From 70025f84e5b79627a6739533c4fe7cef5b605886 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:46:51 +0100 Subject: KEYS: Provide key type operations for asymmetric key ops [ver #2] Provide five new operations in the key_type struct that can be used to provide access to asymmetric key operations. These will be implemented for the asymmetric key type in a later patch and may refer to a key retained in RAM by the kernel or a key retained in crypto hardware. int (*asym_query)(const struct kernel_pkey_params *params, struct kernel_pkey_query *info); int (*asym_eds_op)(struct kernel_pkey_params *params, const void *in, void *out); int (*asym_verify_signature)(struct kernel_pkey_params *params, const void *in, const void *in2); Since encrypt, decrypt and sign are identical in their interfaces, they're rolled together in the asym_eds_op() operation and there's an operation ID in the params argument to distinguish them. Verify is different in that we supply the data and the signature instead and get an error value (or 0) as the only result on the expectation that this may well be how a hardware crypto device may work. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- Documentation/security/keys/core.rst | 106 +++++++++++++++++++++++++++++++++++ include/linux/key-type.h | 11 ++++ include/linux/keyctl.h | 46 +++++++++++++++ include/uapi/linux/keyctl.h | 5 ++ 4 files changed, 168 insertions(+) create mode 100644 include/linux/keyctl.h diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst index 9ce7256c6edb..c144978479d5 100644 --- a/Documentation/security/keys/core.rst +++ b/Documentation/security/keys/core.rst @@ -1483,6 +1483,112 @@ The structure has a number of fields, some of which are mandatory: attempted key link operation. If there is no match, -EINVAL is returned. + * ``int (*asym_eds_op)(struct kernel_pkey_params *params, + const void *in, void *out);`` + ``int (*asym_verify_signature)(struct kernel_pkey_params *params, + const void *in, const void *in2);`` + + These methods are optional. If provided the first allows a key to be + used to encrypt, decrypt or sign a blob of data, and the second allows a + key to verify a signature. + + In all cases, the following information is provided in the params block:: + + struct kernel_pkey_params { + struct key *key; + const char *encoding; + const char *hash_algo; + char *info; + __u32 in_len; + union { + __u32 out_len; + __u32 in2_len; + }; + enum kernel_pkey_operation op : 8; + }; + + This includes the key to be used; a string indicating the encoding to use + (for instance, "pkcs1" may be used with an RSA key to indicate + RSASSA-PKCS1-v1.5 or RSAES-PKCS1-v1.5 encoding or "raw" if no encoding); + the name of the hash algorithm used to generate the data for a signature + (if appropriate); the sizes of the input and output (or second input) + buffers; and the ID of the operation to be performed. + + For a given operation ID, the input and output buffers are used as + follows:: + + Operation ID in,in_len out,out_len in2,in2_len + ======================= =============== =============== =============== + kernel_pkey_encrypt Raw data Encrypted data - + kernel_pkey_decrypt Encrypted data Raw data - + kernel_pkey_sign Raw data Signature - + kernel_pkey_verify Raw data - Signature + + asym_eds_op() deals with encryption, decryption and signature creation as + specified by params->op. Note that params->op is also set for + asym_verify_signature(). + + Encrypting and signature creation both take raw data in the input buffer + and return the encrypted result in the output buffer. Padding may have + been added if an encoding was set. In the case of signature creation, + depending on the encoding, the padding created may need to indicate the + digest algorithm - the name of which should be supplied in hash_algo. + + Decryption takes encrypted data in the input buffer and returns the raw + data in the output buffer. Padding will get checked and stripped off if + an encoding was set. + + Verification takes raw data in the input buffer and the signature in the + second input buffer and checks that the one matches the other. Padding + will be validated. Depending on the encoding, the digest algorithm used + to generate the raw data may need to be indicated in hash_algo. + + If successful, asym_eds_op() should return the number of bytes written + into the output buffer. asym_verify_signature() should return 0. + + A variety of errors may be returned, including EOPNOTSUPP if the operation + is not supported; EKEYREJECTED if verification fails; ENOPKG if the + required crypto isn't available. + + + * ``int (*asym_query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info);`` + + This method is optional. If provided it allows information about the + public or asymmetric key held in the key to be determined. + + The parameter block is as for asym_eds_op() and co. but in_len and out_len + are unused. The encoding and hash_algo fields should be used to reduce + the returned buffer/data sizes as appropriate. + + If successful, the following information is filled in:: + + struct kernel_pkey_query { + __u32 supported_ops; + __u32 key_size; + __u16 max_data_size; + __u16 max_sig_size; + __u16 max_enc_size; + __u16 max_dec_size; + }; + + The supported_ops field will contain a bitmask indicating what operations + are supported by the key, including encryption of a blob, decryption of a + blob, signing a blob and verifying the signature on a blob. The following + constants are defined for this:: + + KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY} + + The key_size field is the size of the key in bits. max_data_size and + max_sig_size are the maximum raw data and signature sizes for creation and + verification of a signature; max_enc_size and max_dec_size are the maximum + raw data and signature sizes for encryption and decryption. The + max_*_size fields are measured in bytes. + + If successful, 0 will be returned. If the key doesn't support this, + EOPNOTSUPP will be returned. + + Request-Key Callback Service ============================ diff --git a/include/linux/key-type.h b/include/linux/key-type.h index 05d8fb5a06c4..bc9af551fc83 100644 --- a/include/linux/key-type.h +++ b/include/linux/key-type.h @@ -17,6 +17,9 @@ #ifdef CONFIG_KEYS +struct kernel_pkey_query; +struct kernel_pkey_params; + /* * key under-construction record * - passed to the request_key actor if supplied @@ -155,6 +158,14 @@ struct key_type { */ struct key_restriction *(*lookup_restriction)(const char *params); + /* Asymmetric key accessor functions. */ + int (*asym_query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + int (*asym_eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); + int (*asym_verify_signature)(struct kernel_pkey_params *params, + const void *in, const void *in2); + /* internal fields */ struct list_head link; /* link in types list */ struct lock_class_key