[pve-devel] [PATCH v2 common 1/4] add Certificate helper

Fabian Grünbichler f.gruenbichler at proxmox.com
Thu Apr 19 14:01:32 CEST 2018


general purpose certificate related helper functions

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---
 src/Makefile           |   1 +
 src/PVE/Certificate.pm | 396 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 397 insertions(+)
 create mode 100644 src/PVE/Certificate.pm

diff --git a/src/Makefile b/src/Makefile
index e544882..c81991d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -8,6 +8,7 @@ PERLDIR=${PREFIX}/share/perl5
 
 LIB_SOURCES = \
 	AtomicFile.pm \
+	Certificate.pm \
 	CLIHandler.pm \
 	CalendarEvent.pm \
 	CpuSet.pm \
diff --git a/src/PVE/Certificate.pm b/src/PVE/Certificate.pm
new file mode 100644
index 0000000..b0b9bbf
--- /dev/null
+++ b/src/PVE/Certificate.pm
@@ -0,0 +1,396 @@
+package PVE::Certificate;
+
+use strict;
+use warnings;
+
+use Date::Parse;
+use Encode qw(decode encode);
+use MIME::Base64 qw(decode_base64 encode_base64);
+use Net::SSLeay;
+
+use PVE::JSONSchema qw(get_standard_option);
+
+Net::SSLeay::load_error_strings();
+Net::SSLeay::randomize();
+
+PVE::JSONSchema::register_format('pem-certificate', sub {
+    my ($content, $noerr) = @_;
+
+    return check_pem($content, noerr => $noerr);
+});
+
+PVE::JSONSchema::register_format('pem-certificate-chain', sub {
+    my ($content, $noerr) = @_;
+
+    return check_pem($content, noerr => $noerr, multiple => 1);
+});
+
+PVE::JSONSchema::register_format('pem-string', sub {
+    my ($content, $noerr) = @_;
+
+    return check_pem($content, noerr => $noerr, label => qr/.*?/);
+});
+
+PVE::JSONSchema::register_standard_option('pve-certificate-info', {
+    type => 'object',
+    properties => {
+	filename => {
+	    type => 'string',
+	    optional => 1,
+	},
+	fingerprint => get_standard_option('fingerprint-sha256', {
+	    optional => 1,
+	}),
+	subject => {
+	    type => 'string',
+	    description => 'Certificate subject name.',
+	    optional => 1,
+	},
+	issuer => {
+	    type => 'string',
+	    description => 'Certificate issuer name.',
+	    optional => 1,
+	},
+	notbefore => {
+	    type => 'integer',
+	    description => 'Certificate\'s notBefore timestamp (UNIX epoch).',
+	    optional => 1,
+	},
+	notafter => {
+	    type => 'integer',
+	    description => 'Certificate\'s notAfter timestamp (UNIX epoch).',
+	    optional => 1,
+	},
+	san => {
+	    type => 'array',
+	    description => 'List of Certificate\'s SubjectAlternativeName entries.',
+	    optional => 1,
+	    items => {
+		type => 'string',
+	    },
+	},
+	pem => {
+	    type => 'string',
+	    description => 'Certificate in PEM format',
+	    format => 'pem-certificate',
+	    optional => 1,
+	},
+    },
+});
+
+# see RFC 7468
+my $b64_char_re = qr![0-9A-Za-z\+/]!;
+my $header_re = sub {
+    my ($label) = @_;
+    return qr!-----BEGIN\ $label-----(?:\s|\n)*!;
+};
+my $footer_re = sub {
+    my ($label) = @_;
+    return qr!-----END\ $label-----(?:\s|\n)*!;
+};
+my $pem_re = sub {
+    my ($label) = @_;
+
+    my $header = $header_re->($label);
+    my $footer = $footer_re->($label);
+
+    return qr{
+	$header
+	(?:(?:$b64_char_re)+\s*\n)*
+	(?:$b64_char_re)*(?:=\s*\n=|={0,2})?\s*\n
+	$footer
+    }x;
+};
+
+sub strip_leading_text {
+    my ($content) = @_;
+
+    my $header = $header_re->(qr/.*?/);
+    $content =~ s/^.*?(?=$header)//s;
+    return $content;
+};
+
+sub split_pem {
+    my ($content, %opts) = @_;
+    my $label = $opts{label} // 'CERTIFICATE';
+
+    my $header = $header_re->($label);
+    return split(/(?=$header)/,$content);
+}
+
+sub check_pem {
+    my ($content, %opts) = @_;
+
+    my $label = $opts{label} // 'CERTIFICATE';
+    my $multiple = $opts{multiple};
+    my $noerr = $opts{noerr};
+
+    $content = strip_leading_text($content);
+
+    my $re = $pem_re->($label);
