X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fkernel%2Fmodule_signing.c;fp=kernel%2Fkernel%2Fmodule_signing.c;h=6528a79d998d08120e9e80524164e5c759d911f3;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=be5b8fac4bd0de72aba1f91674a2d0eb7a296d31;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git diff --git a/kernel/kernel/module_signing.c b/kernel/kernel/module_signing.c index be5b8fac4..6528a79d9 100644 --- a/kernel/kernel/module_signing.c +++ b/kernel/kernel/module_signing.c @@ -10,11 +10,9 @@ */ #include -#include -#include -#include -#include +#include #include +#include #include "module-internal.h" /* @@ -28,170 +26,22 @@ * - Information block */ struct module_signature { - u8 algo; /* Public-key crypto algorithm [enum pkey_algo] */ - u8 hash; /* Digest algorithm [enum hash_algo] */ - u8 id_type; /* Key identifier type [enum pkey_id_type] */ - u8 signer_len; /* Length of signer's name */ - u8 key_id_len; /* Length of key identifier */ + u8 algo; /* Public-key crypto algorithm [0] */ + u8 hash; /* Digest algorithm [0] */ + u8 id_type; /* Key identifier type [PKEY_ID_PKCS7] */ + u8 signer_len; /* Length of signer's name [0] */ + u8 key_id_len; /* Length of key identifier [0] */ u8 __pad[3]; __be32 sig_len; /* Length of signature data */ }; -/* - * Digest the module contents. - */ -static struct public_key_signature *mod_make_digest(enum hash_algo hash, - const void *mod, - unsigned long modlen) -{ - struct public_key_signature *pks; - struct crypto_shash *tfm; - struct shash_desc *desc; - size_t digest_size, desc_size; - int ret; - - pr_devel("==>%s()\n", __func__); - - /* Allocate the hashing algorithm we're going to need and find out how - * big the hash operational data will be. - */ - tfm = crypto_alloc_shash(hash_algo_name[hash], 0, 0); - if (IS_ERR(tfm)) - return (PTR_ERR(tfm) == -ENOENT) ? ERR_PTR(-ENOPKG) : ERR_CAST(tfm); - - desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); - digest_size = crypto_shash_digestsize(tfm); - - /* We allocate the hash operational data storage on the end of our - * context data and the digest output buffer on the end of that. - */ - ret = -ENOMEM; - pks = kzalloc(digest_size + sizeof(*pks) + desc_size, GFP_KERNEL); - if (!pks) - goto error_no_pks; - - pks->pkey_hash_algo = hash; - pks->digest = (u8 *)pks + sizeof(*pks) + desc_size; - pks->digest_size = digest_size; - - desc = (void *)pks + sizeof(*pks); - desc->tfm = tfm; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; - - ret = crypto_shash_init(desc); - if (ret < 0) - goto error; - - ret = crypto_shash_finup(desc, mod, modlen, pks->digest); - if (ret < 0) - goto error; - - crypto_free_shash(tfm); - pr_devel("<==%s() = ok\n", __func__); - return pks; - -error: - kfree(pks); -error_no_pks: - crypto_free_shash(tfm); - pr_devel("<==%s() = %d\n", __func__, ret); - return ERR_PTR(ret); -} - -/* - * Extract an MPI array from the signature data. This represents the actual - * signature. Each raw MPI is prefaced by a BE 2-byte value indicating the - * size of the MPI in bytes. - * - * RSA signatures only have one MPI, so currently we only read one. - */ -static int mod_extract_mpi_array(struct public_key_signature *pks, - const void *data, size_t len) -{ - size_t nbytes; - MPI mpi; - - if (len < 3) - return -EBADMSG; - nbytes = ((const u8 *)data)[0] << 8 | ((const u8 *)data)[1]; - data += 2; - len -= 2; - if (len != nbytes) - return -EBADMSG; - - mpi = mpi_read_raw_data(data, nbytes); - if (!mpi) - return -ENOMEM; - pks->mpi[0] = mpi; - pks->nr_mpi = 1; - return 0; -} - -/* - * Request an asymmetric key. - */ -static struct key *request_asymmetric_key(const char *signer, size_t signer_len, - const u8 *key_id, size_t key_id_len) -{ - key_ref_t key; - size_t i; - char *id, *q; - - pr_devel("==>%s(,%zu,,%zu)\n", __func__, signer_len, key_id_len); - - /* Construct an identifier. */ - id = kmalloc(signer_len + 2 + key_id_len * 2 + 1, GFP_KERNEL); - if (!id) - return ERR_PTR(-ENOKEY); - - memcpy(id, signer, signer_len); - - q = id + signer_len; - *q++ = ':'; - *q++ = ' '; - for (i = 0; i < key_id_len; i++) { - *q++ = hex_asc[*key_id >> 4]; - *q++ = hex_asc[*key_id++ & 0x0f]; - } - - *q = 0; - - pr_debug("Look up: \"%s\"\n", id); - - key = keyring_search(make_key_ref(system_trusted_keyring, 1), - &key_type_asymmetric, id); - if (IS_ERR(key)) - pr_warn("Request for unknown module key '%s' err %ld\n", - id, PTR_ERR(key)); - kfree(id); - - if (IS_ERR(key)) { - switch (PTR_ERR(key)) { - /* Hide some search errors */ - case -EACCES: - case -ENOTDIR: - case -EAGAIN: - return ERR_PTR(-ENOKEY); - default: - return ERR_CAST(key); - } - } - - pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key_ref_to_ptr(key))); - return key_ref_to_ptr(key); -} - /* * Verify the signature on a module. */ int mod_verify_sig(const void *mod, unsigned long *_modlen) { - struct public_key_signature *pks; struct module_signature ms; - struct key *key; - const void *sig; size_t modlen = *_modlen, sig_len; - int ret; pr_devel("==>%s(,%zu)\n", __func__, modlen); @@ -205,46 +55,24 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) if (sig_len >= modlen) return -EBADMSG; modlen -= sig_len; - if ((size_t)ms.signer_len + ms.key_id_len >= modlen) - return -EBADMSG; - modlen -= (size_t)ms.signer_len + ms.key_id_len; - *_modlen = modlen; - sig = mod + modlen; - - /* For the moment, only support RSA and X.509 identifiers */ - if (ms.algo != PKEY_ALGO_RSA || - ms.id_type != PKEY_ID_X509) - return -ENOPKG; - if (ms.hash >= PKEY_HASH__LAST || - !hash_algo_name[ms.hash]) + if (ms.id_type != PKEY_ID_PKCS7) { + pr_err("Module is not signed with expected PKCS#7 message\n"); return -ENOPKG; - - key = request_asymmetric_key(sig, ms.signer_len, - sig + ms.signer_len, ms.key_id_len); - if (IS_ERR(key)) - return PTR_ERR(key); - - pks = mod_make_digest(ms.hash, mod, modlen); - if (IS_ERR(pks)) { - ret = PTR_ERR(pks); - goto error_put_key; } - ret = mod_extract_mpi_array(pks, sig + ms.signer_len + ms.key_id_len, - sig_len); - if (ret < 0) - goto error_free_pks; - - ret = verify_signature(key, pks); - pr_devel("verify_signature() = %d\n", ret); + if (ms.algo != 0 || + ms.hash != 0 || + ms.signer_len != 0 || + ms.key_id_len != 0 || + ms.__pad[0] != 0 || + ms.__pad[1] != 0 || + ms.__pad[2] != 0) { + pr_err("PKCS#7 signature info has unexpected non-zero params\n"); + return -EBADMSG; + } -error_free_pks: - mpi_free(pks->rsa.s); - kfree(pks); -error_put_key: - key_put(key); - pr_devel("<==%s() = %d\n", __func__, ret); - return ret; + return system_verify_data(mod, modlen, mod + modlen, sig_len, + VERIFYING_MODULE_SIGNATURE); }