Re: [PATCH] crypto: rsa - return raw integer for the ASN.1 parser
On Wed, May 11, 2016 at 07:41:31AM +, Tudor-Dan Ambarus wrote: > > If I move the DMA primitives to the driver context, > I can't assure software coherency enforcement in rsa helper. > > If so, after the ANS.1 parsing, if a driver needs to enforce software > coherency, it will have to allocate coherent memory and copy > the ANS.1 parsed data there. Is this acceptable? Of course you can assume the memory comes from kmalloc. Since your driver is going to be calling the RSA helper to parse the keys we can surely make the guarantee that the RSA helper only returns kmalloced memory. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH] crypto: rsa - return raw integer for the ASN.1 parser
Hi Herbert,
> On Fri, Apr 29, 2016 at 03:51:46PM +0300, Tudor Ambarus wrote:
> >
> > struct rsa_key {
> > + u8 *n;
> > + u8 *e;
> > + u8 *d;
> > + dma_addr_t dma_n;
> > + dma_addr_t dma_e;
> > + dma_addr_t dma_d;
> > + size_t n_sz;
> > + size_t e_sz;
> > + bool coherent;
> > + gfp_t flags;
>
> Please don't put the DMA primitives in the generic helper. They
> should stay in the driver for now.
If I move the DMA primitives to the driver context,
I can't assure software coherency enforcement in rsa helper.
If so, after the ANS.1 parsing, if a driver needs to enforce software
coherency, it will have to allocate coherent memory and copy
the ANS.1 parsed data there. Is this acceptable?
Thanks,
ta
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH] crypto: rsa - return raw integer for the ASN.1 parser
Hi Herbert,
This is related to the suggestion to move the DMA primitives
in the driver.
Please see inline.
> -Original Message-
> From: Tudor Ambarus [mailto:tudor-dan.amba...@nxp.com]
> Sent: Friday, April 29, 2016 3:52 PM
> To: herb...@gondor.apana.org.au
> Cc: linux-crypto@vger.kernel.org; Tudor-Dan Ambarus
> Subject: [PATCH] crypto: rsa - return raw integer for the ASN.1 parser
>
> Return the raw integer with no other processing.
> The scope is to have only one ANS.1 parser for the RSA keys.
>
> Update the RSA software implementation so that it does
> the MPI conversion on top.
>
> Signed-off-by: Tudor Ambarus
> ---
> crypto/rsa.c | 122 ++-
> crypto/rsa_helper.c | 224 --
>
> include/crypto/internal/rsa.h | 41 +++-
> 3 files changed, 287 insertions(+), 100 deletions(-)
>
> diff --git a/crypto/rsa_helper.c b/crypto/rsa_helper.c
> index d226f48..492f37f 100644
> --- a/crypto/rsa_helper.c
> +++ b/crypto/rsa_helper.c
> @@ -14,136 +14,256 @@
> int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
> const void *value, size_t vlen)
> {
> - struct rsa_key *key = context;
> + struct rsa_ctx *ctx = context;
> + struct rsa_key *key = &ctx->key;
> + const char *ptr = value;
> + int ret = -EINVAL;
>
> - key->n = mpi_read_raw_data(value, vlen);
> -
> - if (!key->n)
> - return -ENOMEM;
> + while (!*ptr && vlen) {
> + ptr++;
> + vlen--;
> + }
>
> + key->n_sz = vlen;
> /* In FIPS mode only allow key size 2K & 3K */
> - if (fips_enabled && (mpi_get_size(key->n) != 256 &&
> - mpi_get_size(key->n) != 384)) {
> - pr_err("RSA: key size not allowed in FIPS mode\n");
> - mpi_free(key->n);
> - key->n = NULL;
> - return -EINVAL;
> + if (fips_enabled && (key->n_sz != 256 && key->n_sz != 384)) {
> + dev_err(ctx->dev, "RSA: key size not allowed in FIPS mode\n");
> + goto err;
> }
> + /* invalid key size provided */
> + ret = rsa_check_key_length(key->n_sz << 3);
> + if (ret)
> + goto err;
> +
> + if (key->coherent)
> + key->n = dma_zalloc_coherent(ctx->dev, key->n_sz, &key->dma_n,
> + key->flags);
> + else
> + key->n = kzalloc(key->n_sz, key->flags);
RSA hw implementations that can't enforce hardware coherency may want
to enforce software coherency. As we want a single ASN.1 parser for all
implementations, we need to cover all the cases.
One solution would be to use a common rsa_ctx structure for all
implementations so that the parser's functions can dereference the key
and allocate memory as needed by the user.
Other solution is to move all the device related variables to the driver,
and enforce the software coherency there, by allocating new key members
and copying the parsed data to them.
