#include <linux/kernel.h>
#include <linux/err.h>
-#include <crypto/public_key.h>
-#include <crypto/hash.h>
-#include <keys/asymmetric-type.h>
#include <keys/system_keyring.h>
+#include <crypto/public_key.h>
+#include <crypto/pkcs7.h>
#include "module-internal.h"
/*
* - Information block
*/
struct module_signature {
- u8 algo; /* Public-key crypto algorithm [enum pkey_algo] */
- u8 hash; /* Digest algorithm [enum hash_algo] */
- u8 id_type; /* Key identifier type [enum pkey_id_type] */
- u8 signer_len; /* Length of signer's name */
- u8 key_id_len; /* Length of key identifier */
+ u8 algo; /* Public-key crypto algorithm [0] */
+ u8 hash; /* Digest algorithm [0] */
+ u8 id_type; /* Key identifier type [PKEY_ID_PKCS7] */
+ u8 signer_len; /* Length of signer's name [0] */
+ u8 key_id_len; /* Length of key identifier [0] */
u8 __pad[3];
__be32 sig_len; /* Length of signature data */
};
/*
- * Digest the module contents.
+ * Verify a PKCS#7-based signature on a module.
*/
-static struct public_key_signature *mod_make_digest(enum hash_algo hash,
- const void *mod,
- unsigned long modlen)
+static int mod_verify_pkcs7(const void *mod, unsigned long modlen,
+ const void *raw_pkcs7, size_t pkcs7_len)
{
- struct public_key_signature *pks;
- struct crypto_shash *tfm;
- struct shash_desc *desc;
- size_t digest_size, desc_size;
+ struct pkcs7_message *pkcs7;
+ bool trusted;
int ret;
- pr_devel("==>%s()\n", __func__);
-
- /* Allocate the hashing algorithm we're going to need and find out how
- * big the hash operational data will be.
- */
- tfm = crypto_alloc_shash(hash_algo_name[hash], 0, 0);
- if (IS_ERR(tfm))
- return (PTR_ERR(tfm) == -ENOENT) ? ERR_PTR(-ENOPKG) : ERR_CAST(tfm);
-
- desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
- digest_size = crypto_shash_digestsize(tfm);
-
- /* We allocate the hash operational data storage on the end of our
- * context data and the digest output buffer on the end of that.
- */
- ret = -ENOMEM;
- pks = kzalloc(digest_size + sizeof(*pks) + desc_size, GFP_KERNEL);
- if (!pks)
- goto error_no_pks;
-
- pks->pkey_hash_algo = hash;
- pks->digest = (u8 *)pks + sizeof(*pks) + desc_size;
- pks->digest_size = digest_size;
-
- desc = (void *)pks + sizeof(*pks);
- desc->tfm = tfm;
- desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
-
- ret = crypto_shash_init(desc);
+ pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
+ if (IS_ERR(pkcs7))
+ return PTR_ERR(pkcs7);
+
+ /* The data should be detached - so we need to supply it. */
+ if (pkcs7_supply_detached_data(pkcs7, mod, modlen) < 0) {
+ pr_err("PKCS#7 signature with non-detached data\n");
+ ret = -EBADMSG;
+ goto error;
+ }
+
+ ret = pkcs7_verify(pkcs7);
if (ret < 0)
goto error;
- ret = crypto_shash_finup(desc, mod, modlen, pks->digest);
+ ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
if (ret < 0)
goto error;
- crypto_free_shash(tfm);
- pr_devel("<==%s() = ok\n", __func__);
- return pks;
+ if (!trusted) {
+ pr_err("PKCS#7 signature not signed with a trusted key\n");
+ ret = -ENOKEY;
+ }
error:
- kfree(pks);
-error_no_pks:
- crypto_free_shash(tfm);
+ pkcs7_free_message(pkcs7);
pr_devel("<==%s() = %d\n", __func__, ret);
- return ERR_PTR(ret);
-}
-
-/*
- * Extract an MPI array from the signature data. This represents the actual
- * signature. Each raw MPI is prefaced by a BE 2-byte value indicating the
- * size of the MPI in bytes.
