lib/libcrypto/pem/pem_seal.c

   1 /* $OpenBSD: pem_seal.c,v 1.24 2017/01/29 17:49:23 beck Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <stdio.h>
  60 #include <string.h>
  61
  62 #include <openssl/opensslconf.h>        /* for OPENSSL_NO_RSA */
  63
  64 #ifndef OPENSSL_NO_RSA
  65
  66 #include <openssl/err.h>
  67 #include <openssl/evp.h>
  68 #include <openssl/objects.h>
  69 #include <openssl/pem.h>
  70 #include <openssl/rsa.h>
  71 #include <openssl/x509.h>
  72
  73 static void
  74 PEM_ENCODE_SEAL_CTX_cleanup(PEM_ENCODE_SEAL_CTX *ctx)
  75 {
  76         EVP_CIPHER_CTX_cleanup(&ctx->cipher);
  77         EVP_MD_CTX_cleanup(&ctx->md);
  78         explicit_bzero(&ctx->encode, sizeof(ctx->encode));
  79 }
  80
  81 int
  82 PEM_SealInit(PEM_ENCODE_SEAL_CTX *ctx, EVP_CIPHER *type, EVP_MD *md_type,
  83     unsigned char **ek, int *ekl, unsigned char *iv, EVP_PKEY **pubk, int npubk)
  84 {
  85         unsigned char key[EVP_MAX_KEY_LENGTH];
  86         int ret = -1;
  87         int i, j, max = 0;
  88         char *s = NULL;
  89
  90         /*
  91          * Make sure ctx is properly initialized so that we can always pass
  92          * it to PEM_ENCODE_SEAL_CTX_cleanup() in the error path.
  93          */
  94         EVP_EncodeInit(&ctx->encode);
  95         EVP_MD_CTX_init(&ctx->md);
  96         EVP_CIPHER_CTX_init(&ctx->cipher);
  97
  98         for (i = 0; i < npubk; i++) {
  99                 if (pubk[i]->type != EVP_PKEY_RSA) {
 100                         PEMerror(PEM_R_PUBLIC_KEY_NO_RSA);
 101                         goto err;
 102                 }
 103                 j = RSA_size(pubk[i]->pkey.rsa);
 104                 if (j > max)
 105                         max = j;
 106         }
 107         s = reallocarray(NULL, max, 2);
 108         if (s == NULL) {
 109                 PEMerror(ERR_R_MALLOC_FAILURE);
 110                 goto err;
 111         }
 112
 113         if (!EVP_SignInit(&ctx->md, md_type))
 114                 goto err;
 115
 116         ret = EVP_SealInit(&ctx->cipher, type, ek, ekl, iv, pubk, npubk);
 117         if (ret <= 0)
 118                 goto err;
 119
 120         /* base64 encode the keys */
 121         for (i = 0; i < npubk; i++) {
 122                 j = EVP_EncodeBlock((unsigned char *)s, ek[i],
 123                     RSA_size(pubk[i]->pkey.rsa));
 124                 ekl[i] = j;
 125                 memcpy(ek[i], s, j + 1);
 126         }
 127
 128         ret = npubk;
 129
 130         if (0) {
 131 err:
 132                 PEM_ENCODE_SEAL_CTX_cleanup(ctx);
 133         }
 134         free(s);
 135         explicit_bzero(key, sizeof(key));
 136         return (ret);
 137 }
 138
 139 void
 140 PEM_SealUpdate(PEM_ENCODE_SEAL_CTX *ctx, unsigned char *out, int *outl,
 141     unsigned char *in, int inl)
 142 {
 143         unsigned char buffer[1600];
 144         int i, j;
 145
 146         *outl = 0;
 147         EVP_SignUpdate(&ctx->md, in, inl);
 148         for (;;) {
 149                 if (inl <= 0)
 150                         break;
 151                 if (inl > 1200)
 152                         i = 1200;
 153                 else
 154                         i = inl;
 155                 EVP_EncryptUpdate(&ctx->cipher, buffer, &j, in, i);
 156                 EVP_EncodeUpdate(&ctx->encode, out, &j, buffer, j);
 157                 *outl += j;
 158                 out += j;
 159                 in += i;
 160                 inl -= i;
 161         }
 162 }
 163
 164 int
 165 PEM_SealFinal(PEM_ENCODE_SEAL_CTX *ctx, unsigned char *sig, int *sigl,
 166     unsigned char *out, int *outl, EVP_PKEY *priv)
 167 {
 168         unsigned char *s = NULL;
 169         int ret = 0, j;
 170         unsigned int i;
 171
 172         if (priv->type != EVP_PKEY_RSA) {
 173                 PEMerror(PEM_R_PUBLIC_KEY_NO_RSA);
 174                 goto err;
 175         }
 176         i = RSA_size(priv->pkey.rsa);
 177         if (i < 100)
 178                 i = 100;
 179         s = reallocarray(NULL, i, 2);
 180         if (s == NULL) {
 181                 PEMerror(ERR_R_MALLOC_FAILURE);
 182                 goto err;
 183         }
 184
 185         if (!EVP_EncryptFinal_ex(&ctx->cipher, s, (int *)&i))
 186                 goto err;
 187         EVP_EncodeUpdate(&ctx->encode, out, &j, s, i);
 188         *outl = j;
 189         out += j;
 190         EVP_EncodeFinal(&ctx->encode, out, &j);
 191         *outl += j;
 192
 193         if (!EVP_SignFinal(&ctx->md, s, &i, priv))
 194                 goto err;
 195         *sigl = EVP_EncodeBlock(sig, s, i);
 196
 197         ret = 1;
 198
 199 err:
 200         PEM_ENCODE_SEAL_CTX_cleanup(ctx);
 201         free(s);
 202         return (ret);
 203 }
 204 #endif