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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/lib/crypto/public_key.c | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/lib/crypto/public_key.c')
-rw-r--r-- | roms/u-boot/lib/crypto/public_key.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/roms/u-boot/lib/crypto/public_key.c b/roms/u-boot/lib/crypto/public_key.c new file mode 100644 index 000000000..df6033cdb --- /dev/null +++ b/roms/u-boot/lib/crypto/public_key.c @@ -0,0 +1,443 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* In-software asymmetric public-key crypto subtype + * + * See Documentation/crypto/asymmetric-keys.txt + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) "PKEY: "fmt +#ifdef __UBOOT__ +#include <dm/devres.h> +#include <linux/bug.h> +#include <linux/compat.h> +#include <linux/err.h> +#else +#include <linux/module.h> +#include <linux/export.h> +#endif +#include <linux/kernel.h> +#ifndef __UBOOT__ +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/scatterlist.h> +#include <keys/asymmetric-subtype.h> +#endif +#include <crypto/public_key.h> +#ifdef __UBOOT__ +#include <image.h> +#include <u-boot/rsa.h> +#else +#include <crypto/akcipher.h> +#endif + +MODULE_DESCRIPTION("In-software asymmetric public-key subtype"); +MODULE_AUTHOR("Red Hat, Inc."); +MODULE_LICENSE("GPL"); + +#ifndef __UBOOT__ +/* + * Provide a part of a description of the key for /proc/keys. + */ +static void public_key_describe(const struct key *asymmetric_key, + struct seq_file *m) +{ + struct public_key *key = asymmetric_key->payload.data[asym_crypto]; + + if (key) + seq_printf(m, "%s.%s", key->id_type, key->pkey_algo); +} +#endif + +/* + * Destroy a public key algorithm key. + */ +void public_key_free(struct public_key *key) +{ + if (key) { + kfree(key->key); + kfree(key->params); + kfree(key); + } +} +EXPORT_SYMBOL_GPL(public_key_free); + +#ifdef __UBOOT__ +/* + * from <linux>/crypto/asymmetric_keys/signature.c + * + * Destroy a public key signature. + */ +void public_key_signature_free(struct public_key_signature *sig) +{ + int i; + + if (sig) { + for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++) + free(sig->auth_ids[i]); + free(sig->s); + free(sig->digest); + free(sig); + } +} +EXPORT_SYMBOL_GPL(public_key_signature_free); + +/** + * public_key_verify_signature - Verify a signature using a public key. + * + * @pkey: Public key + * @sig: Signature + * + * Verify a signature, @sig, using a RSA public key, @pkey. + * + * Return: 0 - verified, non-zero error code - otherwise + */ +int public_key_verify_signature(const struct public_key *pkey, + const struct public_key_signature *sig) +{ + struct image_sign_info info; + int ret; + + pr_devel("==>%s()\n", __func__); + + if (!pkey || !sig) + return -EINVAL; + + if (pkey->key_is_private) + return -EINVAL; + + memset(&info, '\0', sizeof(info)); + info.padding = image_get_padding_algo("pkcs-1.5"); + /* + * Note: image_get_[checksum|crypto]_algo takes a string + * argument like "<checksum>,<crypto>" + * TODO: support other hash algorithms + */ + if (strcmp(sig->pkey_algo, "rsa") || (sig->s_size * 8) != 2048) { + pr_warn("Encryption is not RSA2048: %s%d\n", + sig->pkey_algo, sig->s_size * 8); + return -ENOPKG; + } + if (!strcmp(sig->hash_algo, "sha1")) { + info.checksum = image_get_checksum_algo("sha1,rsa2048"); + info.name = "sha1,rsa2048"; + } else if (!strcmp(sig->hash_algo, "sha256")) { + info.checksum = image_get_checksum_algo("sha256,rsa2048"); + info.name = "sha256,rsa2048"; + } else { + pr_warn("unknown msg digest algo: %s\n", sig->hash_algo); + return -ENOPKG; + } + info.crypto = image_get_crypto_algo(info.name); + if (IS_ERR(info.checksum) || IS_ERR(info.crypto)) + return -ENOPKG; + + info.key = pkey->key; + info.keylen = pkey->keylen; + + if (rsa_verify_with_pkey(&info, sig->digest, sig->s, sig->s_size)) + ret = -EKEYREJECTED; + else + ret = 0; + + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +#else +/* + * Destroy a public key algorithm key. + */ +static void