Add a subtype for supporting asymmetric public-key encryption algorithms such
as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337).
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
security/keys/Kconfig | 9 ++++
security/keys/Makefile | 1
security/keys/public_key.c | 55 ++++++++++++++++++++++
security/keys/public_key.h | 109 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 174 insertions(+), 0 deletions(-)
create mode 100644 security/keys/public_key.c
create mode 100644 security/keys/public_key.h
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index 290c9d3..07c7f3b 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -77,3 +77,12 @@ config CRYPTO_KEY_TYPE
This option provides support for a type of key that holds the keys
required for cryptographic operations such as encryption, decryption,
signature generation and signature verification.
+
+config CRYPTO_KEY_PUBLIC_KEY_SUBTYPE
+ tristate "Asymmetric public-key crypto algorithm subtype"
+ depends on CRYPTO_KEY_TYPE
+ help
+ This option provides support for asymmetric public key type handling.
+ If signature generation and/or verification are to be used,
+ appropriate hash algorithms (such as SHA-1) must be available.
+ ENOPKG will be reported if the requisite algorithm is unavailable.
diff --git a/security/keys/Makefile b/security/keys/Makefile
index 8462904..dc3281f 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -25,5 +25,6 @@ obj-$(CONFIG_SYSCTL) += sysctl.o
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/
obj-$(CONFIG_CRYPTO_KEY_TYPE) += crypto_keys.o
+obj-$(CONFIG_CRYPTO_KEY_PUBLIC_KEY_SUBTYPE) += public_key.o
crypto_keys-y := crypto_type.o crypto_verify.o
diff --git a/security/keys/public_key.c b/security/keys/public_key.c
new file mode 100644
index 0000000..c00ddac
--- /dev/null
+++ b/security/keys/public_key.c
@@ -0,0 +1,55 @@
+/* Asymmetric public key crypto subtype
+ *
+ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ *
+ * 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) "PKEY: "fmt
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include "public_key.h"
+
+MODULE_LICENSE("GPL");
+
+/*
+ * Provide a part of a description of the key for /proc/keys.
+ */
+static void public_key_describe(const struct key *crypto_key,
+ struct seq_file *m)
+{
+ struct public_key *key = crypto_key->payload.data;
+
+ if (key)
+ seq_puts(m, key->algo->name);
+}
+
+/*
+ * Destroy a public key algorithm key
+ */
+static void public_key_destroy(void *payload)
+{
+ struct public_key *key = payload;
+ int i;
+
+ if (key) {
+ for (i = 0; i < ARRAY_SIZE(key->mpi); i++)
+ mpi_free(key->mpi[i]);
+ kfree(key);
+ }
+}
+
+/*
+ * Public key algorithm crypto key subtype
+ */
+struct crypto_key_subtype public_key_crypto_key_subtype = {
+ .owner = THIS_MODULE,
+ .name = "public_key",
+ .describe = public_key_describe,
+ .destroy = public_key_destroy,
+};
+EXPORT_SYMBOL_GPL(public_key_crypto_key_subtype);
diff --git a/security/keys/public_key.h b/security/keys/public_key.h
new file mode 100644
index 0000000..b5aab3d
--- /dev/null
+++ b/security/keys/public_key.h
@@ -0,0 +1,109 @@
+/* Asymmetric public-key algorithm definitions
+ *
+ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ *
+ * 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.
+ */
+
+#ifndef _LINUX_PUBLIC_KEY_H
+#define _LINUX_PUBLIC_KEY_H
+
+#include <linux/mpi.h>
+#include <crypto/hash.h>
+#include <keys/crypto-subtype.h>
+
+struct public_key;
+struct public_key_signature;
+
+enum pkey_hash_algo {
+ PKEY_HASH_MD5,
+ PKEY_HASH_SHA1,
+ PKEY_HASH_RIPE_MD_160,
+ PKEY_HASH_SHA256,
+ PKEY_HASH_SHA384,
+ PKEY_HASH_SHA512,
+ PKEY_HASH_SHA224,
+ PKEY_HASH__LAST
+};
+
+/*
+ * Public key type definition
+ */
+struct public_key_algorithm {
+ const char *name;
+ u8 n_pub_mpi; /* Number of MPIs in public key */
+ u8 n_sec_mpi; /* Number of MPIs in secret key */
+ u8 n_sig_mpi; /* Number of MPIs in a signature */
+ int (*verify)(const struct public_key *key,
+ const struct public_key_signature *sig);
+};
+
+extern const struct public_key_algorithm DSA_public_key_algorithm;
+extern const struct public_key_algorithm RSA_public_key_algorithm;
+
+/*
+ * Asymmetric public key data
+ */
+struct public_key {
+ const struct public_key_algorithm *algo;
+ u8 capabilities;
+#define PKEY_CAN_ENCRYPT 0x01
+#define PKEY_CAN_DECRYPT 0x02
+#define PKEY_CAN_ENCDEC (PKEY_CAN_ENCRYPT | PKEY_CAN_DECRYPT)
+#define PKEY_CAN_SIGN 0x04
+#define PKEY_CAN_VERIFY 0x08
+#define PKEY_CAN_SIGVER (PKEY_CAN_SIGN | PKEY_CAN_VERIFY)
+ union {
+ MPI mpi[5];
+ struct {
+ MPI p; /* DSA prime */
+ MPI q; /* DSA group order */
+ MPI g; /* DSA group generator */
+ MPI y; /* DSA public-key value = g^x mod p */
+ MPI x; /* DSA secret exponent (if present) */
+ } dsa;
+ struct {
+ MPI n; /* RSA public modulus */
+ MPI e; /* RSA public encryption exponent */
+ MPI d; /* RSA secret encryption exponent (if present) */
+ MPI p; /* RSA secret prime (if present) */
+ MPI q; /* RSA secret prime (if present) */
+ } rsa;
+ };
+
+ u8 key_id[8]; /* ID of this key pair */
+ u8 key_id_size; /* Number of bytes in key_id */
+};
+
+/*
+ * Asymmetric public key algorithm signature data
+ */
+struct public_key_signature {
+ struct crypto_key_verify_context base;
+ u8 *digest;
+ enum pkey_hash_algo pkey_hash_algo : 8;
+ u8 signed_hash_msw[2];
+ u8 digest_size; /* Number of bytes in digest */
+ union {
+ MPI mpi[2];
+ struct {
+ MPI s; /* m^d mod n */
+ } rsa;
+ struct {
+ MPI r;
+ MPI s;
+ } dsa;
+ };
+ struct shash_desc hash; /* This must go last! */
+};
+
+extern struct crypto_key_verify_context *pgp_pkey_verify_sig_begin(
+ struct key *crypto_key, const u8 *sigdata, size_t siglen);
+
+extern struct crypto_key_subtype public_key_crypto_key_subtype;
+
+#endif /* _LINUX_PUBLIC_KEY_H */
--
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