[U-Boot] [PATCH 2/4] [RFC] crypto/fsl: Add support for RSA Modular Exponentiation

[Ruchika Gupta]

Support added for offloading Modular Exponentiation required
in RSA Verify functionality to hardware which depends on
CONFIG_RSA_MOD_EXP_HW.

Signed-off-by: Ruchika Gupta <ruchika.gupta at freescale.com>
CC: Simon Glass <sjg at chromium.org>
---
 drivers/crypto/fsl/Makefile   |  1 +
 drivers/crypto/fsl/fsl_rsa.c  | 44 +++++++++++++++++++++++++++++++++++++++++++
 drivers/crypto/fsl/jobdesc.c  | 28 +++++++++++++++++++++++++++
 drivers/crypto/fsl/jobdesc.h  |  5 +++++
 drivers/crypto/fsl/rsa_caam.h | 27 ++++++++++++++++++++++++++
 5 files changed, 105 insertions(+)
 create mode 100644 drivers/crypto/fsl/fsl_rsa.c
 create mode 100644 drivers/crypto/fsl/rsa_caam.h

diff --git a/drivers/crypto/fsl/Makefile b/drivers/crypto/fsl/Makefile
index 067d0a9..ef36f67 100644
--- a/drivers/crypto/fsl/Makefile
+++ b/drivers/crypto/fsl/Makefile
@@ -8,4 +8,5 @@
 
 obj-y += sec.o
 obj-$(CONFIG_FSL_CAAM) += jr.o fsl_hash.o jobdesc.o error.o
+obj-$(CONFIG_RSA_MOD_EXP_HW) += fsl_rsa.o
 obj-$(CONFIG_CMD_BLOB) += fsl_blob.o
diff --git a/drivers/crypto/fsl/fsl_rsa.c b/drivers/crypto/fsl/fsl_rsa.c
new file mode 100644
index 0000000..1100316
--- /dev/null
+++ b/drivers/crypto/fsl/fsl_rsa.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2013, Google Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/types.h>
+#include <malloc.h>
+#include "jobdesc.h"
+#include "desc.h"
+#include "jr.h"
+#include "rsa_caam.h"
+#include <u-boot/rsa-mod-exp.h>
+
+int rsa_mod_exp(const uint8_t *sig, uint32_t sig_len,
+		struct key_prop *prop, uint8_t *out)
+{
+	uint32_t keylen;
+	struct pk_in_params pkin;
+	uint32_t desc[MAX_CAAM_DESCSIZE];
+	int ret;
+
+	/* Length in bytes */
+	keylen = prop->num_bits / 8;
+
+	pkin.a = sig;
+	pkin.a_siz = sig_len;
+	pkin.n = prop->modulus;
+	pkin.n_siz = keylen;
+	pkin.e = prop->public_exponent;
+	pkin.e_siz = prop->exp_len;
+
+	inline_cnstr_jobdesc_pkha_rsaexp(desc, &pkin, out, sig_len);
+
+	ret = run_descriptor_jr(desc);
+
+	if (ret) {
+		debug("%s: RSA failed to verify: %d\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
diff --git a/drivers/crypto/fsl/jobdesc.c b/drivers/crypto/fsl/jobdesc.c
index 1386bae..cc0dced 100644
--- a/drivers/crypto/fsl/jobdesc.c
+++ b/drivers/crypto/fsl/jobdesc.c
@@ -11,6 +11,7 @@
 #include <common.h>
 #include "desc_constr.h"
 #include "jobdesc.h"
+#include "rsa_caam.h"
 
 #define KEY_BLOB_SIZE			32
 #define MAC_SIZE			16
@@ -123,3 +124,30 @@ void inline_cnstr_jobdesc_rng_instantiation(uint32_t *desc)
 	append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
 			 OP_ALG_RNG4_SK);
 }
+
+/* Change key size to bytes form bits in calling function*/
+void inline_cnstr_jobdesc_pkha_rsaexp(uint32_t *desc,
+				      struct pk_in_params *pkin, uint8_t *out,
+				      uint32_t out_siz)
+{
+	dma_addr_t dma_addr_e, dma_addr_a, dma_addr_n, dma_addr_out;
+
+	dma_addr_e = virt_to_phys((void *)pkin->e);
+	dma_addr_a = virt_to_phys((void *)pkin->a);
+	dma_addr_n = virt_to_phys((void *)pkin->n);
+	dma_addr_out = virt_to_phys((void *)out);
+
+	init_job_desc(desc, 0);
+	append_key(desc, dma_addr_e, pkin->e_siz, KEY_DEST_PKHA_E | CLASS_1);
+
+	append_fifo_load(desc, dma_addr_a,
+			 pkin->a_siz, LDST_CLASS_1_CCB | FIFOLD_TYPE_PK_A);
+
+	append_fifo_load(desc, dma_addr_n,
+			 pkin->n_siz, LDST_CLASS_1_CCB | FIFOLD_TYPE_PK_N);
+
+	append_operation(desc, OP_TYPE_PK | OP_ALG_PK | OP_ALG_PKMODE_MOD_EXPO);
+
+	append_fifo_store(desc, dma_addr_out, out_siz,
+			  LDST_CLASS_1_CCB | FIFOST_TYPE_PKHA_B);
+}
diff --git a/drivers/crypto/fsl/jobdesc.h b/drivers/crypto/fsl/jobdesc.h
index 3cf7226..84b3edd 100644
--- a/drivers/crypto/fsl/jobdesc.h
+++ b/drivers/crypto/fsl/jobdesc.h
@@ -10,6 +10,7 @@
 
 #include <common.h>
 #include <asm/io.h>
+#include "rsa_caam.h"
 
 #define KEY_IDNFR_SZ_BYTES		16
 
@@ -26,4 +27,8 @@ void inline_cnstr_jobdesc_blob_decap(uint32_t *desc, uint8_t *key_idnfr,
 				     uint32_t out_sz);
 
 void inline_cnstr_jobdesc_rng_instantiation(uint32_t *desc);
+
+void inline_cnstr_jobdesc_pkha_rsaexp(uint32_t *desc,
+				      struct pk_in_params *pkin, uint8_t *out,
+				      uint32_t out_siz);
 #endif
diff --git a/drivers/crypto/fsl/rsa_caam.h b/drivers/crypto/fsl/rsa_caam.h
new file mode 100644
index 0000000..d1dc7eb
--- /dev/null
+++ b/drivers/crypto/fsl/rsa_caam.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2014 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __RSA_SEC_H
+#define __RSA_SEC_H
+
+#include <common.h>
+
+/**
+ * struct pk_in_params - holder for input to PKHA block in CAAM
+ *
+ */
+struct pk_in_params {
+	const uint8_t *e;	/* public exponent as byte array */
+	uint32_t e_siz;		/* size of e[] in number of bytes */
+	const uint8_t *n;	/* modulus as byte array */
+	uint32_t n_siz;		/* size of n[] in number of bytes */
+	const uint8_t *a;		/* Signature as byte array */
+	uint32_t a_siz;		/* size of a[] in number of bytes */
+	uint8_t *b;		/* Result exp. modulus in number of bytes */
+	uint32_t b_siz;		/* size of b[] in number of bytes */
+};
+
+#endif
-- 
1.8.1.4