- *
- * RSA signatures only have one MPI, so currently we only read one.
- */
-static int mod_extract_mpi_array(struct public_key_signature *pks,
- const void *data, size_t len)
-{
- size_t nbytes;
- MPI mpi;
-
- if (len < 3)
- return -EBADMSG;
- nbytes = ((const u8 *)data)[0] << 8 | ((const u8 *)data)[1];
- data += 2;
- len -= 2;
- if (len != nbytes)
- return -EBADMSG;
-
- mpi = mpi_read_raw_data(data, nbytes);
- if (!mpi)
- return -ENOMEM;
- pks->mpi[0] = mpi;
- pks->nr_mpi = 1;
- return 0;
-}
-
-/*
- * Request an asymmetric key.
- */
-static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
- const u8 *key_id, size_t key_id_len)
-{
- key_ref_t key;
- size_t i;
- char *id, *q;
-
- pr_devel("==>%s(,%zu,,%zu)\n", __func__, signer_len, key_id_len);
-
- /* Construct an identifier. */
- id = kmalloc(signer_len + 2 + key_id_len * 2 + 1, GFP_KERNEL);
- if (!id)
- return ERR_PTR(-ENOKEY);
-
- memcpy(id, signer, signer_len);
-
- q = id + signer_len;
- *q++ = ':';
- *q++ = ' ';
- for (i = 0; i < key_id_len; i++) {
- *q++ = hex_asc[*key_id >> 4];
- *q++ = hex_asc[*key_id++ & 0x0f];
- }
-
- *q = 0;
-
- pr_debug("Look up: \"%s\"\n", id);
-
- key = keyring_search(make_key_ref(system_trusted_keyring, 1),
- &key_type_asymmetric, id);
- if (IS_ERR(key))
- pr_warn("Request for unknown module key '%s' err %ld\n",
- id, PTR_ERR(key));
- kfree(id);
-
- if (IS_ERR(key)) {
- switch (PTR_ERR(key)) {
- /* Hide some search errors */
- case -EACCES:
- case -ENOTDIR:
- case -EAGAIN:
- return ERR_PTR(-ENOKEY);
- default:
- return ERR_CAST(key);
- }
- }
-
- pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key_ref_to_ptr(key)));
- return key_ref_to_ptr(key);
+ return ret;
}
/*
*/
int mod_verify_sig(const void *mod, unsigned long *_modlen)
{
- struct public_key_signature *pks;
struct module_signature ms;
- struct key *key;
- const void *sig;
size_t modlen = *_modlen, sig_len;
- int ret;
pr_devel("==>%s(,%zu)\n", __func__, modlen);
if (sig_len >= modlen)
return -EBADMSG;
modlen -= sig_len;
- if ((size_t)ms.signer_len + ms.key_id_len >= modlen)
- return -EBADMSG;
- modlen -= (size_t)ms.signer_len + ms.key_id_len;
-
*_modlen = modlen;
- sig = mod + modlen;
-
- /* For the moment, only support RSA and X.509 identifiers */
- if (ms.algo != PKEY_ALGO_RSA ||
- ms.id_type != PKEY_ID_X509)
- return -ENOPKG;
- if (ms.hash >= PKEY_HASH__LAST ||
- !hash_algo_name[ms.hash])
+ if (ms.id_type != PKEY_ID_PKCS7) {
+ pr_err("Module is not signed with expected PKCS#7 message\n");
return -ENOPKG;
-
- key = request_asymmetric_key(sig, ms.signer_len,
- sig + ms.signer_len, ms.key_id_len);
- if (IS_ERR(key))
- return PTR_ERR(key);
-
- pks = mod_make_digest(ms.hash, mod, modlen);
- if (IS_ERR(pks)) {
- ret = PTR_ERR(pks);
- goto error_put_key;
}
- ret = mod_extract_mpi_array(pks, sig + ms.signer_len + ms.key_id_len,
- sig_len);
- if (ret < 0)
- goto error_free_pks;
-
- ret = verify_signature(key, pks);
- pr_devel("verify_signature() = %d\n", ret);
+ if (ms.algo != 0 ||
+ ms.hash != 0 ||
+ ms.signer_len != 0 ||
+ ms.key_id_len != 0 ||
+ ms.__pad[0] != 0 ||
+ ms.__pad[1] != 0 ||
+ ms.__pad[2] != 0) {
+ pr_err("PKCS#7 signature info has unexpected non-zero params\n");
+ return -EBADMSG;
+ }
-error_free_pks:
- mpi_free(pks->rsa.s);
- kfree(pks);
-error_put_key:
- key_put(key);
- pr_devel("<==%s() = %d\n", __func__, ret);
- return ret;
+ return mod_verify_pkcs7(mod, modlen, mod + modlen, sig_len);
}
+++ /dev/null
-#!/usr/bin/perl -w
-#
-# Sign a module file using the given key.