lock_class; /* key->sem lock class */ diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h new file mode 100644 index 000000000000..c7c48c79ce0e --- /dev/null +++ b/include/linux/keyctl.h @@ -0,0 +1,46 @@ +/* keyctl kernel bits + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * 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_KEYCTL_H +#define __LINUX_KEYCTL_H + +#include + +struct kernel_pkey_query { + __u32 supported_ops; /* Which ops are supported */ + __u32 key_size; /* Size of the key in bits */ + __u16 max_data_size; /* Maximum size of raw data to sign in bytes */ + __u16 max_sig_size; /* Maximum size of signature in bytes */ + __u16 max_enc_size; /* Maximum size of encrypted blob in bytes */ + __u16 max_dec_size; /* Maximum size of decrypted blob in bytes */ +}; + +enum kernel_pkey_operation { + kernel_pkey_encrypt, + kernel_pkey_decrypt, + kernel_pkey_sign, + kernel_pkey_verify, +}; + +struct kernel_pkey_params { + struct key *key; + const char *encoding; /* Encoding (eg. "oaep" or "raw" for none) */ + const char *hash_algo; /* Digest algorithm used (eg. "sha1") or NULL if N/A */ + char *info; /* Modified info string to be released later */ + __u32 in_len; /* Input data size */ + union { + __u32 out_len; /* Output buffer size (enc/dec/sign) */ + __u32 in2_len; /* 2nd input data size (verify) */ + }; + enum kernel_pkey_operation op : 8; +}; + +#endif /* __LINUX_KEYCTL_H */ diff --git a/include/uapi/linux/keyctl.h b/include/uapi/linux/keyctl.h index 0f3cb13db8e9..1d1e9f2877af 100644 --- a/include/uapi/linux/keyctl.h +++ b/include/uapi/linux/keyctl.h @@ -82,4 +82,9 @@ struct keyctl_kdf_params { __u32 __spare[8]; }; +#define KEYCTL_SUPPORTS_ENCRYPT 0x01 +#define KEYCTL_SUPPORTS_DECRYPT 0x02 +#define KEYCTL_SUPPORTS_SIGN 0x04 +#define KEYCTL_SUPPORTS_VERIFY 0x08 + #endif /* _LINUX_KEYCTL_H */ -- cgit v1.2.3 From 00d60fd3b93219ea854220f0fd264b86398cbc53 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:46:59 +0100 Subject: KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2] Provide five keyctl functions that permit userspace to make use of the new key type ops for accessing and driving asymmetric keys. (*) Query an asymmetric key. long keyctl(KEYCTL_PKEY_QUERY, key_serial_t key, unsigned long reserved, struct keyctl_pkey_query *info); Get information about an asymmetric key. The information is returned in the keyctl_pkey_query struct: __u32 supported_ops; A bit mask of flags indicating which ops are supported. This is constructed from a bitwise-OR of: KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY} __u32 key_size; The size in bits of the key. __u16 max_data_size; __u16 max_sig_size; __u16 max_enc_size; __u16 max_dec_size; The maximum sizes in bytes of a blob of data to be signed, a signature blob, a blob to be encrypted and a blob to be decrypted. reserved must be set to 0. This is intended for future use to hand over one or more passphrases needed unlock a key. If successful, 0 is returned. If the key is not an asymmetric key, EOPNOTSUPP is returned. (*) Encrypt, decrypt, sign or verify a blob using an asymmetric key. long keyctl(KEYCTL_PKEY_ENCRYPT, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_DECRYPT, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_SIGN, const struct keyctl_pkey_params *params, const char *info, const void *in, void *out); long keyctl(KEYCTL_PKEY_VERIFY, const struct keyctl_pkey_params *params, const char *info, const void *in, const void *in2); Use an asymmetric key to perform a public-key cryptographic operation a blob of data. The parameter block pointed to by params contains a number of integer values: __s32 key_id; __u32 in_len; __u32 out_len; __u32 in2_len; For a given operation, the in and out buffers are used as follows: Operation ID in,in_len out,out_len in2,in2_len ======================= =============== =============== =========== KEYCTL_PKEY_ENCRYPT Raw data Encrypted data - KEYCTL_PKEY_DECRYPT Encrypted data Raw data - KEYCTL_PKEY_SIGN Raw data Signature - KEYCTL_PKEY_VERIFY Raw data - Signature info is a string of key=value pairs that supply supplementary information. The __spare space in the parameter block must be set to 0. This is intended, amongst other things, to allow the passing of passphrases required to unlock a key. If successful, encrypt, decrypt and sign all return the amount of data written into the output buffer. Verification returns 0 on success. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- Documentation/security/keys/core.rst | 111 ++++++++++++ include/uapi/linux/keyctl.h | 25 +++ security/keys/Makefile | 1 + security/keys/compat.c | 18 ++ security/keys/internal.h | 39 +++++ security/keys/keyctl.c | 24 +++ security/keys/keyctl_pkey.c | 323 +++++++++++++++++++++++++++++++++++ 7 files changed, 541 insertions(+) create mode 100644 security/keys/keyctl_pkey.c diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst index c144978479d5..9521c4207f01 100644 --- a/Documentation/security/keys/core.rst +++ b/Documentation/security/keys/core.rst @@ -859,6 +859,7 @@ The keyctl syscall functions are: and either the buffer length or the OtherInfo length exceeds the allowed length. + * Restrict keyring linkage:: long keyctl(KEYCTL_RESTRICT_KEYRING, key_serial_t keyring, @@ -890,6 +891,116 @@ The keyctl syscall functions are: applicable to the asymmetric key type. + * Query an asymmetric key:: + + long keyctl(KEYCTL_PKEY_QUERY, + key_serial_t key_id, unsigned long reserved, + struct keyctl_pkey_query *info); + + Get information about an asymmetric key. The information is returned in + the keyctl_pkey_query struct:: + + __u32 supported_ops; + __u32 key_size; + __u16 max_data_size; + __u16 max_sig_size; + __u16 max_enc_size; + __u16 max_dec_size; + __u32 __spare[10]; + + ``supported_ops`` contains a bit mask of flags indicating which ops are + supported. This is constructed from a bitwise-OR of:: + + KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY} + + ``key_size`` indicated the size of the key in bits. + + ``max_*_size`` indicate the maximum sizes in bytes of a blob of data to be + signed, a signature blob, a blob to be encrypted and a blob to be + decrypted. + + ``__spare[]`` must be set to 0. This is intended for future use to hand + over one or more passphrases needed unlock a key. + + If successful, 0 is returned. If the key is not an asymmetric key, + EOPNOTSUPP is returned. + + + * Encrypt, decrypt, sign or verify a blob using an asymmetric key:: + + long keyctl(KEYCTL_PKEY_ENCRYPT, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_DECRYPT, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_SIGN, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + void *out); + + long keyctl(KEYCTL_PKEY_VERIFY, + const struct keyctl_pkey_params *params, + const char *info, + const void *in, + const void *in2); + + Use an asymmetric key to perform a public-key cryptographic operation a + blob of data. For encryption