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 = DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), 25 BITS_PER_BYTE); 26 unsigned int ndigits = DIV_ROUND_UP_POW2(keylen, sizeof(u64)); 27 struct ecdsa_raw_sig sig; 28 29 if (slen != 2 * keylen) 30 return -EINVAL; 31 32 ecc_digits_from_bytes(src, keylen, sig.r, ndigits); 33 ecc_digits_from_bytes(src + keylen, keylen, sig.s, ndigits); 34 35 return crypto_sig_verify(ctx->child, &sig, sizeof(sig), digest, dlen); 36 } 37 38 static unsigned int ecdsa_p1363_key_size(struct crypto_sig *tfm) 39 { 40 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 41 42 return crypto_sig_keysize(ctx->child); 43 } 44 45 static unsigned int ecdsa_p1363_max_size(struct crypto_sig *tfm) 46 { 47 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 48 49 return 2 * DIV_ROUND_UP_POW2(crypto_sig_keysize(ctx->child), 50 BITS_PER_BYTE); 51 } 52 53 static unsigned int ecdsa_p1363_digest_size(struct crypto_sig *tfm) 54 { 55 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 56 57 return crypto_sig_digestsize(ctx->child); 58 } 59 60 static int ecdsa_p1363_set_pub_key(struct crypto_sig *tfm, 61 const void *key, unsigned int keylen) 62 { 63 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 64 65 return crypto_sig_set_pubkey(ctx->child, key, keylen); 66 } 67 68 static int ecdsa_p1363_init_tfm(struct crypto_sig *tfm) 69 { 70 struct sig_instance *inst = sig_alg_instance(tfm); 71 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst); 72 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 73 struct crypto_sig *child_tfm; 74 75 child_tfm = crypto_spawn_sig(spawn); 76 if (IS_ERR(child_tfm)) 77 return PTR_ERR(child_tfm); 78 79 ctx->child = child_tfm; 80 81 return 0; 82 } 83 84 static void ecdsa_p1363_exit_tfm(struct crypto_sig *tfm) 85 { 86 struct ecdsa_p1363_ctx *ctx = crypto_sig_ctx(tfm); 87 88 crypto_free_sig(ctx->child); 89 } 90 91 static void ecdsa_p1363_free(struct sig_instance *inst) 92 { 93 struct crypto_sig_spawn *spawn = sig_instance_ctx(inst); 94 95 crypto_drop_sig(spawn); 96 kfree(inst); 97 } 98 99 static int ecdsa_p1363_create(struct crypto_template *tmpl, struct rtattr **tb) 100 { 101 struct crypto_sig_spawn *spawn; 102 struct sig_instance *inst; 103 struct sig_alg *ecdsa_alg; 104 u32 mask; 105 int err; 106 107 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SIG, &mask); 108 if (err) 109 return err; 110 111 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 112 if (!inst) 113 return -ENOMEM; 114 115 spawn = sig_instance_ctx(inst); 116 117 err = crypto_grab_sig(spawn, sig_crypto_instance(inst), 118 crypto_attr_alg_name(tb[1]), 0, mask); 119 if (err) 120 goto err_free_inst; 121 122 ecdsa_alg = crypto_spawn_sig_alg(spawn); 123 124 err = -EINVAL; 125 if (strncmp(ecdsa_alg->base.cra_name, "ecdsa", 5) != 0) 126 goto err_free_inst; 127 128 err = crypto_inst_setname(sig_crypto_instance(inst), tmpl->name, 129 &ecdsa_alg->base); 130 if (err) 131 goto err_free_inst; 132 133 inst->alg.base.cra_priority = ecdsa_alg->base.cra_priority; 134 inst->alg.base.cra_ctxsize = sizeof(struct ecdsa_p1363_ctx); 135 136 inst->alg.init = ecdsa_p1363_init_tfm; 137 inst->alg.exit = ecdsa_p1363_exit_tfm; 138 139 inst->alg.verify = ecdsa_p1363_verify; 140 inst->alg.key_size = ecdsa_p1363_key_size; 141 inst->alg.max_size = ecdsa_p1363_max_size; 142 inst->alg.digest_size = ecdsa_p1363_digest_size; 143 inst->alg.set_pub_key = ecdsa_p1363_set_pub_key; 144 145 inst->free = ecdsa_p1363_free; 146 147 err = sig_register_instance(tmpl, inst); 148 if (err) { 149 err_free_inst: 150 ecdsa_p1363_free(inst); 151 } 152 return err; 153 } 154 155 struct crypto_template ecdsa_p1363_tmpl = { 156 .name = "p1363", 157 .create = ecdsa_p1363_create, 158 .module = THIS_MODULE, 159 }; 160 161 MODULE_ALIAS_CRYPTO("p1363"); 162