1 files changed, 75 insertions, 0 deletions
diff --git a/include/u-boot/rsa-mod-exp.h b/include/u-boot/rsa-mod-exp.h
new file mode 100644
index 0000000..fce445a
--- /dev/null
+++ b/include/u-boot/rsa-mod-exp.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2014, Ruchika Gupta.
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+*/
+
+#ifndef _RSA_MOD_EXP_H
+#define _RSA_MOD_EXP_H
+
+#include <errno.h>
+#include <image.h>
+
+/**
+ * struct key_prop - holder for a public key properties
+ *
+ * The struct has pointers to modulus (Typically called N),
+ * The inverse, R^2, exponent. These can be typecasted and
+ * used as byte arrays or converted to the required format
+ * as per requirement of RSA implementation.
+ */
+struct key_prop {
+	const void *rr;		/* R^2 can be treated as byte array */
+	const void *modulus;	/* modulus as byte array */
+	const void *public_exponent; /* public exponent as byte array */
+	uint32_t n0inv;		/* -1 / modulus[0] mod 2^32 */
+	int num_bits;		/* Key length in bits */
+	uint32_t exp_len;	/* Exponent length in number of uint8_t */
+};
+
+/**
+ * rsa_mod_exp_sw() - Perform RSA Modular Exponentiation in sw
+ *
+ * Operation: out[] = sig ^ exponent % modulus
+ *
+ * @sig:	RSA PKCS1.5 signature
+ * @sig_len:	Length of signature in number of bytes
+ * @node:	Node with RSA key elements like modulus, exponent, R^2, n0inv
+ * @out:	Result in form of byte array of len equal to sig_len
+ */
+int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len,
+		struct key_prop *node, uint8_t *out);
+
+int rsa_mod_exp(struct udevice *dev, const uint8_t *sig, uint32_t sig_len,
+		struct key_prop *node, uint8_t *out);
+
+/**
+ * struct struct mod_exp_ops - Driver model for RSA Modular Exponentiation
+ *				operations
+ *
+ * The uclass interface is implemented by all crypto devices which use
+ * driver model.
+ */
+struct mod_exp_ops {
+	/**
+	 * Perform Modular Exponentiation
+	 *
+	 * Operation: out[] = sig ^ exponent % modulus
+	 *
+	 * @dev:	RSA Device
+	 * @sig:	RSA PKCS1.5 signature
+	 * @sig_len:	Length of signature in number of bytes
+	 * @node:	Node with RSA key elements like modulus, exponent,
+	 *		R^2, n0inv
+	 * @out:	Result in form of byte array of len equal to sig_len
+	 *
+	 * This function computes exponentiation over the signature.
+	 * Returns: 0 if exponentiation is successful, or a negative value
+	 * if it wasn't.
+	 */
+	int (*mod_exp)(struct udevice *dev, const uint8_t *sig,
+			   uint32_t sig_len, struct key_prop *node,
+			   uint8_t *outp);
+};
+
+#endif