-#
-
-my $USAGE =
-"Usage: scripts/sign-file [-v] <hash algo> <key> <x509> <module> [<dest>]\n" .
-" scripts/sign-file [-v] -s <raw sig> <hash algo> <x509> <module> [<dest>]\n";
-
-use strict;
-use FileHandle;
-use IPC::Open2;
-use Getopt::Std;
-
-my %opts;
-getopts('vs:', \%opts) or die $USAGE;
-my $verbose = $opts{'v'};
-my $signature_file = $opts{'s'};
-
-die $USAGE if ($#ARGV > 4);
-die $USAGE if (!$signature_file && $#ARGV < 3 || $signature_file && $#ARGV < 2);
-
-my $dgst = shift @ARGV;
-my $private_key;
-if (!$signature_file) {
- $private_key = shift @ARGV;
-}
-my $x509 = shift @ARGV;
-my $module = shift @ARGV;
-my ($dest, $keep_orig);
-if (@ARGV) {
- $dest = $ARGV[0];
- $keep_orig = 1;
-} else {
- $dest = $module . "~";
-}
-
-die "Can't read private key\n" if (!$signature_file && !-r $private_key);
-die "Can't read signature file\n" if ($signature_file && !-r $signature_file);
-die "Can't read X.509 certificate\n" unless (-r $x509);
-die "Can't read module\n" unless (-r $module);
-
-#
-# Function to read the contents of a file into a variable.
-#
-sub read_file($)
-{
- my ($file) = @_;
- my $contents;
- my $len;
-
- open(FD, "<$file") || die $file;
- binmode FD;
- my @st = stat(FD);
- die $file if (!@st);
- $len = read(FD, $contents, $st[7]) || die $file;
- close(FD) || die $file;
- die "$file: Wanted length ", $st[7], ", got ", $len, "\n"
- if ($len != $st[7]);
- return $contents;
-}
-
-###############################################################################
-#
-# First of all, we have to parse the X.509 certificate to find certain details
-# about it.
-#
-# We read the DER-encoded X509 certificate and parse it to extract the Subject
-# name and Subject Key Identifier. Theis provides the data we need to build
-# the certificate identifier.
-#
-# The signer's name part of the identifier is fabricated from the commonName,
-# the organizationName or the emailAddress components of the X.509 subject
-# name.
-#
-# The subject key ID is used to select which of that signer's certificates
-# we're intending to use to sign the module.
