use.
 --savecrt           path where to save untrusted and leaf certificates
---curves            test ECC curves supported by server (req. OpenSSL 1.0.2)
+--[no-]curves       test ECC curves supported by server (req. OpenSSL 1.0.2)
 -v | --verbose      Increase verbosity.
 
 The rest of the arguments will be interpreted as openssl s_client argument.
@@ -123,6 +123,68 @@ debug(){
     fi
 }
 
+# obtain an array of curves supported by openssl
+CURVES=(sect163k1 # K-163
+    sect163r1
+    sect163r2 # B-163
+    sect193r1
+    sect193r2
+    sect233k1 # K-233
+    sect233r1 # B-233
+    sect239k1
+    sect283k1 # K-283
+    sect283r1 # B-283
+    sect409k1 # K-409
+    sect409r1 # B-409
+    sect571k1 # K-571
+    sect571r1 # B-571
+    secp160k1
+    secp160r1
+    secp160r2
+    secp192k1
+    prime192v1 # P-192 secp192r1
+    secp224k1
+    secp224r1 # P-224
+    secp256k1
+    prime256v1 # P-256 secp256r1
+    secp384r1 # P-384
+    secp521r1 # P-521
+    brainpoolP256r1
+    brainpoolP384r1
+    brainpoolP512r1)
+
+# many curves have alternative names, this array provides a mapping to find the IANA
+# name of a curve using its alias
+CURVES_MAP=("sect163k1 K-163"
+      "sect163r2 B-163"
+      "sect233k1 K-233"
+      "sect233r1 B-233"
+      "sect283k1 K-283"
+      "sect283r1 B-283"
+      "sect409k1 K-409"
+      "sect409r1 B-409"
+      "sect571k1 K-571"
+      "sect571r1 B-571"
+      "prime192v1 P-192 secp192r1"
+      "secp224r1 P-224"
+      "prime256v1 P-256 secp256r1"
+      "secp384r1 P-384"
+      "secp521r1 P-521")
+
+get_curve_name() {
+    local identifier=$1
+    for c in "${CURVES_MAP[@]}"; do
+        if [[ "$c" =~ $identifier ]]; then
+            verbose "$c matches identifier $identifier"
+            local map=(${c// / })
+            echo ${map[0]}
+            return
+        fi
+    done
+    echo $identifier
+    return
+}
+
 c_hash() {
     local h=$(${OPENSSLBIN} x509 -hash -noout -in "$1/$2" 2>/dev/null)
     for ((num=0; num<=100; num++)) ; do
@@ -366,6 +428,7 @@ test_cipher_on_target() {
         fi
         cipher=$current_cipher
         pfs=$current_pfs
+        [ -z $pfs ] && pfs="None"
         pubkey=$current_pubkey
         sigalg=$current_sigalg
         trusted=$current_trusted
@@ -383,13 +446,23 @@ test_cipher_on_target() {
 
     # if cipher contains NONE, the cipher wasn't accepted
     elif [ "$cipher" == '(NONE)  ' ]; then
-        result="$cipher $protocols $pubkey $sigalg $trusted $tickethint $ocspstaple $pfs"
+        result="$cipher $protocols $pubkey $sigalg $trusted $tickethint $ocspstaple $pfs $curves_ordering"
         verbose "handshake failed, server returned ciphersuite '$result'"
         return 1
 
     # the connection succeeded
     else
-        result="$cipher $protocols $pubkey $sigalg $trusted $tickethint $ocspstaple $pfs"
+        # if pfs uses ECDH, test supported curves
+        if [[ $pfs =~ ECDH ]]; then
+            if [ $TEST_CURVES == "True" ]; then
+                test_ecc_curves
+                pfs=$current_curves
+            else
+                # resolve the openssl curve to the proper IANA name
+                pfs="$(get_curve_name $(echo $pfs|cut -d ',' -f2))"
+            fi
+        fi
+        result="$cipher $protocols $pubkey $sigalg $trusted $tickethint $ocspstaple $pfs $curves_ordering"
         verbose "handshake succeeded, server returned ciphersuite '$result'"
         return 0
     fi
@@ -481,23 +554,24 @@ display_results_in_terminal() {
             if [ "$tickethint" != "${cipher_data[5]}" ]; then
                 different=True
             fi
+            if [ "$ocspstaple" != "${cipher_data[6]}" ]; then
+                different=True
+            fi
         fi
         results=("${results[@]}" "$r")
         ctr=$((ctr+1))
     done
 