and verification, the asymmetric key may + only need the public parts to be available, but for decryption and signing + the private parts are required also. + + The parameter block pointed to by params contains a number of integer + values:: + + __s32 key_id; + __u32 in_len; + __u32 out_len; + __u32 in2_len; + + ``key_id`` is the ID of the asymmetric key to be used. ``in_len`` and + ``in2_len`` indicate the amount of data in the in and in2 buffers and + ``out_len`` indicates the size of the out buffer as appropriate for the + above operations. + + For a given operation, the in and out buffers are used as follows:: + + Operation ID in,in_len out,out_len in2,in2_len + ======================= =============== =============== =============== + KEYCTL_PKEY_ENCRYPT Raw data Encrypted data - + KEYCTL_PKEY_DECRYPT Encrypted data Raw data - + KEYCTL_PKEY_SIGN Raw data Signature - + KEYCTL_PKEY_VERIFY Raw data - Signature + + ``info`` is a string of key=value pairs that supply supplementary + information. These include: + + ``enc=`` The encoding of the encrypted/signature blob. This + can be "pkcs1" for RSASSA-PKCS1-v1.5 or + RSAES-PKCS1-v1.5; "pss" for "RSASSA-PSS"; "oaep" for + "RSAES-OAEP". If omitted or is "raw", the raw output + of the encryption function is specified. + + ``hash=`` If the data buffer contains the output of a hash + function and the encoding includes some indication of + which hash function was used, the hash function can be + specified with this, eg. "hash=sha256". + + The ``__spare[]`` space in the parameter block must be set to 0. This is + intended, amongst other things, to allow the passing of passphrases + required to unlock a key. + + If successful, encrypt, decrypt and sign all return the amount of data + written into the output buffer. Verification returns 0 on success. + + Kernel Services =============== diff --git a/include/uapi/linux/keyctl.h b/include/uapi/linux/keyctl.h index 1d1e9f2877af..f45ee0f69c0c 100644 --- a/include/uapi/linux/keyctl.h +++ b/include/uapi/linux/keyctl.h @@ -61,6 +61,11 @@ #define KEYCTL_INVALIDATE 21 /* invalidate a key */ #define KEYCTL_GET_PERSISTENT 22 /* get a user's persistent keyring */ #define KEYCTL_DH_COMPUTE 23 /* Compute Diffie-Hellman values */ +#define KEYCTL_PKEY_QUERY 24 /* Query public key parameters */ +#define KEYCTL_PKEY_ENCRYPT 25 /* Encrypt a blob using a public key */ +#define KEYCTL_PKEY_DECRYPT 26 /* Decrypt a blob using a public key */ +#define KEYCTL_PKEY_SIGN 27 /* Create a public key signature */ +#define KEYCTL_PKEY_VERIFY 28 /* Verify a public key signature */ #define KEYCTL_RESTRICT_KEYRING 29 /* Restrict keys allowed to link to a keyring */ /* keyctl structures */ @@ -87,4 +92,24 @@ struct keyctl_kdf_params { #define KEYCTL_SUPPORTS_SIGN 0x04 #define KEYCTL_SUPPORTS_VERIFY 0x08 +struct keyctl_pkey_query { + __u32 supported_ops; /* Which ops are supported */ + __u32 key_size; /* Size of the key in bits */ + __u16 max_data_size; /* Maximum size of raw data to sign in bytes */ + __u16 max_sig_size; /* Maximum size of signature in bytes */ + __u16 max_enc_size; /* Maximum size of encrypted blob in bytes */ + __u16 max_dec_size; /* Maximum size of decrypted blob in bytes */ + __u32 __spare[10]; +}; + +struct keyctl_pkey_params { + __s32 key_id; /* Serial no. of public key to use */ + __u32 in_len; /* Input data size */ + union { + __u32 out_len; /* Output buffer size (encrypt/decrypt/sign) */ + __u32 in2_len; /* 2nd input data size (verify) */ + }; + __u32 __spare[7]; +}; + #endif /* _LINUX_KEYCTL_H */ diff --git a/security/keys/Makefile b/security/keys/Makefile index ef1581b337a3..9cef54064f60 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_SYSCTL) += sysctl.o obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o obj-$(CONFIG_KEY_DH_OPERATIONS) += dh.o +obj-$(CONFIG_ASYMMETRIC_KEY_TYPE) += keyctl_pkey.o # # Key types diff --git a/security/keys/compat.c b/security/keys/compat.c index e87c89c0177c..9482df601dc3 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -141,6 +141,24 @@ COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, return keyctl_restrict_keyring(arg2, compat_ptr(arg3), compat_ptr(arg4)); + case KEYCTL_PKEY_QUERY: + if (arg3 != 0) + return -EINVAL; + return keyctl_pkey_query(arg2, + compat_ptr(arg4), + compat_ptr(arg5)); + + case KEYCTL_PKEY_ENCRYPT: + case KEYCTL_PKEY_DECRYPT: + case KEYCTL_PKEY_SIGN: + return keyctl_pkey_e_d_s(option, + compat_ptr(arg2), compat_ptr(arg3), + compat_ptr(arg4), compat_ptr(arg5)); + + case KEYCTL_PKEY_VERIFY: + return keyctl_pkey_verify(compat_ptr(arg2), compat_ptr(arg3), + compat_ptr(arg4), compat_ptr(arg5)); + default: return -EOPNOTSUPP; } diff --git a/security/keys/internal.h b/security/keys/internal.h index 9f8208dc0e55..74cb0ff42fed 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -298,6 +298,45 @@ static inline long compat_keyctl_dh_compute( #endif #endif +#ifdef CONFIG_ASYMMETRIC_KEY_TYPE +extern long keyctl_pkey_query(key_serial_t, + const char __user *, + struct keyctl_pkey_query __user *); + +extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *, + const char __user *, + const void __user *, const void __user *); + +extern long keyctl_pkey_e_d_s(int, + const struct keyctl_pkey_params __user *, + const char __user *, + const void __user *, void __user *); +#else +static inline long keyctl_pkey_query(key_serial_t id, + const char __user *_info, + struct keyctl_pkey_query __user *_res) +{ + return -EOPNOTSUPP; +} + +static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params, + const char __user *_info, + const void __user *_in, + const void __user *_in2) +{ + return -EOPNOTSUPP; +} + +static inline long keyctl_pkey_e_d_s(int op, + const struct keyctl_pkey_params __user *params, + const char __user *_info, + const void __user *_in, + void __user *_out) +{ + return -EOPNOTSUPP; +} +#endif + /* * Debugging key validation */ diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 1ffe60bb2845..18619690ce77 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1747,6 +1747,30 @@ SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, (const char __user *) arg3, (const char __user *) arg4); + case KEYCTL_PKEY_QUERY: + if (arg3 != 0) + return -EINVAL; + return keyctl_pkey_query((key_serial_t)arg2, + (const char __user *)arg4, + (struct keyctl_pkey_query *)arg5); + + case KEYCTL_PKEY_ENCRYPT: + case KEYCTL_PKEY_DECRYPT: + case KEYCTL_PKEY_SIGN: + return keyctl_pkey_e_d_s( + option, + (const struct keyctl_pkey_params __user *)arg2, + (const char __user *)arg3, + (const void __user *)arg4, + (void __user *)arg5); + + case KEYCTL_PKEY_VERIFY: + return keyctl_pkey_verify( + (const struct keyctl_pkey_params __user *)arg2, + (const char __user *)arg3, + (const void __user *)arg4, + (const void __user *)arg5); + default: return -EOPNOTSUPP; } diff --git a/security/keys/keyctl_pkey.c b/security/keys/keyctl_pkey.c new file mode 100644 index 000000000000..783978842f13 --- /dev/null +++ b/security/keys/keyctl_pkey.c @@ -0,0 +1,323 @@ +/* Public-key operation keyctls + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * 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 +#include +#include +#include +#include +#include +#include +#include "internal.h" + +static void keyctl_pkey_params_free(struct kernel_pkey_params *params) +{ + kfree(params->info); + key_put(params->key); +} + +enum { + Opt_err = -1, + Opt_enc, /* "enc=" eg. "enc=oaep" */ + Opt_hash, /* "hash=" eg. "hash=sha1" */ +}; + +static const match_table_t param_keys = { + { Opt_enc, "enc=%s" }, + { Opt_hash, "hash=%s" }, + { Opt_err, NULL } +}; + +/* + * Parse the information string which consists of key=val pairs. + */ +static int keyctl_pkey_params_parse(struct kernel_pkey_params *params) +{ + unsigned long token_mask = 0; + substring_t args[MAX_OPT_ARGS]; + char *c = params->info, *p, *q; + int token; + + while ((p = strsep(&c, " \t"))) { + if (*p == '\0' || *p == ' ' || *p == '\t') + continue; + token = match_token(p, param_keys, args); + if (__test_and_set_bit(token, &token_mask)) + return -EINVAL; + q = args[0].from; + if (!q[0]) + return -EINVAL; + + switch (token) { + case Opt_enc: + params->encoding = q; + break; + + case Opt_hash: + params->hash_algo = q; + break; + + default: + return -EINVAL; + } + } + + return 0; +} + +/* + * Interpret parameters. Callers must always call the free function + * on params, even if an error is returned. + */ +static int keyctl_pkey_params_get(key_serial_t id, + const char __user *_info, + struct kernel_pkey_params *params) +{ + key_ref_t key_ref; + void *p; + int ret; + + memset(params, 0, sizeof(*params)); + params->encoding = "raw"; + + p = strndup_user(_info, PAGE_SIZE); + if (IS_ERR(p)) + return PTR_ERR(p); + params->info = p; + + ret = keyctl_pkey_params_parse(params); + if (ret < 0) + return ret; + + key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + params->key = key_ref_to_ptr(key_ref); + + if (!params->key->type->asym_query) + return -EOPNOTSUPP; + + return 0; +} + +/* + * Get parameters from userspace. Callers must always call the free function + * on params, even if an error is returned. + */ +static int keyctl_pkey_params_get_2(const struct keyctl_pkey_params __user *_params, + const char __user *_info, + int op, + struct kernel_pkey_params *params) +{ + struct keyctl_pkey_params uparams; + struct kernel_pkey_query info; + int ret; + + memset(params, 0, sizeof(*params)); + params->encoding = "raw"; + + if (copy_from_user(&uparams, _params, sizeof(uparams)) != 0) + return -EFAULT; + + ret = keyctl_pkey_params_get(uparams.key_id, _info, params); + if (ret < 0) + return ret; + + ret = params->key->type->asym_query(params, &info); + if (ret < 0) + return ret; + + switch (op) { + case KEYCTL_PKEY_ENCRYPT: + case KEYCTL_PKEY_DECRYPT: + if (uparams.in_len > info.max_enc_size || + uparams.out_len > info.max_dec_size) + return -EINVAL; + break; + case KEYCTL_PKEY_SIGN: + case KEYCTL_PKEY_VERIFY: + if (uparams.in_len > info.max_sig_size || + uparams.out_len > info.max_data_size) + return -EINVAL; + break; + default: + BUG(); + } + + params->in_len = uparams.in_len; + params->out_len = uparams.out_len; + return 0; +} + +/* + * Query information about an asymmetric key. + */ +long keyctl_pkey_query(key_serial_t id, + const char __user *_info, + struct keyctl_pkey_query __user *_res) +{ + struct kernel_pkey_params params; + struct kernel_pkey_query res; + long ret; + + memset(¶ms, 0, sizeof(params)); + + ret = keyctl_pkey_params_get(id, _info, ¶ms); + if (ret < 0) + goto error; + + ret = params.key->type->asym_query(¶ms, &res); + if (ret < 0) + goto error; + + ret = -EFAULT; + if (copy_to_user(_res, &res, sizeof(res)) == 0 && + clear_user(_res->__spare, sizeof(_res->__spare)) == 0) + ret = 0; + +error: + keyctl_pkey_params_free(¶ms); + return ret; +} + +/* + * Encrypt/decrypt/sign + * + * Encrypt data, decrypt data or sign data using a public key. + * + * _info is a string of supplementary information in key=val format. For + * instance, it might contain: + * + * "enc=pkcs1 hash=sha256" + * + * where enc= specifies the encoding and hash= selects the OID to go in that + * particular encoding if required. If enc= isn't supplied, it's assumed that + * the caller is supplying raw values. + * + * If successful, the amount of data written into the output buffer is + * returned. + */ +long keyctl_pkey_e_d_s(int op, + const struct keyctl_pkey_params __user *_params, + const char __user *_info, + const void __user *_in, + void __user *_out) +{ + struct kernel_pkey_params params; + void *in, *out; + long ret; + + ret = keyctl_pkey_params_get_2(_params, _info, op, ¶ms); + if (ret < 0) + goto error_params; + + ret = -EOPNOTSUPP; + if (!params.key->type->asym_eds_op) + goto error_params; + + switch (op) { + case KEYCTL_PKEY_ENCRYPT: + params.op = kernel_pkey_encrypt; + break; + case KEYCTL_PKEY_DECRYPT: + params.op = kernel_pkey_decrypt; + break; + case KEYCTL_PKEY_SIGN: + params.op = kernel_pkey_sign; + break; + default: + BUG(); + } + + in = memdup_user(_in, params.in_len); + if (IS_ERR(in)) { + ret = PTR_ERR(in); + goto error_params; + } + + ret = -ENOMEM; + out = kmalloc(params.out_len, GFP_KERNEL); + if (!out) + goto error_in; + + ret = params.key->type->asym_eds_op(¶ms, in, out); + if (ret < 0) + goto error_out; + + if (copy_to_user(_out, out, ret) != 0) + ret = -EFAULT; + +error_out: + kfree(out); +error_in: + kfree(in); +error_params: + keyctl_pkey_params_free(¶ms); + return ret; +} + +/* + * Verify a signature. + * + * Verify a public key signature using the given key, or if not given, search + * for a matching key. + * + * _info is a string of supplementary information in key=val format. For + * instance, it might contain: + * + * "enc=pkcs1 hash=sha256" + * + * where enc= specifies the signature blob encoding and hash= selects the OID + * to go in that particular encoding. If enc= isn't supplied, it's assumed + * that the caller is supplying raw values. + * + * If successful, 0 is returned. + */ +long keyctl_pkey_verify(const struct keyctl_pkey_params __user *_params, + const char __user *_info, + const void __user *_in, + const void __user *_in2) +{ + struct kernel_pkey_params params; + void *in, *in2; + long ret; + + ret = keyctl_pkey_params_get_2(_params, _info, KEYCTL_PKEY_VERIFY, + ¶ms); + if (ret < 0) + goto error_params; + + ret = -EOPNOTSUPP; + if (!params.key->type->asym_verify_signature) + goto error_params; + + in = memdup_user(_in, params.in_len); + if (IS_ERR(in)) { + ret = PTR_ERR(in); + goto error_params; + } + + in2 = memdup_user(_in2, params.in2_len); + if (IS_ERR(in2)) { + ret = PTR_ERR(in2); + goto error_in; + } + + params.op = kernel_pkey_verify; + ret = params.key->type->asym_verify_signature(¶ms, in, in2); + + kfree(in2); +error_in: + kfree(in); +error_params: + keyctl_pkey_params_free(¶ms); + return ret; +} -- cgit v1.2.3 From 5a30771832aab228e0863e414f9182f86797429e Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:07 +0100 Subject: KEYS: Provide missing asymmetric key subops for new key type ops [ver #2] Provide the missing asymmetric key subops for new key type ops. This include query, encrypt, decrypt and create signature. Verify signature already exists. Also provided are accessor functions for this: int query_asymmetric_key(const struct key *key, struct kernel_pkey_query *info); int encrypt_blob(struct kernel_pkey_params *params, const void *data, void *enc); int decrypt_blob(struct kernel_pkey_params *params, const void *enc, void *data); int create_signature(struct kernel_pkey_params *params, const void *data, void *enc); The public_key_signature struct gains an encoding field to carry the encoding for verify_signature(). Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- Documentation/crypto/asymmetric-keys.txt | 24 ++++++-- crypto/asymmetric_keys/asymmetric_keys.h | 3 + crypto/asymmetric_keys/asymmetric_type.c | 43 +++++++++++++++ crypto/asymmetric_keys/signature.c | 95 ++++++++++++++++++++++++++++++++ include/crypto/public_key.h | 13 ++++- include/keys/asymmetric-subtype.h | 9 +++ 6 files changed, 180 insertions(+), 7 deletions(-) diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt index 5969bf42562a..deb656ef008b 100644 --- a/Documentation/crypto/asymmetric-keys.txt +++ b/Documentation/crypto/asymmetric-keys.txt @@ -183,6 +183,10 @@ and looks like the following: void (*describe)(const struct key *key, struct seq_file *m); void (*destroy)(void *payload); + int (*query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + int (*eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); int (*verify_signature)(const struct key *key, const struct public_key_signature *sig); }; @@ -207,12 +211,22 @@ There are a number of operations defined by the subtype: asymmetric key will look after freeing the fingerprint and releasing the reference on the subtype module. - (3) verify_signature(). + (3) query(). - Optional. These are the entry points for the key usage operations. - Currently there is only the one defined. If not set, the caller will be - given -ENOTSUPP. The subtype may do anything it likes to implement an - operation, including offloading to hardware. + Mandatory. This is a function for querying the capabilities of a key. + + (4) eds_op(). + + Optional. This is the entry point for the encryption, decryption and + signature creation operations (which are distinguished by the operation ID + in the parameter struct). The subtype may do anything it likes to + implement an operation, including offloading to hardware. + + (5) verify_signature(). + + Optional. This is the entry point for signature verification. The + subtype may do anything it likes to implement an operation, including + offloading to hardware. ========================== diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h index ca8e9ac34ce6..7be1ccf4fa9f 100644 --- a/crypto/asymmetric_keys/asymmetric_keys.h +++ b/crypto/asymmetric_keys/asymmetric_keys.h @@ -16,3 +16,6 @@ extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id); extern int __asymmetric_key_hex_to_key_id(const char *id, struct asymmetric_key_id *match_id, size_t hexlen); + +extern int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out); diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c index 26539e9a8bda..69a0788a7de5 100644 --- a/crypto/asymmetric_keys/asymmetric_type.c +++ b/crypto/asymmetric_keys/asymmetric_type.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "asymmetric_keys.h" MODULE_LICENSE("GPL"); @@ -538,6 +539,45 @@ out: return ret; } +int asymmetric_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->eds_op) + return -ENOTSUPP; + + ret = subtype->eds_op(params, in, out); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + +static int asymmetric_key_verify_signature(struct kernel_pkey_params *params, + const void *in, const void *in2) +{ + struct public_key_signature sig = { + .s_size = params->in2_len, + .digest_size = params->in_len, + .encoding = params->encoding, + .hash_algo = params->hash_algo, + .digest = (void *)in, + .s = (void *)in2, + }; + + return verify_signature(params->key, &sig); +} + struct key_type key_type_asymmetric = { .name = "asymmetric", .preparse = asymmetric_key_preparse, @@ -548,6 +588,9 @@ struct key_type key_type_asymmetric = { .destroy = asymmetric_key_destroy, .describe = asymmetric_key_describe, .lookup_restriction = asymmetric_lookup_restriction, + .asym_query = query_asymmetric_key, + .asym_eds_op = asymmetric_key_eds_op, + .asym_verify_signature = asymmetric_key_verify_signature, }; EXPORT_SYMBOL_GPL(key_type_asymmetric); diff --git a/crypto/asymmetric_keys/signature.c b/crypto/asymmetric_keys/signature.c index 28198314bc39..ad95a58c6642 100644 --- a/crypto/asymmetric_keys/signature.c +++ b/crypto/asymmetric_keys/signature.c @@ -16,7 +16,9 @@ #include #include #include +#include #include +#include #include "asymmetric_keys.h" /* @@ -36,6 +38,99 @@ void public_key_signature_free(struct public_key_signature *sig) } EXPORT_SYMBOL_GPL(public_key_signature_free); +/** + * query_asymmetric_key - Get information about an aymmetric key. + * @params: Various parameters. + * @info: Where to put the information. + */ +int query_asymmetric_key(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + const struct asymmetric_key_subtype *subtype; + struct key *key = params->key; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (key->type != &key_type_asymmetric) + return -EINVAL; + subtype = asymmetric_key_subtype(key); + if (!subtype || + !key->payload.data[0]) + return -EINVAL; + if (!subtype->query) + return -ENOTSUPP; + + ret = subtype->query(params, info); + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(query_asymmetric_key); + +/** + * encrypt_blob - Encrypt data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be encrypted, length params->data_len + * @enc: Encrypted data buffer, length params->enc_len + * + * Encrypt the specified data blob using the private key specified by + * params->key. The encrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the encrypted data buffer or an + * error. + */ +int encrypt_blob(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_encrypt; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(encrypt_blob); + +/** + * decrypt_blob - Decrypt data using an asymmetric key + * @params: Various parameters + * @enc: Encrypted data to be decrypted, length params->enc_len + * @data: Decrypted data buffer, length params->data_len + * + * Decrypt the specified data blob using the private key specified by + * params->key. The decrypted data is wrapped in an encoding if + * params->encoding is specified (eg. "pkcs1"). + * + * Returns the length of the data placed in the decrypted data buffer or an + * error. + */ +int decrypt_blob(struct kernel_pkey_params *params, + const void *enc, void *data) +{ + params->op = kernel_pkey_decrypt; + return asymmetric_key_eds_op(params, enc, data); +} +EXPORT_SYMBOL_GPL(decrypt_blob); + +/** + * create_signature - Sign some data using an asymmetric key + * @params: Various parameters + * @data: Data blob to be signed, length params->data_len + * @enc: Signature buffer, length params->enc_len + * + * Sign the specified data blob using the private key specified by params->key. + * The signature is wrapped in an encoding if params->encoding is specified + * (eg. "pkcs1"). If the encoding needs to know the digest type, this can be + * passed through params->hash_algo (eg. "sha1"). + * + * Returns the length of the data placed in the signature buffer or an error. + */ +int create_signature(struct kernel_pkey_params *params, + const void *data, void *enc) +{ + params->op = kernel_pkey_sign; + return asymmetric_key_eds_op(params, data, enc); +} +EXPORT_SYMBOL_GPL(create_signature); + /** * verify_signature - Initiate the use of an asymmetric key to verify a signature * @key: The asymmetric key to verify against diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index e0b681a717ba..3a1047a0195c 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -14,6 +14,8 @@ #ifndef _LINUX_PUBLIC_KEY_H #define _LINUX_PUBLIC_KEY_H +#include + /* * Cryptographic data for the public-key subtype of the asymmetric key type. * @@ -40,6 +42,7 @@ struct public_key_signature { u8 digest_size; /* Number of bytes in digest */ const char *pkey_algo; const char *hash_algo; + const char *encoding; }; extern void public_key_signature_free(struct public_key_signature *sig); @@ -65,8 +68,14 @@ extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring, const union key_payload *payload, struct key *trusted); -extern int verify_signature(const struct key *key, - const struct public_key_signature *sig); +extern int query_asymmetric_key(const struct kernel_pkey_params *, + struct kernel_pkey_query *); + +extern int encrypt_blob(struct kernel_pkey_params *, const void *, void *); +extern int decrypt_blob(struct kernel_pkey_params *, const void *, void *); +extern int create_signature(struct kernel_pkey_params *, const void *, void *); +extern int verify_signature(const struct key *, + const struct public_key_signature *); int public_key_verify_signature(const struct public_key *pkey, const struct public_key_signature *sig); diff --git a/include/keys/asymmetric-subtype.h b/include/keys/asymmetric-subtype.h index e0a9c2368872..9ce2f0fae57e 100644 --- a/include/keys/asymmetric-subtype.h +++ b/include/keys/asymmetric-subtype.h @@ -17,6 +17,8 @@ #include #include +struct kernel_pkey_query; +struct kernel_pkey_params; struct public_key_signature; /* @@ -34,6 +36,13 @@ struct asymmetric_key_subtype { /* Destroy a key of this subtype */ void (*destroy)(void *payload_crypto, void *payload_auth); + int (*query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + + /* Encrypt/decrypt/sign data */ + int (*eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); + /* Verify the signature on a key of this subtype (optional) */ int (*verify_signature)(const struct key *key, const struct public_key_signature *sig); -- cgit v1.2.3 From 039884907787e55166e84e0b654a5342cc8a04ab Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:15 +0100 Subject: KEYS: Make the X.509 and PKCS7 parsers supply the sig encoding type [ver #2] Make the X.509 and PKCS7 parsers fill in the signature encoding type field recently added to the public_key_signature struct. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- crypto/asymmetric_keys/pkcs7_parser.c | 1 + crypto/asymmetric_keys/x509_cert_parser.c | 21 +++++++++------------ 2 files changed, 10 insertions(+), 12 deletions(-) diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c index 0f134162cef4..f0d56e1a8b7e 100644 --- a/crypto/asymmetric_keys/pkcs7_parser.c +++ b/crypto/asymmetric_keys/pkcs7_parser.c @@ -271,6 +271,7 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen, switch (ctx->last_oid) { case OID_rsaEncryption: ctx->sinfo->sig->pkey_algo = "rsa"; + ctx->sinfo->sig->encoding = "pkcs1"; break; default: printk("Unsupported pkey algo: %u\n", ctx->last_oid); diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index b6cabac4b62b..991f4d735a4e 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -199,35 +199,32 @@ int x509_note_pkey_algo(void *context, size_t hdrlen, case OID_md4WithRSAEncryption: ctx->cert->sig->hash_algo = "md4"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha1WithRSAEncryption: ctx->cert->sig->hash_algo = "sha1"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha256WithRSAEncryption: ctx->cert->sig->hash_algo = "sha256"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha384WithRSAEncryption: ctx->cert->sig->hash_algo = "sha384"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha512WithRSAEncryption: ctx->cert->sig->hash_algo = "sha512"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; case OID_sha224WithRSAEncryption: ctx->cert->sig->hash_algo = "sha224"; - ctx->cert->sig->pkey_algo = "rsa"; - break; + goto rsa_pkcs1; } +rsa_pkcs1: + ctx->cert->sig->pkey_algo = "rsa"; + ctx->cert->sig->encoding = "pkcs1"; ctx->algo_oid = ctx->last_oid; return 0; } -- cgit v1.2.3 From 82f94f24475c89c6d5cb673e1277b5b4394499c8 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:23 +0100 Subject: KEYS: Provide software public key query function [ver #2] Provide a query function for the software public key implementation. This permits information about such a key to be obtained using query_asymmetric_key() or KEYCTL_PKEY_QUERY. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- crypto/asymmetric_keys/public_key.c | 99 ++++++++++++++++++++++++++++++------- 1 file changed, 82 insertions(+), 17 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index e929fe1e4106..761bfab352dc 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -59,6 +59,81 @@ static void public_key_destroy(void *payload0, void *payload3) public_key_signature_free(payload3); } +/* + * Determine the crypto algorithm name. + */ +static +int software_key_determine_akcipher(const char *encoding, + const char *hash_algo, + const struct public_key *pkey, + char alg_name[CRYPTO_MAX_ALG_NAME]) +{ + int n; + + if (strcmp(encoding, "pkcs1") == 0) { + /* The data wangled by the RSA algorithm is typically padded + * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447 + * sec 8.2]. + */ + if (!hash_algo) + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, + "pkcs1pad(%s)", + pkey->pkey_algo); + else + n = snprintf(alg_name, CRYPTO_MAX_ALG_NAME, + "pkcs1pad(%s,%s)", + pkey->pkey_algo, hash_algo); + return n >= CRYPTO_MAX_ALG_NAME ? -EINVAL : 0; + } + + if (strcmp(encoding, "raw") == 0) { + strcpy(alg_name, pkey->pkey_algo); + return 0; + } + + return -ENOPKG; +} + +/* + * Query information about a key. + */ +static int