> +
> + if (!key->n) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + memcpy(key->n, ptr, key->n_sz);
> +
> return 0;
> +err:
> + key->n_sz = 0;
> + key->n = NULL;
> + return ret;
> }
>
> diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h
> index c7585bd..a0a7431 100644
> --- a/include/crypto/internal/rsa.h
> +++ b/include/crypto/internal/rsa.h
> @@ -14,19 +14,52 @@
> #define _RSA_HELPER_
> #include
>
> +/**
> + * rsa_key - RSA key structure
> + * @n : RSA modulus raw byte stream
> + * @e : RSA public exponent raw byte stream
> + * @d : RSA private exponent raw byte stream
> + * @dma_n : DMA address of RSA modulus
> + * @dma_e : DMA address of RSA public exponent
> + * @dma_d : DMA address of RSA private exponent
> + * @n_sz: length in bytes of RSA modulus n
> + * @e_sz: length in bytes of RSA public exponent
> + * @coherent: set true to enforce software coherency for all key
> members
> + * @flags : gfp_t key allocation flags
> + */
> struct rsa_key {
> + u8 *n;
> + u8 *e;
> + u8 *d;
> + dma_addr_t dma_n;
> + dma_addr_t dma_e;
> + dma_addr_t dma_d;
> + size_t n_sz;
> + size_t e_sz;
> + bool coherent;
> + gfp_t flags;
> +};
> +
> +struct rsa_mpi_key {
> MPI n;
> MPI e;
> MPI d;
> };
Re: [PATCH] crypto: rsa - return raw integer for the ASN.1 parser
On Fri, Apr 29, 2016 at 03:51:46PM +0300, Tudor Ambarus wrote:
>
> struct rsa_key {
> + u8 *n;
> + u8 *e;
> + u8 *d;
> + dma_addr_t dma_n;
> + dma_addr_t dma_e;
> + dma_addr_t dma_d;
> + size_t n_sz;
> + size_t e_sz;
> + bool coherent;
> + gfp_t flags;
Please don't put the DMA primitives in the generic helper. They
should stay in the driver for now.
Thanks,
--
Email: Herbert Xu
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-crypto" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] crypto: rsa - return raw integer for the ASN.1 parser
Return the raw integer with no other processing.
The scope is to have only one ANS.1 parser for the RSA keys.
Update the RSA software implementation so that it does
the MPI conversion on top.
Signed-off-by: Tudor Ambarus
---
crypto/rsa.c | 122 ++-
crypto/rsa_helper.c | 224 --
include/crypto/internal/rsa.h | 41 +++-
3 files changed, 287 insertions(+), 100 deletions(-)
diff --git a/crypto/rsa.c b/crypto/rsa.c
index 77d737f..4459cb7 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -19,7 +19,7 @@
* RSAEP function [RFC3447 sec 5.1.1]
* c = m^e mod n;
*/
-static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m)
+static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
{
/* (1) Validate 0 <= m < n */
if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
@@ -33,7 +33,7 @@ static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m)
* RSADP function [RFC3447 sec 5.1.2]
* m = c^d mod n;
*/
-static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c)
+static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
{
/* (1) Validate 0 <= c < n */
if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
@@ -47,7 +47,7 @@ static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c)
* RSASP1 function [RFC3447 sec 5.2.1]
* s = m^d mod n
*/
-static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m)
+static int _rsa_sign(const struct rsa_mpi_key *key, MPI s, MPI m)
{
/* (1) Validate 0 <= m < n */
if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
@@ -61,7 +61,7 @@ static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m)
* RSAVP1 function [RFC3447 sec 5.2.2]
* m = s^e mod n;
*/
-static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s)
+static int _rsa_verify(const struct rsa_mpi_key *key, MPI m, MPI s)
{
/* (1) Validate 0 <= s < n */
if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0)
@@ -71,15 +71,17 @@ static int _rsa_verify(const struct rsa_key *key, MPI m,
MPI s)
return mpi_powm(m, s, key->e, key->n);
}
-static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm)
+static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
{
- return akcipher_tfm_ctx(tfm);
+ struct rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
+
+ return &ctx->mpi_key;
}
static int rsa_enc(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
- const struct rsa_key *pkey = rsa_get_key(tfm);
+ const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
MPI m, c = mpi_alloc(0);
int ret = 0;
int sign;
@@ -118,7 +120,7 @@ err_free_c:
static int rsa_dec(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
- const struct rsa_key *pkey = rsa_get_key(tfm);
+ const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
MPI c, m = mpi_alloc(0);
int ret = 0;
int sign;
@@ -156,7 +158,7 @@ err_free_m:
static int rsa_sign(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
- const struct rsa_key *pkey = rsa_get_key(tfm);
+ const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
MPI m, s = mpi_alloc(0);
int ret = 0;
int sign;
@@ -195,7 +197,7 @@ err_free_s:
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);
+ const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
MPI s, m = mpi_alloc(0);
int ret = 0;
int sign;
@@ -233,67 +235,98 @@ err_free_m:
return ret;
}
-static int rsa_check_key_length(unsigned int len)
-{
- switch (len) {
- case 512:
- case 1024:
- case 1536:
- case 2048:
- case 3072:
- case 4096:
- return 0;
- }
-
- return -EINVAL;
-}
-
static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
- struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
+ struct rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
+ struct rsa_key *pkey = &ctx->key;
+ struct rsa_mpi_key *mpi_key = &ctx->mpi_key;
int ret;
- ret = rsa_parse_pub_key(pkey, key, keylen);
+ /* Free the old MPI key if any */
+ rsa_free_mpi_key(mpi_key);
+
+ ret = rsa_parse_pub_key(ctx, key, keylen);
if (ret)
return ret;
- if (rsa_check_key_length(mpi_get_size(pkey->n) << 3)) {
- rsa_free_key(pkey);
- ret = -EINVAL;
- }
- return ret;
+ mpi_key->e = mpi_read_raw_data(pkey->e, pkey->e_sz);
+ if (!mpi_key->e)
+ goto err;
+
+ mpi_key->n = mpi_read_raw_data(pkey->n, pkey->n_sz);
+ if (!mpi