+    header="prio ciphersuite protocols"
+    if [ $different == "True" ]; then
+        header="$header pubkey_size signature_algoritm trusted ticket_hint ocsp_staple"
+    fi
+    header="$header pfs"
+    if [ $TEST_CURVES == "True" ]; then
+        header="$header curves_ordering"
+    fi
     if [ $DOBENCHMARK -eq 1 ]; then
-        if [ $different == "True" ]; then
+        header="$header avg_handshake_microsec"
-            header="prio ciphersuite protocols pubkey_size signature_algoritm trusted ticket_hint ocsp_staple pfs_keysize avg_handshake_microsec"
-        else
-            header="prio ciphersuite protocols pfs_keysize avg_handshake_microsec"
-        fi
-    else
-        if [ $different == "True" ]; then
-            header="prio ciphersuite protocols pubkey_size signature_algorithm trusted ticket_hint ocsp_staple pfs_keysize"
-        else
-            header="prio ciphersuite protocols pfs_keysize"
-        fi
     fi
     ctr=0
     for result in "${results[@]}"; do
@@ -508,7 +582,7 @@ display_results_in_terminal() {
         if [ $different == "True" ]; then
             echo $result|grep -v '(NONE)'
         else
-            # prints priority, ciphersuite, protocols and pfs_keysize
+            # prints priority, ciphersuite, protocols and pfs
             awk '!/(NONE)/{print $1 " " $2 " " $3 " " $9}' <<<"$result"
         fi
     done|column -t
@@ -531,25 +605,6 @@ display_results_in_terminal() {
     else
         echo "Client side cipher ordering"
     fi
-
-    if [[ $TEST_CURVES == "True" ]]; then
-        if [[ -n $supported_curves ]]; then
-            echo
-            local i=0
-            (echo "prio curve"
-            for curve in ${supported_curves//,/ }; do
-                i=$((i+1))
-                echo "$i $curve"
-            done) | column -t
-            echo
-            if [[ $fallback_supported == True ]]; then
-                echo "Server does fallback on unsupported curves"
-            else
-                echo "Server doesn't fallback on unsupported curves"
-            fi
-            echo "$curves_ordering side curve ordering"
-        fi
-    fi
 }
 
 display_results_in_json() {
@@ -571,17 +626,19 @@ display_results_in_json() {
         echo -n "\"ocsp_stapling\":\"${cipher_arr[6]}\","
         pfs="${cipher_arr[7]}"
         [ "$pfs" == "" ] && pfs="None"
-        echo -n "\"pfs\":\"$pfs\"}"
+        echo -n "\"pfs\":\"$pfs\""
+        if [[ "${cipher_arr[0]}" =~ ECDH ]]; then
+            echo -n ","
+            echo -n "\"elliptic_curves\":[\"${pfs//,/\",\"}\"]"
+            if [ $TEST_CURVES == "True" ]; then
+                echo -n ","
+                echo -n "\"curves_ordering\":\"${cipher_arr[8]}\""
+            fi
+        fi
+        echo -n "}"
         ctr=$((ctr+1))
     done
-    echo -n ']'
+    echo ']}'
-    if [[ -n $supported_curves ]]; then
-        echo -n ","
-        echo -n "\"curve_fallback\":\"$fallback_supported\","
-        echo -n "\"curve_ordering\":\"$curves_ordering\","
-        echo -n "\"curve\":[\"${supported_curves//,/\",\"}\"]"
-    fi
-    echo '}'
 }
 
 test_serverside_ordering() {
@@ -640,109 +697,16 @@ test_serverside_ordering() {
 test_ecc_curves() {
     # openssl formated list of curves that will cause server to select ECC suite
     local ecc_ciphers=""
-    # names of all curves supported in TLS (as supported by openssl)
-    local curves=()
-    # alternative names for curves in TLS (as returned by openssl s_client or
-    # as specified in standard)
-    local curve_names=()
     # "True" if server supports ciphers that don't use ECC at a lower priority
     local fallback_available="False"
 
