[U-Boot] [RFC 9/9] lib: crypto: add rsa public key parser

[AKASHI Takahiro]

Imported from linux kernel v5.0.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 include/crypto/internal/rsa.h | 62 +++++++++++++++++++++++++++
 lib/crypto/Makefile           | 10 ++++-
 lib/crypto/rsa_helper.c       | 81 +++++++++++++++++++++++++++++++++++
 lib/crypto/rsapubkey.asn1     |  4 ++
 4 files changed, 156 insertions(+), 1 deletion(-)
 create mode 100644 include/crypto/internal/rsa.h
 create mode 100644 lib/crypto/rsa_helper.c
 create mode 100644 lib/crypto/rsapubkey.asn1

diff --git a/include/crypto/internal/rsa.h b/include/crypto/internal/rsa.h
new file mode 100644
index 000000000000..9e8f1590de98
--- /dev/null
+++ b/include/crypto/internal/rsa.h
@@ -0,0 +1,62 @@
+/*
+ * RSA internal helpers
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk at intel.com>
+ *
+ * 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/types.h>
+
+/**
+ * rsa_key - RSA key structure
+ * @n           : RSA modulus raw byte stream
+ * @e           : RSA public exponent raw byte stream
+ * @d           : RSA private exponent raw byte stream
+ * @p           : RSA prime factor p of n raw byte stream
+ * @q           : RSA prime factor q of n raw byte stream
+ * @dp          : RSA exponent d mod (p - 1) raw byte stream
+ * @dq          : RSA exponent d mod (q - 1) raw byte stream
+ * @qinv        : RSA CRT coefficient q^(-1) mod p raw byte stream
+ * @n_sz        : length in bytes of RSA modulus n
+ * @e_sz        : length in bytes of RSA public exponent
+ * @d_sz        : length in bytes of RSA private exponent
+ * @p_sz        : length in bytes of p field
+ * @q_sz        : length in bytes of q field
+ * @dp_sz       : length in bytes of dp field
+ * @dq_sz       : length in bytes of dq field
+ * @qinv_sz     : length in bytes of qinv field
+ */
+struct rsa_key {
+	const u8 *n;
+	const u8 *e;
+	const u8 *d;
+	const u8 *p;
+	const u8 *q;
+	const u8 *dp;
+	const u8 *dq;
+	const u8 *qinv;
+	size_t n_sz;
+	size_t e_sz;
+	size_t d_sz;
+	size_t p_sz;
+	size_t q_sz;
+	size_t dp_sz;
+	size_t dq_sz;
+	size_t qinv_sz;
+};
+
+int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
+		      unsigned int key_len);
+
+int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key,
+		       unsigned int key_len);
+
+extern struct crypto_template rsa_pkcs1pad_tmpl;
+#endif
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 3e98d28ea17a..f2cd3fbb0413 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -17,7 +17,9 @@ x509_key_parser-y := \
 	x509.asn1.o \
 	x509_akid.asn1.o \
 	x509_cert_parser.o \
-	x509_public_key.o
+	x509_public_key.o \
+	rsapubkey.asn1.o \
+	rsa_helper.o
 
 $(obj)/x509_cert_parser.o: \
 	$(obj)/x509.asn1.h \
@@ -36,3 +38,9 @@ pkcs7_message-y := \
 
 $(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h
 $(obj)/pkcs7.asn1.o: $(obj)/pkcs7.asn1.c $(obj)/pkcs7.asn1.h
+
+#
+# RSA public key parser
+#
+$(obj)/rsapubkey.asn1.o: $(obj)/rsapubkey.asn1.c $(obj)/rsapubkey.asn1.h
+$(obj)/rsa_helper.o: $(obj)/rsapubkey.asn1.h
diff --git a/lib/crypto/rsa_helper.c b/lib/crypto/rsa_helper.c
new file mode 100644
index 000000000000..577dfbc1c5fd
--- /dev/null
+++ b/lib/crypto/rsa_helper.c
@@ -0,0 +1,81 @@
+/*
+ * RSA key extract helper
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk at intel.com>
+ *
+ * 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/err.h>
+#include <crypto/internal/rsa.h>
+#include "rsapubkey.asn1.h"
+
+int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
+	      const void *value, size_t vlen)
+{
+	struct rsa_key *key = context;
+#ifndef __UBOOT__
+	const u8 *ptr = value;
+	size_t n_sz = vlen;
+#endif
+
+	/* invalid key provided */
+	if (!value || !vlen)
+		return -EINVAL;
+
+#ifndef __UBOOT__
+	if (fips_enabled) {
+		while (n_sz && !*ptr) {
+			ptr++;
+			n_sz--;
+		}
+
+		/* In FIPS mode only allow key size 2K and higher */
+		if (n_sz < 256) {
+			pr_err("RSA: key size not allowed in FIPS mode\n");
+			return -EINVAL;
+		}
+	}
+#endif
+
+	key->n = value;
+	key->n_sz = vlen;
+
+	return 0;
+}
+
+int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
+	      const void *value, size_t vlen)
+{
+	struct rsa_key *key = context;
+
+	/* invalid key provided */
+	if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
+		return -EINVAL;
+
+	key->e = value;
+	key->e_sz = vlen;
+
+	return 0;
+}
+
+/**
+ * rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the
+ *                       provided struct rsa_key, pointers to the raw key as is,
+ *                       so that the caller can copy it or MPI parse it, etc.
+ *
+ * @rsa_key:	struct rsa_key key representation
+ * @key:	key in BER format
+ * @key_len:	length of key
+ *
+ * Return:	0 on success or error code in case of error
+ */
+int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
+		      unsigned int key_len)
+{
+	return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len);
+}
diff --git a/lib/crypto/rsapubkey.asn1 b/lib/crypto/rsapubkey.asn1
new file mode 100644
index 000000000000..725498e461d2
--- /dev/null
+++ b/lib/crypto/rsapubkey.asn1
@@ -0,0 +1,4 @@
+RsaPubKey ::= SEQUENCE {
+	n INTEGER ({ rsa_get_n }),
+	e INTEGER ({ rsa_get_e })
+}
-- 
2.21.0