Merge tag 'keys-pefile-20140709' into keys-next

Here's a set of changes that implement a PE file signature checker.

This provides the following facility:

 (1) Extract the signature from the PE file.  This is a PKCS#7 message
     containing, as its data, a hash of the signed parts of the file.

 (2) Digest the signed parts of the file.

 (3) Compare the digest with the one from the PKCS#7 message.

 (4) Validate the signatures on the PKCS#7 message and indicate
     whether it was matched by a trusted key.

Signed-off-by: David Howells <dhowells@redhat.com>

6 files changed, 678 insertions, 1 deletions

diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index b6df198d1b6f..ca41be5631c7 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -33,7 +33,7 @@ config X509_CERTIFICATE_PARSER
         select ASN1
         select OID_REGISTRY
         help
-          This option procides support for parsing X.509 format blobs for key
+          This option provides support for parsing X.509 format blobs for key
           data and provides the ability to instantiate a crypto key from a
           public key packet found inside the certificate.
 
@@ -59,4 +59,13 @@ config PKCS7_TEST_KEY
 
           This is intended for testing the PKCS#7 parser.
 
+config SIGNED_PE_FILE_VERIFICATION
+        bool "Support for PE file signature verification"
+        depends on PKCS7_MESSAGE_PARSER=y
+        select ASN1
+        select OID_REGISTRY
+        help
+          This option provides support for verifying the signature(s) on a
+          signed PE binary.
+
 endif # ASYMMETRIC_KEY_TYPE
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index 92d0e9af24d5..e47fcd9ac5e8 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -47,3 +47,18 @@ clean-files	+= pkcs7-asn1.c pkcs7-asn1.h
 obj-$(CONFIG_PKCS7_TEST_KEY) += pkcs7_test_key.o
 pkcs7_test_key-y := \
         pkcs7_key_type.o
+
+#
+# Signed PE binary-wrapped key handling
+#
+obj-$(CONFIG_SIGNED_PE_FILE_VERIFICATION) += verify_signed_pefile.o
+
+verify_signed_pefile-y := \
+        verify_pefile.o \
+        mscode_parser.o \
+        mscode-asn1.o
+
+$(obj)/mscode_parser.o: $(obj)/mscode-asn1.h $(obj)/mscode-asn1.h
+$(obj)/mscode-asn1.o: $(obj)/mscode-asn1.c $(obj)/mscode-asn1.h
+
+clean-files     += mscode-asn1.c mscode-asn1.h
diff --git a/crypto/asymmetric_keys/mscode.asn1 b/crypto/asymmetric_keys/mscode.asn1
new file mode 100644
index 000000000000..6d09ba48c41c
--- /dev/null
+++ b/crypto/asymmetric_keys/mscode.asn1
@@ -0,0 +1,28 @@
+--- Microsoft individual code signing data blob parser
+---
+--- Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+--- Written by David Howells (dhowells@redhat.com)
+---
+--- This program is free software; you can redistribute it and/or
+--- modify it under the terms of the GNU General Public Licence
+--- as published by the Free Software Foundation; either version
+--- 2 of the Licence, or (at your option) any later version.
+---
+
+MSCode ::= SEQUENCE {
+        type                    SEQUENCE {
+                contentType     ContentType,
+                parameters      ANY
+        },
+        content                 SEQUENCE {
+                digestAlgorithm DigestAlgorithmIdentifier,
+                digest          OCTET STRING ({ mscode_note_digest })
+        }
+}
+
+ContentType ::= OBJECT IDENTIFIER ({ mscode_note_content_type })
+
+DigestAlgorithmIdentifier ::= SEQUENCE {
+        algorithm   OBJECT IDENTIFIER ({ mscode_note_digest_algo }),
+        parameters  ANY OPTIONAL
+}
diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
new file mode 100644
index 000000000000..214a992123cd
--- /dev/null
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -0,0 +1,126 @@
+/* Parse a Microsoft Individual Code Signing blob
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "MSCODE: "fmt
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include <crypto/pkcs7.h>
+#include "verify_pefile.h"
