[PATCH 2/2] crypto: remove padding logic from rsa.c
From: Tadeusz Struk
Date: Wed Feb 24 2016 - 12:17:26 EST
This reverts back the rsa.c to do the math primitives only.
It also reverts the akcipher api changes as the hash param
will be passed to the rsa-pkcs1 template.
All padding and encoding logic is moved to the rsa-pkcs1pad.
The software_pkey.c uses pkcs1pad template to allocate the akcipher
and the hash param is passed via pksc1pad.
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
---
crypto/asymmetric_keys/software_pkey.c | 28 ++++
crypto/rsa.c | 210 +++++---------------------------
crypto/testmgr.c | 5 -
include/crypto/akcipher.h | 7 -
4 files changed, 56 insertions(+), 194 deletions(-)
diff --git a/crypto/asymmetric_keys/software_pkey.c b/crypto/asymmetric_keys/software_pkey.c
index 8732a41..69693fd 100644
--- a/crypto/asymmetric_keys/software_pkey.c
+++ b/crypto/asymmetric_keys/software_pkey.c
@@ -75,6 +75,9 @@ int software_pkey_verify_signature(const struct software_pkey *pkey,
struct crypto_akcipher *tfm;
struct akcipher_request *req;
struct scatterlist sig_sg, digest_sg;
+ char alg_name[CRYPTO_MAX_ALG_NAME];
+ void *output;
+ unsigned int outlen;
int ret = -ENOMEM;
pr_devel("==>%s()\n", __func__);
@@ -84,7 +87,11 @@ int software_pkey_verify_signature(const struct software_pkey *pkey,
BUG_ON(!sig->digest);
BUG_ON(!sig->s);
- tfm = crypto_alloc_akcipher(sig->pkey_algo, 0, 0);
+ if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
+ sig->pkey_algo, sig->hash_algo) >= CRYPTO_MAX_ALG_NAME)
+ return -EINVAL;
+
+ tfm = crypto_alloc_akcipher(alg_name, 0, 0);
if (IS_ERR(tfm))
return PTR_ERR(tfm);
@@ -96,11 +103,15 @@ int software_pkey_verify_signature(const struct software_pkey *pkey,
if (ret)
goto error_free_req;
+ outlen = crypto_akcipher_maxsize(tfm);
+ output = kmalloc(outlen, GFP_KERNEL);
+ if (!output)
+ goto error_free_req;
+
sg_init_one(&sig_sg, sig->s, sig->s_size);
- sg_init_one(&digest_sg, sig->digest, sig->digest_size);
- akcipher_request_set_crypt(req, &sig_sg, &digest_sg,
- sig->s_size, sig->digest_size,
- sig->hash_algo);
+ sg_init_one(&digest_sg, output, outlen);
+ akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
+ outlen);
init_completion(&compl.completion);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
@@ -112,6 +123,13 @@ int software_pkey_verify_signature(const struct software_pkey *pkey,
ret = compl.err;
}
+ if (!ret) {
+ if (memcmp(sig->digest, output, sig->digest_size) ||
+ req->dst_len != sig->digest_size)
+ ret = -EBADMSG;
+ }
+
+ kfree(output);
error_free_req:
akcipher_request_free(req);
error_free_tfm:
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 9a7c9ca..77d737f 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -16,78 +16,6 @@
#include <crypto/algapi.h>
/*
- * 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_rmd160[] = {
- 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 rsa_asn1_template {
- const char *name;
- const u8 *data;
- size_t size;
-} rsa_asn1_templates[] = {
-#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
- _(md5),
- _(sha1),
- _(rmd160),
- _(sha256),
- _(sha384),
- _(sha512),
- _(sha224),
- { NULL }
-#undef _
-};
-
-static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
