From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44040 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751264AbcDEAQN (ORCPT ); Mon, 4 Apr 2016 20:16:13 -0400 Date: Tue, 5 Apr 2016 01:16:11 +0100 From: Ben Hutchings To: linux-modules@vger.kernel.org Cc: 820010@bugs.debian.org Message-ID: <20160405001611.GJ21187@decadent.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="7SAgGoIHugoKhRwh" Subject: [PATCH] libkmod: Add support for detached module signatures Sender: owner-linux-modules@vger.kernel.org List-ID: --7SAgGoIHugoKhRwh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Debian will not sign modules during the kernel package build, as this conflicts with the goal of reproducible builds. Instead, we will generate detached signatures offline and include them in a second package. We could attach the signatures when building this second package or at installation time, but that leads to duplication of all modules, either in the archive or on users' systems. To avoid this, add support to libkmod for concatenating modules with detached signatures (files with the '.sig' extension) at load time. Signed-off-by: Ben Hutchings --- I should note that I have *not* tested this with gzip or xz compressed modules. Ben. libkmod/libkmod-file.c | 110 +++++++++++++++++++++++++++++++++++++++++++++= ---- 1 file changed, 103 insertions(+), 7 deletions(-) diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c index 5eeba6a912a2..c30a9b92a3ac 100644 --- a/libkmod/libkmod-file.c +++ b/libkmod/libkmod-file.c @@ -52,6 +52,7 @@ struct kmod_file { gzFile gzf; #endif int fd; + int sig_fd; bool direct; off_t size; void *memory; @@ -60,6 +61,37 @@ struct kmod_file { struct kmod_elf *elf; }; =20 +static int append_detached_sig(struct kmod_file *file, size_t buf_size) +{ + struct stat st; + ssize_t read_size; + + if (file->sig_fd < 0) + return 0; + + if (fstat(file->sig_fd, &st) < 0) + return -errno; + + /* Grow the buffer if necessary */ + if ((size_t)st.st_size > buf_size - file->size) { + void *tmp =3D realloc(file->memory, file->size + st.st_size); + if (tmp =3D=3D NULL) + return -errno; + file->memory =3D tmp; + } + + read_size =3D read(file->sig_fd, (char *)file->memory + file->size, + st.st_size); + if (read_size < 0) + return -errno; + if (read_size !=3D st.st_size) + return -EINVAL; + + file->size +=3D read_size; + + return 0; +} + #ifdef ENABLE_XZ static void xz_uncompress_belch(struct kmod_file *file, lzma_ret ret) { @@ -144,6 +176,7 @@ static int load_xz(struct kmod_file *file) { lzma_stream strm =3D LZMA_STREAM_INIT; lzma_ret lzret; + size_t buf_size; int ret; =20 lzret =3D lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); @@ -155,7 +188,14 @@ static int load_xz(struct kmod_file *file) return -EINVAL; } ret =3D xz_uncompress(&strm, file); + buf_size =3D file->size + strm->avail_out; lzma_end(&strm); + + if (!ret) { + ret =3D append_detached_sig(file, buf_size); + if (ret) + free(file->memory); + } return ret; } =20 @@ -214,6 +254,11 @@ static int load_zlib(struct kmod_file *file) =20 file->memory =3D p; file->size =3D did; + + err =3D append_detached_sig(file, total); + if (err) + goto error; + p =3D NULL; return 0; =20 @@ -254,18 +299,50 @@ static int load_reg(struct kmod_file *file) if (fstat(file->fd, &st) < 0) return -errno; =20 - file->size =3D st.st_size; - file->memory =3D mmap(NULL, file->size, PROT_READ, MAP_PRIVATE, - file->fd, 