+
+    $re = qr/($re\n+)*$re/ if $multiple;
+
+    if ($content =~ /^$re$/) {
+	return $content;
+    } else {
+	return undef if $noerr;
+	die "not a valid PEM-formatted string.\n";
+    }
+}
+
+sub pem_to_der {
+    my ($content) = @_;
+
+    my $header = $header_re->(qr/.*?/);
+    my $footer = $footer_re->(qr/.*?/);
+
+    $content = strip_leading_text($content);
+
+    # only take first PEM entry
+    $content =~ s/^$header$//mg;
+    $content =~ s/$footer.*//sg;
+
+    $content = decode_base64($content);
+
+    return $content;
+}
+
+sub der_to_pem {
+    my ($content, %opts) = @_;
+
+    my $label = $opts{label} // 'CERTIFICATE';
+
+    my $b64 = encode_base64($content, '');
+    $b64 = join("\n", ($b64 =~ /.{1,64}/sg));
+    return "-----BEGIN $label-----\n$b64\n-----END $label-----\n";
+}
+
+my $ssl_die = sub {
+    my ($msg) = @_;
+    Net::SSLeay::die_now($msg);
+};
+
+my $ssl_warn = sub {
+    my ($msg) = @_;
+    Net::SSLeay::print_errs();
+    warn $msg if $msg;
+};
+
+my $read_certificate = sub {
+    my ($cert_path) = @_;
+
+    die "'$cert_path' does not exist!\n" if ! -e $cert_path;
+
+    my $bio = Net::SSLeay::BIO_new_file($cert_path, 'r')
+	or $ssl_die->("unable to read '$cert_path' - $!\n");
+
+    my $cert = Net::SSLeay::PEM_read_bio_X509($bio);
+    if (!$cert) {
+	Net::SSLeay::BIO_free($bio);
+	die "unable to read certificate from '$cert_path'\n";
+    }
+
+    return $cert;
+};
+
+sub convert_asn1_to_epoch {
+    my ($asn1_time) = @_;
+
+    $ssl_die->("invalid ASN1 time object\n") if !$asn1_time;
+    my $iso_time = Net::SSLeay::P_ASN1_TIME_get_isotime($asn1_time);
+    $ssl_die->("unable to parse ASN1 time\n") if $iso_time eq '';
+    return Date::Parse::str2time($iso_time);
+}
+
+sub get_certificate_info {
+    my ($cert_path) = @_;
+
+    my $cert = $read_certificate->($cert_path);
+
+    my $parse_san = sub {
+	my $res = [];
+	while (my ($type, $value) = splice(@_, 0, 2)) {
+	    if ($type != 2 && $type != 7) {
+		warn "unexpected SAN type encountered: $type\n";
+		next;
+	    }
+
+	    if ($type == 7) {
+		my $hex = unpack("H*", $value);
+		if (length($hex) == 8) {
+		    # IPv4
+		    $value = join(".", unpack("C4C4C4C4", $value));
+		} elsif (length($hex) == 32) {
+		    # IPv6
+		    $value = join(":", unpack("H4H4H4H4H4H4H4H4", $value));
+		} else {
+		    warn "cannot parse SAN IP entry '0x${hex}'\n";
+		    next;
+		}
+	    }
+
+	    push @$res, $value;
+	}
+	return $res;
+    };
+
+    my $info = {};
+
+    $info->{fingerprint} = Net::SSLeay::X509_get_fingerprint($cert, 'sha256');
+
+    my $subject = Net::SSLeay::X509_get_subject_name($cert);
+    if ($subject) {
+	$info->{subject} = Net::SSLeay::X509_NAME_oneline($subject);
+    }
+
+    my $issuer = Net::SSLeay::X509_get_issuer_name($cert);
+    if ($issuer) {
+	$info->{issuer} = Net::SSLeay::X509_NAME_oneline($issuer);
+    }
+
+    eval { $info->{notbefore} = convert_asn1_to_epoch(Net::SSLeay::X509_get_notBefore($cert)) };
+    warn $@ if $@;
+    eval { $info->{notafter} = convert_asn1_to_epoch(Net::SSLeay::X509_get_notAfter($cert)) };
+    warn $@ if $@;
+
+    $info->{san} = $parse_san->(Net::SSLeay::X509_get_subjectAltNames($cert));
+    $info->{pem} = Net::SSLeay::PEM_get_string_X509($cert);
+
+    Net::SSLeay::X509_free($cert);
+
+    $cert_path =~ s!^.*/!!g;
+    $info->{filename} = $cert_path;
+
+    return $info;
+};
+
+# Checks whether certificate expires before $timestamp (UNIX epoch)
+sub check_expiry {
+    my ($cert_path, $timestamp) = @_;
+
+    $timestamp //= time();
+
+    my $cert = $read_certificate->($cert_path);
+    my $not_after = eval { convert_asn1_to_epoch(Net::SSLeay::X509_get_notAfter($cert)) };
+    my $err = $@;
+
+    Net::SSLeay::X509_free($cert);
+
+    die $err if $err;
+
+    return ($not_after < $timestamp) ? 1 : 0;
+};
+
+# Create a CSR and certificate key for a given order