+#include "mscode-asn1.h"
+
+/*
+ * Parse a Microsoft Individual Code Signing blob
+ */
+int mscode_parse(struct pefile_context *ctx)
+{
+        const void *content_data;
+        size_t data_len;
+        int ret;
+
+        ret = pkcs7_get_content_data(ctx->pkcs7, &content_data, &data_len, 1);
+
+        if (ret) {
+                pr_debug("PKCS#7 message does not contain data\n");
+                return ret;
+        }
+
+        pr_devel("Data: %zu [%*ph]\n", data_len, (unsigned)(data_len),
+                 content_data);
+
+        return asn1_ber_decoder(&mscode_decoder, ctx, content_data, data_len);
+}
+
+/*
+ * Check the content type OID
+ */
+int mscode_note_content_type(void *context, size_t hdrlen,
+                             unsigned char tag,
+                             const void *value, size_t vlen)
+{
+        enum OID oid;
+
+        oid = look_up_OID(value, vlen);
+        if (oid == OID__NR) {
+                char buffer[50];
+
+                sprint_oid(value, vlen, buffer, sizeof(buffer));
+                pr_err("Unknown OID: %s\n", buffer);
+                return -EBADMSG;
+        }
+
+        /*
+         * pesign utility had a bug where it was putting
+         * OID_msIndividualSPKeyPurpose instead of OID_msPeImageDataObjId
+         * So allow both OIDs.
+         */
+        if (oid != OID_msPeImageDataObjId &&
+            oid != OID_msIndividualSPKeyPurpose) {
+                pr_err("Unexpected content type OID %u\n", oid);
+                return -EBADMSG;
+        }
+
+        return 0;
+}
+
+/*
+ * Note the digest algorithm OID
+ */
+int mscode_note_digest_algo(void *context, size_t hdrlen,
+                            unsigned char tag,
+                            const void *value, size_t vlen)
+{
+        struct pefile_context *ctx = context;
+        char buffer[50];
+        enum OID oid;
+
+        oid = look_up_OID(value, vlen);
+        switch (oid) {
+        case OID_md4:
+                ctx->digest_algo = HASH_ALGO_MD4;
+                break;
+        case OID_md5:
+                ctx->digest_algo = HASH_ALGO_MD5;
+                break;
+        case OID_sha1:
+                ctx->digest_algo = HASH_ALGO_SHA1;
+                break;
+        case OID_sha256:
+                ctx->digest_algo = HASH_ALGO_SHA256;
+                break;
+
+        case OID__NR:
+                sprint_oid(value, vlen, buffer, sizeof(buffer));
+                pr_err("Unknown OID: %s\n", buffer);
+                return -EBADMSG;
+
+        default:
+                pr_err("Unsupported content type: %u\n", oid);
+                return -ENOPKG;
+        }
+
+        return 0;
+}
+
+/*
+ * Note the digest we're guaranteeing with this certificate
+ */
+int mscode_note_digest(void *context, size_t hdrlen,
+                       unsigned char tag,
+                       const void *value, size_t vlen)
+{
+        struct pefile_context *ctx = context;
+
+        ctx->digest = value;
+        ctx->digest_len = vlen;
+        return 0;
+}
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
new file mode 100644
index 000000000000..79175e6ea0b2
--- /dev/null
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -0,0 +1,457 @@
+/* Parse a signed PE binary
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "PEFILE: "fmt
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/pe.h>
+#include <linux/asn1.h>
+#include <crypto/pkcs7.h>
+#include <crypto/hash.h>
+#include "verify_pefile.h"
+
+/*
+ * Parse a PE binary.
+ */
+static int pefile_parse_binary(const void *pebuf, unsigned int pelen,
+                               struct pefile_context *ctx)
+{
+        const struct mz_hdr *mz = pebuf;
+        const struct pe_hdr *pe;
+        const struct pe32_opt_hdr *pe32;
+        const struct pe32plus_opt_hdr *pe64;
+        const struct data_directory *ddir;
+        const struct data_dirent *dde;
+        const struct section_header *secs, *sec;
