diff options
Diffstat (limited to 'debian/patches/Fix-post-issuance-validation-logic.patch')
| -rw-r--r-- | debian/patches/Fix-post-issuance-validation-logic.patch | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/debian/patches/Fix-post-issuance-validation-logic.patch b/debian/patches/Fix-post-issuance-validation-logic.patch new file mode 100644 index 0000000..f5ecbed --- /dev/null +++ b/debian/patches/Fix-post-issuance-validation-logic.patch @@ -0,0 +1,211 @@ +From: Guilhem Moulin <guilhem@fripost.org> +Date: Thu, 13 Jun 2024 03:32:04 +0200 +Subject: Fix post-issuance validation logic + +Rather than adding intermediates in the certificate bundle we now +validate the leaf certificate with intermediates as untrusted (used for +chain building only). Only the root certificates are used as trust +anchor. + +Not pining intermediate certificates anymore is in line with Let's +Encrypt's latest recommendations: + + Rotating the set of intermediates we issue from helps keep the + Internet agile and more secure. It encourages automation and + efficiency, and discourages outdated practices like key pinning. + “Key Pinning” is a practice in which clients — either ACME clients + getting certificates for their site, or apps connecting to their own + backend servers — decide to trust only a single issuing intermediate + certificate rather than delegating trust to the system trust store. + Updating pinned keys is a manual process, which leads to an + increased risk of errors and potential business continuity failures. + — https://letsencrypt.org/2024/03/19/new-intermediate-certificates + +Origin: https://git.guilhem.org/lacme/commit/?id=9cb882a468843bf8ce9598de8769d5baaaaae3ea +Bug-Debian: https://bugs.debian.org/1072847 +--- + Makefile | 8 ++----- + lacme | 26 +++++++++++++++++---- + tests/cert-install | 67 ++++++++++++++++++++++++++++++++++++++++++------------ + 3 files changed, 76 insertions(+), 25 deletions(-) + +diff --git a/Makefile b/Makefile +index 10e55c5..cb2f4ed 100644 +--- a/Makefile ++++ b/Makefile +@@ -16,17 +16,13 @@ $(MANUAL_FILES): $(BUILDDIR)/%: $(BUILDDIR)/%.md + # used for validation, see https://letsencrypt.org/certificates/ + $(BUILDDIR)/certs/ca-certificates.crt: \ + certs/isrgrootx1.pem \ +- certs/isrg-root-x2.pem \ +- certs/lets-encrypt-r[34].pem \ +- certs/lets-encrypt-e[12].pem ++ certs/isrg-root-x2.pem + mkdir -pv -- $(@D) + cat -- $^ >$@ + + # Staging Environment for tests, see https://letsencrypt.org/docs/staging-environment/ + $(BUILDDIR)/certs-staging/ca-certificates.crt: \ +- certs-staging/letsencrypt-stg-root-x[12].pem \ +- certs-staging/letsencrypt-stg-int-r[34].pem \ +- certs-staging/letsencrypt-stg-int-e[12].pem ++ certs-staging/letsencrypt-stg-root-x[12].pem + mkdir -pv -- $(@D) + cat -- $^ >$@ + +diff --git a/lacme b/lacme +index 6284c66..86a0516 100755 +--- a/lacme ++++ b/lacme +@@ -822,21 +822,31 @@ elsif ($COMMAND eq 'newOrder' or $COMMAND eq 'new-cert') { + next; + } + +- my $cert; ++ my @chain; + eval { + my $mem = Net::SSLeay::BIO_s_mem() or die; + my $bio = Net::SSLeay::BIO_new($mem) or die; + die "incomplete write" unless + Net::SSLeay::BIO_write($bio, $chain) == length($chain); +- my $x509 = Net::SSLeay::PEM_read_bio_X509($bio); +- $cert = Net::SSLeay::PEM_get_string_X509($x509); ++ ++ my $sk_x509_info = Net::SSLeay::PEM_X509_INFO_read_bio($bio); ++ ++ my $n = Net::SSLeay::sk_X509_INFO_num($sk_x509_info); ++ for (my $i = 0; $i < $n; $i++) { ++ my $x509_info = Net::SSLeay::sk_X509_INFO_value($sk_x509_info, $i); ++ my $x509 = Net::SSLeay::P_X509_INFO_get_x509($x509_info); ++ my $cert = Net::SSLeay::PEM_get_string_X509($x509); ++ push @chain, $cert; ++ } ++ + Net::SSLeay::BIO_free($bio) or die; + }; +- if ($@) { ++ if ($@ or !@chain) { + print STDERR "[$s] Error: Received bogus X.509 certificate from ACME server!