diff mbox series

[ima-evm-utils,v2,2/2] Add test for using sign_hash API

Message ID 20210705154950.497359-3-patrick@puiterwijk.org (mailing list archive)
State New
Headers show
Series Fix use of sign_hash via API | expand

Commit Message

Patrick Uiterwijk July 5, 2021, 3:49 p.m. UTC
This adds a test with a small program that calls the sign_hash API, to
ensure that that codepath works.

Signed-off-by: Patrick Uiterwijk <patrick@puiterwijk.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
 src/evmctl.c                | 23 ----------------
 src/utils.c                 | 20 ++++++++++++++
 src/utils.h                 |  1 +
 tests/.gitignore            |  2 ++
 tests/Makefile.am           |  5 ++++
 tests/sign_verify.apitest.c | 55 +++++++++++++++++++++++++++++++++++++
 tests/sign_verify.test      | 30 ++++++++++++++++----
 7 files changed, 107 insertions(+), 29 deletions(-)
 create mode 100644 tests/sign_verify.apitest.c

Comments

Mimi Zohar July 6, 2021, 3:53 p.m. UTC | #1
Hi Patrick,

On Mon, 2021-07-05 at 17:49 +0200, Patrick Uiterwijk wrote:
> This adds a test with a small program that calls the sign_hash API, to
> ensure that that codepath works.
> 
> Signed-off-by: Patrick Uiterwijk <patrick@puiterwijk.org>
> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

Somehow I missed that running the test without this patch the summary
"SKIP" info matches the "skipped" messages, but running with the patch
there's a discrepancy.

$ ./sign_verify.test &> /tmp/sign_verify.log
$ tail -5  /tmp/sign_verify.log
evmctl ima_sign failed properly with (1) 
  EVP_get_digestbyname(md_gost12_512) failed
  errno: No such file or directory (2)
PASS: 127 SKIP: 20 FAIL: 0

$ grep "skipped" /tmp/sign_verify.log | wc -l
20

$ tail -5  /tmp/sign_verify.log-api
evmctl ima_sign: no detached signature md_gost12_512.txt~.sig

rm: cannot remove 'md_gost12_512.txt~': No such file or directory
PASS: 175 SKIP: 32 FAIL: 0

$ grep "skipped" /tmp/sign_verify.log-api | wc -l
30

> diff --git a/tests/sign_verify.apitest.c b/tests/sign_verify.apitest.c
> new file mode 100644
> index 0000000..3fcd043
> --- /dev/null
> +++ b/tests/sign_verify.apitest.c
> @@ -0,0 +1,55 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * sign_verify.apitest: Test program for verifying sign_hash
> + *
> + * Copyright (C) 2021 Patrick Uiterwijk <patrick@puiterwijk.org>
> + * Copyright (C) 2013,2014 Samsung Electronics
> + * Copyright (C) 2011,2012,2013 Intel Corporation
> + * Copyright (C) 2011 Nokia Corporation
> + */

As this is a new file and test, the copyrights other than your own are
unnecessary.

> +
> +#include <assert.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <sys/types.h>
> +#include <sys/xattr.h>
> +
> +#include "../src/imaevm.h"
> +#include "../src/utils.h"
> +
> +int main(int argc, char **argv)
> +{
> +	unsigned char hash[MAX_DIGEST_SIZE];
> +	unsigned char sig[MAX_SIGNATURE_SIZE];
> +	int len, err;
> +	char *file = argv[1];
> +	char *key = argv[2];
> +	char *algo = argv[3];
> +	char *digest = argv[4];
> +

How about testing 'argc' before continuing?

> +	len = strlen(digest) / 2;
> +	if (hex2bin(hash, digest, len) != 0) {
> +		fprintf(stderr, "Error during hex2bin\n");
> +		return 1;
> +	}
> +
> +	len = sign_hash(algo, hash, len, key, NULL, sig + 1);
> +	if (len <= 1) {
> +		fprintf(stderr, "Error signing\n");
> +		return 1;
> +	}
> +
> +	/* add header */
> +	len++;
> +	sig[0] = EVM_IMA_XATTR_DIGSIG;
> +
> +	bin2file(file, "sig", sig, len);
> +
> +	err = lsetxattr(file, "user.ima", sig, len, 0);
> +	if (err < 0) {
> +		log_err("setxattr failed: %s\n", file);
> +		return 1;
> +	}
> +
> +	return 0;
> +}


> diff --git a/tests/sign_verify.test b/tests/sign_verify.test
> index 3d7aa51..6f92801 100755
> --- a/tests/sign_verify.test
> +++ b/tests/sign_verify.test

