[PATCH V4 06/15] asymmetric keys: support parsing PKCS #8 private key information
From: Lee, Chun-Yi
Date: Sat Sep 14 2013 - 20:57:41 EST
Add ASN.1 files and parser to support parsing PKCS #8 noncompressed private
key information. It's better than direct parsing pure private key because
PKCS #8 has a privateKeyAlgorithm to indicate the algorithm of private
key, e.g. RSA from PKCS #1
v2:
- Removed bitfield declare of privkey_algo in struct pkcs8_info because it does
not help on reduce memory space.
- Replace privkey_algo by pkey_algo in struct pkcs8_info to simplify naming.
Cc: Pavel Machek <pavel@xxxxxx>
Reviewed-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
---
crypto/asymmetric_keys/Kconfig | 11 ++
crypto/asymmetric_keys/Makefile | 16 +++
crypto/asymmetric_keys/pkcs8.asn1 | 19 ++++
crypto/asymmetric_keys/pkcs8_info_parser.c | 152 ++++++++++++++++++++++++++++
crypto/asymmetric_keys/pkcs8_parser.h | 23 ++++
crypto/asymmetric_keys/pkcs8_private_key.c | 148 +++++++++++++++++++++++++++
crypto/asymmetric_keys/pkcs8_rsakey.asn1 | 29 ++++++
crypto/asymmetric_keys/public_key.c | 1 +
include/crypto/public_key.h | 1 +
9 files changed, 400 insertions(+), 0 deletions(-)
create mode 100644 crypto/asymmetric_keys/pkcs8.asn1
create mode 100644 crypto/asymmetric_keys/pkcs8_info_parser.c
create mode 100644 crypto/asymmetric_keys/pkcs8_parser.h
create mode 100644 crypto/asymmetric_keys/pkcs8_private_key.c
create mode 100644 crypto/asymmetric_keys/pkcs8_rsakey.asn1
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
index 6d2c2ea..c0ebd57 100644
--- a/crypto/asymmetric_keys/Kconfig
+++ b/crypto/asymmetric_keys/Kconfig
@@ -35,4 +35,15 @@ config X509_CERTIFICATE_PARSER
data and provides the ability to instantiate a crypto key from a
public key packet found inside the certificate.
+config PKCS8_PRIVATE_KEY_INFO_PARSER
+ tristate "PKCS #8 private key info parser"
+ depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+ select ASN1
+ select OID_REGISTRY
+ select CRYPTO_SHA256
+ help
+ This option provides support for parsing PKCS #8 RSA private key info
+ format blobs for key data and provides the ability to instantiate a
+ crypto key from a private key packet.
+
endif # ASYMMETRIC_KEY_TYPE
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
index 0727204..65fbc45 100644
--- a/crypto/asymmetric_keys/Makefile
+++ b/crypto/asymmetric_keys/Makefile
@@ -23,5 +23,21 @@ $(obj)/x509_cert_parser.o: $(obj)/x509-asn1.h $(obj)/x509_rsakey-asn1.h
$(obj)/x509-asn1.o: $(obj)/x509-asn1.c $(obj)/x509-asn1.h
$(obj)/x509_rsakey-asn1.o: $(obj)/x509_rsakey-asn1.c $(obj)/x509_rsakey-asn1.h
+#
+# PKCS8 Private Key handling
+#
+obj-$(CONFIG_PKCS8_PRIVATE_KEY_INFO_PARSER) += pkcs8_key_parser.o
+pkcs8_key_parser-y := \
+ pkcs8-asn1.o \
+ pkcs8_rsakey-asn1.o \
+ pkcs8_info_parser.o \
+ pkcs8_private_key.o
+
+$(obj)/pkcs8_info_parser.o: $(obj)/pkcs8-asn1.c $(obj)/pkcs8_rsakey-asn1.h
+$(obj)/pkcs8-asn1.o: $(obj)/pkcs8-asn1.c $(obj)/pkcs8-asn1.h
+$(obj)/pkcs8_rsakey-asn1.o: $(obj)/pkcs8_rsakey-asn1.c $(obj)/pkcs8_rsakey-asn1.h
+
clean-files += x509-asn1.c x509-asn1.h
clean-files += x509_rsakey-asn1.c x509_rsakey-asn1.h
+clean-files += pkcs8-asn1.c pkcs8-asn1.h
+clean-files += pkcs8_rsakey-asn1.c pkcs8_rsakey-asn1.h
diff --git a/crypto/asymmetric_keys/pkcs8.asn1 b/crypto/asymmetric_keys/pkcs8.asn1
new file mode 100644
index 0000000..89e845d
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs8.asn1
@@ -0,0 +1,19 @@
+--
+-- Representation of RSA PKCS#8 private key information.
