| Newsgroups: sci.crypt,alt.security,comp.security.misc,alt.privacy |
| 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 |
| From: sterndark@netcom.com (David Sterndark) |
| Subject: RC4 Algorithm revealed. |
| Message-ID: <sternCvKL4B.Hyy@netcom.com> |
| Sender: sterndark@netcom.com |
| Organization: NETCOM On-line Communication Services (408 261-4700 guest) |
| X-Newsreader: TIN [version 1.2 PL1] |
| Date: Wed, 14 Sep 1994 06:35:31 GMT |
| Lines: 263 |
| Xref: ghost.dsi.unimi.it sci.crypt:27332 alt.security:14732 comp.security.misc:11701 alt.privacy:16026 |
| |
| I am shocked, shocked, I tell you, shocked, to discover |
| that the cypherpunks have illegaly and criminally revealed |
| a crucial RSA trade secret and harmed the security of |
| America by reverse engineering the RC4 algorithm and |
| publishing it to the world. |
| |
| On Saturday morning an anonymous cypherpunk wrote: |
| |
| |
| SUBJECT: RC4 Source Code |
| |
| |
| I've tested this. It is compatible with the RC4 object module |
| that comes in the various RSA toolkits. |
| |
| /* rc4.h */ |
| typedef struct rc4_key |
| { |
| unsigned char state[256]; |
| unsigned char x; |
| unsigned char y; |
| } rc4_key; |
| void prepare_key(unsigned char *key_data_ptr,int key_data_len, |
| rc4_key *key); |
| void rc4(unsigned char *buffer_ptr,int buffer_len,rc4_key * key); |
| |
| |
| /*rc4.c */ |
| #include "rc4.h" |
| static void swap_byte(unsigned char *a, unsigned char *b); |
| void prepare_key(unsigned char *key_data_ptr, int key_data_len, |
| rc4_key *key) |
| { |
| unsigned char swapByte; |
| unsigned char index1; |
| unsigned char index2; |
| unsigned char* state; |
| short counter; |
| |
| state = &key->state[0]; |
| for(counter = 0; counter < 256; counter++) |
| state[counter] = counter; |
| key->x = 0; |
| key->y = 0; |
| index1 = 0; |
| index2 = 0; |
| for(counter = 0; counter < 256; counter++) |
| { |
| index2 = (key_data_ptr[index1] + state[counter] + |
| index2) % 256; |
| swap_byte(&state[counter], &state[index2]); |
| |
| index1 = (index1 + 1) % key_data_len; |
| } |
| } |
| |
| void rc4(unsigned char *buffer_ptr, int buffer_len, rc4_key *key) |
| { |
| unsigned char x; |
| unsigned char y; |
| unsigned char* state; |
| unsigned char xorIndex; |
| short counter; |
| |
| x = key->x; |
| y = key->y; |
| |
| state = &key->state[0]; |
| for(counter = 0; counter < buffer_len; counter ++) |
| { |
| x = (x + 1) % 256; |
| y = (state[x] + y) % 256; |
| swap_byte(&state[x], &state[y]); |
| |
| xorIndex = (state[x] + state[y]) % 256; |
| |
| buffer_ptr[counter] ^= state[xorIndex]; |
| } |
| key->x = x; |
| key->y = y; |
| } |
| |
