crypto/poly1305/poly1305_pmeth.c

   1 /*
   2  * Copyright 2007-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/x509.h>
  13 #include <openssl/x509v3.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/err.h>
  16 #include "internal/poly1305.h"
  17 #include "poly1305_local.h"
  18 #include "internal/evp_int.h"
  19
  20 /* POLY1305 pkey context structure */
  21
  22 typedef struct {
  23     ASN1_OCTET_STRING ktmp;     /* Temp storage for key */
  24     POLY1305 ctx;
  25 } POLY1305_PKEY_CTX;
  26
  27 static int pkey_poly1305_init(EVP_PKEY_CTX *ctx)
  28 {
  29     POLY1305_PKEY_CTX *pctx;
  30
  31     if ((pctx = OPENSSL_zalloc(sizeof(*pctx))) == NULL) {
  32         CRYPTOerr(CRYPTO_F_PKEY_POLY1305_INIT, ERR_R_MALLOC_FAILURE);
  33         return 0;
  34     }
  35     pctx->ktmp.type = V_ASN1_OCTET_STRING;
  36
  37     EVP_PKEY_CTX_set_data(ctx, pctx);
  38     EVP_PKEY_CTX_set0_keygen_info(ctx, NULL, 0);
  39     return 1;
  40 }
  41
  42 static void pkey_poly1305_cleanup(EVP_PKEY_CTX *ctx)
  43 {
  44     POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);
  45
  46     if (pctx != NULL) {
  47         OPENSSL_clear_free(pctx->ktmp.data, pctx->ktmp.length);
  48         OPENSSL_clear_free(pctx, sizeof(*pctx));
  49         EVP_PKEY_CTX_set_data(ctx, NULL);
  50     }
  51 }
  52
  53 static int pkey_poly1305_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
  54 {
  55     POLY1305_PKEY_CTX *sctx, *dctx;
  56
  57     /* allocate memory for dst->data and a new POLY1305_CTX in dst->data->ctx */
  58     if (!pkey_poly1305_init(dst))
  59         return 0;
  60     sctx = EVP_PKEY_CTX_get_data(src);
  61     dctx = EVP_PKEY_CTX_get_data(dst);
  62     if (ASN1_STRING_get0_data(&sctx->ktmp) != NULL &&
  63         !ASN1_STRING_copy(&dctx->ktmp, &sctx->ktmp)) {
  64         /* cleanup and free the POLY1305_PKEY_CTX in dst->data */
  65         pkey_poly1305_cleanup(dst);
  66         return 0;
  67     }
  68     memcpy(&dctx->ctx, &sctx->ctx, sizeof(POLY1305));
  69     return 1;
  70 }
  71
  72 static int pkey_poly1305_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
  73 {
  74     ASN1_OCTET_STRING *key;
  75     POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);
  76
  77     if (ASN1_STRING_get0_data(&pctx->ktmp) == NULL)
  78         return 0;
  79     key = ASN1_OCTET_STRING_dup(&pctx->ktmp);
  80     if (key == NULL)
  81         return 0;
  82     return EVP_PKEY_assign_POLY1305(pkey, key);
  83 }
  84
  85 static int int_update(EVP_MD_CTX *ctx, const void *data, size_t count)
  86 {
  87     POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(EVP_MD_CTX_pkey_ctx(ctx));
  88
  89     Poly1305_Update(&pctx->ctx, data, count);
  90     return 1;
  91 }
  92
  93 static int poly1305_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
  94 {
  95     POLY1305_PKEY_CTX *pctx = ctx->data;
  96     ASN1_OCTET_STRING *key = (ASN1_OCTET_STRING *)ctx->pkey->pkey.ptr;
  97
  98     if (key->length != POLY1305_KEY_SIZE)
  99         return 0;
 100     EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);
 101     EVP_MD_CTX_set_update_fn(mctx, int_update);
 102     Poly1305_Init(&pctx->ctx, key->data);
 103     return 1;
 104 }
 105 static int poly1305_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
 106                             EVP_MD_CTX *mctx)
 107 {
 108     POLY1305_PKEY_CTX *pctx = ctx->data;
 109
 110     *siglen = POLY1305_DIGEST_SIZE;
 111     if (sig != NULL)
 112         Poly1305_Final(&pctx->ctx, sig);
 113     return 1;
 114 }
 115
 116 static int pkey_poly1305_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
 117 {
 118     POLY1305_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);
 119     const unsigned char *key;
 120     size_t len;
 121
 122     switch (type) {
 123
 124     case EVP_PKEY_CTRL_MD:
 125         /* ignore */
 126         break;
 127
 128     case EVP_PKEY_CTRL_SET_MAC_KEY:
 129     case EVP_PKEY_CTRL_DIGESTINIT:
 130         if (type == EVP_PKEY_CTRL_SET_MAC_KEY) {
 131             /* user explicitly setting the key */
 132             key = p2;
 133             len = p1;
 134         } else {
 135             /* user indirectly setting the key via EVP_DigestSignInit */
 136             key = EVP_PKEY_get0_poly1305(EVP_PKEY_CTX_get0_pkey(ctx), &len);
 137         }
 138         if (key == NULL || len != POLY1305_KEY_SIZE ||
 139             !ASN1_OCTET_STRING_set(&pctx->ktmp, key, len))
 140             return 0;
 141         Poly1305_Init(&pctx->ctx, ASN1_STRING_get0_data(&pctx->ktmp));
 142         break;
 143
 144     default:
 145         return -2;
 146
 147     }
 148     return 1;
 149 }
 150
 151 static int pkey_poly1305_ctrl_str(EVP_PKEY_CTX *ctx,
 152                                   const char *type, const char *value)
 153 {
 154     if (value == NULL)
 155         return 0;
 156     if (strcmp(type, "key") == 0)
 157         return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);
 158     if (strcmp(type, "hexkey") == 0)
 159         return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);
 160     return -2;
 161 }
 162
 163 const EVP_PKEY_METHOD poly1305_pkey_meth = {
 164     EVP_PKEY_POLY1305,
 165     EVP_PKEY_FLAG_SIGCTX_CUSTOM, /* we don't deal with a separate MD */
 166     pkey_poly1305_init,
 167     pkey_poly1305_copy,
 168     pkey_poly1305_cleanup,
 169
 170     0, 0,
 171
 172     0,
 173     pkey_poly1305_keygen,
 174
 175     0, 0,
 176
 177     0, 0,
 178
 179     0, 0,
 180
 181     poly1305_signctx_init,
 182     poly1305_signctx,
 183
 184     0, 0,
 185
 186     0, 0,
 187
 188     0, 0,
 189
 190     0, 0,
 191
 192     pkey_poly1305_ctrl,
 193     pkey_poly1305_ctrl_str
 194 };