Add a new rsa generic SW implementation.
This implements only cryptographic primitives.
Signed-off-by: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
---
crypto/Kconfig | 7 +
crypto/Makefile | 8 +
crypto/rsa.c | 295 +++++++++++++++++++++++++++++++++++++++++
crypto/rsa_helper.c | 134 +++++++++++++++++++
crypto/rsakey.asn1 | 5 +
include/crypto/internal/rsa.h | 30 ++++
6 files changed, 479 insertions(+)
create mode 100644 crypto/rsa.c
create mode 100644 crypto/rsa_helper.c
create mode 100644 crypto/rsakey.asn1
create mode 100644 include/crypto/internal/rsa.h
diff --git a/crypto/Kconfig b/crypto/Kconfig
index ed413d9..a09404b 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -97,6 +97,13 @@ config CRYPTO_AKCIPHER
help
Crypto API interface for public key algorithms.
+config CRYPTO_RSA
+ tristate "RSA algorithm"
+ select AKCIPHER
+ select MPILIB
+ help
+ Generic implementation of the RSA public key algorithm.
+
config CRYPTO_MANAGER
tristate "Cryptographic algorithm manager"
select CRYPTO_MANAGER2
diff --git a/crypto/Makefile b/crypto/Makefile
index 6f2940a..c6217ea 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -30,6 +30,14 @@ obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
obj-$(CONFIG_CRYPTO_PCOMP2) += pcompress.o
obj-$(CONFIG_CRYPTO_AKCIPHER) += akcipher.o
+$(obj)/rsakey-asn1.o: $(obj)/rsakey-asn1.c $(obj)/rsakey-asn1.h
+clean-files += rsakey-asn1.c rsakey-asn1.h
+
+rsa_generic-y := rsakey-asn1.o
+rsa_generic-y += rsa.o
+rsa_generic-y += rsa_helper.o
+obj-$(CONFIG_CRYPTO_RSA) += rsa_generic.o
+
cryptomgr-y := algboss.o testmgr.o
obj-$(CONFIG_CRYPTO_MANAGER2) += cryptomgr.o
diff --git a/crypto/rsa.c b/crypto/rsa.c
new file mode 100644
index 0000000..176f565
--- /dev/null
+++ b/crypto/rsa.c
@@ -0,0 +1,295 @@
+/* RSA asymmetric public-key algorithm [RFC3447]
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <crypto/internal/rsa.h>
+#include <crypto/akcipher.h>
+
+/*
+ * 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)
+{
+ /* (1) Validate 0 <= m < n */
+ if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
+ return -EINVAL;
+
+ /* (2) c = m^e mod n */
+ return mpi_powm(c, m, key->e, key->n);
+}
+
+/*
+ * 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)
+{
+ /* (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);
+}
+
+/*
+ * 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)
+{
+ /* (1) Validate 0 <= m < n */
+ if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
+ return -EINVAL;
+
+ /* (2) s = m^d mod n */
+ return mpi_powm(s, m, key->d, key->n);
+}
+
+/*
+ * 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)
+{
+ /* (1) Validate 0 <= s < n */
+ if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0)
+ return -EINVAL;
+
+ /* (2) m = s^e mod n */
+ return mpi_powm(m, s, key->e, key->n);
+}
+
+static int rsa_enc(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+ const struct rsa_key *pkey = rsa_get_key(tfm);
+ MPI m, c = mpi_alloc(0);
+ unsigned int len;
+ int ret = 0;
+ int sign;
+
+ if (!c)
+ return -ENOMEM;
+
+ if (!pkey->n || !pkey->e || req->dst_len < mpi_get_size(pkey->n))
+ return -EINVAL;
+
+ m = mpi_read_raw_data(req->src, req->src_len);
+ if (!m) {
+ ret = -ENOMEM;
+ goto err_free_c;
+ }
+
+ ret = _rsa_enc(pkey, c, m);
+ if (ret)
+ goto err_free_m;
+
+ ret = mpi_read_buffer(c, req->dst, req->dst_len, &len, &sign);
+ if (ret)
+ goto err_free_m;
+
+ if (sign < 0) {
+ ret = -EBADMSG;
+ goto err_free_m;
+ }
+
+ if (req->result_len)