+        size_t cursor, datalen = pelen;
+
+        kenter("");
+
+#define chkaddr(base, x, s)                                             \
+        do {                                                            \
+                if ((x) < base || (s) >= datalen || (x) > datalen - (s)) \
+                        return -ELIBBAD;                                \
+        } while (0)
+
+        chkaddr(0, 0, sizeof(*mz));
+        if (mz->magic != MZ_MAGIC)
+                return -ELIBBAD;
+        cursor = sizeof(*mz);
+
+        chkaddr(cursor, mz->peaddr, sizeof(*pe));
+        pe = pebuf + mz->peaddr;
+        if (pe->magic != PE_MAGIC)
+                return -ELIBBAD;
+        cursor = mz->peaddr + sizeof(*pe);
+
+        chkaddr(0, cursor, sizeof(pe32->magic));
+        pe32 = pebuf + cursor;
+        pe64 = pebuf + cursor;
+
+        switch (pe32->magic) {
+        case PE_OPT_MAGIC_PE32:
+                chkaddr(0, cursor, sizeof(*pe32));
+                ctx->image_checksum_offset =
+                        (unsigned long)&pe32->csum - (unsigned long)pebuf;
+                ctx->header_size = pe32->header_size;
+                cursor += sizeof(*pe32);
+                ctx->n_data_dirents = pe32->data_dirs;
+                break;
+
+        case PE_OPT_MAGIC_PE32PLUS:
+                chkaddr(0, cursor, sizeof(*pe64));
+                ctx->image_checksum_offset =
+                        (unsigned long)&pe64->csum - (unsigned long)pebuf;
+                ctx->header_size = pe64->header_size;
+                cursor += sizeof(*pe64);
+                ctx->n_data_dirents = pe64->data_dirs;
+                break;
+
+        default:
+                pr_debug("Unknown PEOPT magic = %04hx\n", pe32->magic);
+                return -ELIBBAD;
+        }
+
+        pr_debug("checksum @ %x\n", ctx->image_checksum_offset);
+        pr_debug("header size = %x\n", ctx->header_size);
+
+        if (cursor >= ctx->header_size || ctx->header_size >= datalen)
+                return -ELIBBAD;
+
+        if (ctx->n_data_dirents > (ctx->header_size - cursor) / sizeof(*dde))
+                return -ELIBBAD;
+
+        ddir = pebuf + cursor;
+        cursor += sizeof(*dde) * ctx->n_data_dirents;
+
+        ctx->cert_dirent_offset =
+                (unsigned long)&ddir->certs - (unsigned long)pebuf;
+        ctx->certs_size = ddir->certs.size;
+
+        if (!ddir->certs.virtual_address || !ddir->certs.size) {
+                pr_debug("Unsigned PE binary\n");
+                return -EKEYREJECTED;
+        }
+
+        chkaddr(ctx->header_size, ddir->certs.virtual_address,
+                ddir->certs.size);
+        ctx->sig_offset = ddir->certs.virtual_address;
+        ctx->sig_len = ddir->certs.size;
+        pr_debug("cert = %x @%x [%*ph]\n",
+                 ctx->sig_len, ctx->sig_offset,
+                 ctx->sig_len, pebuf + ctx->sig_offset);
+
+        ctx->n_sections = pe->sections;
+        if (ctx->n_sections > (ctx->header_size - cursor) / sizeof(*sec))
+                return -ELIBBAD;
+        ctx->secs = secs = pebuf + cursor;
+
+        return 0;
+}
+
+/*
+ * Check and strip the PE wrapper from around the signature and check that the
+ * remnant looks something like PKCS#7.
+ */
+static int pefile_strip_sig_wrapper(const void *pebuf,
+                                    struct pefile_context *ctx)
+{
+        struct win_certificate wrapper;
+        const u8 *pkcs7;
+
+        if (ctx->sig_len < sizeof(wrapper)) {
+                pr_debug("Signature wrapper too short\n");
+                return -ELIBBAD;
+        }
+
+        memcpy(&wrapper, pebuf + ctx->sig_offset, sizeof(wrapper));
+        pr_debug("sig wrapper = { %x, %x, %x }\n",
+                 wrapper.length, wrapper.revision, wrapper.cert_type);
+
+        /* Both pesign and sbsign round up the length of certificate table
+         * (in optional header data directories) to 8 byte alignment.
+         */