software_key_query(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info) +{ + struct crypto_akcipher *tfm; + struct public_key *pkey = params->key->payload.data[asym_crypto]; + char alg_name[CRYPTO_MAX_ALG_NAME]; + int ret, len; + + ret = software_key_determine_akcipher(params->encoding, + params->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen); + if (ret < 0) + goto error_free_tfm; + + len = crypto_akcipher_maxsize(tfm); + info->key_size = len * 8; + info->max_data_size = len; + info->max_sig_size = len; + info->max_enc_size = len; + info->max_dec_size = len; + info->supported_ops = KEYCTL_SUPPORTS_VERIFY; + ret = 0; + +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + /* * Verify a signature using a public key. */ @@ -69,8 +144,7 @@ int public_key_verify_signature(const struct public_key *pkey, struct crypto_akcipher *tfm; struct akcipher_request *req; struct scatterlist sig_sg, digest_sg; - const char *alg_name; - char alg_name_buf[CRYPTO_MAX_ALG_NAME]; + char alg_name[CRYPTO_MAX_ALG_NAME]; void *output; unsigned int outlen; int ret; @@ -81,21 +155,11 @@ int public_key_verify_signature(const struct public_key *pkey, BUG_ON(!sig); BUG_ON(!sig->s); - if (!sig->digest) - return -ENOPKG; - - alg_name = sig->pkey_algo; - if (strcmp(sig->pkey_algo, "rsa") == 0) { - /* The data wangled by the RSA algorithm is typically padded - * and encoded in some manner, such as EMSA-PKCS1-1_5 [RFC3447 - * sec 8.2]. - */ - if (snprintf(alg_name_buf, CRYPTO_MAX_ALG_NAME, - "pkcs1pad(rsa,%s)", sig->hash_algo - ) >= CRYPTO_MAX_ALG_NAME) - return -EINVAL; - alg_name = alg_name_buf; - } + ret = software_key_determine_akcipher(sig->encoding, + sig->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; tfm = crypto_alloc_akcipher(alg_name, 0, 0); if (IS_ERR(tfm)) @@ -167,6 +231,7 @@ struct asymmetric_key_subtype public_key_subtype = { .name_len = sizeof("public_key") - 1, .describe = public_key_describe, .destroy = public_key_destroy, + .query = software_key_query, .verify_signature = public_key_verify_signature_2, }; EXPORT_SYMBOL_GPL(public_key_subtype); -- cgit v1.2.3 From f7c4e06e066c3df282e6e3d4e7d8c498be9e1e46 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:31 +0100 Subject: KEYS: Allow the public_key struct to hold a private key [ver #2] Put a flag in the public_key struct to indicate if the structure is holding a private key. The private key must be held ASN.1 encoded in the format specified in RFC 3447 A.1.2. This is the form required by crypto/rsa.c. The software encryption subtype's verification and query functions then need to select the appropriate crypto function to set the key. Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- crypto/asymmetric_keys/public_key.c | 14 ++++++++++++-- include/crypto/public_key.h | 1 + 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 761bfab352dc..f2dc27897319 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -115,7 +115,12 @@ static int software_key_query(const struct kernel_pkey_params *params, if (IS_ERR(tfm)) return PTR_ERR(tfm); - ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen); + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); if (ret < 0) goto error_free_tfm; @@ -170,7 +175,12 @@ int public_key_verify_signature(const struct public_key *pkey, if (!req) goto error_free_tfm; - ret = crypto_akcipher_set_pub_key(tfm, pkey->key, pkey->keylen); + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); if (ret) goto error_free_req; diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index 3a1047a0195c..be626eac9113 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -25,6 +25,7 @@ struct public_key { void *key; u32 keylen; + bool key_is_private; const char *id_type; const char *pkey_algo; }; -- cgit v1.2.3 From c08fed73712620eb0a19244dbbbbdf00edbe5e47 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:38 +0100 Subject: KEYS: Implement encrypt, decrypt and sign for software asymmetric key [ver #2] Implement the encrypt, decrypt and sign operations for the software asymmetric key subtype. This mostly involves offloading the call to the crypto layer. Note that the decrypt and sign operations require a private key to be supplied. Encrypt (and also verify) will work with either a public or a private key. A public key can be supplied with an X.509 certificate and a private key can be supplied using a PKCS#8 blob: # j=`openssl pkcs8 -in ~/pkcs7/firmwarekey2.priv -topk8 -nocrypt -outform DER | keyctl padd asymmetric foo @s` # keyctl pkey_query $j - enc=pkcs1 key_size=4096 max_data_size=512 max_sig_size=512 max_enc_size=512 max_dec_size=512 encrypt=y decrypt=y sign=y verify=y # keyctl pkey_encrypt $j 0 data enc=pkcs1 >/tmp/enc # keyctl pkey_decrypt $j 0 /tmp/enc enc=pkcs1 >/tmp/dec # cmp data /tmp/dec # keyctl pkey_sign $j 0 data enc=pkcs1 hash=sha1 >/tmp/sig # keyctl pkey_verify $j 0 data /tmp/sig enc=pkcs1 hash=sha1 # Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- crypto/asymmetric_keys/public_key.c | 82 ++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index f2dc27897319..f5d85b47fcc6 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -130,7 +130,11 @@ static int software_key_query(const struct kernel_pkey_params *params, info->max_sig_size = len; info->max_enc_size = len; info->max_dec_size = len; - info->supported_ops = KEYCTL_SUPPORTS_VERIFY; + info->supported_ops = (KEYCTL_SUPPORTS_ENCRYPT | + KEYCTL_SUPPORTS_VERIFY); + if (pkey->key_is_private) + info->supported_ops |= (KEYCTL_SUPPORTS_DECRYPT | + KEYCTL_SUPPORTS_SIGN); ret = 0; error_free_tfm: @@ -139,6 +143,81 @@ error_free_tfm: return ret; } +/* + * Do encryption, decryption and signing ops. + */ +static int software_key_eds_op(struct kernel_pkey_params *params, + const void *in, void *out) +{ + const struct public_key *pkey = params->key->payload.data[asym_crypto]; + struct akcipher_request *req; + struct crypto_akcipher *tfm; + struct crypto_wait cwait; + struct scatterlist in_sg, out_sg; + char alg_name[CRYPTO_MAX_ALG_NAME]; + int ret; + + pr_devel("==>%s()\n", __func__); + + ret = software_key_determine_akcipher(params->encoding, + params->hash_algo, + pkey, alg_name); + if (ret < 0) + return ret; + + tfm = crypto_alloc_akcipher(alg_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + req = akcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) + goto error_free_tfm; + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, + pkey->key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, + pkey->key, pkey->keylen); + if (ret) + goto error_free_req; + + sg_init_one(&in_sg, in, params->in_len); + sg_init_one(&out_sg, out, params->out_len); + akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len, + params->out_len); + crypto_init_wait(&cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &cwait); + + /* Perform the encryption calculation. */ + switch (params->op) { + case kernel_pkey_encrypt: + ret = crypto_akcipher_encrypt(req); + break; + case kernel_pkey_decrypt: + ret = crypto_akcipher_decrypt(req); + break; + case kernel_pkey_sign: + ret = crypto_akcipher_sign(req); + break; + default: + BUG(); + } + + ret = crypto_wait_req(ret, &cwait); + if (ret == 0) + ret = req->dst_len; + +error_free_req: + akcipher_request_free(req); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} + /* * Verify a signature using a public key. */ @@ -242,6 +321,7 @@ struct asymmetric_key_subtype public_key_subtype = { .describe = public_key_describe, .destroy = public_key_destroy, .query = software_key_query, + .eds_op = software_key_eds_op, .verify_signature = public_key_verify_signature_2, }; EXPORT_SYMBOL_GPL(public_key_subtype); -- cgit v1.2.3 From 3c58b2362ba828ee2970c66c6a6fd7b04fde4413 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 9 Oct 2018 17:47:46 +0100 Subject: KEYS: Implement PKCS#8 RSA Private Key parser [ver #2] Implement PKCS#8 RSA Private Key format [RFC 5208] parser for the asymmetric key type. For the moment, this will only support unencrypted DER blobs. PEM and decryption can be added later. PKCS#8 keys can be loaded like this: openssl pkcs8 -in private_key.pem -topk8 -nocrypt -outform DER | \ keyctl padd asymmetric foo @s Signed-off-by: David Howells Tested-by: Marcel Holtmann Reviewed-by: Marcel Holtmann Reviewed-by: Denis Kenzior Tested-by: Denis Kenzior Signed-off-by: James Morris --- Documentation/crypto/asymmetric-keys.txt | 2 + crypto/asymmetric_keys/Kconfig | 10 ++ crypto/asymmetric_keys/Makefile | 13 +++ crypto/asymmetric_keys/pkcs8.asn1 | 24 ++++ crypto/asymmetric_keys/pkcs8_parser.c | 184 +++++++++++++++++++++++++++++++ 5 files changed, 233 insertions(+) create mode 100644 crypto/asymmetric_keys/pkcs8.asn1 create mode 100644 crypto/asymmetric_keys/pkcs8_parser.c diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt index deb656ef008b..8763866b11cf 100644 --- a/Documentation/crypto/asymmetric-keys.txt +++ b/Documentation/crypto/asymmetric-keys.txt @@ -248,6 +248,8 @@ Examples of blob formats for which parsers could be implemented include: - X.509 ASN.1 stream. - Pointer to TPM key. - Pointer to UEFI key. + - PKCS#8 private key [RFC 5208]. + - PKCS#5 encrypted private key [RFC 2898]. During key instantiation each parser in the list is tried until one doesn't return -EBADMSG. diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig index f3702e533ff4..66a7dad7ed3d 100644 --- a/crypto/asymmetric_keys/Kconfig +++ b/crypto/asymmetric_keys/Kconfig @@ -31,6 +31,16 @@ 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_PARSER + tristate "PKCS#8 private key parser" + depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE + select ASN1 + select OID_REGISTRY + help + This option provides support for parsing PKCS#8 format blobs for + private key data and provides the ability to instantiate a crypto key + from that data. + config PKCS7_MESSAGE_PARSER tristate "PKCS#7 message parser" depends on X509_CERTIFICATE_PARSER diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile index d4b2e1b2dc65..c38424f55b08 100644 --- a/crypto/asymmetric_keys/Makefile +++ b/crypto/asymmetric_keys/Makefile @@ -29,6 +29,19 @@ $(obj)/x509_cert_parser.o: \ $(obj)/x509.asn1.o: $(obj)/x509.asn1.c $(obj)/x509.asn1.h $(obj)/x509_akid.asn1.o: $(obj)/x509_akid.asn1.c $(obj)/x509_akid.asn1.h +# +# PKCS#8 private key handling +# +obj-$(CONFIG_PKCS8_PRIVATE_KEY_PARSER) += pkcs8_key_parser.o +pkcs8_key_parser-y := \ + pkcs8.asn1.o \ + pkcs8_parser.o + +$(obj)/pkcs8_parser.o: $(obj)/pkcs8.asn1.h +$(obj)/pkcs8-asn1.o: $(obj)/pkcs8.asn1.c $(obj)/pkcs8.asn1.h + +clean-files += pkcs8.asn1.c pkcs8.asn1.h + # # PKCS#7 message handling # diff --git a/crypto/asymmetric_keys/pkcs8.asn1 b/crypto/asymmetric_keys/pkcs8.asn1 new file mode 100644 index 000000000000..702c41a3c713 --- /dev/null +++ b/crypto/asymmetric_keys/pkcs8.asn1 @@ -0,0 +1,24 @@ +-- +-- This is the unencrypted variant +-- +PrivateKeyInfo ::= SEQUENCE { + version Version, + privateKeyAlgorithm PrivateKeyAlgorithmIdentifier, + privateKey PrivateKey, + attributes [0] IMPLICIT Attributes OPTIONAL +} + +Version ::= INTEGER ({ pkcs8_note_version }) + +PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier ({ pkcs8_note_algo }) + +PrivateKey ::= OCTET STRING ({ pkcs8_note_key }) + +Attributes ::= SET OF Attribute + +Attribute ::= ANY + +AlgorithmIdentifier ::= SEQUENCE { + algorithm OBJECT IDENTIFIER ({ pkcs8_note_OID }), + parameters ANY OPTIONAL +} diff --git a/crypto/asymmetric_keys/pkcs8_parser.c b/crypto/asymmetric_keys/pkcs8_parser.c new file mode 100644 index 000000000000..5f6a7ecc9765 --- /dev/null +++ b/crypto/asymmetric_keys/pkcs8_parser.c @@ -0,0 +1,184 @@ +/* PKCS#8 Private Key parser [RFC 5208]. + * + * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include "pkcs8.asn1.h" + +struct pkcs8_parse_context { + struct public_key *pub; + unsigned long data; /* Start of data */ + enum OID last_oid; /* Last OID encountered */ + enum OID algo_oid; /* Algorithm OID */ + u32 key_size; + const void *key; +}; + +/* + * 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->last_oid = look_up_OID(value, vlen); + if (ctx->last_oid == OID__NR) { + char buffer[50]; + + sprint_oid(value, vlen, buffer, sizeof(buffer)); + pr_info("Unknown OID: [%lu] %s\n", + (unsigned long)value - ctx->data, buffer); + } + return 0; +} + +/* + * Note the version number of the ASN.1 blob. + */ +int pkcs8_note_version(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + if (vlen != 1 || ((const u8 *)value)[0] != 0) { + pr_warn("Unsupported PKCS#8 version\n"); + return -EBADMSG; + } + return 0; +} + +/* + * Note the public algorithm. + */ +int pkcs8_note_algo(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct pkcs8_parse_context *ctx = context; + + if (ctx->last_oid != OID_rsaEncryption) + return -ENOPKG; + + ctx->pub->pkey_algo = "rsa"; + return 0; +} + +/* + * Note the key data of the ASN.1 blob. + */ +int pkcs8_note_key(void *context, size_t hdrlen, + unsigned char tag, + const void *value, size_t vlen) +{ + struct pkcs8_parse_context *ctx = context; + + ctx->key = value; + ctx->key_size = vlen; + return 0; +} + +/* + * Parse a PKCS#8 private key blob. + */ +static struct public_key *pkcs8_parse(const void *data, size_t datalen) +{ + struct pkcs8_parse_context ctx; + struct public_key *pub; + long ret; + + memset(&ctx, 0, sizeof(ctx)); + + ret = -ENOMEM; + ctx.pub = kzalloc(sizeof(struct public_key), GFP_KERNEL); + if (!ctx.pub) + goto error; + + ctx.data = (unsigned long)data; + + /* Attempt to decode the private key */ + ret = asn1_ber_decoder(&pkcs8_decoder, &ctx, data, datalen); + if (ret < 0) + goto error_decode; + + ret = -ENOMEM; + pub = ctx.pub; + pub->key = kmemdup(ctx.key, ctx.key_size, GFP_KERNEL); + if (!pub->key) + goto error_decode; + + pub->keylen = ctx.key_size; + pub->key_is_private = true; + return pub; + +error_decode: + kfree(ctx.pub); +error: + return ERR_PTR(ret); +} + +/* + * Attempt to parse a data blob for a key as a