From ef819fecfed22cab2ccbd128e5ede33db8f2d3e9 Mon Sep 17 00:00:00 2001

From: Jes Sorensen <jsorensen@fb.com>

Date: Thu, 9 Apr 2020 12:58:17 -0400

Subject: [PATCH 21/33] rpmsignverity: Add verity signature headers to the

 package

This adds the array of verity signatures, and a signature length

header. We use 4K block for the Merkle tree, and rely on the kernel

doing the right thing.

Signed-off-by: Jes Sorensen <jsorensen@fb.com>

---

 lib/rpmtag.h         |   6 ++-

 sign/rpmsignverity.c | 112 +++++++++++++++++++++++++++++--------------

 sign/rpmsignverity.h |   7 +++

 3 files changed, 87 insertions(+), 38 deletions(-)

diff --git a/lib/rpmtag.h b/lib/rpmtag.h

index 40ff5fa5d..478457ecb 100644

--- a/lib/rpmtag.h

+++ b/lib/rpmtag.h

@@ -67,6 +67,7 @@ typedef enum rpmTag_e {

     RPMTAG_SHA256HEADER		= RPMTAG_SIG_BASE+17,	/* s */

     /* RPMTAG_SIG_BASE+18 reserved for RPMSIGTAG_FILESIGNATURES */

     /* RPMTAG_SIG_BASE+19 reserved for RPMSIGTAG_FILESIGNATURELENGTH */

+    RPMTAG_VERITYSIGNATURES	= RPMTAG_SIG_BASE+20,	/* s[] */

     RPMTAG_NAME  		= 1000,	/* s */

 #define	RPMTAG_N	RPMTAG_NAME	/* s */

@@ -427,8 +428,9 @@ typedef enum rpmSigTag_e {

     RPMSIGTAG_LONGSIZE	= RPMTAG_LONGSIGSIZE,	/*!< internal Header+Payload size (64bit) in bytes. */

     RPMSIGTAG_LONGARCHIVESIZE = RPMTAG_LONGARCHIVESIZE, /*!< internal uncompressed payload size (64bit) in bytes. */

     RPMSIGTAG_SHA256	= RPMTAG_SHA256HEADER,

-    RPMSIGTAG_FILESIGNATURES           = RPMTAG_SIG_BASE + 18,

-    RPMSIGTAG_FILESIGNATURELENGTH      = RPMTAG_SIG_BASE + 19,

+    RPMSIGTAG_FILESIGNATURES		= RPMTAG_SIG_BASE + 18,

+    RPMSIGTAG_FILESIGNATURELENGTH	= RPMTAG_SIG_BASE + 19,

+    RPMSIGTAG_VERITYSIGNATURES		= RPMTAG_VERITYSIGNATURES,

 } rpmSigTag;

diff --git a/sign/rpmsignverity.c b/sign/rpmsignverity.c

index 5346c3bc8..a9818bd08 100644

--- a/sign/rpmsignverity.c

+++ b/sign/rpmsignverity.c

@@ -33,23 +33,66 @@ static int rpmVerityRead(void *opaque, void *buf, size_t size)

 	return retval;

 }

+static char *rpmVeritySignFile(rpmfi fi, size_t *sig_size, char *key,

+			       char *keypass, char *cert)

+{

+    struct libfsverity_merkle_tree_params params;

+    struct libfsverity_signature_params sig_params;

+    struct libfsverity_digest *digest = NULL;

+    rpm_loff_t file_size;

+    char *digest_hex, *sig_hex = NULL;

+    uint8_t *sig;

+    int status;

+

+    file_size = rpmfiFSize(fi);

+

+    memset(&params, 0, sizeof(struct libfsverity_merkle_tree_params));

+    params.version = 1;

+    params.hash_algorithm = FS_VERITY_HASH_ALG_SHA256;

+    params.block_size = RPM_FSVERITY_BLKSZ;

+    params.salt_size = 0 /* salt_size */;

+    params.salt = NULL /* salt */;

+    params.file_size = file_size;

+    status = libfsverity_compute_digest(fi, rpmVerityRead, &params, &digest);

+    if (status) {

+	rpmlog(RPMLOG_DEBUG, _("failed to compute digest\n"));

+	goto out;

+    }

+

+    digest_hex = pgpHexStr(digest->digest, digest->digest_size);

+    rpmlog(RPMLOG_DEBUG, _("digest(%i): %s\n"),

+	   digest->digest_size, digest_hex);

+    free(digest_hex);

+

+    memset(&sig_params, 0, sizeof(struct libfsverity_signature_params));

+    sig_params.keyfile = key;

+    sig_params.certfile = cert;

+    if (libfsverity_sign_digest(digest, &sig_params, &sig, sig_size)) {

+	rpmlog(RPMLOG_DEBUG, _("failed to sign digest\n"));

+	goto out;

+    }

+

+    sig_hex = pgpHexStr(sig, *sig_size + 1);

+ out:

+    free(digest);