-{
- const struct rsa_asn1_template *p;
-
- for (p = rsa_asn1_templates; p->name; p++)
- if (strcmp(name, p->name) == 0)
- return p;
- return NULL;
-}
-
-/*
* RSAEP function [RFC3447 sec 5.1.1]
* c = m^e mod n;
*/
@@ -143,13 +71,6 @@ static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s)
return mpi_powm(m, s, key->e, key->n);
}
-static int rsa_max_size(struct crypto_akcipher *tfm)
-{
- struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
-
- return pkey->n ? mpi_get_size(pkey->n) : -EINVAL;
-}
-
static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm)
{
return akcipher_tfm_ctx(tfm);
@@ -271,122 +192,44 @@ err_free_s:
return ret;
}
-static int rsa_verify_raw(struct akcipher_request *req, MPI EM)
+static int rsa_verify(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
const struct rsa_key *pkey = rsa_get_key(tfm);
- MPI s, m_calc;
- int ret;
+ MPI s, m = mpi_alloc(0);
+ int ret = 0;
+ int sign;
- m_calc = mpi_alloc(0);
- if (!m_calc)
+ if (!m)
return -ENOMEM;
+ if (unlikely(!pkey->n || !pkey->e)) {
+ ret = -EINVAL;
+ goto err_free_m;
+ }
+
ret = -ENOMEM;
s = mpi_read_raw_from_sgl(req->src, req->src_len);
- if (!s)
- goto err_free_m_calc;
+ if (!s) {
+ ret = -ENOMEM;
+ goto err_free_m;
+ }
- ret = _rsa_verify(pkey, m_calc, s);
+ ret = _rsa_verify(pkey, m, s);
if (ret)
goto err_free_s;
- ret = -EKEYREJECTED;
- if (mpi_cmp(m_calc, EM) != 0)
+ ret = mpi_write_to_sgl(m, req->dst, &req->dst_len, &sign);
+ if (ret)
goto err_free_s;
- ret = 0;
+ if (sign < 0)
+ ret = -EBADMSG;
+
err_free_s:
mpi_free(s);
-err_free_m_calc:
- mpi_free(m_calc);
- return ret;
-}
-
-/*
- * Turn Hash(M) into EM for a key of size k and a specified hash algorithm as
- * per EMSA-PKCS1-v1_5:
- *
- * EM = 0x00 || 0x01 || PS || 0x00 || T
- */
-static MPI rsa_emsa_pkcs1_v1_5(struct scatterlist *H, int H_size, int k,
- const char *hash_algo)
-{
- const struct rsa_asn1_template *asn1;
- MPI EM;
- int PS_end, T_offset;
- u8 *buf;
-
- asn1 = rsa_lookup_asn1(hash_algo);
- if (!asn1)
- return ERR_PTR(-ENOPKG);
-
- if (k < 2 + 1 + asn1->size + H_size)
- return ERR_PTR(-EMSGSIZE);
-
- T_offset = k - (asn1->size + H_size);
- PS_end = T_offset - 1;
- if (PS_end - 2 < 8)
- return ERR_PTR(-EMSGSIZE);
-
- buf = kmalloc(k, GFP_KERNEL);
- if (!buf)
- return ERR_PTR(-ENOMEM);
-
- /* Set the initial zero and block type octets */
- buf[0] = 0x00;
- buf[1] = 0x01;
-
- /* Set the padding string and the divider */
- memset(buf + 2, 0xff, PS_end - 2);
- buf[PS_end] = 0x00;
-
- /* Set the DER-encoded DigestInfo */
- memcpy(buf + T_offset, asn1->data, asn1->size);
-
- /* Finally set the */
- if (sg_copy_to_buffer(H, sg_nents(H),
- buf + T_offset + asn1->size,
- H_size) != H_size) {
- EM = ERR_PTR(-EMSGSIZE);
- goto error_free_buf;
- }
-
- EM = mpi_read_raw_data(buf, k);
- if (!EM)
- EM = ERR_PTR(-ENOMEM);
-
-error_free_buf:
- kfree(buf);
- return EM;
-}
-
-static int rsa_verify_encoded(struct akcipher_request *req)
-{
- struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
- const struct rsa_key *pkey = rsa_get_key(tfm);
- MPI EM;
- int ret, k;
-
- pr_devel("==>%s(%u,%u,%s)\n",
- __func__, req->src_len, req->dst_len, req->hash_algo);
-
- if (unlikely(!pkey->n || !pkey->e || !req->hash_algo))
