1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ECDSA P1363 signature encoding 4 * 5 * Copyright (c) 2024 Intel Corporation 6 */ 7 8 #include <linux/err.h> 9 #include <linux/module.h> 10 #include <crypto/algapi.h> 11 #include <crypto/sig.h> 12 #include <crypto/internal/ecc.h> 13 #include <crypto/internal/sig.h> 14 15 struct ecdsa_p1363_ctx { 16 struct crypto_sig *child; 17 }; 18 19 static int ecdsa_p1363_verify(struct crypto_sig *tfm, 20 const void *src, unsigned int slen, 21 const void *digest, unsigned int dlen) 22 { 23 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 24 unsigned int keylen = crypto_sig_keysize(ctx->child); 25 unsigned int ndigits = DIV_ROUND_UP(keylen, sizeof(u64)); 26 struct ecdsa_raw_sig sig; 27 28 if (slen != 2 * keylen) 29 return -EINVAL; 30 31 ecc_digits_from_bytes(src, keylen, sig.r, ndigits); 32 ecc_digits_from_bytes(src + keylen, keylen, sig.s, ndigits); 33 34 return crypto_sig_verify(ctx->child, &sig, sizeof(sig), digest, dlen); 35 } 36 37 static unsigned int ecdsa_p1363_key_size(struct crypto_sig *tfm) 38 { 39 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 40 41 return crypto_sig_keysize(ctx->child); 42 } 43 44 static unsigned int ecdsa_p1363_max_size(struct crypto_sig *tfm) 45 { 46 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 47 48 return 2 * crypto_sig_keysize(ctx->child); 49 } 50 51 static unsigned int ecdsa_p1363_digest_size(struct crypto_sig *tfm) 52 { 53 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 54 55 return crypto_sig_digestsize(ctx->child); 56 } 57 58 static int ecdsa_p1363_set_pub_key(struct crypto_sig *tfm, 59 const void *key, unsigned int keylen) 60 { 61 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 62 63 return crypto_sig_set_pubkey(ctx->child, key, keylen); 64 } 65 66 static int ecdsa_p1363_init_tfm(struct crypto_sig *tfm) 67 { 68 struct sig_instance *inst = sig_alg_instance(tfm); 69 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst); 70 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 71 struct crypto_sig *child_tfm; 72 73 child_tfm = crypto_spawn_sig(spawn); 74 if (IS_ERR(child_tfm)) 75 return PTR_ERR(child_tfm); 76 77 ctx->child = child_tfm; 78 79 return 0; 80 } 81 82 static void ecdsa_p1363_exit_tfm(struct crypto_sig *tfm) 83 { 84 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 85 86 crypto_free_sig(ctx->child); 87 } 88 89 static void ecdsa_p1363_free(struct sig_instance *inst) 90 { 91 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst); 92 93 crypto_drop_sig(spawn); 94 kfree(inst); 95 } 96 97 static int ecdsa_p1363_create(struct crypto_template *tmpl, struct rtattr **tb) 98 { 99 struct crypto_sig_spawn *spawn; 100 struct sig_instance *inst; 101 struct sig_alg *ecdsa_alg; 102 u32 mask; 103 int err; 104 105 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SIG, &mask); 106 if (err) 107 return err; 108 109 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 110 if (!inst) 111 return -ENOMEM; 112 113 spawn = sig_instance_ctx(inst); 114 115 err = crypto_grab_sig(spawn, sig_crypto_instance(inst), 116 crypto_attr_alg_name(tb[1]), 0, mask); 117 if (err) 118 goto err_free_inst; 119 120 ecdsa_alg = crypto_spawn_sig_alg(spawn); 121 122 err = -EINVAL; 123 if (strncmp(ecdsa_alg->base.cra_name, "ecdsa", 5) != 0) 124 goto err_free_inst; 125 126 err = crypto_inst_setname(sig_crypto_instance(inst), tmpl->name, 127 &ecdsa_alg->base); 128 if (err) 129 goto err_free_inst; 130 131 inst->alg.base.cra_priority = ecdsa_alg->base.cra_priority; 132 inst->alg.base.cra_ctxsize = sizeof(struct ecdsa_p1363_ctx); 133 134 inst->alg.init = ecdsa_p1363_init_tfm; 135 inst->alg.exit = ecdsa_p1363_exit_tfm; 136 137 inst->alg.verify = ecdsa_p1363_verify; 138 inst->alg.key_size = ecdsa_p1363_key_size; 139 inst->alg.max_size = ecdsa_p1363_max_size; 140 inst->alg.digest_size = ecdsa_p1363_digest_size; 141 inst->alg.set_pub_key = ecdsa_p1363_set_pub_key; 142 143 inst->free = ecdsa_p1363_free; 144 145 err = sig_register_instance(tmpl, inst); 146 if (err) { 147 err_free_inst: 148 ecdsa_p1363_free(inst); 149 } 150 return err; 151 } 152 153 struct crypto_template ecdsa_p1363_tmpl = { 154 .name = "p1363", 155 .create = ecdsa_p1363_create, 156 .module = THIS_MODULE, 157 }; 158 159 MODULE_ALIAS_CRYPTO("p1363"); 160