public_key_destroy(void *payload0, void *payload3) +{ + public_key_free(payload0); + 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; +} + +static u8 *pkey_pack_u32(u8 *dst, u32 val) +{ + memcpy(dst, &val, sizeof(val)); + return dst + sizeof(val); +} + +/* + * 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]; + u8 *key, *ptr; + 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); + + key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, + GFP_KERNEL); + if (!key) + goto error_free_tfm; + memcpy(key, pkey->key, pkey->keylen); + ptr = key + pkey->keylen; + ptr = pkey_pack_u32(ptr, pkey->algo); + ptr = pkey_pack_u32(ptr, pkey->paramlen); + memcpy(ptr, pkey->params, pkey->paramlen); + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); + if (ret < 0) + goto error_free_key; + + 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_ENCRYPT | + KEYCTL_SUPPORTS_VERIFY); + if (pkey->key_is_private) + info->supported_ops |= (KEYCTL_SUPPORTS_DECRYPT | + KEYCTL_SUPPORTS_SIGN); + ret = 0; + +error_free_key: + kfree(key); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + 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]; + char *key, *ptr; + 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; + + key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, + GFP_KERNEL); + if (!key) + goto error_free_req; + + memcpy(key, pkey->key, pkey->keylen); + ptr = key + pkey->keylen; + ptr = pkey_pack_u32(ptr, pkey->algo); + ptr = pkey_pack_u32(ptr, pkey->paramlen); + memcpy(ptr, pkey->params, pkey->paramlen); + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); + if (ret) + goto error_free_key; + + 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_key: + kfree(key); +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. + */ +int public_key_verify_signature(const struct public_key *pkey, + const struct public_key_signature *sig) +{ + struct crypto_wait cwait; + struct crypto_akcipher *tfm; + struct akcipher_request *req; + struct scatterlist src_sg[2]; + char alg_name[CRYPTO_MAX_ALG_NAME]; + char *key, *ptr; + int ret; + + pr_devel("==>%s()\n", __func__); + + BUG_ON(!pkey); + BUG_ON(!sig); + BUG_ON(!sig->s); + + 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)) + return PTR_ERR(tfm); + + ret = -ENOMEM; + req = akcipher_request_alloc(tfm, GFP_KERNEL); + if (!req) + goto error_free_tfm; + + key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen, + GFP_KERNEL); + if (!key) + goto error_free_req; + + memcpy(key, pkey->key, pkey->keylen); + ptr = key + pkey->keylen; + ptr = pkey_pack_u32(ptr, pkey->algo); + ptr = pkey_pack_u32(ptr, pkey->paramlen); + memcpy(ptr, pkey->params, pkey->paramlen); + + if (pkey->key_is_private) + ret = crypto_akcipher_set_priv_key(tfm, key, pkey->keylen); + else + ret = crypto_akcipher_set_pub_key(tfm, key, pkey->keylen); + if (ret) + goto error_free_key; + + sg_init_table(src_sg, 2); + sg_set_buf(&src_sg[0], sig->s, sig->s_size); + sg_set_buf(&src_sg[1], sig->digest, sig->digest_size); + akcipher_request_set_crypt(req, src_sg, NULL, sig->s_size, + sig->digest_size); + crypto_init_wait(&cwait); + akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + crypto_req_done, &cwait); + ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait); + +error_free_key: + kfree(key); +error_free_req: + akcipher_request_free(req); +error_free_tfm: + crypto_free_akcipher(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + if (WARN_ON_ONCE(ret > 0)) + ret = -EINVAL; + return ret; +} +EXPORT_SYMBOL_GPL(public_key_verify_signature); + +static int public_key_verify_signature_2(const struct key *key, + const struct public_key_signature *sig) +{ + const struct public_key *pk = key->payload.data[asym_crypto]; + return public_key_verify_signature(pk, sig); +} + +/* + * Public key algorithm asymmetric key subtype + */ +struct asymmetric_key_subtype public_key_subtype = { + .owner = THIS_MODULE, + .name = "public_key", + .name_len = sizeof("public_key") - 1, + .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); +#endif /* !__UBOOT__ */ |