> @@ -125,12 +127,14 @@ _evmctl_sign() {
>  # Run and test {ima_,}sign operation
>  check_sign() {
>    # Arguments are passed via global vars:
> -  # TYPE (ima or evm),
> +  # TYPE (ima, ima_api or evm),

Similarly TYPE should be updated in verify_sign as well.

thanks,

Mimi

>    # KEY,
>    # ALG (hash algo),
>    # PREFIX (signature header prefix in hex),
>    # OPTS (additional options for evmctl),
>    # FILE (working file to sign).
> +  [ "$TYPE" = ima_api ] && [[ "$OPTS" =~ --rsa ]] && return "$SKIP"
> +
>    local "$@"
>    local KEY=${KEY%.*}.key
>    local FILE=${FILE:-$ALG.txt}
> @@ -268,6 +272,20 @@ sign_verify() {
>      # Multiple files and some don't verify
>      expect_fail check_verify FILE="/dev/null $file"
>  
> +    setfattr -x user.ima "$FILE"
> +    rm "$FILE.sig"
> +  fi
> +
> +  TYPE=ima_api
> +  if expect_pass check_sign; then
> +
> +    # Normal verify with proper key should pass
> +    expect_pass check_verify
> +    expect_pass check_verify OPTS="--sigfile"
> +
> +    # Multiple files and some don't verify
> +    expect_fail check_verify FILE="/dev/null $file"
> +
>      rm "$FILE.sig"
>    fi
>
diff mbox series

Patch

diff --git a/src/evmctl.c b/src/evmctl.c
index 7a6f202..867b142 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -166,29 +166,6 @@  struct tpm_bank_info {
 static char *pcrfile[MAX_PCRFILE];
 static unsigned npcrfile;
 
-static int bin2file(const char *file, const char *ext, const unsigned char *data, int len)
-{
-	FILE *fp;
-	char name[strlen(file) + (ext ? strlen(ext) : 0) + 2];
-	int err;
-
-	if (ext)
-		sprintf(name, "%s.%s", file, ext);
-	else
-		sprintf(name, "%s", file);
-
-	log_info("Writing to %s\n", name);
-
-	fp = fopen(name, "w");
-	if (!fp) {
-		log_err("Failed to open: %s\n", name);
-		return -1;
-	}
-	err = fwrite(data, len, 1, fp);
-	fclose(fp);
-	return err;
-}
-
 static unsigned char *file2bin(const char *file, const char *ext, int *size)
 {
 	FILE *fp;
diff --git a/src/utils.c b/src/utils.c
index fbb6a4b..ce2cc28 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -112,3 +112,23 @@  int hex2bin(void *dst, const char *src, size_t count)
 	}
 	return 0;
 }
+
+int bin2file(const char *file, const char *ext, const unsigned char *data, int len)
+{
+	FILE *fp;
+	char name[strlen(file) + (ext ? strlen(ext) : 0) + 2];
+	int err;
+
+	if (ext)
+		sprintf(name, "%s.%s", file, ext);
+	else
+		sprintf(name, "%s", file);
+
+	fp = fopen(name, "w");
+	if (!fp)
+		return -1;
+
+	err = fwrite(data, len, 1, fp);
+	fclose(fp);
+	return err;
+}
diff --git a/src/utils.h b/src/utils.h
index 9ea179f..081997a 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -4,3 +4,4 @@ 
 int get_cmd_path(const char *prog_name, char *buf, size_t buf_len);
 int hex_to_bin(char ch);
 int hex2bin(void *dst, const char *src, size_t count);
+int bin2file(const char *file, const char *ext, const unsigned char *data, int len);
diff --git a/tests/.gitignore b/tests/.gitignore
index 9ecc984..c40735d 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -14,3 +14,5 @@ 
 *.key
 *.conf
 