- return -EINVAL;
-
- /* Find k - the size of E(M). */
- k = rsa_max_size(tfm);
- if (k < 0)
- return k;
-
- EM = rsa_emsa_pkcs1_v1_5(req->dst, req->dst_len, k, req->hash_algo);
- if (IS_ERR(EM))
- return PTR_ERR(EM);
-
- ret = rsa_verify_raw(req, EM);
-
- mpi_free(EM);
- pr_devel("<==%s() = %d\n", __func__, ret);
+err_free_m:
+ mpi_free(m);
return ret;
}
@@ -439,6 +282,13 @@ static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
return ret;
}
+static int rsa_max_size(struct crypto_akcipher *tfm)
+{
+ struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
+
+ return pkey->n ? mpi_get_size(pkey->n) : -EINVAL;
+}
+
static void rsa_exit_tfm(struct crypto_akcipher *tfm)
{
struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
@@ -450,7 +300,7 @@ static struct akcipher_alg rsa = {
.encrypt = rsa_enc,
.decrypt = rsa_dec,
.sign = rsa_sign,
- .verify = rsa_verify_encoded,
+ .verify = rsa_verify,
.set_priv_key = rsa_set_priv_key,
.set_pub_key = rsa_set_pub_key,
.max_size = rsa_max_size,
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 94879a3..ae8c57fd 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1882,7 +1882,7 @@ static int do_test_rsa(struct crypto_akcipher *tfm,
sg_set_buf(&src_tab[1], vecs->m + 8, vecs->m_size - 8);
sg_init_one(&dst, outbuf_enc, out_len_max);
akcipher_request_set_crypt(req, src_tab, &dst, vecs->m_size,
- out_len_max, NULL);
+ out_len_max);
akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);
@@ -1916,8 +1916,7 @@ static int do_test_rsa(struct crypto_akcipher *tfm,
sg_init_one(&src, vecs->c, vecs->c_size);
sg_init_one(&dst, outbuf_dec, out_len_max);
init_completion(&result.completion);
- akcipher_request_set_crypt(req, &src, &dst, vecs->c_size, out_len_max,
- NULL);
+ akcipher_request_set_crypt(req, &src, &dst, vecs->c_size, out_len_max);
/* Run RSA decrypt - m = c^d mod n;*/
err = wait_async_op(&result, crypto_akcipher_decrypt(req));
diff --git a/include/crypto/akcipher.h b/include/crypto/akcipher.h
index a59a6a0..354de15 100644
--- a/include/crypto/akcipher.h
+++ b/include/crypto/akcipher.h
@@ -27,7 +27,6 @@
* result.
* In case of error where the dst sgl size was insufficient,
* it will be updated to the size required for the operation.
- * @hash_algo: The hash algorithm used for sign/verify operations.
* @__ctx: Start of private context data
*/
struct akcipher_request {
@@ -36,7 +35,6 @@ struct akcipher_request {
struct scatterlist *dst;
unsigned int src_len;
unsigned int dst_len;
- const char *hash_algo;
void *__ctx[] CRYPTO_MINALIGN_ATTR;
};
@@ -243,20 +241,17 @@ static inline void akcipher_request_set_callback(struct akcipher_request *req,
* @dst: ptr to output scatter list
* @src_len: size of the src input scatter list to be processed
* @dst_len: size of the dst output scatter list
- * @hash_algo: The hash algorithm that was used for a signature (or NULL).
*/
static inline void akcipher_request_set_crypt(struct akcipher_request *req,
struct scatterlist *src,
struct scatterlist *dst,
unsigned int src_len,
- unsigned int dst_len,
- const char *hash_algo)
+ unsigned int dst_len)
{
req->src = src;
req->dst = dst;
req->src_len = src_len;
req->dst_len = dst_len;
- req->hash_algo = hash_algo;
}
/**