-#
-###############################################################################
-my $x509_certificate = read_file($x509);
-
-my $UNIV = 0 << 6;
-my $APPL = 1 << 6;
-my $CONT = 2 << 6;
-my $PRIV = 3 << 6;
-
-my $CONS = 0x20;
-
-my $BOOLEAN = 0x01;
-my $INTEGER = 0x02;
-my $BIT_STRING = 0x03;
-my $OCTET_STRING = 0x04;
-my $NULL = 0x05;
-my $OBJ_ID = 0x06;
-my $UTF8String = 0x0c;
-my $SEQUENCE = 0x10;
-my $SET = 0x11;
-my $UTCTime = 0x17;
-my $GeneralizedTime = 0x18;
-
-my %OIDs = (
- pack("CCC", 85, 4, 3) => "commonName",
- pack("CCC", 85, 4, 6) => "countryName",
- pack("CCC", 85, 4, 10) => "organizationName",
- pack("CCC", 85, 4, 11) => "organizationUnitName",
- pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 1) => "rsaEncryption",
- pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 1, 5) => "sha1WithRSAEncryption",
- pack("CCCCCCCCC", 42, 134, 72, 134, 247, 13, 1, 9, 1) => "emailAddress",
- pack("CCC", 85, 29, 35) => "authorityKeyIdentifier",
- pack("CCC", 85, 29, 14) => "subjectKeyIdentifier",
- pack("CCC", 85, 29, 19) => "basicConstraints"
-);
-
-###############################################################################
-#
-# Extract an ASN.1 element from a string and return information about it.
-#
-###############################################################################
-sub asn1_extract($$@)
-{
- my ($cursor, $expected_tag, $optional) = @_;
-
- return [ -1 ]
- if ($cursor->[1] == 0 && $optional);
-
- die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (elem ", $cursor->[1], ")\n"
- if ($cursor->[1] < 2);
-
- my ($tag, $len) = unpack("CC", substr(${$cursor->[2]}, $cursor->[0], 2));
-
- if ($expected_tag != -1 && $tag != $expected_tag) {
- return [ -1 ]
- if ($optional);
- die $x509, ": ", $cursor->[0], ": ASN.1 unexpected tag (", $tag,
- " not ", $expected_tag, ")\n";
- }
-
- $cursor->[0] += 2;
- $cursor->[1] -= 2;
-
- die $x509, ": ", $cursor->[0], ": ASN.1 long tag\n"
- if (($tag & 0x1f) == 0x1f);
- die $x509, ": ", $cursor->[0], ": ASN.1 indefinite length\n"
- if ($len == 0x80);
-
- if ($len > 0x80) {
- my $l = $len - 0x80;
- die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (len len $l)\n"
- if ($cursor->[1] < $l);
-
- if ($l == 0x1) {
- $len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1));
- } elsif ($l == 0x2) {
- $len = unpack("n", substr(${$cursor->[2]}, $cursor->[0], 2));
- } elsif ($l == 0x3) {
- $len = unpack("C", substr(${$cursor->[2]}, $cursor->[0], 1)) << 16;
- $len = unpack("n", substr(${$cursor->[2]}, $cursor->[0] + 1, 2));
- } elsif ($l == 0x4) {
- $len = unpack("N", substr(${$cursor->[2]}, $cursor->[0], 4));
- } else {
- die $x509, ": ", $cursor->[0], ": ASN.1 element too long (", $l, ")\n";
- }
-
- $cursor->[0] += $l;
- $cursor->[1] -= $l;
- }
-
- die $x509, ": ", $cursor->[0], ": ASN.1 data underrun (", $len, ")\n"
- if ($cursor->[1] < $len);
-
- my $ret = [ $tag, [ $cursor->[0], $len, $cursor->[2] ] ];
- $cursor->[0] += $len;
- $cursor->[1] -= $len;
-
- return $ret;
-}
-
-###############################################################################
-#
-# Retrieve the data referred to by a cursor
-#
-###############################################################################
-sub asn1_retrieve($)
-{
- my ($cursor) = @_;
- my ($offset, $len, $data) = @$cursor;
- return substr($$data, $offset, $len);
-}
-
-###############################################################################