+    free(sig);

+    return sig_hex;

+}

+

 rpmRC rpmSignVerity(FD_t fd, Header sigh, Header h, char *key,

 		    char *keypass, char *cert)

 {

-    int rc, status;

+    int rc;

     FD_t gzdi;

     rpmfiles files = NULL;

     rpmfi fi = NULL;

     rpmts ts = rpmtsCreate();

-    struct libfsverity_digest *digest = NULL;

-    struct libfsverity_merkle_tree_params params;

-    struct libfsverity_signature_params sig_params;

+    struct rpmtd_s td;

     rpm_loff_t file_size;

     off_t offset = Ftell(fd);

     const char *compr;

     char *rpmio_flags = NULL;

-    char *digest_hex;

-    uint8_t *sig;

+    char *sig_hex;

     size_t sig_size;

     Fseek(fd, 0, SEEK_SET);

@@ -75,43 +118,40 @@ rpmRC rpmSignVerity(FD_t fd, Header sigh, Header h, char *key,

     fi = rpmfiNewArchiveReader(gzdi, files,

 			       RPMFI_ITER_READ_ARCHIVE_OMIT_HARDLINKS);

+    /*

+     * Should this be sigh from the cloned fd or the sigh we received?

+     */

+    headerDel(sigh, RPMSIGTAG_VERITYSIGNATURES);

+

+    rpmtdReset(&td);

+    td.tag = RPMSIGTAG_VERITYSIGNATURES;

+    td.type = RPM_STRING_ARRAY_TYPE;

+    td.count = 1;

+

     while (rpmfiNext(fi) >= 0) {

-	if (!S_ISREG(rpmfiFMode(fi)))

-	    continue;

 	file_size = rpmfiFSize(fi);

-	rpmlog(RPMLOG_DEBUG, _("file: %s, (size %li)\n"),

-	       rpmfiFN(fi), file_size);

-

-	memset(&params, 0, sizeof(struct libfsverity_merkle_tree_params));

-	params.version = 1;

-	params.hash_algorithm = FS_VERITY_HASH_ALG_SHA256;

-	params.block_size = sysconf(_SC_PAGESIZE);

-	params.salt_size = 0 /* salt_size */;

-	params.salt = NULL /* salt */;

-	params.file_size = file_size;

-	status = libfsverity_compute_digest(fi, rpmVerityRead,

-					    &params, &digest);

-	if (!status) {

-	    digest_hex = pgpHexStr(digest->digest, digest->digest_size);

-	    rpmlog(RPMLOG_DEBUG, _("digest(%i): %s\n"),

-		   digest->digest_size, digest_hex);

-	    free(digest_hex);

-	}

-	memset(&sig_params, 0, sizeof(struct libfsverity_signature_params));

-	sig_params.keyfile = key;

-	sig_params.certfile = cert;

-	if (libfsverity_sign_digest(digest, &sig_params, &sig, &sig_size)) {

-	    rpmlog(RPMLOG_DEBUG, _("failed to sign digest\n"));

+

+	rpmlog(RPMLOG_DEBUG, _("file: %s, (size %li, link %s, idx %i)\n"),

+	       rpmfiFN(fi), file_size, rpmfiFLink(fi), rpmfiFX(fi));

+

+	sig_hex = rpmVeritySignFile(fi, &sig_size, key, keypass, cert);

+	td.data = &sig_hex;

+	rpmlog(RPMLOG_DEBUG, _("digest signed, len: %li\n"), sig_size);

+#if 0

+	rpmlog(RPMLOG_DEBUG, _("digest: %s\n"), (char *)sig_hex);

+#endif

+	if (!headerPut(sigh, &td, HEADERPUT_APPEND)) {

+	    rpmlog(RPMLOG_ERR, _("headerPutString failed\n"));

 	    rc = RPMRC_FAIL;

 	    goto out;

 	}

-	rpmlog(RPMLOG_DEBUG, _("digest signing success\n"));

-

-	free(digest);

-	free(sig);

+	free(sig_hex);

     }

-out:

+    rpmlog(RPMLOG_DEBUG, _("sigh size: %i\n"), headerSizeof(sigh, 0));

+

+    rc = RPMRC_OK;

+ out:

     Fseek(fd, offset, SEEK_SET);

     rpmfilesFree(files);

diff --git a/sign/rpmsignverity.h b/sign/rpmsignverity.h

index f3ad3bb18..69bbaf7f7 100644

--- a/sign/rpmsignverity.h

+++ b/sign/rpmsignverity.h

@@ -8,6 +8,13 @@

 extern "C" {

 #endif

+/*

+ * Block size used to generate the Merkle tree for fsverity. For now

+ * we only support 4K blocks, if we ever decide to support different

+ * block sizes, we will need a tag to indicate this.

+ */

+#define RPM_FSVERITY_BLKSZ	4096

+

 /**

  * Sign file digests in header into signature header

  * @param fd		file descriptor of RPM

-- 

2.27.0