| static void swap_byte(unsigned char *a, unsigned char *b) |
| { |
| unsigned char swapByte; |
| |
| swapByte = *a; |
| *a = *b; |
| *b = swapByte; |
| } |
| |
| |
| |
| Another cypherpunk, this one not anonymous, tested the |
| output from this algorithm against the output from |
| official RC4 object code |
| |
| |
| Date: Tue, 13 Sep 94 18:37:56 PDT |
| From: ekr@eit.COM (Eric Rescorla) |
| Message-Id: <9409140137.AA17743@eitech.eit.com> |
| Subject: RC4 compatibility testing |
| Cc: cypherpunks@toad.com |
| |
| One data point: |
| |
| I can't say anything about the internals of RC4 versus the |
| algorithm that Bill Sommerfeld is rightly calling 'Alleged RC4', |
| since I don't know anything about RC4's internals. |
| |
| However, I do have a (legitimately acquired) copy of BSAFE2 and |
| so I'm able to compare the output of this algorithm to the output |
| of genuine RC4 as found in BSAFE. I chose a set of test vectors |
| and ran them through both algorithms. The algorithms appear to |
| give identical results, at least with these key/plaintext pairs. |
| |
| I note that this is the algorithm _without_ Hal Finney's |
| proposed modification |
| |
| (see <199409130605.XAA24133@jobe.shell.portal.com>). |
| |
| The vectors I used (together with the ciphertext they produce) |
| follow at the end of this message. |
| |
| -Ekr |
| |
| Disclaimer: This posting does not reflect the opinions of EIT. |
| |
| --------------------results follow-------------- |
| Test vector 0 |
| Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| Input: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| 0 Output: 0x75 0xb7 0x87 0x80 0x99 0xe0 0xc5 0x96 |
| |
| Test vector 1 |
| Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 0 Output: 0x74 0x94 0xc2 0xe7 0x10 0x4b 0x08 0x79 |
| |
| Test vector 2 |
| Key: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 0 Output: 0xde 0x18 0x89 0x41 0xa3 0x37 0x5d 0x3a |
| |
| Test vector 3 |
| Key: 0xef 0x01 0x23 0x45 |
| Input: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 |
| 0 Output: 0xd6 0xa1 0x41 0xa7 0xec 0x3c 0x38 0xdf 0xbd 0x61 |
| |
| Test vector 4 |
| Key: 0x01 0x23 0x45 0x67 0x89 0xab 0xcd 0xef |
| Input: 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 |
| 0x01 |
| 0 Output: 0x75 0x95 0xc3 0xe6 0x11 0x4a 0x09 0x78 0x0c 0x4a 0xd4 |
| 0x52 0x33 0x8e 0x1f 0xfd 0x9a 0x1b 0xe9 0x49 0x8f |
| 0x81 0x3d 0x76 0x53 0x34 0x49 0xb6 0x77 0x8d 0xca |
| 0xd8 0xc7 0x8a 0x8d 0x2b 0xa9 0xac 0x66 0x08 0x5d |
| 0x0e 0x53 0xd5 0x9c 0x26 0xc2 0xd1 0xc4 0x90 0xc1 |
| 0xeb 0xbe 0x0c 0xe6 0x6d 0x1b 0x6b 0x1b 0x13 0xb6 |
| 0xb9 0x19 0xb8 0x47 0xc2 0x5a 0x91 0x44 0x7a 0x95 |
| 0xe7 0x5e 0x4e 0xf1 0x67 0x79 0xcd 0xe8 0xbf 0x0a |