+# returns path to CSR file or path to CSR and key files
+sub generate_csr {
+    my (%attr) = @_;
+
+    # optional
+    my $bits = delete($attr{bits}) // 4096;
+    my $dig_alg = delete($attr{digest}) // 'sha256';
+    my $pem_key = delete($attr{private_key});
+
+    # required
+    my $identifiers = delete($attr{identifiers});
+
+    die "Identifiers are required to generate a CSR.\n"
+	if !defined($identifiers);
+
+    my $san = [ map { $_->{value} } grep { $_->{type} eq 'dns' } @$identifiers ];
+    die "DNS identifiers are required to generate a CSR.\n" if !scalar @$san;
+
+    my $md = eval { Net::SSLeay::EVP_get_digestbyname($dig_alg) };
+    die "Invalid digest algorithm '$dig_alg'\n" if !$md;
+
+    my ($bio, $pk, $req);
+
+    my $cleanup = sub {
+	my ($warn, $die_msg) = @_;
+	$ssl_warn->() if $warn;
+
+	Net::SSLeay::X509_REQ_free($req) if  $req;
+	Net::SSLeay::EVP_PKEY_free($pk) if $pk;
+	Net::SSLeay::BIO_free($bio) if $bio;
+
+	die $die_msg if $die_msg;
+    };
+
+    # this unfortunately causes a small memory leak, since there is no
+    # X509_NAME_free() (yet)
+    my $name = Net::SSLeay::X509_NAME_new();
+    $ssl_die->("Failed to allocate X509_NAME object\n") if !$name;
+    my $add_name_entry = sub {
+	my ($k, $v) = @_;
+	if (!Net::SSLeay::X509_NAME_add_entry_by_txt($name,
+	                                             $k,
+	                                             &Net::SSLeay::MBSTRING_UTF8,
+	                                             encode('utf-8', $v))) {
+	    $cleanup->(1, "Failed to add '$k'='$v' to DN\n");
+	}
+    };
+
+    $add_name_entry->('CN', @$san[0]);
+    for (qw(C ST L O OU)) {
+        if (defined(my $v = $attr{$_})) {
+	    $add_name_entry->($_, $v);
+        }
+    }
+
+    if (defined($pem_key)) {
+	my $bio_s_mem = Net::SSLeay::BIO_s_mem();
+	$cleanup->(1, "Failed to allocate BIO_s_mem for private key\n")
+	    if !$bio_s_mem;
+
+	$bio = Net::SSLeay::BIO_new($bio_s_mem);
+	$cleanup->(1, "Failed to allocate BIO for private key\n") if !$bio;
+
+	$cleanup->(1, "Failed to write PEM-encoded key to BIO\n")
+	    if Net::SSLeay::BIO_write($bio, $pem_key) <= 0;
+
+	$pk = Net::SSLeay::PEM_read_bio_PrivateKey($bio);
+	$cleanup->(1, "Failed to read private key into EVP_PKEY\n") if !$pk;
+    } else {
+	$pk = Net::SSLeay::EVP_PKEY_new();
+	$cleanup->(1, "Failed to allocate EVP_PKEY for private key\n") if !$pk;
+
+	my $rsa = Net::SSLeay::RSA_generate_key($bits, 65537);
+	$cleanup->(1, "Failed to generate RSA key pair\n") if !$rsa;
+
+	$cleanup->(1, "Failed to assign RSA key to EVP_PKEY\n")
+	    if !Net::SSLeay::EVP_PKEY_assign_RSA($pk, $rsa);
+    }
+
+    $req = Net::SSLeay::X509_REQ_new();
+    $cleanup->(1, "Failed to allocate X509_REQ\n") if !$req;
+
+    $cleanup->(1, "Failed to set subject name\n")
+	if (!Net::SSLeay::X509_REQ_set_subject_name($req, $name));
+
+    $cleanup->(1, "Failed to add extensions to CSR\n")
+	if !Net::SSLeay::P_X509_REQ_add_extensions($req,
+	        &Net::SSLeay::NID_key_usage => 'digitalSignature,keyEncipherment',
+	        &Net::SSLeay::NID_basic_constraints => 'CA:FALSE',
+	        &Net::SSLeay::NID_ext_key_usage => 'serverAuth,clientAuth',
+	        &Net::SSLeay::NID_subject_alt_name => join(',', map { "DNS:$_" } @$san),
+	);
+
+    $cleanup->(1, "Failed to set public key\n")
+	if !Net::SSLeay::X509_REQ_set_pubkey($req, $pk);
+
+    $cleanup->(1, "Failed to set CSR version\n")
+	if !Net::SSLeay::X509_REQ_set_version($req, 2);
+
+    $cleanup->(1, "Failed to sign CSR\n")
+	if !Net::SSLeay::X509_REQ_sign($req, $pk, $md);
+
+    my $pk_pem = Net::SSLeay::PEM_get_string_PrivateKey($pk);
+    my $req_pem = Net::SSLeay::PEM_get_string_X509_REQ($req);
+
+    $cleanup->();
+
+    return wantarray ? ($req_pem, $pk_pem) : $req_pem;
+}
+
+1;
-- 
2.14.2





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