Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | Newsgroups: sci.crypt,alt.security,comp.security.misc,alt.privacy |
| 2 | Path: ghost.dsi.unimi.it!univ-lyon1.fr!jussieu.fr!zaphod.crihan.fr!warwick!clyde.open.ac.uk!strath-cs!bnr.co.uk!bt!pipex!howland.reston.ans.net!europa.eng.gtefsd.com!MathWorks.Com!yeshua.marcam.com!charnel.ecst.csuchico.edu!csusac!csus.edu!netcom.com!sterndark |
| 3 | From: sterndark@netcom.com (David Sterndark) |
| 4 | Subject: RC4 Algorithm revealed. |
| 5 | Message-ID: <sternCvKL4B.Hyy@netcom.com> |
| 6 | Sender: sterndark@netcom.com |
| 7 | Organization: NETCOM On-line Communication Services (408 261-4700 guest) |
| 8 | X-Newsreader: TIN [version 1.2 PL1] |
| 9 | Date: Wed, 14 Sep 1994 06:35:31 GMT |
| 10 | Lines: 263 |
| 11 | Xref: ghost.dsi.unimi.it sci.crypt:27332 alt.security:14732 comp.security.misc:11701 alt.privacy:16026 |
| 12 | |
| 13 | I am shocked, shocked, I tell you, shocked, to discover |
| 14 | that the cypherpunks have illegaly and criminally revealed |
| 15 | a crucial RSA trade secret and harmed the security of |
| 16 | America by reverse engineering the RC4 algorithm and |
| 17 | publishing it to the world. |
| 18 | |
| 19 | On Saturday morning an anonymous cypherpunk wrote: |
| 20 | |
| 21 | |
| 22 | SUBJECT: RC4 Source Code |
| 23 | |
| 24 | |
| 25 | I've tested this. It is compatible with the RC4 object module |
| 26 | that comes in the various RSA toolkits. |
| 27 | |
| 28 | /* rc4.h */ |
| 29 | typedef struct rc4_key |
| 30 | { |
| 31 | unsigned char state[256]; |
| 32 | unsigned char x; |
| 33 | unsigned char y; |
| 34 | } rc4_key; |
| 35 | void prepare_key(unsigned char *key_data_ptr,int key_data_len, |
| 36 | rc4_key *key); |
| 37 | void rc4(unsigned char *buffer_ptr,int buffer_len,rc4_key * key); |
| 38 | |
| 39 | |
| 40 | /*rc4.c */ |
| 41 | #include "rc4.h" |
| 42 | static void swap_byte(unsigned char *a, unsigned char *b); |
| 43 | void prepare_key(unsigned char *key_data_ptr, int key_data_len, |
| 44 | rc4_key *key) |
| 45 | { |
| 46 | unsigned char swapByte; |
| 47 | unsigned char index1; |
| 48 | unsigned char index2; |
| 49 | unsigned char* state; |
| 50 | short counter; |
| 51 | |
| 52 | state = &key->state[0]; |
| 53 | for(counter = 0; counter < 256; counter++) |
| 54 | state[counter] = counter; |
| 55 | key->x = 0; |
| 56 | key->y = 0; |
| 57 | index1 = 0; |
| 58 | index2 = 0; |
| 59 | for(counter = 0; counter < 256; counter++) |
| 60 | { |
| 61 | index2 = (key_data_ptr[index1] + state[counter] + |
| 62 | index2) % 256; |
| 63 | swap_byte(&state[counter], &state[index2]); |
| 64 | |
| 65 | index1 = (index1 + 1) % key_data_len; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | void rc4(unsigned char *buffer_ptr, int buffer_len, rc4_key *key) |
| 70 | { |
| 71 | unsigned char x; |
| 72 | unsigned char y; |
| 73 | unsigned char* state; |
| 74 | unsigned char xorIndex; |
| 75 | short counter; |
| 76 | |
| 77 | x = key->x; |
| 78 | y = key->y; |
| 79 | |
| 80 | state = &key->state[0]; |
| 81 | for(counter = 0; counter < buffer_len; counter ++) |
| 82 | { |
| 83 | x = (x + 1) % 256; |
| 84 | y = (state[x] + y) % 256; |
