[PATCH v2 1/2] move pefile_parse_binary to its own file

[Jan Hendrik Farr]

Signed-off-by: Jan Hendrik Farr <kernel@xxxxxxxx>
---
 crypto/asymmetric_keys/mscode_parser.c |   2 +-
 crypto/asymmetric_keys/verify_pefile.c |  99 +---------------------
 crypto/asymmetric_keys/verify_pefile.h |  16 ----
 include/linux/parse_pefile.h           |  32 +++++++
 lib/Makefile                           |   2 +
 lib/parse_pefile.c                     | 110 +++++++++++++++++++++++++
 6 files changed, 146 insertions(+), 115 deletions(-)
 create mode 100644 include/linux/parse_pefile.h
 create mode 100644 lib/parse_pefile.c

diff --git a/crypto/asymmetric_keys/mscode_parser.c b/crypto/asymmetric_keys/mscode_parser.c
index 839591ad21ac..996528b3f11c 100644
--- a/crypto/asymmetric_keys/mscode_parser.c
+++ b/crypto/asymmetric_keys/mscode_parser.c
@@ -11,7 +11,7 @@
 #include <linux/err.h>
 #include <linux/oid_registry.h>
 #include <crypto/pkcs7.h>
-#include "verify_pefile.h"
+#include <linux/parse_pefile.h>
 #include "mscode.asn1.h"
 
 /*
diff --git a/crypto/asymmetric_keys/verify_pefile.c b/crypto/asymmetric_keys/verify_pefile.c
index f440767bd727..68592a328db7 100644
--- a/crypto/asymmetric_keys/verify_pefile.c
+++ b/crypto/asymmetric_keys/verify_pefile.c
@@ -14,106 +14,9 @@
 #include <linux/asn1.h>
 #include <linux/verification.h>
 #include <crypto/hash.h>
+#include <linux/parse_pefile.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_warn("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_warn("Unsigned PE binary\n");
-		return -ENODATA;
-	}
-
-	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
diff --git a/crypto/asymmetric_keys/verify_pefile.h b/crypto/asymmetric_keys/verify_pefile.h
index e1628e100cde..5ab2f9a5b2ef 100644
--- a/crypto/asymmetric_keys/verify_pefile.h
+++ b/crypto/asymmetric_keys/verify_pefile.h
@@ -8,22 +8,6 @@
 #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;
-
-	/* PKCS#7 MS Individual Code Signing content */
-	const void	*digest;		/* Digest */
-	unsigned	digest_len;		/* Digest length */
-	const char	*digest_algo;		/* Digest algorithm */
-};
 
 #define kenter(FMT, ...)					\
 	pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
diff --git a/include/linux/parse_pefile.h b/include/linux/parse_pefile.h
new file mode 100644
index 000000000000..c29f8c98ee66
--- /dev/null
+++ b/include/linux/parse_pefile.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ *
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#ifndef _ASM_PARSE_PEFILE_H
+#define _ASM_PARSE_PEFILE_H
+
+#include <linux/pe.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;
+
+	/* PKCS#7 MS Individual Code Signing content */
+	const void	*digest;		/* Digest */
+	unsigned	digest_len;		/* Digest length */
+	const char	*digest_algo;		/* Digest algorithm */
+};
+int pefile_parse_binary(const void *pebuf, unsigned int pelen,
+			       struct pefile_context *ctx);
+
+#endif // _ASM_PARSE_PEFILE_H
diff --git a/lib/Makefile b/lib/Makefile
index 2e08397f6210..01a6c13565b6 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -365,6 +365,8 @@ obj-$(CONFIG_SBITMAP) += sbitmap.o
 
 obj-$(CONFIG_PARMAN) += parman.o
 
+obj-$(CONFIG_SIGNED_PE_FILE_VERIFICATION) += parse_pefile.o
+
 obj-y += group_cpus.o
 
 # GCC library routines
diff --git a/lib/parse_pefile.c b/lib/parse_pefile.c
new file mode 100644
index 000000000000..9a8496b2588e
--- /dev/null
+++ b/lib/parse_pefile.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Parse a PE binary
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ *
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#include <linux/parse_pefile.h>
+#include <linux/err.h>
+
+#define pr_fmt(fmt)	"parse_pefile: " fmt
+#include <linux/module.h>
+/*
+ * Parse a PE binary.
+ */
+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;
+
+
+#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_warn("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_warn("Unsigned PE binary\n");
+		return -ENODATA;
+	}
+
+	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;
+}
-- 
2.40.1