1 files changed, 168 insertions, 16 deletions

diff --git a/crypto/rsa.c b/crypto/rsa.c
index 4cdbec95d077..6c7734083c98 100644
--- a/crypto/rsa.c
+++ b/crypto/rsa.c
@@ -5,6 +5,7 @@
  * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
  */
 
+#include <linux/fips.h>
 #include <linux/module.h>
 #include <linux/mpi.h>
 #include <crypto/internal/rsa.h>
@@ -16,16 +17,45 @@ struct rsa_mpi_key {
 	MPI n;
 	MPI e;
 	MPI d;
+	MPI p;
+	MPI q;
+	MPI dp;
+	MPI dq;
+	MPI qinv;
 };
 
+static int rsa_check_payload(MPI x, MPI n)
+{
+	MPI n1;
+
+	if (mpi_cmp_ui(x, 1) <= 0)
+		return -EINVAL;
+
+	n1 = mpi_alloc(0);
+	if (!n1)
+		return -ENOMEM;
+
+	if (mpi_sub_ui(n1, n, 1) || mpi_cmp(x, n1) >= 0) {
+		mpi_free(n1);
+		return -EINVAL;
+	}
+
+	mpi_free(n1);
+	return 0;
+}
+
 /*
  * RSAEP function [RFC3447 sec 5.1.1]
  * c = m^e mod n;
  */
 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)
+	/*
+	 * Even though (1) in RFC3447 only requires 0 <= m <= n - 1, we are
+	 * slightly more conservative and require 1 < m < n - 1. This is in line
+	 * with SP 800-56Br2, Section 7.1.1.
+	 */
+	if (rsa_check_payload(m, key->n))
 		return -EINVAL;
 
 	/* (2) c = m^e mod n */
@@ -34,16 +64,52 @@ 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)
 {
-	/* (1) Validate 0 <= c < n */
-	if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
+	MPI m2, m12_or_qh;
+	int ret = -ENOMEM;
+
+	/*
+	 * Even though (1) in RFC3447 only requires 0 <= c <= n - 1, we are
+	 * slightly more conservative and require 1 < c < n - 1. This is in line
+	 * with SP 800-56Br2, Section 7.1.2.
+	 */
+	if (rsa_check_payload(c, key->n))
 		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 */
+	ret = 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 */
+	ret = ret ?:
+	      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);
+
+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)
@@ -111,7 +177,7 @@ 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;
 
@@ -133,9 +199,19 @@ 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)
@@ -144,6 +220,9 @@ static int rsa_check_key_length(unsigned int len)
 	case 512:
 	case 1024:
 	case 1536:
+		if (fips_enabled)
+			return -EINVAL;
+		fallthrough;
 	case 2048:
 	case 3072:
 	case 4096:
@@ -153,6 +232,40 @@ static int rsa_check_key_length(unsigned int len)
 	return -EINVAL;
 }
 
+static int rsa_check_exponent_fips(MPI e)
+{
+	MPI e_max = NULL;
+	int err;
+
+	/* check if odd */
+	if (!mpi_test_bit(e, 0)) {
+		return -EINVAL;
+	}
+
+	/* check if 2^16 < e < 2^256. */
+	if (mpi_cmp_ui(e, 65536) <= 0) {
+		return -EINVAL;
+	}
+
+	e_max = mpi_alloc(0);
+	if (!e_max)
+		return -ENOMEM;
+
+	err = mpi_set_bit(e_max, 256);
+	if (err) {
+		mpi_free(e_max);
+		return err;
+	}
+
+	if (mpi_cmp(e, e_max) >= 0) {
+		mpi_free(e_max);
+		return -EINVAL;
+	}
+
+	mpi_free(e_max);
+	return 0;
+}
+
 static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 			   unsigned int keylen)
 {
@@ -180,6 +293,11 @@ static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
 		return -EINVAL;
 	}
 
+	if (fips_enabled && rsa_check_exponent_fips(mpi_key->e)) {
+		rsa_free_mpi_key(mpi_key);
+		return -EINVAL;
+	}
+
 	return 0;
 
 err:
@@ -213,11 +331,36 @@ 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;
 	}
 
+	if (fips_enabled && rsa_check_exponent_fips(mpi_key->e)) {
+		rsa_free_mpi_key(mpi_key);
+		return -EINVAL;
+	}
+
 	return 0;
 
 err:
@@ -255,7 +398,7 @@ static struct akcipher_alg rsa = {
 	},
 };
 
-static int rsa_init(void)
+static int __init rsa_init(void)
 {
 	int err;
 
@@ -264,21 +407,30 @@ static int rsa_init(void)
 		return err;
 
 	err = crypto_register_template(&rsa_pkcs1pad_tmpl);
-	if (err) {
-		crypto_unregister_akcipher(&rsa);
-		return err;
-	}
+	if (err)
+		goto err_unregister_rsa;
+
+	err = crypto_register_template(&rsassa_pkcs1_tmpl);
+	if (err)
+		goto err_unregister_rsa_pkcs1pad;
 
 	return 0;
+
+err_unregister_rsa_pkcs1pad:
+	crypto_unregister_template(&rsa_pkcs1pad_tmpl);
+err_unregister_rsa:
+	crypto_unregister_akcipher(&rsa);
+	return err;
 }
 
-static void rsa_exit(void)
+static void __exit rsa_exit(void)
 {
+	crypto_unregister_template(&rsassa_pkcs1_tmpl);
 	crypto_unregister_template(&rsa_pkcs1pad_tmpl);
 	crypto_unregister_akcipher(&rsa);
 }
 
-subsys_initcall(rsa_init);
+module_init(rsa_init);
 module_exit(rsa_exit);
 MODULE_ALIAS_CRYPTO("rsa");
 MODULE_LICENSE("GPL");