+--
+
+PrivateKeyInfo ::= SEQUENCE {
+ version Version,
+ privateKeyAlgorithm AlgorithmIdentifier,
+ privateKey OCTET STRING ({ pkcs8_extract_key_data })
+ -- Does not support attributes
+ -- attributes [ 0 ] Attributes OPTIONAL
+ }
+
+-- Version ::= INTEGER { two-prime(0), multi(1) }
+Version ::= INTEGER
+
+AlgorithmIdentifier ::= SEQUENCE {
+ algorithm OBJECT IDENTIFIER ({ pkcs8_note_OID }),
+ parameters ANY OPTIONAL
+ }
diff --git a/crypto/asymmetric_keys/pkcs8_info_parser.c b/crypto/asymmetric_keys/pkcs8_info_parser.c
new file mode 100644
index 0000000..7475732
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs8_info_parser.c
@@ -0,0 +1,152 @@
+/* X.509 certificate parser
+ *
+ * Copyright (C) 2013 SUSE Linux Products GmbH. All rights reserved.
+ * Written by Lee, Chun-Yi (jlee@xxxxxxxx)
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "PKCS8: "fmt
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#include "public_key.h"
+#include "pkcs8_parser.h"
+#include "pkcs8-asn1.h"
+#include "pkcs8_rsakey-asn1.h"
+
+struct pkcs8_parse_context {
+ struct pkcs8_info *info; /* Certificate being constructed */
+ unsigned long data; /* Start of data */
+ const void *key; /* Key data */
+ size_t key_size; /* Size of key data */
+ enum OID algo_oid; /* Algorithm OID */
+ unsigned char nr_mpi; /* Number of MPIs stored */
+};
+
+/*
+ * Free an PKCS #8 private key info
+ */
+void pkcs8_free_info(struct pkcs8_info *info)
+{
+ if (info) {
+ public_key_destroy(info->priv);
+ kfree(info);
+ }
+}
+
+/*
+ * Parse an PKCS #8 Private Key Info
+ */
+struct pkcs8_info *pkcs8_info_parse(const void *data, size_t datalen)
+{
+ struct pkcs8_info *info;
+ struct pkcs8_parse_context *ctx;
+ long ret;
+
+ ret = -ENOMEM;
+ info = kzalloc(sizeof(struct pkcs8_info), GFP_KERNEL);
+ if (!info)
+ goto error_no_info;
+ info->priv = kzalloc(sizeof(struct private_key), GFP_KERNEL);
+ if (!info->priv)
+ goto error_no_ctx;
+ ctx = kzalloc(sizeof(struct pkcs8_parse_context), GFP_KERNEL);
+ if (!ctx)
+ goto error_no_ctx;
+
+ ctx->info = info;
+ ctx->data = (unsigned long)data;
+
+ /* Attempt to decode the private key info */
+ ret = asn1_ber_decoder(&pkcs8_decoder, ctx, data, datalen);
+ if (ret < 0)
+ goto error_decode;
+
+ /* Decode the private key */
+ ret = asn1_ber_decoder(&pkcs8_rsakey_decoder, ctx,
+ ctx->key, ctx->key_size);
+ if (ret < 0)
+ goto error_decode;
+
+ kfree(ctx);
+ return info;
+
+error_decode:
+ kfree(ctx);
+error_no_ctx:
+ pkcs8_free_info(info);
+error_no_info:
+ return ERR_PTR(ret);
+}
+
+/*
+ * Note an OID when we find one for later processing when we know how
+ * to interpret it.
+ */
+int pkcs8_note_OID(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs8_parse_context *ctx = context;
+
+ ctx->algo_oid = look_up_OID(value, vlen);
+ if (ctx->algo_oid == OID__NR) {
+ char buffer[50];
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("Unknown OID: [%lu] %s\n",
+ (unsigned long)value - ctx->data, buffer);
+ }
+ return 0;
+}
+
+/*
+ * Extract the data for the private key algorithm
+ */
+int pkcs8_extract_key_data(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs8_parse_context *ctx = context;
+
+ if (ctx->algo_oid != OID_rsaEncryption)
+ return -ENOPKG;
+
+ ctx->info->pkey_algo = PKEY_ALGO_RSA;
+ ctx->key = value;
+ ctx->key_size = vlen;
+ return 0;
+}
+
+/*
+ * Extract a RSA private key value
+ */
+int rsa_priv_extract_mpi(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct pkcs8_parse_context *ctx = context;
+ MPI mpi;
+
+ if (ctx->nr_mpi >= ARRAY_SIZE(ctx->info->priv->mpi)) {
+ /* does not grab exponent1, exponent2 and coefficient */
+ if (ctx->nr_mpi > 8) {
+ pr_err("Too many public key MPIs in pkcs1 private key\n");
+ return -EBADMSG;
+ } else {
+ ctx->nr_mpi++;
+ return 0;
+ }
+ }
+
+ mpi = mpi_read_raw_data(value, vlen);
+ if (!mpi)
+ return -ENOMEM;
+
+ ctx->info->priv->mpi[ctx->nr_mpi++] = mpi;
+ return 0;
+}
diff --git a/crypto/asymmetric_keys/pkcs8_parser.h b/crypto/asymmetric_keys/pkcs8_parser.h
new file mode 100644
index 0000000..9abaf01
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs8_parser.h
@@ -0,0 +1,23 @@
+/* PKCS #8 parser internal definitions
+ *
+ * Copyright (C) 2013 SUSE Linux Products GmbH. All rights reserved.
