diff options
Diffstat (limited to 'kernel/crypto/rsa_helper.c')
| -rw-r--r-- | kernel/crypto/rsa_helper.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/kernel/crypto/rsa_helper.c b/kernel/crypto/rsa_helper.c new file mode 100644 index 000000000..d226f48d0 --- /dev/null +++ b/kernel/crypto/rsa_helper.c @@ -0,0 +1,149 @@ +/* + * RSA key extract helper + * + * Copyright (c) 2015, Intel Corporation + * Authors: Tadeusz Struk <tadeusz.struk@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/kernel.h> +#include <linux/export.h> +#include <linux/err.h> +#include <linux/fips.h> +#include <crypto/internal/rsa.h> +#include "rsapubkey-asn1.h" +#include "rsaprivkey-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; + + key->n = mpi_read_raw_data(value, vlen); + + if (!key->n) + return -ENOMEM; + + /* In FIPS mode only allow key size 2K & 3K */ + if (fips_enabled && (mpi_get_size(key->n) != 256 && + mpi_get_size(key->n) != 384)) { + pr_err("RSA: key size not allowed in FIPS mode\n"); + mpi_free(key->n); + key->n = NULL; + return -EINVAL; + } + 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; + + key->e = mpi_read_raw_data(value, vlen); + + if (!key->e) + return -ENOMEM; + + 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; + + key->d = mpi_read_raw_data(value, vlen); + + if (!key->d) + return -ENOMEM; + + /* In FIPS mode only allow key size 2K & 3K */ + if (fips_enabled && (mpi_get_size(key->d) != 256 && + mpi_get_size(key->d) != 384)) { + pr_err("RSA: key size not allowed in FIPS mode\n"); + mpi_free(key->d); + key->d = NULL; + return -EINVAL; + } + return 0; +} + +static void free_mpis(struct rsa_key *key) +{ + mpi_free(key->n); + mpi_free(key->e); + mpi_free(key->d); + key->n = NULL; + key->e = NULL; + key->d = NULL; +} + +/** + * rsa_free_key() - frees rsa key allocated by rsa_parse_key() + * + * @rsa_key: struct rsa_key key representation + */ +void rsa_free_key(struct rsa_key *key) +{ + free_mpis(key); +} +EXPORT_SYMBOL_GPL(rsa_free_key); + +/** + * rsa_parse_pub_key() - extracts an rsa public key from BER encoded buffer + * and stores it in the provided struct rsa_key + * + * @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) +{ + int ret; + + free_mpis(rsa_key); + ret = asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len); + if (ret < 0) + goto error; + + return 0; +error: + free_mpis(rsa_key); + return ret; +} +EXPORT_SYMBOL_GPL(rsa_parse_pub_key); + +/** + * rsa_parse_pub_key() - extracts an rsa private key from BER encoded buffer + * and stores it in the provided struct rsa_key + * + * @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) +{ + int ret; + + free_mpis(rsa_key); + ret = asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len); + if (ret < 0) + goto error; + + return 0; +error: + free_mpis(rsa_key); + return ret; +} +EXPORT_SYMBOL_GPL(rsa_parse_priv_key); |