/* * Copyright (C) 2011 Nokia Corporation * Copyright (C) 2011 Intel Corporation * * Author: * Dmitry Kasatkin * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2 of the License. * * File: sign.c * implements signature (RSA) verification * pkcs decoding is based on LibTomCrypt code */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include static struct crypto_shash *shash; static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg, unsigned long msglen, unsigned long modulus_bitlen, unsigned long *outlen) { unsigned long modulus_len, ps_len, i; modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0); /* test message size */ if ((msglen > modulus_len) || (modulus_len < 11)) return NULL; /* separate encoded message */ if (msg[0] != 0x00 || msg[1] != 0x01) return NULL; for (i = 2; i < modulus_len - 1; i++) if (msg[i] != 0xFF) break; /* separator check */ if (msg[i] != 0) /* There was no octet with hexadecimal value 0x00 to separate ps from m. */ return NULL; ps_len = i - 2; *outlen = (msglen - (2 + ps_len + 1)); return msg + 2 + ps_len + 1; } /* * RSA Signature verification with public key */ static int digsig_verify_rsa(struct key *key, const char *sig, int siglen, const char *h, int hlen) { int err = -EINVAL; unsigned long len; unsigned long mlen, mblen; unsigned nret, l; int head, i; unsigned char *out1 = NULL; const char *m; MPI in = NULL, res = NULL, pkey[2]; uint8_t *p, *datap; const uint8_t *endp; const struct user_key_payload *ukp; struct pubkey_hdr *pkh; down_read(&key->sem); ukp = user_key_payload(key); if (ukp->datalen < sizeof(*pkh)) goto err1; pkh = (struct pubkey_hdr *)ukp->data; if (pkh->version != 1) goto err1; if (pkh->algo != PUBKEY_ALGO_RSA) goto err1; if (pkh->nmpi != 2) goto err1; datap = pkh->mpi; endp = ukp->data + ukp->datalen; for (i = 0; i < pkh->nmpi; i++) { unsigned int remaining = endp - datap; pkey[i] = mpi_read_from_buffer(datap, &remaining); if (IS_ERR(pkey[i])) { err = PTR_ERR(pkey[i]); goto err; } datap += remaining; } mblen = mpi_get_nbits(pkey[0]); mlen = DIV_ROUND_UP(mblen, 8); if (mlen == 0) { err = -EINVAL; goto err; } err = -ENOMEM; out1 = kzalloc(mlen, GFP_KERNEL); if (!out1) goto err; nret = siglen; in = mpi_read_from_buffer(sig, &nret); if (IS_ERR(in)) { err = PTR_ERR(in); goto err; } res = mpi_alloc(mpi_get_nlimbs(in) * 2); if (!res) goto err; err = mpi_powm(res, in, pkey[1], pkey[0]); if (err) goto err; if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) { err = -EINVAL; goto err; } p = mpi_get_buffer(res, &l, NULL); if (!p) { err = -EINVAL; goto err; } len = mlen; head = len - l; memset(out1, 0, head); memcpy(out1 + head, p, l); kfree(p); m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len); if (!m || len != hlen || memcmp(m, h, hlen)) err = -EINVAL; err: mpi_free(in); mpi_free(res); kfree(out1); while (--i >= 0) mpi_free(pkey[i]); err1: up_read(&key->sem); return err; } /** * digsig_verify() - digital signature verification with public key * @keyring: keyring to search key in * @sig: digital signature * @siglen: length of the signature * @data: data * @datalen: length of the data * * Returns 0 on success, -EINVAL otherwise * * Verifies data integrity against digital signature. * Currently only RSA is supported. * Normally hash of the content is used as a data for this function. * */ int digsig_verify(struct key *keyring, const char *sig, int siglen, const char *data, int datalen) { int err = -ENOMEM; struct signature_hdr *sh = (struct signature_hdr *)sig; struct shash_desc *desc = NULL; unsigned char hash[SHA1_DIGEST_SIZE]; struct key *key; char name[20]; if (siglen < sizeof(*sh) + 2) return -EINVAL; if (sh->algo != PUBKEY_ALGO_RSA) return -ENOTSUPP; sprintf(name, "%llX", __be64_to_cpup((uint64_t *)sh->keyid)); if (keyring) { /* search in specific keyring */ key_ref_t kref; kref = keyring_search(make_key_ref(keyring, 1UL), &key_type_user, name); if (IS_ERR(kref)) key = ERR_CAST(kref); else key = key_ref_to_ptr(kref); } else { key = request_key(&key_type_user, name, NULL); } if (IS_ERR(key)) { pr_err("key not found, id: %s\n", name); return PTR_ERR(key); } desc = kzalloc(sizeof(*desc) + crypto_shash_descsize(shash), GFP_KERNEL); if (!desc) goto err; desc->tfm = shash; desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; crypto_shash_init(desc); crypto_shash_update(desc, data, datalen); crypto_shash_update(desc, sig, sizeof(*sh)); crypto_shash_final(desc, hash); kfree(desc); /* pass signature mpis address */ err = digsig_verify_rsa(key, sig + sizeof(*sh), siglen - sizeof(*sh), hash, sizeof(hash)); err: key_put(key); return err ? -EINVAL : 0; } EXPORT_SYMBOL_GPL(digsig_verify); static int __init digsig_init(void) { shash = crypto_alloc_shash("sha1", 0, 0); if (IS_ERR(shash)) { pr_err("shash allocation failed\n"); return PTR_ERR(shash); } return 0; } static void __exit digsig_cleanup(void) { crypto_free_shash(shash); } module_init(digsig_init); module_exit(digsig_cleanup); MODULE_LICENSE("GPL"); 649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'net/strparser/strparser.c')