+ * Written by Lee, Chun-Yi (jlee@xxxxxxxx)
+ *
+ * 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 <crypto/public_key.h>
+
+struct pkcs8_info {
+ enum pkey_algo pkey_algo; /* Private key algorithm */
+ struct private_key *priv; /* Private key */
+};
+
+/*
+ * pkcs8_parser.c
+ */
+extern void pkcs8_free_info(struct pkcs8_info *info);
+extern struct pkcs8_info *pkcs8_info_parse(const void *data, size_t datalen);
diff --git a/crypto/asymmetric_keys/pkcs8_private_key.c b/crypto/asymmetric_keys/pkcs8_private_key.c
new file mode 100644
index 0000000..b52d7aa
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs8_private_key.c
@@ -0,0 +1,148 @@
+/* Instantiate a private key crypto key
+ *
+ * Copyright (C) 2013 SUSE Linux Products GmbH. All rights reserved.
+ * Written by Chun-Yi Lee (jlee@xxxxxxxx)
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "PKCS8: "fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <keys/asymmetric-subtype.h>
+#include <keys/asymmetric-parser.h>
+#include <crypto/hash.h>
+#include "private_key.h"
+#include "pkcs8-asn1.h"
+#include "pkcs8_parser.h"
+
+#define KEY_PREFIX "Private Key: "
+#define FINGERPRINT_HASH "sha256"
+
+static const
+struct private_key_algorithm *pkcs8_private_key_algorithms[PKEY_ALGO__LAST] = {
+ [PKEY_ALGO_DSA] = NULL,
+#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
+ defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
+ [PKEY_ALGO_RSA] = &RSA_private_key_algorithm,
+#endif
+};
+
+/*
+ * Attempt to parse a data blob for a private key.
+ */
+static int pkcs8_key_preparse(struct key_preparsed_payload *prep)
+{
+ struct pkcs8_info *info;
+ struct crypto_shash *tfm;
+ struct shash_desc *desc;
+ u8 *digest;
+ size_t digest_size, desc_size;
+ char *fingerprint, *description;
+ int i, ret;
+
+ pr_info("pkcs8_key_preparse start\n");
+
+ info = pkcs8_info_parse(prep->data, prep->datalen);
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ info->priv->algo = pkcs8_private_key_algorithms[info->pkey_algo];
+ info->priv->id_type = PKEY_ID_PKCS8;
+
+ /* Hash the pkcs #8 blob to generate fingerprint */
+ tfm = crypto_alloc_shash(FINGERPRINT_HASH, 0, 0);
+ if (IS_ERR(tfm)) {
+ ret = PTR_ERR(tfm);
+ goto error_shash;
+ }
+ desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
+ digest_size = crypto_shash_digestsize(tfm);
+
+ ret = -ENOMEM;
+
+ digest = kzalloc(digest_size + desc_size, GFP_KERNEL);
+ if (!digest)
+ goto error_digest;
+ desc = (void *) digest + digest_size;
+ desc->tfm = tfm;
+ desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ ret = crypto_shash_init(desc);
+ if (ret < 0)
+ goto error_shash_init;
+ ret = crypto_shash_finup(desc, prep->data, prep->datalen, digest);
+ if (ret < 0)
+ goto error_shash_finup;
+
+ fingerprint = kzalloc(digest_size * 2 + 1, GFP_KERNEL);
+ if (!fingerprint)
+ goto error_fingerprint;
+ for (i = 0; i < digest_size; i++)
+ sprintf(fingerprint + i * 2, "%02x", digest[i]);
+
+ /* Propose a description */
+ description = kzalloc(strlen(KEY_PREFIX) + strlen(fingerprint) + 1, GFP_KERNEL);
+ if (!description)
+ goto error_description;
+ sprintf(description, "%s", KEY_PREFIX);
+ memcpy(description + strlen(KEY_PREFIX), fingerprint, strlen(fingerprint));
+
+ /* We're pinning the module by being linked against it */
