On Mon, Nov 19, 2018 at 6:00 AM Yauheni Kaliuta
<yauheni.kaliuta@xxxxxxxxxx> wrote:
>
> The patch adds data fetching from the PKCS#7 certificate using
> gnutls library.
>
> In general the certificate can contain many signatures, but since
> kmod (modinfo) supports only one signature at the moment, only first
> one is taken.
>
> With the current sign-file.c certificate doesn't contain signer
> key's fingerprint, so "serial number" is used for the key id.
>
> gnutls has LGPL2.1 license, same as libkmod.
but... why are you adding both openssl and gnutls?
Lucas De Marchi
>
> Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
> ---
> Makefile.am | 4 +-
> configure.ac | 11 ++
> libkmod/libkmod-internal.h | 3 +
> libkmod/libkmod-module.c | 3 +
> libkmod/libkmod-signature.c | 208 +++++++++++++++++++++++++++++++++++-
> 5 files changed, 224 insertions(+), 5 deletions(-)
>
> diff --git a/Makefile.am b/Makefile.am
> index 194e1115ae70..2fd44fca69f2 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -35,6 +35,8 @@ SED_PROCESS = \
> -e 's,@liblzma_LIBS\@,${liblzma_LIBS},g' \
> -e 's,@zlib_CFLAGS\@,${zlib_CFLAGS},g' \
> -e 's,@zlib_LIBS\@,${zlib_LIBS},g' \
> + -e 's,@gnutls_CFLAGS\@,${gnutls_CFLAGS},g' \
> + -e 's,@gnutls_LIBS\@,${gnutls_LIBS},g' \
> < $< > $@ || rm $@
>
> %.pc: %.pc.in Makefile
> @@ -87,7 +89,7 @@ libkmod_libkmod_la_DEPENDENCIES = \
> ${top_srcdir}/libkmod/libkmod.sym
> libkmod_libkmod_la_LIBADD = \
> shared/libshared.la \
> - ${liblzma_LIBS} ${zlib_LIBS}
> + ${liblzma_LIBS} ${zlib_LIBS} ${gnutls_LIBS}
>
> noinst_LTLIBRARIES += libkmod/libkmod-internal.la
> libkmod_libkmod_internal_la_SOURCES = $(libkmod_libkmod_la_SOURCES)
> diff --git a/configure.ac b/configure.ac
> index fbc7391b2d1b..0a6787fa9a36 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -106,6 +106,17 @@ AS_IF([test "x$with_zlib" != "xno"], [
> ])
> CC_FEATURE_APPEND([with_features], [with_zlib], [ZLIB])
>
> +AC_ARG_WITH([gnutls],
> + AS_HELP_STRING([--with-gnutls], [handle PKCS7 signatures @<:@default=disabled@:>@]),
> + [], [with_gnutls=no])
> +AS_IF([test "x$with_gnutls" != "xno"], [
> + PKG_CHECK_MODULES([gnutls], [gnutls])
> + AC_DEFINE([ENABLE_GNUTLS], [1], [Enable gnutls for modinfo.])