| 0x95 0x85 0x0e 0x32 0xaf 0x96 0x89 0x44 0x4f 0xd3 |
| 0x77 0x10 0x8f 0x98 0xfd 0xcb 0xd4 0xe7 0x26 0x56 |
| 0x75 0x00 0x99 0x0b 0xcc 0x7e 0x0c 0xa3 0xc4 0xaa |
| 0xa3 0x04 0xa3 0x87 0xd2 0x0f 0x3b 0x8f 0xbb 0xcd |
| 0x42 0xa1 0xbd 0x31 0x1d 0x7a 0x43 0x03 0xdd 0xa5 |
| 0xab 0x07 0x88 0x96 0xae 0x80 0xc1 0x8b 0x0a 0xf6 |
| 0x6d 0xff 0x31 0x96 0x16 0xeb 0x78 0x4e 0x49 0x5a |
| 0xd2 0xce 0x90 0xd7 0xf7 0x72 0xa8 0x17 0x47 0xb6 |
| 0x5f 0x62 0x09 0x3b 0x1e 0x0d 0xb9 0xe5 0xba 0x53 |
| 0x2f 0xaf 0xec 0x47 0x50 0x83 0x23 0xe6 0x71 0x32 |
| 0x7d 0xf9 0x44 0x44 0x32 0xcb 0x73 0x67 0xce 0xc8 |
| 0x2f 0x5d 0x44 0xc0 0xd0 0x0b 0x67 0xd6 0x50 0xa0 |
| 0x75 0xcd 0x4b 0x70 0xde 0xdd 0x77 0xeb 0x9b 0x10 |
| 0x23 0x1b 0x6b 0x5b 0x74 0x13 0x47 0x39 0x6d 0x62 |
| 0x89 0x74 0x21 0xd4 0x3d 0xf9 0xb4 0x2e 0x44 0x6e |
| 0x35 0x8e 0x9c 0x11 0xa9 0xb2 0x18 0x4e 0xcb 0xef |
| 0x0c 0xd8 0xe7 0xa8 0x77 0xef 0x96 0x8f 0x13 0x90 |
| 0xec 0x9b 0x3d 0x35 0xa5 0x58 0x5c 0xb0 0x09 0x29 |
| 0x0e 0x2f 0xcd 0xe7 0xb5 0xec 0x66 0xd9 0x08 0x4b |
| 0xe4 0x40 0x55 0xa6 0x19 0xd9 0xdd 0x7f 0xc3 0x16 |
| 0x6f 0x94 0x87 0xf7 0xcb 0x27 0x29 0x12 0x42 0x64 |
| 0x45 0x99 0x85 0x14 0xc1 0x5d 0x53 0xa1 0x8c 0x86 |
| 0x4c 0xe3 0xa2 0xb7 0x55 0x57 0x93 0x98 0x81 0x26 |
| 0x52 0x0e 0xac 0xf2 0xe3 0x06 0x6e 0x23 0x0c 0x91 |
| 0xbe 0xe4 0xdd 0x53 0x04 0xf5 0xfd 0x04 0x05 0xb3 |
| 0x5b 0xd9 0x9c 0x73 0x13 0x5d 0x3d 0x9b 0xc3 0x35 |
| 0xee 0x04 0x9e 0xf6 0x9b 0x38 0x67 0xbf 0x2d 0x7b |
| 0xd1 0xea 0xa5 0x95 0xd8 0xbf 0xc0 0x06 0x6f 0xf8 |
| 0xd3 0x15 0x09 0xeb 0x0c 0x6c 0xaa 0x00 0x6c 0x80 |
| 0x7a 0x62 0x3e 0xf8 0x4c 0x3d 0x33 0xc1 0x95 0xd2 |
| 0x3e 0xe3 0x20 0xc4 0x0d 0xe0 0x55 0x81 0x57 0xc8 |
| 0x22 0xd4 0xb8 0xc5 0x69 0xd8 0x49 0xae 0xd5 0x9d |
| 0x4e 0x0f 0xd7 0xf3 0x79 0x58 0x6b 0x4b 0x7f 0xf6 |
| 0x84 0xed 0x6a 0x18 0x9f 0x74 0x86 0xd4 0x9b 0x9c |
| 0x4b 0xad 0x9b 0xa2 0x4b 0x96 0xab 0xf9 0x24 0x37 |
| 0x2c 0x8a 0x8f 0xff 0xb1 0x0d 0x55 0x35 0x49 0x00 |
| 0xa7 0x7a 0x3d 0xb5 0xf2 0x05 0xe1 0xb9 0x9f 0xcd |
| 0x86 0x60 0x86 0x3a 0x15 0x9a 0xd4 0xab 0xe4 0x0f |
| 0xa4 0x89 0x34 0x16 0x3d 0xdd 0xe5 0x42 0xa6 0x58 |
| 0x55 0x40 0xfd 0x68 0x3c 0xbf 0xd8 0xc0 0x0f 0x12 |
| 0x12 0x9a 0x28 0x4d 0xea 0xcc 0x4c 0xde 0xfe 0x58 |
| 0xbe 0x71 0x37 0x54 0x1c 0x04 0x71 0x26 0xc8 0xd4 |
| 0x9e 0x27 0x55 0xab 0x18 0x1a 0xb7 0xe9 0x40 0xb0 |
| 0xc0 |
| |
| |
| |
| -- |
| --------------------------------------------------------------------- |
| We have the right to defend ourselves and our |
| property, because of the kind of animals that we James A. Donald |
| are. True law derives from this right, not from |
| the arbitrary power of the omnipotent state. jamesd@netcom.com |
| |
| |