+        if (round_up(wrapper.length, 8) != ctx->sig_len) {
+                pr_debug("Signature wrapper len wrong\n");
+                return -ELIBBAD;
+        }
+        if (wrapper.revision != WIN_CERT_REVISION_2_0) {
+                pr_debug("Signature is not revision 2.0\n");
+                return -ENOTSUPP;
+        }
+        if (wrapper.cert_type != WIN_CERT_TYPE_PKCS_SIGNED_DATA) {
+                pr_debug("Signature certificate type is not PKCS\n");
+                return -ENOTSUPP;
+        }
+
+        /* Looks like actual pkcs signature length is in wrapper->length.
+         * size obtained from data dir entries lists the total size of
+         * certificate table which is also aligned to octawrod boundary.
+         *
+         * So set signature length field appropriately.
+         */
+        ctx->sig_len = wrapper.length;
+        ctx->sig_offset += sizeof(wrapper);
+        ctx->sig_len -= sizeof(wrapper);
+        if (ctx->sig_len == 0) {
+                pr_debug("Signature data missing\n");
+                return -EKEYREJECTED;
+        }
+
+        /* What's left should a PKCS#7 cert */
+        pkcs7 = pebuf + ctx->sig_offset;
+        if (pkcs7[0] == (ASN1_CONS_BIT | ASN1_SEQ)) {
+                if (pkcs7[1] == 0x82 &&
+                    pkcs7[2] == (((ctx->sig_len - 4) >> 8) & 0xff) &&
+                    pkcs7[3] ==  ((ctx->sig_len - 4)       & 0xff))
+                        return 0;
+                if (pkcs7[1] == 0x80)
+                        return 0;
+                if (pkcs7[1] > 0x82)
+                        return -EMSGSIZE;
+        }
+
+        pr_debug("Signature data not PKCS#7\n");
+        return -ELIBBAD;
+}
+
+/*
+ * Compare two sections for canonicalisation.
+ */
+static int pefile_compare_shdrs(const void *a, const void *b)
+{
+        const struct section_header *shdra = a;
+        const struct section_header *shdrb = b;
+        int rc;
+
+        if (shdra->data_addr > shdrb->data_addr)
+                return 1;
+        if (shdrb->data_addr > shdra->data_addr)
+                return -1;
+
+        if (shdra->virtual_address > shdrb->virtual_address)
+                return 1;
+        if (shdrb->virtual_address > shdra->virtual_address)
+                return -1;
+
+        rc = strcmp(shdra->name, shdrb->name);
+        if (rc != 0)
+                return rc;
+
+        if (shdra->virtual_size > shdrb->virtual_size)
+                return 1;
+        if (shdrb->virtual_size > shdra->virtual_size)
+                return -1;
+
+        if (shdra->raw_data_size > shdrb->raw_data_size)
+                return 1;
+        if (shdrb->raw_data_size > shdra->raw_data_size)
+                return -1;
+
+        return 0;
+}
+
+/*
+ * Load the contents of the PE binary into the digest, leaving out the image
+ * checksum and the certificate data block.
+ */
+static int pefile_digest_pe_contents(const void *pebuf, unsigned int pelen,
+                                     struct pefile_context *ctx,
+                                     struct shash_desc *desc)
+{
+        unsigned *canon, tmp, loop, i, hashed_bytes;
+        int ret;
+
+        /* Digest the header and data directory, but leave out the image
+         * checksum and the data dirent for the signature.
+         */
+        ret = crypto_shash_update(desc, pebuf, ctx->image_checksum_offset);
+        if (ret < 0)
+                return ret;
+
+        tmp = ctx->image_checksum_offset + sizeof(uint32_t);
+        ret = crypto_shash_update(desc, pebuf + tmp,
+                                  ctx->cert_dirent_offset - tmp);
+        if (ret < 0)
+                return ret;
+
+        tmp = ctx->cert_dirent_offset + sizeof(struct data_dirent);
+        ret = crypto_shash_update(desc, pebuf + tmp, ctx->header_size - tmp);
+        if (ret < 0)
+                return ret;
+
+        canon = kcalloc(ctx->n_sections, sizeof(unsigned), GFP_KERNEL);
+        if (!canon)