> +], [
> + AC_MSG_NOTICE([gnutls support not requested])
> +])
> +CC_FEATURE_APPEND([with_features], [with_gnutls], [GNUTLS])
> +
> AC_ARG_WITH([bashcompletiondir],
> AS_HELP_STRING([--with-bashcompletiondir=DIR], [Bash completions directory]),
> [],
> diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
> index 346579c71aab..a65ddd156f18 100644
> --- a/libkmod/libkmod-internal.h
> +++ b/libkmod/libkmod-internal.h
> @@ -188,5 +188,8 @@ struct kmod_signature_info {
> const char *algo, *hash_algo, *id_type;
> const char *sig;
> size_t sig_len;
> + void (*free)(void *);
> + void *private;
> };
> bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2)));
> +void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull));
> diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
> index 889f26479a98..bffe715cdef4 100644
> --- a/libkmod/libkmod-module.c
> +++ b/libkmod/libkmod-module.c
> @@ -2357,6 +2357,9 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod, struct kmod_
> ret = count;
>
> list_error:
> + /* aux structures freed in normal case also */
> + kmod_module_signature_info_free(&sig_info);
> +
> if (ret < 0) {
> kmod_module_info_free_list(*list);
> *list = NULL;
> diff --git a/libkmod/libkmod-signature.c b/libkmod/libkmod-signature.c
> index 429ffbd8a957..326fa2ea776a 100644
> --- a/libkmod/libkmod-signature.c
> +++ b/libkmod/libkmod-signature.c
> @@ -19,6 +19,9 @@
>
> #include <endian.h>
> #include <inttypes.h>
> +#ifdef ENABLE_GNUTLS
> +#include <gnutls/pkcs7.h>
> +#endif
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> @@ -92,6 +95,13 @@ struct module_signature {
> uint32_t sig_len; /* Length of signature data (big endian) */
> };
>
> +static const char *pkey_hash_algo_to_str(enum pkey_hash_algo algo)
> +{
> + if (algo < 0 || algo >= PKEY_HASH__LAST)
> + return "unknown";
> + return pkey_hash_algo[algo];
> +}
> +
> static bool fill_default(const char *mem, off_t size,
> const struct module_signature *modsig, size_t sig_len,
> struct kmod_signature_info *sig_info)
> @@ -115,15 +125,199 @@ static bool fill_default(const char *mem, off_t size,
> return true;
> }
>
> -static bool fill_unknown(const char *mem, off_t size,
> - const struct module_signature *modsig, size_t sig_len,
> - struct kmod_signature_info *sig_info)
> +#ifdef ENABLE_GNUTLS
> +
> +struct pkcs7_private {
> + gnutls_pkcs7_t pkcs7;
> + gnutls_pkcs7_signature_info_st si;
> + gnutls_x509_dn_t dn;
> + gnutls_datum_t dn_data;
> + char *issuer;
> +};
> +
> +static void pkcs7_free(void *s)
> +{
> + struct kmod_signature_info *si = s;
> + struct pkcs7_private *pvt = si->private;
> +
> + free(pvt->issuer);
> + gnutls_free(pvt->dn_data.data);
> + gnutls_x509_dn_deinit(pvt->dn);
> + gnutls_pkcs7_signature_info_deinit(&pvt->si);
> + gnutls_pkcs7_deinit(pvt->pkcs7);
> +
> + free(pvt);
> + si->private = NULL;
> +}
> +
> +static int gnutls_algo_translate(gnutls_sign_algorithm_t algo)
> +{
> + switch (algo) {
> + case GNUTLS_SIGN_RSA_SHA1:
> + case GNUTLS_SIGN_DSA_SHA1:
> + case GNUTLS_SIGN_ECDSA_SHA1:
> + return PKEY_HASH_SHA1;
> + case GNUTLS_SIGN_RSA_MD5:
> + return PKEY_HASH_MD5;
> + case GNUTLS_SIGN_RSA_RMD160:
> + return PKEY_HASH_RIPE_MD_160;
> + case GNUTLS_SIGN_RSA_SHA256:
> + case GNUTLS_SIGN_DSA_SHA256:
> + case GNUTLS_SIGN_ECDSA_SHA256:
> + return PKEY_HASH_SHA256;
> + case GNUTLS_SIGN_RSA_SHA384:
> + case GNUTLS_SIGN_ECDSA_SHA384:
> + case GNUTLS_SIGN_DSA_SHA384:
> + return PKEY_HASH_SHA384;
> + case GNUTLS_SIGN_RSA_SHA512:
> + case GNUTLS_SIGN_ECDSA_SHA512:
> + case GNUTLS_SIGN_DSA_SHA512:
> + return PKEY_HASH_SHA512;
> + case GNUTLS_SIGN_RSA_SHA224:
> + case GNUTLS_SIGN_DSA_SHA224:
> + case GNUTLS_SIGN_ECDSA_SHA224:
> + return PKEY_HASH_SHA224;
