Alexandre Lision | ddd731e | 2014-01-31 11:50:08 -0500 | [diff] [blame] | 1 | // Copyright (C) 2010 David Sugar, Tycho Softworks. |
| 2 | // |
| 3 | // This file is part of GNU uCommon C++. |
| 4 | // |
| 5 | // GNU uCommon C++ is free software: you can redistribute it and/or modify |
| 6 | // it under the terms of the GNU Lesser General Public License as published |
| 7 | // by the Free Software Foundation, either version 3 of the License, or |
| 8 | // (at your option) any later version. |
| 9 | // |
| 10 | // GNU uCommon C++ is distributed in the hope that it will be useful, |
| 11 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | // GNU Lesser General Public License for more details. |
| 14 | // |
| 15 | // You should have received a copy of the GNU Lesser General Public License |
| 16 | // along with GNU uCommon C++. If not, see <http://www.gnu.org/licenses/>. |
| 17 | |
| 18 | #include "local.h" |
| 19 | |
| 20 | static const unsigned char *_salt = NULL; |
| 21 | static unsigned _rounds = 1; |
| 22 | |
| 23 | void Cipher::Key::assign(const char *text, size_t size) |
| 24 | { |
| 25 | assign(text, size, _salt, _rounds); |
| 26 | } |
| 27 | |
| 28 | void Cipher::Key::options(const unsigned char *salt, unsigned rounds) |
| 29 | { |
| 30 | _salt = salt; |
| 31 | _rounds = rounds; |
| 32 | } |
| 33 | |
| 34 | void Cipher::Key::assign(const char *text, size_t size, const unsigned char *salt, unsigned rounds) |
| 35 | { |
| 36 | if(!algotype || !hashtype) |
| 37 | return; |
| 38 | |
| 39 | if(!size) |
| 40 | size = strlen((const char *)text); |
| 41 | |
| 42 | if(!rounds) |
| 43 | rounds = _rounds; |
| 44 | |
| 45 | if(!salt) |
| 46 | salt = _salt; |
| 47 | |
| 48 | if(EVP_BytesToKey((const EVP_CIPHER*)algotype, (const EVP_MD*)hashtype, salt, (const unsigned char *)text, size, rounds, keybuf, ivbuf) < (int)keysize) |
| 49 | keysize = 0; |
| 50 | } |
| 51 | |
| 52 | void Cipher::Key::set(const char *cipher, const char *digest) |
| 53 | { |
| 54 | set(cipher); |
| 55 | |
| 56 | // never use sha0... |
| 57 | if(eq_case(digest, "sha")) |
| 58 | digest = "sha1"; |
| 59 | |
| 60 | hashtype = EVP_get_digestbyname(digest); |
| 61 | } |
| 62 | |
| 63 | void Cipher::Key::set(const char *cipher) |
| 64 | { |
| 65 | char algoname[64]; |
| 66 | |
| 67 | clear(); |
| 68 | String::set(algoname, sizeof(algoname), cipher); |
| 69 | char *fpart = strchr(algoname, '-'); |
| 70 | char *lpart = strrchr(algoname, '-'); |
| 71 | |
| 72 | if(fpart && fpart == lpart) |
| 73 | strcpy(fpart, fpart + 1); |
| 74 | |
| 75 | algotype = EVP_get_cipherbyname(algoname); |
| 76 | |
| 77 | if(!algotype) |
| 78 | return; |
| 79 | |
| 80 | keysize = EVP_CIPHER_key_length((const EVP_CIPHER*)algotype); |
| 81 | blksize = EVP_CIPHER_block_size((const EVP_CIPHER*)algotype); |
| 82 | } |
| 83 | |
| 84 | |
| 85 | bool Cipher::has(const char *id) |
| 86 | { |
| 87 | // make sure cipher-bitsize forms without -mode do not fail... |
| 88 | char algoname[64]; |
| 89 | String::set(algoname, sizeof(algoname), id); |
| 90 | char *fpart = strchr(algoname, '-'); |
| 91 | char *lpart = strrchr(algoname, '-'); |
| 92 | |
