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Diffstat (limited to 'plugins/fishlim/fish.c')
| -rw-r--r-- | plugins/fishlim/fish.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/plugins/fishlim/fish.c b/plugins/fishlim/fish.c new file mode 100644 index 00000000..cb977d7f --- /dev/null +++ b/plugins/fishlim/fish.c @@ -0,0 +1,192 @@ +/* + + Copyright (c) 2010 Samuel Lidén Borell <samuel@slbdata.se> + + Permission is hereby granted, free of charge, to any person obtaining a copy + of this software and associated documentation files (the "Software"), to deal + in the Software without restriction, including without limitation the rights + to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + copies of the Software, and to permit persons to whom the Software is + furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + THE SOFTWARE. + +*/ + +#include <stdlib.h> +#include <string.h> +#include <openssl/blowfish.h> + +#include "keystore.h" +#include "fish.h" + +#define IB 64 +static const char fish_base64[64] = "./0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; +static const signed char fish_unbase64[256] = { + IB,IB,IB,IB,IB,IB,IB,IB, IB,IB,IB,IB,IB,IB,IB,IB, + IB,IB,IB,IB,IB,IB,IB,IB, IB,IB,IB,IB,IB,IB,IB,IB, +// ! " # $ % & ' ( ) * + , - . / + IB,IB,IB,IB,IB,IB,IB,IB, IB,IB,IB,IB,IB,IB, 0, 1, +// 0 1 2 3 4 5 6 7 8 9 : ; < = > ? + 2, 3, 4, 5, 6, 7, 8, 9, 10,11,IB,IB,IB,IB,IB,IB, +// @ A B C D E F G H I J K L M N O + IB,38,39,40,41,42,43,44, 45,46,47,48,49,50,51,52, +// P Q R S T U V W X Y Z [ \ ] ^ _ + 53,54,55,56,57,58,59,60, 61,62,63,IB,IB,IB,IB,IB, +// ` a b c d e f g h i j k l m n o + IB,12,13,14,15,16,17,18, 19,20,21,22,23,24,25,26, +// p q r s t u v w x y z { | } ~ <del> + 27,28,29,30,31,32,33,34, 35,36,37,IB,IB,IB,IB,IB, +}; + +#define GET_BYTES(dest, source) do { \ + *((dest)++) = ((source) >> 24) & 0xFF; \ + *((dest)++) = ((source) >> 16) & 0xFF; \ + *((dest)++) = ((source) >> 8) & 0xFF; \ + *((dest)++) = (source) & 0xFF; \ +} while (0); + + +char *fish_encrypt(const char *key, size_t keylen, const char *message) { + BF_KEY bfkey; + size_t messagelen; + size_t i; + int j; + char *encrypted; + char *end; + unsigned char bit; + unsigned char word; + unsigned char d; + BF_set_key(&bfkey, keylen, (const unsigned char*)key); + + messagelen = strlen(message); + if (messagelen == 0) return NULL; + encrypted = malloc(((messagelen-1)/8)*12 + 12 + 1); // each 8-byte block becomes 12 bytes + end = encrypted; + if (!encrypted) return NULL; + + while (*message) { + // Read 8 bytes (a Blowfish block) + BF_LONG binary[2] = { 0, 0 }; + unsigned char c; + for (i = 0; i < 8; i++) { + c = message[i]; + binary[i >> 2] |= c << 8*(3 - (i&3)); + if (c == '\0') break; + } + message += 8; + + // Encrypt block + BF_encrypt(binary, &bfkey); + + // Emit FiSH-BASE64 + bit = 0; + word = 1; + for (j = 0; j < 12; j++) { + d = fish_base64[(binary[word] >> bit) & 63]; + *(end++) = d; + bit += 6; + if (j == 5) { + bit = 0; + word = 0; + } + } + + // Stop if a null terminator was found + if (c == '\0') break; + } + *end = '\0'; + return encrypted; +} + + +char *fish_decrypt(const char *key, size_t keylen, const char *data) { + BF_KEY bfkey; + size_t i; + char *decrypted; + char *end; + unsigned char bit; + unsigned char word; + unsigned char d; + BF_set_key(&bfkey, keylen, (const unsigned char*)key); + + decrypted = malloc(strlen(data)+1); + end = decrypted; + if (!decrypted) return NULL; + + while (*data) { + // Convert from FiSH-BASE64 + BF_LONG binary[2] = { 0, 0 }; + bit = 0; + word = 1; + for (i = 0; i < 12; i++) { + d = fish_unbase64[(const unsigned char)*(data++)]; + if (d == IB) goto decrypt_end; + binary[word] |= d << bit; + bit += 6; + if (i == 5) { + bit = 0; + word = 0; + } + } + + // Decrypt block + BF_decrypt(binary, &bfkey); + + // Copy to buffer + GET_BYTES(end, binary[0]); + GET_BYTES(end, binary[1]); + } + + decrypt_end: + *end = '\0'; + return decrypted; +} + +/** + * Encrypts a message (see fish_decrypt). The key is searched for in the + * key store. + */ +char *fish_encrypt_for_nick(const char *nick, const char *data) { + char *key; + char *encrypted; + + // Look for key + key = keystore_get_key(nick); + if (!key) return NULL; + + // Encrypt + encrypted = fish_encrypt(key, strlen(key), data); + + free(key); + return encrypted; +} + +/** + * Decrypts a message (see fish_decrypt). The key is searched for in the + * key store. + */ +char *fish_decrypt_from_nick(const char *nick, const char *data) { + char *key; + char *decrypted; + // Look for key + key = keystore_get_key(nick); + if (!key) return NULL; + + // Decrypt + decrypted = fish_decrypt(key, strlen(key), data); + + free(key); + return decrypted; +} + + |