\n"; + $rv = 1; + next; + } ++ my $cert = shift @chain; # leave only the intermediate in @chain + + # extract pubkeys from CSR and cert, and ensure they match + # XXX would be nice to use X509_get_X509_PUBKEY and X509_REQ_get_X509_PUBKEY here, +@@ -852,9 +862,15 @@ elsif ($COMMAND eq 'newOrder' or $COMMAND eq 'new-cert') { + + # verify certificate validity against the CA bundle + if ((my $CAfile = $conf->{CAfile} // '@@datadir@@/lacme/ca-certificates.crt') ne '') { ++ my $chain_tmp = File::Temp::->new(SUFFIX => '.crt', TMPDIR => 1) // die; ++ $chain_tmp->say($_) foreach @chain; ++ $chain_tmp->flush(); ++ + my %args = (in => $cert); + $args{out} = \*STDERR if $OPTS{debug}; +- my @options = ('-trusted', $CAfile, '-purpose', 'sslserver', '-x509_strict'); ++ my @options = ('-trusted', $CAfile); ++ push @options, '-untrusted', $chain_tmp->filename() if @chain; ++ push @options, ('-purpose', 'sslserver', '-x509_strict'); + push @options, '-show_chain' if $OPTS{debug}; + if (spawn(\%args, 'openssl', 'verify', @options)) { + print STDERR "[$s] Error: Received invalid X.509 certificate from ACME server!\n"; +diff --git a/tests/cert-install b/tests/cert-install +index 4b3e820..4415cdd 100644 +--- a/tests/cert-install ++++ b/tests/cert-install +@@ -28,6 +28,55 @@ EOF + grepstderr -Fxq "[bad3] Warning: Couldn't generate CSR, skipping" + + ++check_spki() { ++ local p1="$1" p2="$2" s1 s2 ++ s1="$(openssl x509 -in "$p1" -noout -pubkey \ ++ | openssl pkey -pubin -outform DER \ ++ | openssl dgst -sha256 \ ++ | sed 's/.*=\s*//')" ++ s2="$(openssl pkey -in "$p2" -pubout -outform DER \ ++ | openssl dgst -sha256 \ ++ | sed 's/.*=\s*//')" ++ if [ -n "$s1" ] && [ "$s1" = "$s2" ]; then ++ return 0 ++ else ++ printf "%s != %s\\n" "$s1" "$s2" >&2 ++ return 1 ++ fi ++} ++check_chain() { ++ local priv="$1" chain="$2" leaf="${3-}" pem0 ++ ++ csplit -f "${chain%.crt}.chain.pem" "$chain" \ ++ "/-----BEGIN CERTIFICATE-----/" "{*}" ++ ++ pem0="${chain%.crt}.chain.pem00" ++ if [ ! -s "$pem0" ]; then ++ # 00 is empty, leaf cert is at 01 ++ rm -f -- "$pem0" ++ pem0="${chain%.crt}.chain.pem01" ++ fi ++ test -s "$pem0" || return 1 ++ check_spki "$pem0" "$priv" ++ ++ if [ -n "$leaf" ]; then ++ diff --ignore-blank-lines --unified "$pem0" "$leaf" || return 1 ++ fi ++ ++ leaf="${chain%.crt}.leaf.pem" ++ mv -T -- "$pem0" "$leaf" ++ ++ intermediates="${chain%.crt}.intermediates.pem" ++ sed "/^$/d" "${chain%.crt}.chain.pem"[0-9]* >"$intermediates" ++ test -s "$intermediates" || return 1 # ensure there is at least one intermediate ++ ++ openssl verify -trusted /usr/share/lacme/ca-certificates.crt \ ++ -untrusted "$intermediates" \ ++ -purpose sslserver -x509_strict \ ++ -show_chain \ ++ -- "$leaf" || return 1 ++} ++ + # 'certificate' installs only the leaf certificate + openssl genpkey -algorithm RSA -out /etc/lacme/test1.key + subject="/CN=$(head -c10 /dev/urandom | base32 -w0).$DOMAINNAME" +@@ -42,6 +91,7 @@ lacme newOrder test1 2>"$STDERR" || fail newOrder test1 + test /etc/lacme/test1.crt -nt /etc/lacme/test1.key + sed -n "0,/^-----END CERTIFICATE-----$/ p" /etc/lacme/test1.crt >/etc/lacme/test1.pem + diff --unified /etc/lacme/test1.crt /etc/lacme/test1.pem ++check_spki /etc/lacme/test1.crt /etc/lacme/test1.key + + + check_hash() { +@@ -70,16 +120,7 @@ EOF + + lacme newOrder test2 2>"$STDERR" || fail newOrder test2 + test /etc/lacme/test2.crt -nt /etc/lacme/test2.key +-csplit -f /etc/lacme/test2.chain.pem /etc/lacme/test2.crt \ +- "/-----BEGIN CERTIFICATE-----/" "{*}" +-test -s /etc/lacme/test2.chain.pem01 # leaf cert (00 is empty) +-rm -f /etc/lacme/test2.chain.pem0[01] +-test -s /etc/lacme/test2.chain.pem02 # depth 1 +- +-# all certificates at depth >=1 must be in our CA bundle +-for p in /etc/lacme/test2.chain.pem*; do +- check_hash "$p" +-done ++check_chain /etc/lacme/test2.key /etc/lacme/test2.crt + + # 'certificate' + 'certificate-chain' + openssl genpkey -algorithm RSA -out /etc/lacme/test3.key +@@ -94,10 +135,8 @@ EOF + lacme newOrder test3 2>"$STDERR" || fail newOrder test3 + test /etc/lacme/test3.pem -nt /etc/lacme/test3.key + test /etc/lacme/test3.crt -nt /etc/lacme/test3.key +-csplit -f /etc/lacme/test3.chain.pem /etc/lacme/test3.crt \ +- "/-----BEGIN CERTIFICATE-----/" "{*}" +-sed -i "/^$/d" /etc/lacme/test3.chain.pem* +-diff -q /etc/lacme/test3.chain.pem01 /etc/lacme/test3.pem ++check_chain /etc/lacme/test3.key /etc/lacme/test3.crt /etc/lacme/test3.pem ++ + st="$(stat -c "%U:%G %#a" /etc/lacme/test3.pem)" + [ "$st" = "root:root 0644" ] + st="$(stat -c "%U:%G %#a" /etc/lacme/test3.crt)" |