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Merge pull request #2265 from dcooper16/server_sig_algs
Show server supported signature algorithms
2 parents 462a602 + c7644ad commit a466608

2 files changed

Lines changed: 155 additions & 3 deletions

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‎t/baseline_data/default_testssl.csvfile‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -66,6 +66,8 @@
6666
"FS_ciphers","testssl.sh/81.169.166.184","443","INFO","TLS_AES_256_GCM_SHA384 TLS_CHACHA20_POLY1305_SHA256 ECDHE-RSA-AES256-GCM-SHA384 ECDHE-RSA-AES256-SHA384 ECDHE-RSA-AES256-SHA DHE-RSA-AES256-GCM-SHA384 DHE-RSA-AES256-SHA256 DHE-RSA-AES256-SHA DHE-RSA-CAMELLIA256-SHA TLS_AES_128_GCM_SHA256 ECDHE-RSA-AES128-GCM-SHA256 ECDHE-RSA-AES128-SHA DHE-RSA-AES128-GCM-SHA256 DHE-RSA-AES128-SHA256 DHE-RSA-AES128-SHA DHE-RSA-CAMELLIA128-SHA","",""
6767
"FS_ECDHE_curves","testssl.sh/81.169.166.184","443","OK","prime256v1 secp384r1 secp521r1 X25519 X448","",""
6868
"DH_groups","testssl.sh/81.169.166.184","443","OK","Unknown DH group (2048 bits)","",""
69+
"FS_TLS12_sig_algs","testssl.sh/81.169.166.184","443","INFO","RSA-PSS+SHA256 RSA-PSS+SHA384 RSA-PSS+SHA512 RSA+SHA256 RSA+SHA384 RSA+SHA512 RSA+SHA224","",""
70+
"FS_TLS13_sig_algs","testssl.sh/81.169.166.184","443","INFO","RSA-PSS+SHA256 RSA-PSS+SHA384 RSA-PSS+SHA512","",""
6971
"HTTP_status_code","testssl.sh/81.169.166.184","443","INFO","200 OK ('/')","",""
7072
"HTTP_clock_skew","testssl.sh/81.169.166.184","443","INFO","0 seconds from localtime","",""
7173
"HTTP_headerTime","testssl.sh/81.169.166.184","443","INFO","1654006271","",""

‎testssl.sh‎

Lines changed: 153 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -6265,6 +6265,19 @@ run_cipherlists() {
62656265
return $ret
62666266
}
62676267