0); - if (file->memory =3D=3D MAP_FAILED) - return -errno; - file->direct =3D true; + if (file->sig_fd < 0) { + file->size =3D st.st_size; + file->memory =3D mmap(NULL, file->size, PROT_READ, MAP_PRIVATE, + file->fd, 0); + if (file->memory =3D=3D MAP_FAILED) + return -errno; + file->direct =3D true; + } else { + size_t plain_size =3D st.st_size, sig_size; + _cleanup_free_ unsigned char *p =3D NULL; + ssize_t ret; + + if (fstat(file->sig_fd, &st) < 0) + return -errno; + sig_size =3D st.st_size; + + p =3D malloc(plain_size + sig_size); + if (!p) + return -errno; + + ret =3D read(file->fd, p, plain_size); + if (ret < 0) + return -errno; + if ((size_t)ret !=3D plain_size) + return -EINVAL; + file->memory =3D p; + file->size =3D plain_size; + + ret =3D append_detached_sig(file, plain_size + sig_size); + if (ret) + return ret; + + p =3D NULL; + } + return 0; } =20 static void unload_reg(struct kmod_file *file) { - munmap(file->memory, file->size); + if (file->direct) + munmap(file->memory, file->size); + else + free(file->memory); } =20 static const struct file_ops reg_ops =3D { @@ -285,6 +362,7 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx = *ctx, const char *filename) { struct kmod_file *file =3D calloc(1, sizeof(struct kmod_file)); + char *sig_filename =3D NULL; const struct comp_type *itr; size_t magic_size_max =3D 0; int err; @@ -292,12 +370,25 @@ struct kmod_file *kmod_file_open(const struct kmod_ct= x *ctx, if (file =3D=3D NULL) return NULL; =20 + file->sig_fd =3D -1; + file->fd =3D open(filename, O_RDONLY|O_CLOEXEC); if (file->fd < 0) { err =3D -errno; goto error; } =20 + /* Try to open a detached signature. If it's missing, that's OK. */ + if (asprintf(&sig_filename, "%s.sig", filename) < 0) { + err =3D -errno; + goto error; + } + file->sig_fd =3D open(sig_filename, O_RDONLY|O_CLOEXEC); + if (file->sig_fd < 0 && errno !=3D ENOENT) { + err =3D -errno; + goto error; + } + for (itr =3D comp_types; itr->ops.load !=3D NULL; itr++) { if (magic_size_max < itr->magic_size) magic_size_max =3D itr->magic_size; @@ -336,7 +427,10 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx= *ctx, err =3D file->ops->load(file); file->ctx =3D ctx; error: + free(sig_filename); if (err < 0) { + if (file->sig_fd >=3D 0) + close(file->sig_fd); if (file->fd >=3D 0) close(file->fd); free(file); @@ -373,6 +467,8 @@ void kmod_file_unref(struct kmod_file *file) kmod_elf_unref(file->elf); =20 file->ops->unload(file); + if (file->sig_fd >=3D 0) + close(file->sig_fd); if (file->fd >=3D 0) close(file->fd); free(file); --7SAgGoIHugoKhRwh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUBVwMDy+e/yOyVhhEJAQpndRAAn6oUEmdS6h+xEVZJM9Z97lL8sB7Yqy1o UhtlCT0kSrI1Pue/JCaXMcE4HN0OO/BdYXuvv8J2vTIhgZUYz3K7SqBJ2EeMQ4mv cXs7nH85amy+Yc+N6XM5ZvEIyBpvJylyahpMoBzeyGhCOV6h05T72JRPnaXcy3M6 vvTA7CNXkn8PNYl5+XEPZep47JbfDsUSPaKaoBGPmWvNn0DiUcUF2wPlE6QKIbQn wiIw8kX8HMA8j60rn/VKKVRk4AaKkcvNGknLefx+WlmI9bzczwQkhQmvB08g0mrA 32F6PNmoobXgyNTQMutJNJDYMFMBIMnn0iMWi6WIJOnkGdQrjWyu2cwp5M/SKppK 4ndv5d5lpDf9FtUC9pmS1xFg1QSs1w4eQ6EFbbjQ7v0W3GXUFRUwGfT5CKYvHIH2 u0gkPiUoYtM+SHSFSlLq91XJ4MV8z2nROux5a6FMcZXy0t/stz/ZubcyuJ81+I+q oLLT4F1OXPuVEmN5kGNA5OBlMEE6iByxh4EeIF/LWPDk6w+GlfCagxAH/J7M2Wkr tcIgoxp8wNcm5LSyJuFII52YFv+yL/k7QMNnspB2Mw3oKM0zD+Uxry6/7p+qvNGl 2GFSJCSKP+UhrG8iBCEQeoQbJSluTFkEcyPZvWgk28PGIjgDECnRYP7W4MFp7VFd 5lca80K+I2A= =A+pe -----END PGP SIGNATURE----- --7SAgGoIHugoKhRwh--