lib: crypto: add rsa public key parser
Imported from linux kernel v5.3:
rsapubkey.asn1 without changes
rsa.h without changes
rsa_helper.c with changes marked as __UBOOT__
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig
index b8e8288..9572ea8 100644
--- a/lib/crypto/Kconfig
+++ b/lib/crypto/Kconfig
@@ -16,4 +16,15 @@
appropriate hash algorithms (such as SHA-1) must be available.
ENOPKG will be reported if the requisite algorithm is unavailable.
+config RSA_PUBLIC_KEY_PARSER
+ bool "RSA public key parser"
+ depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+ select ASN1_DECODER
+ select ASN1_COMPILER
+ select OID_REGISTRY
+ help
+ This option provides support for parsing a blob containing RSA
+ public key data and provides the ability to instantiate a public
+ key.
+
endif # ASYMMETRIC_KEY_TYPE
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index a284de9..69330a9 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -8,3 +8,14 @@
asymmetric_keys-y := asymmetric_type.o
obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
+
+#
+# RSA public key parser
+#
+obj-$(CONFIG_RSA_PUBLIC_KEY_PARSER) += rsa_public_key.o
+rsa_public_key-y := \
+ rsapubkey.asn1.o \
+ rsa_helper.o
+
+$(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 0000000..aca627a
--- /dev/null
+++ b/lib/crypto/rsa_helper.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RSA key extract helper
+ *
+ * Copyright (c) 2015, Intel Corporation
+ * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
+ */
+#ifndef __UBOOT__
+#include <linux/kernel.h>
+#include <linux/export.h>
+#endif
+#include <linux/err.h>
+#ifndef __UBOOT__
+#include <linux/fips.h>
+#endif
+#include <crypto/internal/rsa.h>
+#include "rsapubkey.asn1.h"
+#ifndef __UBOOT__
+#include "rsaprivkey.asn1.h"
+#endif
+
+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;
+}
+
+int rsa_get_d(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->d = value;
+ key->d_sz = vlen;
+
+ return 0;
+}
+
+int rsa_get_p(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsa_key *key = context;
+
+ /* invalid key provided */
+ if (!value || !vlen || vlen > key->n_sz)
+ return -EINVAL;
+
+ key->p = value;
+ key->p_sz = vlen;
+
+ return 0;
+}
+
+int rsa_get_q(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsa_key *key = context;
+
+ /* invalid key provided */
+ if (!value || !vlen || vlen > key->n_sz)
+ return -EINVAL;
+
+ key->q = value;
+ key->q_sz = vlen;
+
+ return 0;
+}
+
+int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsa_key *key = context;
+
+ /* invalid key provided */
+ if (!value || !vlen || vlen > key->n_sz)
+ return -EINVAL;
+
+ key->dp = value;
+ key->dp_sz = vlen;
+
+ return 0;
+}
+
+int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsa_key *key = context;
+
+ /* invalid key provided */
+ if (!value || !vlen || vlen > key->n_sz)
+ return -EINVAL;
+
+ key->dq = value;
+ key->dq_sz = vlen;
+
+ return 0;
+}
+
+int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct rsa_key *key = context;
+
+ /* invalid key provided */
+ if (!value || !vlen || vlen > key->n_sz)
+ return -EINVAL;
+
+ key->qinv = value;
+ key->qinv_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);
+}
+EXPORT_SYMBOL_GPL(rsa_parse_pub_key);
+
+#ifndef __UBOOT__
+/**
+ * rsa_parse_priv_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_priv_key(struct rsa_key *rsa_key, const void *key,
+ unsigned int key_len)
+{
+ return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len);
+}
+EXPORT_SYMBOL_GPL(rsa_parse_priv_key);
+#endif
diff --git a/lib/crypto/rsapubkey.asn1 b/lib/crypto/rsapubkey.asn1
new file mode 100644
index 0000000..725498e
--- /dev/null
+++ b/lib/crypto/rsapubkey.asn1
@@ -0,0 +1,4 @@
+RsaPubKey ::= SEQUENCE {
+ n INTEGER ({ rsa_get_n }),
+ e INTEGER ({ rsa_get_e })
+}