+                return -ENOMEM;
+
+        /* We have to canonicalise the section table, so we perform an
+         * insertion sort.
+         */
+        canon[0] = 0;
+        for (loop = 1; loop < ctx->n_sections; loop++) {
+                for (i = 0; i < loop; i++) {
+                        if (pefile_compare_shdrs(&ctx->secs[canon[i]],
+                                                 &ctx->secs[loop]) > 0) {
+                                memmove(&canon[i + 1], &canon[i],
+                                        (loop - i) * sizeof(canon[0]));
+                                break;
+                        }
+                }
+                canon[i] = loop;
+        }
+
+        hashed_bytes = ctx->header_size;
+        for (loop = 0; loop < ctx->n_sections; loop++) {
+                i = canon[loop];
+                if (ctx->secs[i].raw_data_size == 0)
+                        continue;
+                ret = crypto_shash_update(desc,
+                                          pebuf + ctx->secs[i].data_addr,
+                                          ctx->secs[i].raw_data_size);
+                if (ret < 0) {
+                        kfree(canon);
+                        return ret;
+                }
+                hashed_bytes += ctx->secs[i].raw_data_size;
+        }
+        kfree(canon);
+
+        if (pelen > hashed_bytes) {
+                tmp = hashed_bytes + ctx->certs_size;
+                ret = crypto_shash_update(desc,
+                                          pebuf + hashed_bytes,
+                                          pelen - tmp);
+                if (ret < 0)
+                        return ret;
+        }
+
+        return 0;
+}
+
+/*
+ * Digest the contents of the PE binary, leaving out the image checksum and the
+ * certificate data block.
+ */
+static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
+                            struct pefile_context *ctx)
+{
+        struct crypto_shash *tfm;
+        struct shash_desc *desc;
+        size_t digest_size, desc_size;
+        void *digest;
+        int ret;
+
+        kenter(",%u", ctx->digest_algo);
+
+        /* 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[ctx->digest_algo], 0, 0);
+        if (IS_ERR(tfm))
+                return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm);
+
+        desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
+        digest_size = crypto_shash_digestsize(tfm);
+
+        if (digest_size != ctx->digest_len) {
+                pr_debug("Digest size mismatch (%zx != %x)\n",
+                         digest_size, ctx->digest_len);
+                ret = -EBADMSG;
+                goto error_no_desc;
+        }
+        pr_debug("Digest: desc=%zu size=%zu\n", desc_size, digest_size);
+
+        ret = -ENOMEM;
+        desc = kzalloc(desc_size + digest_size, GFP_KERNEL);
+        if (!desc)
+                goto error_no_desc;
+
+        desc->tfm   = tfm;
+        desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+        ret = crypto_shash_init(desc);
+        if (ret < 0)
+                goto error;
+
+        ret = pefile_digest_pe_contents(pebuf, pelen, ctx, desc);
+        if (ret < 0)
+                goto error;
+
+        digest = (void *)desc + desc_size;
+        ret = crypto_shash_final(desc, digest);
+        if (ret < 0)
+                goto error;
+
+        pr_debug("Digest calc = [%*ph]\n", ctx->digest_len, digest);
+
+        /* Check that the PE file digest matches that in the MSCODE part of the
+         * PKCS#7 certificate.
+         */
+        if (memcmp(digest, ctx->digest, ctx->digest_len) != 0) {
+                pr_debug("Digest mismatch\n");
+                ret = -EKEYREJECTED;
+        } else {
+                pr_debug("The digests match!\n");
+        }
+
+error:
+        kfree(desc);
+error_no_desc:
+        crypto_free_shash(tfm);
+        kleave(" = %d", ret);
+        return ret;