     # return variable: list of curves supported by server, in order
-    supported_curves=""
+    current_curves=""
-    # return variable: whatever a server will fall back to non ECC suite when
-    # client doesn't advertise support for curves the server needs
-    fallback_supported="False"
     # return variable: check if server uses server side or client side ordering
     # for curves
     curves_ordering="server"
 
-    # get ciphers that will cause server to select suite that uses ECC, if most
+    local curves=(${CURVES[*]})
-    # preferred ciphers do not, exclude them from list
-    for pref in "${cipherspref[@]}"; do
-        # get first value from space separated array
-        cipher=($pref)
-
-        # ECDH uses curve from certificate, so no way to negotiate it, the two
-        # below are ephemeral so they can select the curve independent of cert
-        if [[ $cipher =~ ECDHE ]] || [[ $cipher =~ AECDH ]]; then
-            # colon on end of string is ignored by openssl
-            ecc_ciphers+="${cipher}:"
-        elif [[ -n $ecc_ciphers ]]; then
-            # add fallback ciphers
-            ecc_ciphers+="${cipher}:"
-            fallback_available="True"
-        fi
-    done
-
-    if [[ -z $ecc_ciphers ]]; then
-        verbose "Server does not support ephemeral ECC"
-        return
-    fi
-
-    verbose "ECC curves testing, cipher preference: $ecc_ciphers"
-
-    # only some curves have defined TLS code points, so no use parsing openssl
-    # output checking what it supports, see
-    # http://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-8
-    curves=(sect163k1 # K-163
-          sect163r1
-          sect163r2 # B-163
-          sect193r1
-          sect193r2
-          sect233k1 # K-233
-          sect233r1 # B-233
-          sect239k1
-          sect283k1 # K-283
-          sect283r1 # B-283
-          sect409k1 # K-409
-          sect409r1 # B-409
-          sect571k1 # K-571
-          sect571r1 # B-571
-          secp160k1
-          secp160r1
-          secp160r2
-          secp192k1
-          prime192v1 # P-192 secp192r1
-          secp224k1
-          secp224r1 # P-224
-          secp256k1
-          prime256v1 # P-256 secp256r1
-          secp384r1 # P-384
-          secp521r1 # P-521
-          brainpoolP256r1
-          brainpoolP384r1
-          brainpoolP512r1)
-
-    # many curves have alternative names, save those too
-    curve_names=("sect163k1 K-163"
-          "sect163r1"
-          "sect163r2 B-163"
-          "sect193r1"
-          "sect193r2"
-          "sect233k1 K-233"
-          "sect233r1 B-233"
-          "sect239k1"
-          "sect283k1 K-283"
-          "sect283r1 B-283"
-          "sect409k1 K-409"
-          "sect409r1 B-409"
-          "sect571k1 K-571"
-          "sect571r1 B-571"
-          "secp160k1"
-          "secp160r1"
-          "secp160r2"
-          "secp192k1"
-          "prime192v1 P-192 secp192r1"
-          "secp224k1"
-          "secp224r1 P-224"
-          "secp256k1"
-          "prime256v1 P-256 secp256r1"
-          "secp384r1 P-384"
-          "secp521r1 P-521"
-          "brainpoolP256r1"
-          "brainpoolP384r1"
-          "brainpoolP512r1")
 
