summaryrefslogtreecommitdiff
path: root/crypto/asymmetric_keys/rsa.c
diff options
context:
space:
mode:
Diffstat (limited to 'crypto/asymmetric_keys/rsa.c')
-rw-r--r--crypto/asymmetric_keys/rsa.c278
1 files changed, 0 insertions, 278 deletions
diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c
deleted file mode 100644
index 508b57b77474..000000000000
--- a/crypto/asymmetric_keys/rsa.c
+++ /dev/null
@@ -1,278 +0,0 @@
-/* RSA asymmetric public-key algorithm [RFC3447]
- *
- * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-
-#define pr_fmt(fmt) "RSA: "fmt
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <crypto/algapi.h>
-#include "public_key.h"
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("RSA Public Key Algorithm");
-
-#define kenter(FMT, ...) \
- pr_devel("==> %s("FMT")\n", __func__, ##__VA_ARGS__)
-#define kleave(FMT, ...) \
- pr_devel("<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
-
-/*
- * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
- */
-static const u8 RSA_digest_info_MD5[] = {
- 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
- 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */
- 0x05, 0x00, 0x04, 0x10
-};
-
-static const u8 RSA_digest_info_SHA1[] = {
- 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
- 0x2B, 0x0E, 0x03, 0x02, 0x1A,
- 0x05, 0x00, 0x04, 0x14
-};
-
-static const u8 RSA_digest_info_RIPE_MD_160[] = {
- 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
- 0x2B, 0x24, 0x03, 0x02, 0x01,
- 0x05, 0x00, 0x04, 0x14
-};
-
-static const u8 RSA_digest_info_SHA224[] = {
- 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
- 0x05, 0x00, 0x04, 0x1C
-};
-
-static const u8 RSA_digest_info_SHA256[] = {
- 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
- 0x05, 0x00, 0x04, 0x20
-};
-
-static const u8 RSA_digest_info_SHA384[] = {
- 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
- 0x05, 0x00, 0x04, 0x30
-};
-
-static const u8 RSA_digest_info_SHA512[] = {
- 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
- 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
- 0x05, 0x00, 0x04, 0x40
-};
-
-static const struct {
- const u8 *data;
- size_t size;
-} RSA_ASN1_templates[PKEY_HASH__LAST] = {
-#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) }
- [HASH_ALGO_MD5] = _(MD5),
- [HASH_ALGO_SHA1] = _(SHA1),
- [HASH_ALGO_RIPE_MD_160] = _(RIPE_MD_160),
- [HASH_ALGO_SHA256] = _(SHA256),
- [HASH_ALGO_SHA384] = _(SHA384),
- [HASH_ALGO_SHA512] = _(SHA512),
- [HASH_ALGO_SHA224] = _(SHA224),
-#undef _
-};
-
-/*
- * RSAVP1() function [RFC3447 sec 5.2.2]
- */
-static int RSAVP1(const struct public_key *key, MPI s, MPI *_m)
-{
- MPI m;
- int ret;
-
- /* (1) Validate 0 <= s < n */
- if (mpi_cmp_ui(s, 0) < 0) {
- kleave(" = -EBADMSG [s < 0]");
- return -EBADMSG;
- }
- if (mpi_cmp(s, key->rsa.n) >= 0) {
- kleave(" = -EBADMSG [s >= n]");
- return -EBADMSG;
- }
-
- m = mpi_alloc(0);
- if (!m)
- return -ENOMEM;
-
- /* (2) m = s^e mod n */
- ret = mpi_powm(m, s, key->rsa.e, key->rsa.n);
- if (ret < 0) {
- mpi_free(m);
- return ret;
- }
-
- *_m = m;
- return 0;
-}
-
-/*
- * Integer to Octet String conversion [RFC3447 sec 4.1]
- */
-static int RSA_I2OSP(MPI x, size_t xLen, u8 **pX)
-{
- unsigned X_size, x_size;
- int X_sign;
- u8 *X;
-
- /* Make sure the string is the right length. The number should begin
- * with { 0x00, 0x01, ... } so we have to account for 15 leading zero
- * bits not being reported by MPI.
- */
- x_size = mpi_get_nbits(x);
- pr_devel("size(x)=%u xLen*8=%zu\n", x_size, xLen * 8);
- if (x_size != xLen * 8 - 15)
- return -ERANGE;
-
- X = mpi_get_buffer(x, &X_size, &X_sign);
- if (!X)
- return -ENOMEM;
- if (X_sign < 0) {
- kfree(X);
- return -EBADMSG;
- }
- if (X_size != xLen - 1) {
- kfree(X);
- return -EBADMSG;
- }
-
- *pX = X;
- return 0;
-}
-
-/*
- * Perform the RSA signature verification.