| 85 | swap_byte(&state[x], &state[y]); |
| 86 | |
| 87 | xorIndex = (state[x] + state[y]) % 256; |
| 88 | |
| 89 | buffer_ptr[counter] ^= state[xorIndex]; |
| 90 | } |
| 91 | key->x = x; |
| 92 | key->y = y; |
| 93 | } |
| 94 | |
| 95 | static void swap_byte(unsigned char *a, unsigned char *b) |
| 96 | { |
| 97 | unsigned char swapByte; |
| 98 | |
| 99 | swapByte = *a; |
| 100 | *a = *b; |
| 101 | *b = swapByte; |
| 102 | } |
| 103 | |
| 104 | |
| 105 | |
| 106 | Another cypherpunk, this one not anonymous, tested the |
| 107 | output from this algorithm against the output from |
| 108 | official RC4 object code |
| 109 | |
| 110 | |
| 111 | Date: Tue, 13 Sep 94 18:37:56 PDT |
| 112 | From: ekr@eit.COM (Eric Rescorla) |
| 113 | Message-Id: <9409140137.AA17743@eitech.eit.com> |
| 114 | Subject: RC4 compatibility testing |
| 115 | Cc: cypherpunks@toad.com |
| 116 | |
| 117 | One data point: |
| 118 | |
| 119 | I can't say anything about the internals of RC4 versus the |
| 120 | algorithm that Bill Sommerfeld is rightly calling 'Alleged RC4', |
| 121 | since I don't know anything about RC4's internals. |
| 122 | |
| 123 | However, I do have a (legitimately acquired) copy of BSAFE2 and |
| 124 | so I'm able to compare the output of this algorithm to the output |
| 125 | of genuine RC4 as found in BSAFE. I chose a set of test vectors |
| 126 | and ran them through both algorithms. The algorithms appear to |
| 127 | give identical results, at least with these key/plaintext pairs. |
| 128 | |
| 129 | I note that this is the algorithm _without_ Hal Finney's |
| 130 | proposed modification |
| 131 | |
| 132 | (see <199409130605.XAA24133@jobe.shell.portal.com>). |
| 133 | |
| 134 | The vectors I used (together with the ciphertext they produce) |
| 135 | follow at the end of this message. |
| 136 | |
| 137 | -Ekr |
| 138 | |
| 139 | Disclaimer: This posting does not reflect the opinions of EIT. |
| 140 | |
| 141 | --------------------results follow-------------- |
| 142 | Test vector 0 |
| 143 | Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| 144 | Input: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| 145 | 0 Output: 0x75 0xb7 0x87 0x80 0x99 0xe0 0xc5 0x96 |
| 146 | |
| 147 | Test vector 1 |
| 148 | Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| 149 | Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 150 | 0 Output: 0x74 0x94 0xc2 0xe7 0x10 0x4b 0x08 0x79 |
| 151 | |
| 152 | Test vector 2 |
| 153 | Key: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 154 | Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 155 | 0 Output: 0xde 0x18 0x89 0x41 0xa3 0x37 0x5d 0x3a |
| 156 | |
| 157 | Test vector 3 |
| 158 | Key: 0xef 0x01 0x23 0x45 |
| 159 | Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 160 | 0 Output: 0xd6 0xa1 0x41 0xa7 0xec 0x3c 0x38 0xdf 0xbd 0x61 |
| 161 | |
| 162 | Test vector 4 |
