[PATCH v4] crypto: rsa - return raw integers for the ASN.1 parser

2016-06-13 Thread Tudor Ambarus
Return the raw key with no other processing so that the caller
can copy it or MPI parse it, etc.

The scope is to have only one ANS.1 parser for all RSA
implementations.

Update the RSA software implementation so that it does
the MPI conversion on top.

Signed-off-by: Tudor Ambarus 
---
Changes in v4:
1. Remove the skipping of leading zeros from rsa_get_n/e/d helper functions.
2. Remove FIPS RSA key length checking for the RSA private exponent.
FIPS check is done only for the RSA modulus.

 crypto/rsa.c  | 120 --
 crypto/rsa_helper.c   | 111 ++
 include/crypto/internal/rsa.h |  22 +---
 3 files changed, 148 insertions(+), 105 deletions(-)

diff --git a/crypto/rsa.c b/crypto/rsa.c
index 77d737f..bb31c5b 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -10,16 +10,28 @@
  */
 
 #include 
+#include 
 #include 
 #include 
 #include 
 #include 
 
+struct rsa_mpi_key {
+   MPI n;
+   MPI e;
+   MPI d;
+};
+
+struct rsa_ctx {
+   struct rsa_key key;
+   struct rsa_mpi_key mpi_key;
+};
+
 /*
  * 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 +45,7 @@ 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 +59,7 @@ 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 +73,7 @@ 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 +83,17 @@ 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 +132,7 @@ 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 +170,7 @@ 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 +209,7 @@ 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;
@@ -233,6 +247,16 @@ err_free_m:
return ret;
 }
 
+static void rsa_free_mpi_key(struct rsa_mpi_key *key)
+{
+   mpi_free(key->d);
+   mpi_free(key->e);
+   mpi_free(key->n);
+   key->d = NULL;
+   key->e = NULL;
+   key->n = NULL;
+}
+
 static int rsa_check_key_length(unsigned int len)
 {
switch (len) {
@@ -251,49 +275,91 @@ static int rsa_check_key_length(unsigned int len)
 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 *raw_key = &ctx->key;
+   struct rsa_mpi_ke

Re: [PATCH v4] crypto: rsa - return raw integers for the ASN.1 parser

2016-06-14 Thread Herbert Xu
On Mon, Jun 13, 2016 at 05:12:53PM +0300, Tudor Ambarus wrote:
> +
> +struct rsa_ctx {
> + struct rsa_key key;

This isn't necessary and worse it may lead to bugs in future.
The raw keys will be invalid as soon as the setkey functions
return.

So just store it on the stack.

Thanks,
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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