- * @H: Value of hash of data and metadata
- * @EM: The computed signature value
- * @k: The size of EM (EM[0] is an invalid location but should hold 0x00)
- * @hash_size: The size of H
- * @asn1_template: The DigestInfo ASN.1 template
- * @asn1_size: Size of asm1_template[]
- */
-static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size,
- const u8 *asn1_template, size_t asn1_size)
-{
- unsigned PS_end, T_offset, i;
-
- kenter(",,%zu,%zu,%zu", k, hash_size, asn1_size);
-
- if (k < 2 + 1 + asn1_size + hash_size)
- return -EBADMSG;
-
- /* Decode the EMSA-PKCS1-v1_5 */
- if (EM[1] != 0x01) {
- kleave(" = -EBADMSG [EM[1] == %02u]", EM[1]);
- return -EBADMSG;
- }
-
- T_offset = k - (asn1_size + hash_size);
- PS_end = T_offset - 1;
- if (EM[PS_end] != 0x00) {
- kleave(" = -EBADMSG [EM[T-1] == %02u]", EM[PS_end]);
- return -EBADMSG;
- }
-
- for (i = 2; i < PS_end; i++) {
- if (EM[i] != 0xff) {
- kleave(" = -EBADMSG [EM[PS%x] == %02u]", i - 2, EM[i]);
- return -EBADMSG;
- }
- }
-
- if (crypto_memneq(asn1_template, EM + T_offset, asn1_size) != 0) {
- kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]");
- return -EBADMSG;
- }
-
- if (crypto_memneq(H, EM + T_offset + asn1_size, hash_size) != 0) {
- kleave(" = -EKEYREJECTED [EM[T] hash mismatch]");
- return -EKEYREJECTED;
- }
-
- kleave(" = 0");
- return 0;
-}
-
-/*
- * Perform the verification step [RFC3447 sec 8.2.2].
- */
-static int RSA_verify_signature(const struct public_key *key,
- const struct public_key_signature *sig)
-{
- size_t tsize;
- int ret;
-
- /* Variables as per RFC3447 sec 8.2.2 */
- const u8 *H = sig->digest;
- u8 *EM = NULL;
- MPI m = NULL;
- size_t k;
-
- kenter("");
-
- if (!RSA_ASN1_templates[sig->pkey_hash_algo].data)
- return -ENOTSUPP;
-
- /* (1) Check the signature size against the public key modulus size */
- k = mpi_get_nbits(key->rsa.n);
- tsize = mpi_get_nbits(sig->rsa.s);
-
- /* According to RFC 4880 sec 3.2, length of MPI is computed starting
- * from most significant bit. So the RFC 3447 sec 8.2.2 size check
- * must be relaxed to conform with shorter signatures - so we fail here
- * only if signature length is longer than modulus size.
- */
- pr_devel("step 1: k=%zu size(S)=%zu\n", k, tsize);
- if (k < tsize) {
- ret = -EBADMSG;
- goto error;
- }
-
- /* Round up and convert to octets */
- k = (k + 7) / 8;
-
- /* (2b) Apply the RSAVP1 verification primitive to the public key */
- ret = RSAVP1(key, sig->rsa.s, &m);
- if (ret < 0)
- goto error;
-
- /* (2c) Convert the message representative (m) to an encoded message
- * (EM) of length k octets.
- *
- * NOTE! The leading zero byte is suppressed by MPI, so we pass a
- * pointer to the _preceding_ byte to RSA_verify()!
- */
- ret = RSA_I2OSP(m, k, &EM);
- if (ret < 0)
- goto error;
-
- ret = RSA_verify(H, EM - 1, k, sig->digest_size,
- RSA_ASN1_templates[sig->pkey_hash_algo].data,
- RSA_ASN1_templates[sig->pkey_hash_algo].size);
-
-error:
- kfree(EM);
- mpi_free(m);
- kleave(" = %d", ret);
- return ret;
-}
-
-const struct public_key_algorithm RSA_public_key_algorithm = {
- .name = "RSA",
- .n_pub_mpi = 2,
- .n_sec_mpi = 3,
- .n_sig_mpi = 1,
- .verify_signature = RSA_verify_signature,
-};
-EXPORT_SYMBOL_GPL(RSA_public_key_algorithm);