| 163 | Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| 164 | Input: 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 165 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 166 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 167 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 168 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 169 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 170 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 171 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 172 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 173 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 174 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 175 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 176 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 177 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 178 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 179 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 180 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 181 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 182 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 183 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 184 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 185 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 186 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 187 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 188 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 189 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 190 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 191 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 192 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 193 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 194 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 195 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 196 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 197 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 198 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 199 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 200 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 201 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 202 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 203 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 204 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 205 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 206 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 207 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 208 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 209 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 210 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 211 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 212 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 213 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 214 | 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 215 | 0x01 |
| 216 | 0 Output: 0x75 0x95 0xc3 0xe6 0x11 0x4a 0x09 0x78 0x0c 0x4a 0xd4 |
| 217 | 0x52 0x33 0x8e 0x1f 0xfd 0x9a 0x1b 0xe9 0x49 0x8f |
| 218 | 0x81 0x3d 0x76 0x53 0x34 0x49 0xb6 0x77 0x8d 0xca |
| 219 | 0xd8 0xc7 0x8a 0x8d 0x2b 0xa9 0xac 0x66 0x08 0x5d |
| 220 | 0x0e 0x53 0xd5 0x9c 0x26 0xc2 0xd1 0xc4 0x90 0xc1 |
| 221 | 0xeb 0xbe 0x0c 0xe6 0x6d 0x1b 0x6b 0x1b 0x13 0xb6 |