     OLDIFS="$IFS"
     IFS=':'
@@ -757,7 +721,7 @@ test_ecc_curves() {
     elif [ -e "$CACERTS" ]; then
         sslcommand+=" -CAfile $CACERTS"
     fi
-    sslcommand+=" -status $SCLIENTARGS -connect $TARGET -cipher $ecc_ciphers"
+    sslcommand+=" -status $SCLIENTARGS -connect $TARGET -cipher $current_cipher"
     # force the TLS to send a TLS1.0 client hello at least, as with SSLv2
     # ciphers present it will try to send a SSLv2 compatible client hello
     sslcommand+=" -no_ssl2 -no_ssl3"
@@ -773,49 +737,34 @@ test_ecc_curves() {
         IFS=':'
         local test_curves="${curves[*]}"
         IFS="$OLDIFS"
-        verbose "Testing $test_curves"
+        verbose "Testing $test_curves with command $sslcommand"
 
         ratelimit
         local tmp=$(echo Q | $sslcommand -curves $test_curves 2>/dev/null)
         parse_openssl_output <<<"$tmp"
 
-        if [[ -z $current_protocol || $current_cipher == "(NONE)" \
+        if [[ -z $current_protocol || $current_cipher == "(NONE)" || $current_cipher == '0000' ]]; then
-            || $current_cipher == '0000' ]]; then
-                # server aborted connection
-                if [[ $fallback_available == "True" ]]; then
-                    fallback_supported="False"
-                else
-                    fallback_supported="unknown"
-                fi
             break
         else
             # server accepted connection
             local ephem_data=(${current_pfs//,/ })
-
+            local cname=""
             if [[ ${ephem_data[0]} =~ ECDH ]]; then
-                # ok, we got an ECC connection, now, what curve did we get
+                if [ "$current_curves" != "" ]; then
-                for id in "${!curves[@]}"; do
+                    current_curves+=","
-                    # compare to alternative names
-                    if [[ ${curve_names[$id]} =~ ${ephem_data[1]} ]]; then
-                        if [[ -n $supported_curves ]]; then
-                            supported_curves+=","
                 fi
-                        supported_curves+="${curves[$id]}"
+                cname="$(get_curve_name ${ephem_data[1]})"
-                        verbose "Server selected ${ephem_data[1]}, a.k.a ${curves[$id]}"
+                verbose "Server selected ${ephem_data[1]}, a.k.a $cname"
-                        # ok, we know it's supported, remove it from set of offered ones
+                current_curves+="$cname"
+            fi
+            for id in "${!curves[@]}"; do
+                if [ "$cname" == ${curves[$id]} ]; then
+                    # we know it's supported, remove it from set of offered ones
                     unset curves[$id]
                     break
                 fi
             done
-
-            else
-                verbose "Server fell back to $current_cipher"
-                # ok, we got a fallback
-                fallback_supported="True"
-                break
         fi
-        fi
-
         [ "$OUTPUTFORMAT" == "terminal" ] && [ $DEBUG -lt 1 ] && echo -n '.'
     done
 
@@ -828,7 +777,7 @@ test_ecc_curves() {
     # check if curves ordering is server of client side
     #
 
-    local tmp_curves=(${supported_curves//,/ })
+    local tmp_curves=(${current_curves//,/ })
     verbose "Server supported curves: ${tmp_curves[@]}"
 
     # server supports just one or none, so it effectively uses server side
@@ -941,6 +890,10 @@ do
             TEST_CURVES="True"
             shift 1
             ;;
+        --no-curves)
+            TEST_CURVES="False"
+            shift 1
+            ;;
         --) # End of all options
             shift
             break
@@ -981,6 +934,13 @@ if [ ! -x $OPENSSLBIN ]; then
     fi
 fi
 
+if [ $TEST_CURVES == "True" ]; then
+    if [ ! -z "$($OPENSSLBIN s_client -curves 2>&1|head -1|grep 'unknown option')" ]; then
+        echo "curves testing not available with your version of openssl, disabling it"
+        TEST_CURVES="False"
+    fi
+fi
+
 if [ $VERBOSE != 0 ] ; then
     [ -n "$CACERTS" ] && echo "Using trust anchors from $CACERTS"
     echo "Loading $($OPENSSLBIN ciphers -v $CIPHERSUITE 2>/dev/null|grep Kx|wc -l) ciphersuites from $(echo -n $($OPENSSLBIN version 2>/dev/null))"