6268+
pr_sigalg_quality() {
6269+
local sigalg="$1"
6270+
6271+
if [[ "$sigalg" =~ MD5 ]]; then
6272+
pr_svrty_high "$sigalg"
6273+
elif [[ "$sigalg" =~ SHA1 ]]; then
6274+
pr_svrty_low "$sigalg"
6275+
else
6276+
out "$sigalg"
6277+
fi
6278+
}
6279+
6280+
62686281
# The return value is an indicator of the quality of the DH key length in $1:
62696282
# 1 = pr_svrty_critical, 2 = pr_svrty_high, 3 = pr_svrty_medium, 4 = pr_svrty_low
62706283
# 5 = neither good nor bad, 6 = pr_svrty_good, 7 = pr_svrty_best
@@ -10319,7 +10332,7 @@ get_san_dns_from_cert() {
1031910332
run_fs() {
1032010333
local -i sclient_success
1032110334
local fs_offered=false ecdhe_offered=false ffdhe_offered=false
10322-
local fs_tls13_offered=false
10335+
local fs_tls13_offered=false fs_tls12_offered=false
1032310336
local protos_to_try proto hexc dash fs_cipher sslvers auth mac export curve dhlen
1032410337
local -a hexcode normalized_hexcode ciph rfc_ciph kx enc ciphers_found sigalg ossl_supported
1032510338
# generated from 'kEECDH:kEDH:!aNULL:!eNULL:!DES:!3DES:!RC4' with openssl 1.0.2i and openssl 1.1.0
@@ -10336,10 +10349,16 @@ run_fs() {
1033610349
local -a ffdhe_groups_hex=("01,00" "01,01" "01,02" "01,03" "01,04")
1033710350
local -a ffdhe_groups_output=("ffdhe2048" "ffdhe3072" "ffdhe4096" "ffdhe6144" "ffdhe8192")
1033810351
local -a supported_curve
10352+
local -a sigalgs_hex=("01,01" "01,02" "01,03" "02,01" "02,02" "02,03" "03,01" "03,02" "03,03" "04,01" "04,02" "04,03" "04,20" "05,01" "05,02" "05,03" "05,20" "06,01" "06,02" "06,03" "06,20" "07,08" "08,04" "08,05" "08,06" "08,07" "08,08" "08,09" "08,0a" "08,0b" "08,1a" "08,1b" "08,1c")
10353+
local -a sigalgs_strings=("RSA+MD5" "DSA+MD5" "ECDSA+MD5" "RSA+SHA1" "DSA+SHA1" "ECDSA+SHA1" "RSA+SHA224" "DSA+SHA224" "ECDSA+SHA224" "RSA+SHA256" "DSA+SHA256" "ECDSA+SHA256" "RSA+SHA256" "RSA+SHA384" "DSA+SHA384" "ECDSA+SHA384" "RSA+SHA384" "RSA+SHA512" "DSA+SHA512" "ECDSA+SHA512" "RSA+SHA512" "SM2+SM3" "RSA-PSS+SHA256" "RSA-PSS+SHA384" "RSA-PSS+SHA512" "Ed25519" "Ed448" "RSA-PSS+SHA256" "RSA-PSS+SHA384" "RSA-PSS+SHA512" "ECDSA+SHA256" "ECDSA+SHA384" "ECDSA+SHA512")
10354+
local -a tls13_supported_sigalgs=("false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false")
10355+
local -a tls12_supported_sigalgs=("false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false" "false")
10356+
local rsa_cipher="" ecdsa_cipher="" dss_cipher=""
10357+
local sigalgs_to_test tls12_supported_sigalg_list="" tls13_supported_sigalg_list=""
1033910358
local -i nr_supported_ciphers=0 nr_curves=0 nr_ossl_curves=0 i j low high
1034010359
local fs_ciphers curves_offered="" curves_to_test temp
1034110360
local curves_option="" curves_list1="" curves_list2=""
10342-
local len1 len2 curve_found
10361+
local len1 len2 curve_found sigalg_found
1034310362
local key_bitstring quality_str
1034410363
local -i len_dh_p quality
1034510364
local has_dh_bits="$HAS_DH_BITS"
@@ -10526,6 +10545,9 @@ run_fs() {
1052610545
"$WIDE" && kx[i]="$(read_dhtype_from_file $TMPFILE)"
1052710546
elif [[ "$fs_cipher" == ECDHE-* ]]; then
1052810547
ecdhe_offered=true
10548+
! "$fs_tls12_offered" && [[ "$(get_protocol "$TMPFILE")" == TLSv1.2 ]] && fs_tls12_offered=true
10549+
else
10550+
! "$fs_tls12_offered" && [[ "$(get_protocol "$TMPFILE")" == TLSv1.2 ]] && fs_tls12_offered=true
1052910551
fi
1053010552
if "$WIDE"; then
1053110553
dhlen=$(read_dhbits_from_file "$TMPFILE" quiet)
@@ -10569,6 +10591,12 @@ run_fs() {
1056910591