+ *req->result_len = len;
+
+err_free_m:
+ mpi_free(m);
+err_free_c:
+ mpi_free(c);
+ return ret;
+}
+
+static int rsa_dec(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+ const struct rsa_key *pkey = rsa_get_key(tfm);
+ MPI c, m = mpi_alloc(0);
+ unsigned int len;
+ int ret = 0;
+ int sign;
+
+ if (!m)
+ return -ENOMEM;
+
+ if (!pkey->n || !pkey->d || req->dst_len < mpi_get_size(pkey->n))
+ return -EINVAL;
+
+ c = mpi_read_raw_data(req->src, req->src_len);
+ if (!c) {
+ ret = -ENOMEM;
+ goto err_free_m;
+ }
+
+ ret = _rsa_dec(pkey, m, c);
+ if (ret)
+ goto err_free_c;
+
+ ret = mpi_read_buffer(m, req->dst, req->dst_len, &len, &sign);
+ if (ret)
+ goto err_free_c;
+
+ if (sign < 0) {
+ ret = -EBADMSG;
+ goto err_free_c;
+ }
+
+ if (req->result_len)
+ *req->result_len = len;
+
+err_free_c:
+ mpi_free(c);
+err_free_m:
+ mpi_free(m);
+ return ret;
+}
+
+static int rsa_sign(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+ const struct rsa_key *pkey = rsa_get_key(tfm);
+ MPI m, s = mpi_alloc(0);
+ unsigned int len;
+ int ret = 0;
+ int sign;
+
+ if (!s)
+ return -ENOMEM;
+
+ if (!pkey->n || !pkey->d || req->dst_len < mpi_get_size(pkey->n))
+ return -EINVAL;
+
+ m = mpi_read_raw_data(req->src, req->src_len);
+ if (!m) {
+ ret = -ENOMEM;
+ goto err_free_s;
+ }
+
+ ret = _rsa_sign(pkey, s, m);
+ if (ret)
+ goto err_free_m;
+
+ ret = mpi_read_buffer(s, req->dst, req->dst_len, &len, &sign);
+ if (ret)
+ goto err_free_m;
+
+ if (sign < 0) {
+ ret = -EBADMSG;
+ goto err_free_m;
+ }
+
+ if (req->result_len)
+ *req->result_len = len;
+
+err_free_m:
+ mpi_free(m);
+err_free_s:
+ mpi_free(s);
+ return ret;
+}
+
+static int rsa_verify(struct akcipher_request *req)
+{
+ struct crypto_akcipher *tfm = akcipher_request_get_tfm(req);
+ const struct rsa_key *pkey = rsa_get_key(tfm);
+ MPI s, m = mpi_alloc(0);
+ unsigned int len;
+ int ret = 0;
+ int sign;
+
+ if (!m)
+ return -ENOMEM;
+
+ if (!pkey->n || !pkey->e || req->dst_len < mpi_get_size(pkey->n))
+ return -EINVAL;
+
+ s = mpi_read_raw_data(req->src, req->src_len);
+ if (!s) {
+ ret = -ENOMEM;
+ goto err_free_m;
+ }
+
+ ret = _rsa_verify(pkey, m, s);
+ if (ret)
+ goto err_free_s;
+
+ ret = mpi_read_buffer(m, req->dst, req->dst_len, &len, &sign);
+ if (ret)
+ goto err_free_s;
+
+ if (sign < 0) {
+ ret = -EBADMSG;
+ goto err_free_s;
+ }
+
+ if (req->result_len)
+ *req->result_len = len;
+
+err_free_s:
+ mpi_free(s);
+err_free_m:
+ mpi_free(m);
+ return ret;
+}
+
+static int rsa_maxsize(struct crypto_akcipher *tfm)
+{
+ const struct rsa_key *pkey = rsa_get_key(tfm);
+
+ if (pkey && pkey->n)
+ return mpi_get_size(pkey->n);
+
+ return -EINVAL;
+}
+
+static int rsa_setkey(struct crypto_akcipher *tfm, const void *key,
+ unsigned int keylen)
+{
+ return rsa_parse_key(tfm, key, keylen);
+}
+
+static struct akcipher_alg rsa = {
+ .encrypt = rsa_enc,
+ .decrypt = rsa_dec,
+ .sign = rsa_sign,
+ .verify = rsa_verify,
+ .maxsize = rsa_maxsize,
+ .setkey = rsa_setkey,
+ .base = {
+ .cra_name = "rsa",
+ .cra_driver_name = "rsa-generic",
+ .cra_priority = 100,
+ .cra_ctxsize = 0,
+ .cra_alignmask = 0,
+ .cra_module = THIS_MODULE,
+ },
+};
+
+static int rsa_init(void)
+{
+ return crypto_register_akcipher(&rsa);
+}
+
+static void rsa_exit(void)
+{
+ crypto_unregister_akcipher(&rsa);
+}
+
+module_init(rsa_init);
+module_exit(rsa_exit);
+MODULE_ALIAS_CRYPTO("rsa");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RSA generic algorithm");
diff --git a/crypto/rsa_helper.c b/crypto/rsa_helper.c
