Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[sfrench/cifs-2.6.git] / crypto / rsa.c

diff --git a/crypto/rsa.c b/crypto/rsa.c
index 39e04176b04b22f93c238b43b3bb601c97ad790c..0e555ee4addb7db47d7868b0062b5d6263ae02cf 100644 (file)
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -17,6 +17,11 @@ struct rsa_mpi_key {
        MPI n;
        MPI e;
        MPI d;
+       MPI p;
+       MPI q;
+       MPI dp;
+       MPI dq;
+       MPI qinv;
 };
 
 /*
@@ -35,16 +40,49 @@ static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
 
 /*
  * RSADP function [RFC3447 sec 5.1.2]
- * m = c^d mod n;
+ * m_1 = c^dP mod p;
+ * m_2 = c^dQ mod q;
+ * h = (m_1 - m_2) * qInv mod p;
+ * m = m_2 + q * h;
  */
-static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
+static int _rsa_dec_crt(const struct rsa_mpi_key *key, MPI m_or_m1_or_h, MPI c)
 {
+       MPI m2, m12_or_qh;
+       int ret = -ENOMEM;
+
        /* (1) Validate 0 <= c < n */
        if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
                return -EINVAL;
 
-       /* (2) m = c^d mod n */
-       return mpi_powm(m, c, key->d, key->n);
+       m2 = mpi_alloc(0);
+       m12_or_qh = mpi_alloc(0);
+       if (!m2 || !m12_or_qh)
+               goto err_free_mpi;
+
+       /* (2i) m_1 = c^dP mod p */
+       ret = mpi_powm(m_or_m1_or_h, c, key->dp, key->p);
+       if (ret)
+               goto err_free_mpi;
+
+       /* (2i) m_2 = c^dQ mod q */
+       ret = mpi_powm(m2, c, key->dq, key->q);
+       if (ret)
+               goto err_free_mpi;
+
+       /* (2iii) h = (m_1 - m_2) * qInv mod p */
+       mpi_sub(m12_or_qh, m_or_m1_or_h, m2);
+       mpi_mulm(m_or_m1_or_h, m12_or_qh, key->qinv, key->p);
+
+       /* (2iv) m = m_2 + q * h */
+       mpi_mul(m12_or_qh, key->q, m_or_m1_or_h);
+       mpi_addm(m_or_m1_or_h, m2, m12_or_qh, key->n);
+
+       ret = 0;
+
+err_free_mpi:
+       mpi_free(m12_or_qh);
+       mpi_free(m2);
+       return ret;
 }
 
 static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
@@ -112,7 +150,7 @@ static int rsa_dec(struct akcipher_request *req)
        if (!c)
                goto err_free_m;
 
-       ret = _rsa_dec(pkey, m, c);
+       ret = _rsa_dec_crt(pkey, m, c);
        if (ret)
                goto err_free_c;
 
@@ -134,9 +172,19 @@ static void rsa_free_mpi_key(struct rsa_mpi_key *key)
        mpi_free(key->d);
        mpi_free(key->e);
        mpi_free(key->n);
+       mpi_free(key->p);
+       mpi_free(key->q);
+       mpi_free(key->dp);
+       mpi_free(key->dq);
+       mpi_free(key->qinv);
        key->d = NULL;
        key->e = NULL;
        key->n = NULL;
+       key->p = NULL;
+       key->q = NULL;
+       key->dp = NULL;
+       key->dq = NULL;
+       key->qinv = NULL;
 }
 
 static int rsa_check_key_length(unsigned int len)
@@ -217,6 +265,26 @@ static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
        if (!mpi_key->n)
                goto err;
 
+       mpi_key->p = mpi_read_raw_data(raw_key.p, raw_key.p_sz);
+       if (!mpi_key->p)
+               goto err;
+
+       mpi_key->q = mpi_read_raw_data(raw_key.q, raw_key.q_sz);
+       if (!mpi_key->q)
+               goto err;
+
+       mpi_key->dp = mpi_read_raw_data(raw_key.dp, raw_key.dp_sz);
+       if (!mpi_key->dp)
+               goto err;
+
+       mpi_key->dq = mpi_read_raw_data(raw_key.dq, raw_key.dq_sz);
+       if (!mpi_key->dq)
+               goto err;
+
+       mpi_key->qinv = mpi_read_raw_data(raw_key.qinv, raw_key.qinv_sz);
+       if (!mpi_key->qinv)
+               goto err;
+
        if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
                rsa_free_mpi_key(mpi_key);
                return -EINVAL;