+# Compiled version of apitest
+sign_verify_apitest
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ff928e1..74f6125 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -10,3 +10,8 @@  distclean: distclean-keys
 .PHONY: distclean-keys
 distclean-keys:
 	./gen-keys.sh clean
+
+AUTOMAKE_OPTIONS = subdir-objects
+bin_PROGRAMS = sign_verify_apitest
+sign_verify_apitest_SOURCES = sign_verify.apitest.c ../src/utils.c
+sign_verify_apitest_LDFLAGS = -limaevm -L../src/.libs
diff --git a/tests/sign_verify.apitest.c b/tests/sign_verify.apitest.c
new file mode 100644
index 0000000..3fcd043
--- /dev/null
+++ b/tests/sign_verify.apitest.c
@@ -0,0 +1,55 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sign_verify.apitest: Test program for verifying sign_hash
+ *
+ * Copyright (C) 2021 Patrick Uiterwijk <patrick@puiterwijk.org>
+ * Copyright (C) 2013,2014 Samsung Electronics
+ * Copyright (C) 2011,2012,2013 Intel Corporation
+ * Copyright (C) 2011 Nokia Corporation
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/xattr.h>
+
+#include "../src/imaevm.h"
+#include "../src/utils.h"
+
+int main(int argc, char **argv)
+{
+	unsigned char hash[MAX_DIGEST_SIZE];
+	unsigned char sig[MAX_SIGNATURE_SIZE];
+	int len, err;
+	char *file = argv[1];
+	char *key = argv[2];
+	char *algo = argv[3];
+	char *digest = argv[4];
+
+	len = strlen(digest) / 2;
+	if (hex2bin(hash, digest, len) != 0) {
+		fprintf(stderr, "Error during hex2bin\n");
+		return 1;
+	}
+
+	len = sign_hash(algo, hash, len, key, NULL, sig + 1);
+	if (len <= 1) {
+		fprintf(stderr, "Error signing\n");
+		return 1;
+	}
+
+	/* add header */
+	len++;
+	sig[0] = EVM_IMA_XATTR_DIGSIG;
+
+	bin2file(file, "sig", sig, len);
+
+	err = lsetxattr(file, "user.ima", sig, len, 0);
+	if (err < 0) {
+		log_err("setxattr failed: %s\n", file);
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/tests/sign_verify.test b/tests/sign_verify.test
index 3d7aa51..6f92801 100755
--- a/tests/sign_verify.test
+++ b/tests/sign_verify.test
@@ -66,14 +66,14 @@  _keyid_from_cert() {
 
 # Convert test $type into evmctl op prefix
 _op() {
-  if [ "$1" = ima ]; then
+  if [ "$1" = ima -o "$1" = ima_api ]; then
     echo ima_
   fi
 }
 
 # Convert test $type into xattr name
 _xattr() {
-  if [ "$1" = ima ]; then
+  if [ "$1" = ima -o "$1" = ima_api ]; then
     echo user.ima
   else
     echo user.evm
@@ -113,11 +113,13 @@  _evmctl_sign() {
   [ "$type" = ima ] && opts+=" --sigfile"
 
   # shellcheck disable=SC2086
-  ADD_TEXT_FOR="$alg ($key)" ADD_DEL=$file \
+  [ "$type" = ima -o "$type" = evm ] && (ADD_TEXT_FOR="$alg ($key)" ADD_DEL=$file \
     _evmctl_run "$(_op "$type")sign" $opts \
-    --hashalgo "$alg" --key "$key" --xattr-user "$file" || return
+    --hashalgo "$alg" --key "$key" --xattr-user "$file" || return)
+  [ "$type" = ima_api ] && ADD_TEXT_FOR="$alg ($key)" ADD_DEL=$file \
+    ./sign_verify_apitest "$file" "$key" "$alg" "$(openssl dgst $OPENSSL_ENGINE -$ALG -hex -r $FILE | awk '{print $1}')"
 
-  if [ "$type" = ima ]; then
+  if [ "$type" = ima -o "$type" = ima_api ]; then
     _test_sigfile "$file" "$(_xattr "$type")" "$file.sig" "$file.sig2"
   fi
 }
@@ -125,12 +127,14 @@  _evmctl_sign() {
 # Run and test {ima_,}sign operation
 check_sign() {
   # Arguments are passed via global vars:
-  # TYPE (ima or evm),
+  # TYPE (ima, ima_api or evm),
   # KEY,
   # ALG (hash algo),
   # PREFIX (signature header prefix in hex),
   # OPTS (additional options for evmctl),
   # FILE (working file to sign).
+  [ "$TYPE" = ima_api ] && [[ "$OPTS" =~ --rsa ]] && return "$SKIP"
+
   local "$@"
   local KEY=${KEY%.*}.key
   local FILE=${FILE:-$ALG.txt}
@@ -268,6 +272,20 @@  sign_verify() {
     # Multiple files and some don't verify
     expect_fail check_verify FILE="/dev/null $file"
 
+    setfattr -x user.ima "$FILE"
+    rm "$FILE.sig"
+  fi
+
+  TYPE=ima_api
+  if expect_pass check_sign; then
+
+    # Normal verify with proper key should pass
+    expect_pass check_verify
+    expect_pass check_verify OPTS="--sigfile"
+
+    # Multiple files and some don't verify
+    expect_fail check_verify FILE="/dev/null $file"
+
     rm "$FILE.sig"
   fi