-#
-# Roughly parse the X.509 certificate
-#
-###############################################################################
-my $cursor = [ 0, length($x509_certificate), \$x509_certificate ];
-
-my $cert = asn1_extract($cursor, $UNIV | $CONS | $SEQUENCE);
-my $tbs = asn1_extract($cert->[1], $UNIV | $CONS | $SEQUENCE);
-my $version = asn1_extract($tbs->[1], $CONT | $CONS | 0, 1);
-my $serial_number = asn1_extract($tbs->[1], $UNIV | $INTEGER);
-my $sig_type = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
-my $issuer = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
-my $validity = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
-my $subject = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
-my $key = asn1_extract($tbs->[1], $UNIV | $CONS | $SEQUENCE);
-my $issuer_uid = asn1_extract($tbs->[1], $CONT | $CONS | 1, 1);
-my $subject_uid = asn1_extract($tbs->[1], $CONT | $CONS | 2, 1);
-my $extension_list = asn1_extract($tbs->[1], $CONT | $CONS | 3, 1);
-
-my $subject_key_id = ();
-my $authority_key_id = ();
-
-#
-# Parse the extension list
-#
-if ($extension_list->[0] != -1) {
- my $extensions = asn1_extract($extension_list->[1], $UNIV | $CONS | $SEQUENCE);
-
- while ($extensions->[1]->[1] > 0) {
- my $ext = asn1_extract($extensions->[1], $UNIV | $CONS | $SEQUENCE);
- my $x_oid = asn1_extract($ext->[1], $UNIV | $OBJ_ID);
- my $x_crit = asn1_extract($ext->[1], $UNIV | $BOOLEAN, 1);
- my $x_val = asn1_extract($ext->[1], $UNIV | $OCTET_STRING);
-
- my $raw_oid = asn1_retrieve($x_oid->[1]);
- next if (!exists($OIDs{$raw_oid}));
- my $x_type = $OIDs{$raw_oid};
-
- my $raw_value = asn1_retrieve($x_val->[1]);
-
- if ($x_type eq "subjectKeyIdentifier") {
- my $vcursor = [ 0, length($raw_value), \$raw_value ];
-
- $subject_key_id = asn1_extract($vcursor, $UNIV | $OCTET_STRING);
- }
- }
-}
-
-###############################################################################
-#
-# Determine what we're going to use as the signer's name. In order of
-# preference, take one of: commonName, organizationName or emailAddress.
-#
-###############################################################################
-my $org = "";
-my $cn = "";
-my $email = "";
-
-while ($subject->[1]->[1] > 0) {
- my $rdn = asn1_extract($subject->[1], $UNIV | $CONS | $SET);
- my $attr = asn1_extract($rdn->[1], $UNIV | $CONS | $SEQUENCE);
- my $n_oid = asn1_extract($attr->[1], $UNIV | $OBJ_ID);
- my $n_val = asn1_extract($attr->[1], -1);
-
- my $raw_oid = asn1_retrieve($n_oid->[1]);
- next if (!exists($OIDs{$raw_oid}));
- my $n_type = $OIDs{$raw_oid};
-
- my $raw_value = asn1_retrieve($n_val->[1]);
-
- if ($n_type eq "organizationName") {
- $org = $raw_value;
- } elsif ($n_type eq "commonName") {
- $cn = $raw_value;
- } elsif ($n_type eq "emailAddress") {
- $email = $raw_value;
- }
-}
-
-my $signers_name = $email;
-
-if ($org && $cn) {
- # Don't use the organizationName if the commonName repeats it
- if (length($org) <= length($cn) &&
- substr($cn, 0, length($org)) eq $org) {
- $signers_name = $cn;
- goto got_id_name;
- }
-
- # Or a signifcant chunk of it
- if (length($org) >= 7 &&
- length($cn) >= 7 &&
- substr($cn, 0, 7) eq substr($org, 0, 7)) {
- $signers_name = $cn;
- goto got_id_name;
- }
-
- $signers_name = $org . ": " . $cn;
-} elsif ($org) {
- $signers_name = $org;
-} elsif ($cn) {
- $signers_name = $cn;
-}
-
-got_id_name:
-