> + default:
> + return -1;
> + }
> + return -1;
> +}
> +
> +/*
> + * Extracts CN from O=Org,CN=CommonName,EMAIL=email
> + */
> +static char *dn_str_to_cn(unsigned char *dn)
> +{
> + char *s;
> + char *e;
> + char *r;
> + size_t len;
> +
> + s = strstr((char *)dn, "CN=");
> + if (s == NULL)
> + return NULL;
> +
> + len = strlen(s);
> + if (len < strlen("CN=") + 1) /* at least one symbol */
> + return NULL;
> + s += strlen("CN=");
> +
> + e = strchr(s, ',');
> + if (e == NULL)
> + e = s + len;
> + len = e - s;
> +
> + r = malloc(len + 1);
> + if (r == NULL)
> + return NULL;
> +
> + memcpy(r, s, len);
> + r[len] = '\0';
> + return r;
> +}
> +static bool fill_pkcs7(const char *mem, off_t size,
> + const struct module_signature *modsig, size_t sig_len,
> + struct kmod_signature_info *sig_info)
> +{
> + int rc;
> + const char *pkcs7_raw;
> + gnutls_pkcs7_t pkcs7;
> + gnutls_datum_t data;
> + gnutls_pkcs7_signature_info_st si;
> + gnutls_x509_dn_t dn;
> + struct pkcs7_private *pvt;
> + char *issuer;
> +
> + size -= sig_len;
> + pkcs7_raw = mem + size;
> +
> + rc = gnutls_pkcs7_init(&pkcs7);
> + if (rc < 0)
> + return false;
> +
> + data.data = (unsigned char *)pkcs7_raw;
> + data.size = sig_len;
> + rc = gnutls_pkcs7_import(pkcs7, &data, GNUTLS_X509_FMT_DER);
> + if (rc < 0)
> + goto err1;
> +
> + rc = gnutls_pkcs7_get_signature_info(pkcs7, 0, &si);
> + if (rc < 0)
> + goto err1;
> +
> + rc = gnutls_x509_dn_init(&dn);
> + if (rc < 0)
> + goto err2;
> +
> + rc = gnutls_x509_dn_import(dn, &si.issuer_dn);
> + if (rc < 0)
> + goto err3;
> +
> + /*
> + * I could not find simple wrapper to extract the data
> + * directly from ASN1, so get the string and parse it.
> + *
> + * Returns null-terminated string in data.data
> + */
> + rc = gnutls_x509_dn_get_str(dn, &data);
> + if (rc < 0)
> + goto err3;
> +
> + sig_info->sig = (const char *)si.sig.data;
> + sig_info->sig_len = si.sig.size;
> +
> + sig_info->key_id = (const char *)si.signer_serial.data;
> + sig_info->key_id_len = si.signer_serial.size;
> +
> + issuer = dn_str_to_cn(data.data);
> + if (issuer != NULL) {
> + sig_info->signer = issuer;
> + sig_info->signer_len = strlen(issuer);
> + }
> +
> + sig_info->hash_algo = pkey_hash_algo_to_str(gnutls_algo_translate(si.algo));
> + sig_info->id_type = pkey_id_type[modsig->id_type];
> +
> + pvt = malloc(sizeof(*pvt));
> + if (pvt == NULL)
> + goto err4;
> +
> + pvt->pkcs7 = pkcs7;
> + pvt->si = si;
> + pvt->dn = dn;
> + pvt->dn_data = data;
> + pvt->issuer = issuer;
> +
> + sig_info->private = pvt;
> + sig_info->free = pkcs7_free;
> +
> + return true;
> +
> +err4:
> + gnutls_free(data.data);
> +err3:
> + gnutls_x509_dn_deinit(dn);
> +err2:
> + gnutls_pkcs7_signature_info_deinit(&si);
> +err1:
> + gnutls_pkcs7_deinit(pkcs7);
> +
> + return false;
> +}
> +
> +#else /* ENABLE GNUTLS */
> +
> +static bool fill_pkcs7(const char *mem, off_t size,
> + const struct module_signature *modsig, size_t sig_len,
> + struct kmod_signature_info *sig_info)
> {
> sig_info->hash_algo = "unknown";
> sig_info->id_type = pkey_id_type[modsig->id_type];
> return true;
> }
>
> +#endif /* ENABLE GNUTLS */
> +
> #define SIG_MAGIC "~Module signature appended~\n"
>
> /*
> @@ -167,8 +361,14 @@ bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signat
>
> switch (modsig->id_type) {
> case PKEY_ID_PKCS7:
> - return fill_unknown(mem, size, modsig, sig_len, sig_info);
> + return fill_pkcs7(mem, size, modsig, sig_len, sig_info);
> default:
> return fill_default(mem, size, modsig, sig_len, sig_info);
> }
> }
> +
> +void kmod_module_signature_info_free(struct kmod_signature_info *sig_info)
> +{
> + if (sig_info->free)
> + sig_info->free(sig_info);
> +}
> --
> 2.19.1
>
--
Lucas De Marchi