+ __module_get(private_key_subtype.owner);
+ prep->type_data[0] = &private_key_subtype;
+ prep->type_data[1] = fingerprint;
+ prep->payload = info->priv;
+ prep->description = description;
+
+ /* size of 4096 bits private key file is 2.3K */
+ prep->quotalen = 700;
+
+ pr_info("pkcs8_key_preparse done\n");
+
+ /* We've finished with the information */
+ kfree(digest);
+ crypto_free_shash(tfm);
+ info->priv = NULL;
+ pkcs8_free_info(info);
+
+ return 0;
+
+error_description:
+ kfree(fingerprint);
+error_fingerprint:
+error_shash_finup:
+error_shash_init:
+ kfree(digest);
+error_digest:
+ crypto_free_shash(tfm);
+error_shash:
+ info->priv = NULL;
+ pkcs8_free_info(info);
+ return ret;
+}
+
+static struct asymmetric_key_parser pkcs8_private_key_parser = {
+ .owner = THIS_MODULE,
+ .name = "pkcs8",
+ .parse = pkcs8_key_preparse,
+};
+
+/*
+ * Module stuff
+ */
+static int __init pkcs8_private_key_init(void)
+{
+ return register_asymmetric_key_parser(&pkcs8_private_key_parser);
+}
+
+static void __exit pkcs8_private_key_exit(void)
+{
+ unregister_asymmetric_key_parser(&pkcs8_private_key_parser);
+}
+
+module_init(pkcs8_private_key_init);
+module_exit(pkcs8_private_key_exit);
diff --git a/crypto/asymmetric_keys/pkcs8_rsakey.asn1 b/crypto/asymmetric_keys/pkcs8_rsakey.asn1
new file mode 100644
index 0000000..d997c5e
--- /dev/null
+++ b/crypto/asymmetric_keys/pkcs8_rsakey.asn1
@@ -0,0 +1,29 @@
+--
+-- Representation of RSA private key with information.
+--
+
+RSAPrivateKey ::= SEQUENCE {
+ version Version,
+ modulus INTEGER ({ rsa_priv_extract_mpi }), -- n
+ publicExponent INTEGER ({ rsa_priv_extract_mpi }), -- e
+ privateExponent INTEGER ({ rsa_priv_extract_mpi }), -- d
+ prime1 INTEGER ({ rsa_priv_extract_mpi }), -- p
+ prime2 INTEGER ({ rsa_priv_extract_mpi }), -- q
+ exponent1 INTEGER ({ rsa_priv_extract_mpi }), -- d mod (p-1)
+ exponent2 INTEGER ({ rsa_priv_extract_mpi }), -- d mod (q-1)
+ coefficient INTEGER ({ rsa_priv_extract_mpi }) -- (inverse of q) mod p
+ -- Doesn't support multi-prime
+ -- otherPrimeInfos [ 0 ] OtherPrimeInfos OPTIONAL
+ }
+
+-- Version ::= INTEGER { two-prime(0), multi(1) }
+Version ::= INTEGER
+
+-- OtherPrimeInfos ::= SEQUENCE SIZE(1..MAX) OF OtherPrimeInfo
+OtherPrimeInfos ::= SEQUENCE OF OtherPrimeInfo
+
+OtherPrimeInfo ::= SEQUENCE {
+ prime INTEGER, -- ri
+ exponent INTEGER, -- di
+ coefficient INTEGER -- ti
+}
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
index 80c19cd..829788d 100644
--- a/crypto/asymmetric_keys/public_key.c
+++ b/crypto/asymmetric_keys/public_key.c
@@ -44,6 +44,7 @@ EXPORT_SYMBOL_GPL(pkey_hash_algo);
const char *const pkey_id_type[PKEY_ID_TYPE__LAST] = {
[PKEY_ID_PGP] = "PGP",
[PKEY_ID_X509] = "X509",
+ [PKEY_ID_PKCS8] = "PKCS8",
};
EXPORT_SYMBOL_GPL(pkey_id_type);
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 1cdf457..e51f294 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -41,6 +41,7 @@ extern const char *const pkey_hash_algo[PKEY_HASH__LAST];
enum pkey_id_type {
PKEY_ID_PGP, /* OpenPGP generated key ID */
PKEY_ID_X509, /* X.509 arbitrary subjectKeyIdentifier */
+ PKEY_ID_PKCS8, /* PKCS #8 Private Key */
PKEY_ID_TYPE__LAST
};
--
1.6.0.2
--
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