new file mode 100644
index 0000000..6569b02
--- /dev/null
+++ b/crypto/rsa_helper.c
@@ -0,0 +1,134 @@
+/*
+ * RSA key extract helper
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#include <linux/fips.h>
+#include <crypto/internal/rsa.h>
+#include "rsakey-asn1.h"
+
+int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct crypto_akcipher *tfm = context;
+ struct rsa_key *key = tfm->key;
+
+ key->n = mpi_read_raw_data(value, vlen);
+
+ if (!key->n)
+ return -ENOMEM;
+
+ /* In FIPS mode only allow key size minimum 2K */
+ if (fips_enabled && (mpi_get_size(key->n) < 256)) {
+ pr_err("RSA: key size not allowed in FIPS mode\n");
+ mpi_free(key->n);
+ key->n = NULL;
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct crypto_akcipher *tfm = context;
+ struct rsa_key *key = tfm->key;
+
+ key->e = mpi_read_raw_data(value, vlen);
+
+ if (!key->e)
+ return -ENOMEM;
+
+ return 0;
+}
+
+int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct crypto_akcipher *tfm = context;
+ struct rsa_key *key = tfm->key;
+
+ key->d = mpi_read_raw_data(value, vlen);
+
+ if (!key->d)
+ return -ENOMEM;
+
+ /* In FIPS mode only allow key size minimum 2K */
+ if (fips_enabled && (mpi_get_size(key->d) < 256)) {
+ pr_err("RSA: key size not allowed in FIPS mode\n");
+ mpi_free(key->d);
+ key->d = NULL;
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static void free_mpis(struct rsa_key *key)
+{
+ if (key->n)
+ mpi_free(key->n);
+
+ if (key->e)
+ mpi_free(key->e);
+
+ if (key->d)
+ mpi_free(key->d);
+
+ key->n = NULL;
+ key->e = NULL;
+ key->d = NULL;
+}
+
+static void rsa_free_key(struct crypto_tfm *tfm_base)
+{
+ struct crypto_akcipher *tfm = __crypto_akcipher_tfm(tfm_base);
+ struct crypto_alg *alg = tfm_base->__crt_alg;
+
+ if (alg->cra_exit)
+ alg->cra_exit(tfm_base);
+
+ free_mpis(tfm->key);
+ kfree(tfm->key);
+ tfm->key = NULL;
+}
+
+/**
+ * rsa_parse_key() - extracts an rsa key from BER encoded buffer
+ * and stores it in tfm
+ *
+ * @tfm: akcipher handler
+ * @key: key in BER format
+ * @key_len: length of key
+ *
+ * Return: 0 on success or error code in case of error
+ */
+int rsa_parse_key(struct crypto_akcipher *tfm, const void *key,
+ unsigned int key_len)
+{
+ int ret;
+
+ if (!tfm->key) {
+ tfm->key = kzalloc(sizeof(struct rsa_key), GFP_KERNEL);
+ tfm->base.exit = rsa_free_key;
+ } else {
+ free_mpis(tfm->key);
+ }
+
+ ret = asn1_ber_decoder(&rsakey_decoder, tfm, key, key_len);
+ if (ret < 0)
+ goto error;
+
+ return 0;
+error:
+ free_mpis(tfm->key);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rsa_parse_key);
diff --git a/crypto/rsakey.asn1 b/crypto/rsakey.asn1
new file mode 100644
index 0000000..3c7b5df
--- /dev/null
+++ b/crypto/rsakey.asn1
@@ -0,0 +1,5 @@
+RsaKey ::= SEQUENCE {
+ n INTEGER ({ rsa_get_n }),
+ e INTEGER ({ rsa_get_e }),
+ d INTEGER ({ rsa_get_d })
+}
diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h
new file mode 100644
index 0000000..475d52b
--- /dev/null
+++ b/include/crypto/internal/rsa.h
@@ -0,0 +1,30 @@
+/*
+ * RSA internal helpers
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#ifndef _RSA_HELPER_
+#define _RSA_HELPER_
+#include <linux/mpi.h>
+#include <crypto/akcipher.h>
+
+struct rsa_key {
+ MPI n;
+ MPI e;
+ MPI d;
+};
+
+int rsa_parse_key(struct crypto_akcipher *tfm, const void *key,
+ unsigned int key_len);
+static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm)
+{
+ return tfm->key;
+}
+#endif
--
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