+}
+
+/**
+ * verify_pefile_signature - Verify the signature on a PE binary image
+ * @pebuf: Buffer containing the PE binary image
+ * @pelen: Length of the binary image
+ * @trust_keyring: Signing certificates to use as starting points
+ * @_trusted: Set to true if trustworth, false otherwise
+ *
+ * Validate that the certificate chain inside the PKCS#7 message inside the PE
+ * binary image intersects keys we already know and trust.
+ *
+ * Returns, in order of descending priority:
+ *
+ *  (*) -ELIBBAD if the image cannot be parsed, or:
+ *
+ *  (*) -EKEYREJECTED if a signature failed to match for which we have a valid
+ *      key, or:
+ *
+ *  (*) 0 if at least one signature chain intersects with the keys in the trust
+ *      keyring, or:
+ *
+ *  (*) -ENOPKG if a suitable crypto module couldn't be found for a check on a
+ *      chain.
+ *
+ *  (*) -ENOKEY if we couldn't find a match for any of the signature chains in
+ *      the message.
+ *
+ * May also return -ENOMEM.
+ */
+int verify_pefile_signature(const void *pebuf, unsigned pelen,
+                            struct key *trusted_keyring, bool *_trusted)
+{
+        struct pkcs7_message *pkcs7;
+        struct pefile_context ctx;
+        const void *data;
+        size_t datalen;
+        int ret;
+
+        kenter("");
+
+        memset(&ctx, 0, sizeof(ctx));
+        ret = pefile_parse_binary(pebuf, pelen, &ctx);
+        if (ret < 0)
+                return ret;
+
+        ret = pefile_strip_sig_wrapper(pebuf, &ctx);
+        if (ret < 0)
+                return ret;
+
+        pkcs7 = pkcs7_parse_message(pebuf + ctx.sig_offset, ctx.sig_len);
+        if (IS_ERR(pkcs7))
+                return PTR_ERR(pkcs7);
+        ctx.pkcs7 = pkcs7;
+
+        ret = pkcs7_get_content_data(ctx.pkcs7, &data, &datalen, false);
+        if (ret < 0 || datalen == 0) {
+                pr_devel("PKCS#7 message does not contain data\n");
+                ret = -EBADMSG;
+                goto error;
+        }
+
+        ret = mscode_parse(&ctx);
+        if (ret < 0)
+                goto error;
+
+        pr_debug("Digest: %u [%*ph]\n",
+                 ctx.digest_len, ctx.digest_len, ctx.digest);
+
+        /* Generate the digest and check against the PKCS7 certificate
+         * contents.
+         */
+        ret = pefile_digest_pe(pebuf, pelen, &ctx);
+        if (ret < 0)
+                goto error;
+
+        ret = pkcs7_verify(pkcs7);
+        if (ret < 0)
+                goto error;
+
+        ret = pkcs7_validate_trust(pkcs7, trusted_keyring, _trusted);
+
+error:
+        pkcs7_free_message(ctx.pkcs7);
+        return ret;
+}
diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h
new file mode 100644
index 000000000000..55d5f7ebc45a
--- /dev/null
+++ b/crypto/asymmetric_keys/verify_pefile.h
@@ -0,0 +1,42 @@
+/* PE Binary parser bits
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/verify_pefile.h>
+#include <crypto/pkcs7.h>
+#include <crypto/hash_info.h>
+
+struct pefile_context {
+        unsigned        header_size;
+        unsigned        image_checksum_offset;
+        unsigned        cert_dirent_offset;
+        unsigned        n_data_dirents;
+        unsigned        n_sections;
+        unsigned        certs_size;
+        unsigned        sig_offset;
+        unsigned        sig_len;
+        const struct section_header *secs;
+        struct pkcs7_message *pkcs7;
+
+        /* PKCS#7 MS Individual Code Signing content */
+        const void      *digest;                /* Digest */
+        unsigned        digest_len;             /* Digest length */
+        enum hash_algo  digest_algo;            /* Digest algorithm */
+};
+
+#define kenter(FMT, ...)                                        \
+        pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+        pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+
+/*
+ * mscode_parser.c
+ */
+extern int mscode_parse(struct pefile_context *ctx);