fi
1057010592
"$WIDE" && "$SHOW_SIGALGO" && [[ -r "$HOSTCERT" ]] && \
1057110593
sigalg[i]="$(read_sigalg_from_file "$HOSTCERT")"
10594+
if [[ "$proto" == 03 ]]; then
10595+
[[ $sclient_success -eq 0 ]] && fs_tls12_offered=true
10596+
elif ! "$fs_tls12_offered" && [[ $sclient_success -eq 2 ]] && \
10597+
[[ "$(get_protocol "$TEMPDIR/$NODEIP.parse_tls_serverhello.txt")" == TLSv1.2 ]]; then
10598+
fs_tls12_offered=true
10599+
fi
1057210600
done
1057310601
done
1057410602
fi
@@ -10861,9 +10889,131 @@ run_fs() {
1086110889
else
1086210890
fileout "DH_groups" "$quality_str" "$curves_offered"
1086310891
fi
10892+
outln
10893+
fi
10894+
fi
10895+
if "$using_sockets"; then
10896+
protos_to_try=""
10897+
"$fs_tls13_offered" && protos_to_try="04-01 04-02"
10898+
# For TLS 1.2, find a supported cipher suite corresponding to each of the key types (RSA, ECDSA, DSS).
10899+
# Need to try each key type separately, otherwise not all supported signature algorithms will be found.
10900+
if "$fs_tls12_offered"; then
10901+
for (( i=0; i < nr_supported_ciphers; i++ )); do
10902+
! "${ciphers_found[i]}" && continue
10903+
if [[ -z "$rsa_cipher" ]] && { [[ "${rfc_ciph[i]}" == TLS_DHE_RSA* ]] ||
10904+
[[ "${rfc_ciph[i]}" == TLS_ECDHE_RSA* ]] || [[ "${ciph[i]}" == DHE-RSA-* ]] ||
10905+
[[ "${ciph[i]}" == ECDHE-RSA-* ]]; }; then
10906+
rsa_cipher="${hexcode[i]}"
10907+
elif [[ -z "$ecdsa_cipher" ]] && { [[ "${rfc_ciph[i]}" == TLS_ECDHE_ECDSA* ]] || [[ "${ciph[i]}" == ECDHE-ECDSA-* ]]; }; then
10908+
ecdsa_cipher="${hexcode[i]}"
10909+
elif [[ -z "$dss_cipher" ]] && { [[ "${rfc_ciph[i]}" == TLS_DHE_DSS* ]] || [[ "${ciph[i]}" == DHE-DSS-* ]]; }; then
10910+
dss_cipher="${hexcode[i]}"
10911+
fi
10912+
done
10913+
[[ -n "$rsa_cipher" ]] && protos_to_try+=" 03-rsa-$rsa_cipher"
10914+
[[ -n "$ecdsa_cipher" ]] && protos_to_try+=" 03-ecdsa-$ecdsa_cipher"
10915+
[[ -n "$dss_cipher" ]] && protos_to_try+=" 03-dss-$dss_cipher"
10916+
fi
10917+
for proto in $protos_to_try; do
10918+
while true; do
10919+
i=0
10920+
sigalgs_to_test=""
10921+
# A few servers get confused if the signature_algorithms extension contains too many entries. So:
10922+
# * For TLS 1.3, break the list into two and test each half separately.
10923+
# * For TLS 1.2, generally limit the signature_algorithms extension to algorithms that are consistent with the key type.
10924+
for hexc in "${sigalgs_hex[@]}"; do
10925+
if [[ "$proto" == 04* ]]; then
10926+
if ! "${tls13_supported_sigalgs[i]}"; then
10927+
if [[ "${proto##*-}" == 01 ]]; then
10928+
[[ $i -le 16 ]] && sigalgs_to_test+=", $hexc"
10929+
else
10930+
[[ $i -gt 16 ]] && sigalgs_to_test+=", $hexc"
10931+
fi
10932+
fi
10933+
elif ! "${tls12_supported_sigalgs[i]}"; then
10934+
if [[ "$proto" =~ rsa ]]; then
10935+
if [[ "${hexc:3:2}" == 01 ]] || [[ "${hexc:0:2}" == 08 ]]; then
10936+
sigalgs_to_test+=", $hexc"
10937+
fi
10938+
elif [[ "$proto" =~ dss ]]; then
10939+
[[ "${hexc:3:2}" == 02 ]] && sigalgs_to_test+=", $hexc"
10940+
else
10941+
if [[ "${hexc:3:2}" == 03 ]] || [[ "${hexc:0:2}" == 08 ]]; then
10942+
sigalgs_to_test+=", $hexc"
10943+
fi
10944+
fi
10945+
fi
10946+
i+=1
10947+
done
10948+
[[ -z "$sigalgs_to_test" ]] && break
10949+
len1=$(printf "%02x" "$((2*${#sigalgs_to_test}/7))")
10950+
len2=$(printf "%02x" "$((2*${#sigalgs_to_test}/7+2))")
10951+
if [[ "$proto" == 04* ]]; then
10952+
tls_sockets "${proto%%-*}" "$TLS13_CIPHER" "all+" "00,0d, 00,$len2, 00,$len1, ${sigalgs_to_test:2}"
10953+
else
10954+
