1 /* 2 * Copyright (c) 2003 Markus Friedl. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #include "includes.h" 26 27 /* compatibility with old or broken OpenSSL versions */ 28 #include "openbsd-compat/openssl-compat.h" 29 30 #ifdef USE_BUILTIN_RIJNDAEL 31 #include <sys/types.h> 32 33 #include <openssl/evp.h> 34 35 #include <stdarg.h> 36 #include <string.h> 37 38 #include "rijndael.h" 39 #include "xmalloc.h" 40 #include "log.h" 41 42 #define RIJNDAEL_BLOCKSIZE 16 43 struct ssh_rijndael_ctx 44 { 45 rijndael_ctx r_ctx; 46 u_char r_iv[RIJNDAEL_BLOCKSIZE]; 47 }; 48 49 const EVP_CIPHER * evp_rijndael(void); 50 void ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int); 51 52 static int 53 ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 54 int enc) 55 { 56 struct ssh_rijndael_ctx *c; 57 58 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 59 c = xmalloc(sizeof(*c)); 60 EVP_CIPHER_CTX_set_app_data(ctx, c); 61 } 62 if (key != NULL) { 63 if (enc == -1) 64 enc = ctx->encrypt; 65 rijndael_set_key(&c->r_ctx, (u_char *)key, 66 8*EVP_CIPHER_CTX_key_length(ctx), enc); 67 } 68 if (iv != NULL) 69 memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); 70 return (1); 71 } 72 73 static int 74 ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, 75 LIBCRYPTO_EVP_INL_TYPE len) 76 { 77 struct ssh_rijndael_ctx *c; 78 u_char buf[RIJNDAEL_BLOCKSIZE]; 79 u_char *cprev, *cnow, *plain, *ivp; 80 int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; 81 82 if (len == 0) 83 return (1); 84 if (len % RIJNDAEL_BLOCKSIZE) 85 fatal("ssh_rijndael_cbc: bad len %d", len); 86 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 87 error("ssh_rijndael_cbc: no context"); 88 return (0); 89 } 90 if (ctx->encrypt) { 91 cnow = dest; 92 plain = (u_char *)src; 93 cprev = c->r_iv; 94 for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, 95 cnow+=RIJNDAEL_BLOCKSIZE) { 96 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 97 buf[j] = plain[j] ^ cprev[j]; 98 rijndael_encrypt(&c->r_ctx, buf, cnow); 99 cprev = cnow; 100 } 101 memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); 102 } else { 103 cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); 104 plain = dest+len-RIJNDAEL_BLOCKSIZE; 105 106 memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); 107 for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, 108 plain-=RIJNDAEL_BLOCKSIZE) { 109 rijndael_decrypt(&c->r_ctx, cnow, plain); 110 ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; 111 for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 112 plain[j] ^= ivp[j]; 113 } 114 memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); 115 } 116 return (1); 117 } 118 119 static int 120 ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) 121 { 122 struct ssh_rijndael_ctx *c; 123 124 if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 125 memset(c, 0, sizeof(*c)); 126 xfree(c); 127 EVP_CIPHER_CTX_set_app_data(ctx, NULL); 128 } 129 return (1); 130 } 131 132 void 133 ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len) 134 { 135 struct ssh_rijndael_ctx *c; 136 137 if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) 138 fatal("ssh_rijndael_iv: no context"); 139 if (doset) 140 memcpy(c->r_iv, iv, len); 141 else 142 memcpy(iv, c->r_iv, len); 143 } 144 145 const EVP_CIPHER * 146 evp_rijndael(void) 147 { 148 static EVP_CIPHER rijndal_cbc; 149 150 memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); 151 rijndal_cbc.nid = NID_undef; 152 rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; 153 rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; 154 rijndal_cbc.key_len = 16; 155 rijndal_cbc.init = ssh_rijndael_init; 156 rijndal_cbc.cleanup = ssh_rijndael_cleanup; 157 rijndal_cbc.do_cipher = ssh_rijndael_cbc; 158 #ifndef SSH_OLD_EVP 159 rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | 160 EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; 161 #endif 162 return (&rijndal_cbc); 163 } 164 #endif /* USE_BUILTIN_RIJNDAEL */ 165