| 93 | if(fpart && fpart == lpart) |
| 94 | strcpy(fpart, fpart + 1); |
| 95 | |
| 96 | return (EVP_get_cipherbyname(algoname) != NULL); |
| 97 | } |
| 98 | |
| 99 | void Cipher::push(unsigned char *address, size_t size) |
| 100 | { |
| 101 | } |
| 102 | |
| 103 | void Cipher::release(void) |
| 104 | { |
| 105 | keys.clear(); |
| 106 | if(context) { |
| 107 | EVP_CIPHER_CTX_cleanup((EVP_CIPHER_CTX*)context); |
| 108 | delete (EVP_CIPHER_CTX*)context; |
| 109 | context = NULL; |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | void Cipher::set(key_t key, mode_t mode, unsigned char *address, size_t size) |
| 114 | { |
| 115 | release(); |
| 116 | |
| 117 | bufsize = size; |
| 118 | bufmode = mode; |
| 119 | bufaddr = address; |
| 120 | |
| 121 | memcpy(&keys, key, sizeof(keys)); |
| 122 | if(!keys.keysize) |
| 123 | return; |
| 124 | |
| 125 | context = new EVP_CIPHER_CTX; |
| 126 | EVP_CIPHER_CTX_init((EVP_CIPHER_CTX *)context); |
| 127 | EVP_CipherInit_ex((EVP_CIPHER_CTX *)context, (EVP_CIPHER *)keys.algotype, NULL, keys.keybuf, keys.ivbuf, (int)mode); |
| 128 | EVP_CIPHER_CTX_set_padding((EVP_CIPHER_CTX *)context, 0); |
| 129 | } |
| 130 | |
| 131 | size_t Cipher::put(const unsigned char *data, size_t size) |
| 132 | { |
| 133 | int outlen; |
| 134 | size_t count = 0; |
| 135 | |
| 136 | if(!bufaddr) |
| 137 | return 0; |
| 138 | |
| 139 | if(size % keys.iosize()) |
| 140 | return 0; |
| 141 | |
| 142 | while(bufsize && size + bufpos > bufsize) { |
| 143 | size_t diff = bufsize - bufpos; |
| 144 | count += put(data, diff); |
| 145 | data += diff; |
| 146 | size -= diff; |
| 147 | } |
| 148 | |
| 149 | if(!EVP_CipherUpdate((EVP_CIPHER_CTX *)context, bufaddr + bufpos, &outlen, data, size)) { |
| 150 | release(); |
| 151 | return count; |
| 152 | } |
| 153 | bufpos += outlen; |
| 154 | count += outlen; |
| 155 | if(bufsize && bufpos >= bufsize) { |
| 156 | push(bufaddr, bufsize); |
| 157 | bufpos = 0; |
| 158 | } |
| 159 | return count; |
| 160 | } |
| 161 | |
| 162 | size_t Cipher::pad(const unsigned char *data, size_t size) |
| 163 | { |
| 164 | size_t padsize = 0; |
| 165 | unsigned char padbuf[64]; |
| 166 | const unsigned char *ep; |
| 167 | |
| 168 | if(!bufaddr) |
| 169 | return 0; |
| 170 | |
| 171 | switch(bufmode) { |
| 172 | case DECRYPT: |
| 173 | if(size % keys.iosize()) |
| 174 | return 0; |
| 175 | put(data, size); |
| 176 | ep = data + size - 1; |
| 177 | bufpos -= *ep; |
| 178 | size -= *ep; |
| 179 | break; |
| 180 | case ENCRYPT: |
| 181 | padsize = size % keys.iosize(); |
| 182 | put(data, size - padsize); |
| 183 | if(padsize) { |
| 184 | memcpy(padbuf, data + size - padsize, padsize); |
| 185 | memset(padbuf + padsize, keys.iosize() - padsize, keys.iosize() - padsize); |
| 186 | size = (size - padsize) + keys.iosize(); |
| 187 | } |
| 188 | else { |
| 189 | size += keys.iosize(); |
| 190 | memset(padbuf, keys.iosize(), keys.iosize()); |
| 191 | } |
| 192 | |
| 193 | put((const unsigned char *)padbuf, keys.iosize()); |
| 194 | zerofill(padbuf, sizeof(padbuf)); |
| 195 | } |
| 196 | |
| 197 | flush(); |
| 198 | return size; |
| 199 | } |
| 200 | |