tls_sockets "${proto%%-*}" "${proto##*-}, 00,ff" "ephemeralkey" "00,0d, 00,$len2, 00,$len1, ${sigalgs_to_test:2}"
10955+
fi
10956+
[[ $? -eq 0 ]] || break
10957+
sigalg_found="$(awk -F ': ' '/^Peer signing digest/ { print $2 } ' "$TEMPDIR/$NODEIP.parse_tls_serverhello.txt")"
10958+
[[ -n "$sigalg_found" ]] && sigalg_found="+$sigalg_found"
10959+
sigalg_found="$(awk -F ': ' '/^Peer signature type/ { print $2 } ' "$TEMPDIR/$NODEIP.parse_tls_serverhello.txt")$sigalg_found"
10960+
i=0
10961+
for hexc in "${sigalgs_hex[@]}"; do
10962+
[[ "${sigalgs_strings[i]}" == $sigalg_found ]] && break
10963+
i+=1
10964+
done
10965+
[[ -z "${sigalgs_hex[i]}" ]] && break
10966+
if [[ "$proto" == 04* ]]; then
10967+
"${tls13_supported_sigalgs[i]}" && break
10968+
tls13_supported_sigalgs[i]=true
10969+
tls13_supported_sigalg_list+=" $sigalg_found"
10970+
else
10971+
"${tls12_supported_sigalgs[i]}" && break
10972+
tls12_supported_sigalgs[i]=true
10973+
tls12_supported_sigalg_list+=" $sigalg_found"
10974+
fi
10975+
done
10976+
done
10977+
tls12_supported_sigalg_list="${tls12_supported_sigalg_list:1}"
10978+
tls13_supported_sigalg_list="${tls13_supported_sigalg_list:1}"
10979+
if "$fs_tls12_offered"; then
10980+
pr_bold " TLS 1.2 sig_algs offered: "
10981+
if [[ -z "$(sed -e 's/[A-Za-z\-]*+SHA1//g' -e 's/[A-Za-z\-]*+MD5//g' -e 's/ //g' <<< "$tls12_supported_sigalg_list")" ]]; then
10982+
prln_svrty_critical "$(out_row_aligned_max_width "$tls12_supported_sigalg_list " " " $TERM_WIDTH)"
10983+
fileout "${jsonID}_TLS12_sig_algs" "CRITICAL" "$tls12_supported_sigalg_list"
10984+
else
10985+
out_row_aligned_max_width_by_entry "$tls12_supported_sigalg_list " " " $TERM_WIDTH pr_sigalg_quality
10986+
outln
10987+
if [[ "$tls12_supported_sigalg_list" =~ MD5 ]]; then
10988+
fileout "${jsonID}_TLS12_sig_algs" "HIGH" "$tls12_supported_sigalg_list"
10989+
elif [[ "$tls12_supported_sigalg_list" =~ SHA1 ]]; then
10990+
fileout "${jsonID}_TLS12_sig_algs" "LOW" "$tls12_supported_sigalg_list"
10991+
else
10992+
fileout "${jsonID}_TLS12_sig_algs" "INFO" "$tls12_supported_sigalg_list"
10993+
fi
10994+
fi
10995+
fi
10996+
if "$fs_tls13_offered"; then
10997+
pr_bold " TLS 1.3 sig_algs offered: "
10998+
# If only SHA1 and MD5 signature algorithms are supported, this is a critical finding.
10999+
# If SHA1 and/or MD5 are supported, but stronger algorithms are also supported, the
11000+
# severity is less.
11001+
if [[ -z "$(sed -e 's/[A-Za-z\-]*+SHA1//g' -e 's/[A-Za-z\-]*+MD5//g' -e 's/ //g' <<< "$tls13_supported_sigalg_list")" ]]; then
11002+
prln_svrty_critical "$(out_row_aligned_max_width "$tls13_supported_sigalg_list " " " $TERM_WIDTH)"
11003+
fileout "${jsonID}_TLS13_sig_algs" "CRITICAL" "$tls13_supported_sigalg_list"
11004+
else
11005+
out_row_aligned_max_width_by_entry "$tls13_supported_sigalg_list " " " $TERM_WIDTH pr_sigalg_quality
11006+
outln
11007+
if [[ "$tls13_supported_sigalg_list" =~ MD5 ]]; then
11008+
fileout "${jsonID}_TLS13_sig_algs" "HIGH" "$tls13_supported_sigalg_list"
11009+
elif [[ "$tls13_supported_sigalg_list" =~ SHA1 ]]; then
11010+
fileout "${jsonID}_TLS13_sig_algs" "LOW" "$tls13_supported_sigalg_list"
11011+
else
11012+
fileout "${jsonID}_TLS13_sig_algs" "INFO" "$tls13_supported_sigalg_list"
11013+
fi
11014+
fi
1086411015
fi
1086511016
fi
10866-
outln
1086711017

1086811018
tmpfile_handle ${FUNCNAME[0]}.txt
1086911019
"$using_sockets" && HAS_DH_BITS="$has_dh_bits"

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