| 222 | 0xb9 0x19 0xb8 0x47 0xc2 0x5a 0x91 0x44 0x7a 0x95 |
| 223 | 0xe7 0x5e 0x4e 0xf1 0x67 0x79 0xcd 0xe8 0xbf 0x0a |
| 224 | 0x95 0x85 0x0e 0x32 0xaf 0x96 0x89 0x44 0x4f 0xd3 |
| 225 | 0x77 0x10 0x8f 0x98 0xfd 0xcb 0xd4 0xe7 0x26 0x56 |
| 226 | 0x75 0x00 0x99 0x0b 0xcc 0x7e 0x0c 0xa3 0xc4 0xaa |
| 227 | 0xa3 0x04 0xa3 0x87 0xd2 0x0f 0x3b 0x8f 0xbb 0xcd |
| 228 | 0x42 0xa1 0xbd 0x31 0x1d 0x7a 0x43 0x03 0xdd 0xa5 |
| 229 | 0xab 0x07 0x88 0x96 0xae 0x80 0xc1 0x8b 0x0a 0xf6 |
| 230 | 0x6d 0xff 0x31 0x96 0x16 0xeb 0x78 0x4e 0x49 0x5a |
| 231 | 0xd2 0xce 0x90 0xd7 0xf7 0x72 0xa8 0x17 0x47 0xb6 |
| 232 | 0x5f 0x62 0x09 0x3b 0x1e 0x0d 0xb9 0xe5 0xba 0x53 |
| 233 | 0x2f 0xaf 0xec 0x47 0x50 0x83 0x23 0xe6 0x71 0x32 |
| 234 | 0x7d 0xf9 0x44 0x44 0x32 0xcb 0x73 0x67 0xce 0xc8 |
| 235 | 0x2f 0x5d 0x44 0xc0 0xd0 0x0b 0x67 0xd6 0x50 0xa0 |
| 236 | 0x75 0xcd 0x4b 0x70 0xde 0xdd 0x77 0xeb 0x9b 0x10 |
| 237 | 0x23 0x1b 0x6b 0x5b 0x74 0x13 0x47 0x39 0x6d 0x62 |
| 238 | 0x89 0x74 0x21 0xd4 0x3d 0xf9 0xb4 0x2e 0x44 0x6e |
| 239 | 0x35 0x8e 0x9c 0x11 0xa9 0xb2 0x18 0x4e 0xcb 0xef |
| 240 | 0x0c 0xd8 0xe7 0xa8 0x77 0xef 0x96 0x8f 0x13 0x90 |
| 241 | 0xec 0x9b 0x3d 0x35 0xa5 0x58 0x5c 0xb0 0x09 0x29 |
| 242 | 0x0e 0x2f 0xcd 0xe7 0xb5 0xec 0x66 0xd9 0x08 0x4b |
| 243 | 0xe4 0x40 0x55 0xa6 0x19 0xd9 0xdd 0x7f 0xc3 0x16 |
| 244 | 0x6f 0x94 0x87 0xf7 0xcb 0x27 0x29 0x12 0x42 0x64 |
| 245 | 0x45 0x99 0x85 0x14 0xc1 0x5d 0x53 0xa1 0x8c 0x86 |
| 246 | 0x4c 0xe3 0xa2 0xb7 0x55 0x57 0x93 0x98 0x81 0x26 |
| 247 | 0x52 0x0e 0xac 0xf2 0xe3 0x06 0x6e 0x23 0x0c 0x91 |
| 248 | 0xbe 0xe4 0xdd 0x53 0x04 0xf5 0xfd 0x04 0x05 0xb3 |
| 249 | 0x5b 0xd9 0x9c 0x73 0x13 0x5d 0x3d 0x9b 0xc3 0x35 |
| 250 | 0xee 0x04 0x9e 0xf6 0x9b 0x38 0x67 0xbf 0x2d 0x7b |
| 251 | 0xd1 0xea 0xa5 0x95 0xd8 0xbf 0xc0 0x06 0x6f 0xf8 |
| 252 | 0xd3 0x15 0x09 0xeb 0x0c 0x6c 0xaa 0x00 0x6c 0x80 |
| 253 | 0x7a 0x62 0x3e 0xf8 0x4c 0x3d 0x33 0xc1 0x95 0xd2 |
| 254 | 0x3e 0xe3 0x20 0xc4 0x0d 0xe0 0x55 0x81 0x57 0xc8 |
| 255 | 0x22 0xd4 0xb8 0xc5 0x69 0xd8 0x49 0xae 0xd5 0x9d |
| 256 | 0x4e 0x0f 0xd7 0xf3 0x79 0x58 0x6b 0x4b 0x7f 0xf6 |
| 257 | 0x84 0xed 0x6a 0x18 0x9f 0x74 0x86 0xd4 0x9b 0x9c |
| 258 | 0x4b 0xad 0x9b 0xa2 0x4b 0x96 0xab 0xf9 0x24 0x37 |
| 259 | 0x2c 0x8a 0x8f 0xff 0xb1 0x0d 0x55 0x35 0x49 0x00 |
| 260 | 0xa7 0x7a 0x3d 0xb5 0xf2 0x05 0xe1 0xb9 0x9f 0xcd |
| 261 | 0x86 0x60 0x86 0x3a 0x15 0x9a 0xd4 0xab 0xe4 0x0f |
| 262 | 0xa4 0x89 0x34 0x16 0x3d 0xdd 0xe5 0x42 0xa6 0x58 |
| 263 | 0x55 0x40 0xfd 0x68 0x3c 0xbf 0xd8 0xc0 0x0f 0x12 |
| 264 | 0x12 0x9a 0x28 0x4d 0xea 0xcc 0x4c 0xde 0xfe 0x58 |
| 265 | 0xbe 0x71 0x37 0x54 0x1c 0x04 0x71 0x26 0xc8 0xd4 |
| 266 | 0x9e 0x27 0x55 0xab 0x18 0x1a 0xb7 0xe9 0x40 0xb0 |
| 267 | 0xc0 |
| 268 | |
| 269 | |
| 270 | |
| 271 | -- |
| 272 | --------------------------------------------------------------------- |
| 273 | We have the right to defend ourselves and our |
| 274 | property, because of the kind of animals that we James A. Donald |
| 275 | are. True law derives from this right, not from |
| 276 | the arbitrary power of the omnipotent state. jamesd@netcom.com |
| 277 | |
| 278 | |