-die $x509, ": ", "X.509: Couldn't find the Subject Key Identifier extension\n"
- if (!$subject_key_id);
-
-my $key_identifier = asn1_retrieve($subject_key_id->[1]);
-
-###############################################################################
-#
-# Create and attach the module signature
-#
-###############################################################################
-
-#
-# Signature parameters
-#
-my $algo = 1; # Public-key crypto algorithm: RSA
-my $hash = 0; # Digest algorithm
-my $id_type = 1; # Identifier type: X.509
-
-#
-# Digest the data
-#
-my $prologue;
-if ($dgst eq "sha1") {
- $prologue = pack("C*",
- 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
- 0x2B, 0x0E, 0x03, 0x02, 0x1A,
- 0x05, 0x00, 0x04, 0x14);
- $hash = 2;
-} elsif ($dgst eq "sha224") {
- $prologue = pack("C*",
- 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
- 0x05, 0x00, 0x04, 0x1C);
- $hash = 7;
-} elsif ($dgst eq "sha256") {
- $prologue = pack("C*",
- 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
- 0x05, 0x00, 0x04, 0x20);
- $hash = 4;
-} elsif ($dgst eq "sha384") {
- $prologue = pack("C*",
- 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
- 0x05, 0x00, 0x04, 0x30);
- $hash = 5;
-} elsif ($dgst eq "sha512") {
- $prologue = pack("C*",
- 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
- 0x05, 0x00, 0x04, 0x40);
- $hash = 6;
-} else {
- die "Unknown hash algorithm: $dgst\n";
-}
-
-my $signature;
-if ($signature_file) {
- $signature = read_file($signature_file);
-} else {
- #
- # Generate the digest and read from openssl's stdout
- #
- my $digest;
- $digest = readpipe("openssl dgst -$dgst -binary $module") || die "openssl dgst";
-
- #
- # Generate the binary signature, which will be just the integer that
- # comprises the signature with no metadata attached.
- #
- my $pid;
- $pid = open2(*read_from, *write_to,
- "openssl rsautl -sign -inkey $private_key -keyform PEM") ||
- die "openssl rsautl";
- binmode write_to;
- print write_to $prologue . $digest || die "pipe to openssl rsautl";
- close(write_to) || die "pipe to openssl rsautl";
-
- binmode read_from;
- read(read_from, $signature, 4096) || die "pipe from openssl rsautl";
- close(read_from) || die "pipe from openssl rsautl";
- waitpid($pid, 0) || die;
- die "openssl rsautl died: $?" if ($? >> 8);
-}
-$signature = pack("n", length($signature)) . $signature,
-
-#
-# Build the signed binary
-#
-my $unsigned_module = read_file($module);
-
-my $magic_number = "~Module signature appended~\n";
-
-my $info = pack("CCCCCxxxN",
- $algo, $hash, $id_type,
- length($signers_name),
- length($key_identifier),
- length($signature));
-
-if ($verbose) {
- print "Size of unsigned module: ", length($unsigned_module), "\n";
- print "Size of signer's name : ", length($signers_name), "\n";
- print "Size of key identifier : ", length($key_identifier), "\n";
- print "Size of signature : ", length($signature), "\n";
- print "Size of information : ", length($info), "\n";
- print "Size of magic number : ", length($magic_number), "\n";
- print "Signer's name : '", $signers_name, "'\n";
- print "Digest : $dgst\n";
-}
-
-open(FD, ">$dest") || die $dest;
-binmode FD;
-print FD
- $unsigned_module,
- $signers_name,
- $key_identifier,
- $signature,
- $info,
- $magic_number
- ;
-close FD || die $dest;
-
-if (!$keep_orig) {
- rename($dest, $module) || die $module;
-}
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff