Network Working Group R. Rivest INTERNET-DRAFT MIT Laboratory for Computer Science S. Dusse RSA Data Security, Inc. 1 July 1991 The MD4 Message-Digest Algorithm STATUS OF THIS MEMO This draft document will be submitted to the RFC editor as a protocol specification. Comments should be sent to or to the authors. Distribution of this memo is unlimited. ACKNOWLEDGEMENT We would like to thank Don Coppersmith, Burt Kaliski, Ralph Merkle, and Noam Nisan for numerous helpful comments and suggestions. Table of Contents 1. Executive Summary 1 2. Terminology and Notation 2 3. MD4 Algorithm Description 2 4. Summary 6 5. Security Considerations 6 References 7 Authors' Addresses 7 APPENDIX - Reference Implementation 8 1. Executive Summary This document describes the MD4 message-digest algorithm. The algorithm takes as input an input message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest. The MD4 algorithm is intended for digital signature applications, where a large file must be "compressed" in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA. The MD4 algorithm is designed to be quite fast on 32-bit machines. In addition, the MD4 algorithm does not require any large substitution tables; the algorithm can be coded quite compactly. Rivest and Dusse [Page 1] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 The MD4 algorithm is being placed in the public domain for review and possible adoption as a standard. This document is a proposed update to the October 1990 RFC 1186 [1]. The main difference is that the reference implementation of MD4 in the appendix is more portable. A version of this document including the C source code in the ap- pendix is available by FTP from RSA.COM in the file "md4.doc". This document may be referred to, unofficially, as Internet draft [1186D]. For OSI-based applications, MD4's object identifier is md4 OBJECT IDENTIFIER ::= {iso(1) member-body(2) US(840) rsadsi(113549) digestAlgorithm(2) 4} In the X.509 type AlgorithmIdentifier [3], the parameters for MD4 should have type NULL. 2. Terminology and Notation In this document a "word" is a 32-bit quantity and a "byte" is an eight-bit quantity. A sequence of bits can be interpreted in a natural manner as a sequence of bytes, where each consecutive group of eight bits is interpreted as a byte with the high-order (most significant) bit of each byte listed first. Similarly, a sequence of bytes can be interpreted as a sequence of 32-bit words, where each consecutive group of four bytes is interpreted as a word with the low-order (least significant) byte given first. Let x_i denote "x sub i". If the subscript is an expression, we sur- round it in braces, as in x_{i+1}. Similarly, we use ^ for super- scripts (exponentiation), so that x^i denotes x to the i-th power. Let the symbol "+" denote addition of words (i.e., modulo-2^32 addi- tion). Let X <<< s denote the 32-bit value obtained by circularly shifting (rotating) X left by s bit positions. Let not(X) denote the bit-wise complement of X, and let X v Y denote the bit-wise OR of X and Y. Let X xor Y denote the bit-wise XOR of X and Y, and let XY de- note the bit-wise AND of X and Y. 3. MD4 Algorithm Description We begin by supposing that we have a b-bit message as input, and that we wish to find its message digest. Here b is an arbitrary nonnega- tive integer; b may be zero, it need not be a multiple of eight, and it may be arbitrarily large. We imagine the bits of the message writ- ten down as follows: Rivest and Dusse [Page 2] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 m_0 m_1 ... m_{b-1} The following five steps are performed to compute the message digest of the message. 3.1 Step 1. Append Padding Bits The message is "padded" (extended) so that its length (in bits) is congruent to 448, modulo 512. That is, the message is extended so that it is just 64 bits shy of being a multiple of 512 bits long. Padding is always performed, even if the length of the message is al- ready congruent to 448, modulo 512 (in which case 512 bits of padding are added). Padding is performed as follows: a single "1" bit is appended to the message, and then enough zero bits are appended so that the length in bits of the padded message becomes congruent to 448, modulo 512. 3.2 Step 2. Append Length A 64-bit representation of b (the length of the message before the padding bits were added) is appended to the result of the previous step. In the unlikely event that b is greater than 2^64, then only the low-order 64 bits of b are used. (These bits are appended as two 32-bit words and appended low-order word first in accordance with the previous conventions.) At this point the resulting message (after padding with bits and with b) has a length that is an exact multiple of 512 bits. Equivalently, this message has a length that is an exact multiple of 16 (32-bit) words. Let M[0 ... N-1] denote the words of the resulting message, where N is a multiple of 16. 3.3 Step 3. Initialize MD Buffer A four-word buffer (A,B,C,D) is used to compute the message digest. Here each of A, B, C, D is a 32-bit register. These registers are initialized to the following values in hexadecimal, low-order bytes first): word A: 01 23 45 67 word B: 89 ab cd ef word C: fe dc ba 98 word D: 76 54 32 10 Rivest and Dusse [Page 3] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 3.4 Step 4. Process Message in 16-Word Blocks We first define three auxiliary functions that each take as input three 32-bit words and produce as output one 32-bit word. F(X,Y,Z) = XY v not(X)Z G(X,Y,Z) = XY v XZ v YZ H(X,Y,Z) = X xor Y xor Z In each bit position F acts as a conditional: if X then Y else Z. (The function F could have been defined using + instead of v since XY and not(X)Z will never have "1" bits in the same bit position.) In each bit position G acts as a majority function: if at least two of X, Y, Z are on, then G has a "1" bit in that bit position, else G has a "0" bit. It is interesting to note that if the bits of X, Y, and Z are independent and unbiased, the each bit of f(X,Y,Z) will be inde- pendent and unbiased, and similarly each bit of g(X,Y,Z) will be in- dependent and unbiased. The function H is the bit-wise XOR or "parity" function; it has properties similar to those of F and G. Do the following: /* Process each 16-word block. */ For i = 0 to N/16-1 do /* Copy block i into X. */ For j = 0 to 15 do Set X[j] to M[i*16+j]. end /* of loop on j */ /* Save A as AA, B as BB, C as CC, and D as DD. */ AA = A BB = B CC = C DD = D /* Round 1. */ /* Let [a b c d k s] denote the operation a = (a + F(b,c,d) + X[k]) <<< s. */ /* Do the following 16 operations. */ [A B C D 0 3] [D A B C 1 7] [C D A B 2 11] [B C D A 3 19] [A B C D 4 3] [D A B C 5 7] [C D A B 6 11] [B C D A 7 19] [A B C D 8 3] [D A B C 9 7] [C D A B 10 11] Rivest and Dusse [Page 4] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 [B C D A 11 19] [A B C D 12 3] [D A B C 13 7] [C D A B 14 11] [B C D A 15 19] /* Round 2. */ /* Let [a b c d k s] denote the operation a = (a + G(b,c,d) + X[k] + 5A827999) <<< s. */ /* Do the following 16 operations. */ [A B C D 0 3] [D A B C 4 5] [C D A B 8 9] [B C D A 12 13] [A B C D 1 3] [D A B C 5 5] [C D A B 9 9] [B C D A 13 13] [A B C D 2 3] [D A B C 6 5] [C D A B 10 9] [B C D A 14 13] [A B C D 3 3] [D A B C 7 5] [C D A B 11 9] [B C D A 15 13] /* Round 3. */ /* Let [a b c d k s] denote the operation a = (a + H(b,c,d) + X[k] + 6ED9EBA1) <<< s. */ /* Do the following 16 operations. */ [A B C D 0 3] [D A B C 8 9] [C D A B 4 11] [B C D A 12 15] [A B C D 2 3] [D A B C 10 9] [C D A B 6 11] [B C D A 14 15] [A B C D 1 3] [D A B C 9 9] [C D A B 5 11] [B C D A 13 15] [A B C D 3 3] [D A B C 11 9] [C D A B 7 11] [B C D A 15 15] /* Then perform the following additions. (That is, increment each of the four registers by the value it had before this block Rivest and Dusse [Page 5] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 was started.) */ A = A + AA B = B + BB C = C + CC D = D + DD end /* of loop on i */ Note. The value 5A..99 is a hexadecimal 32-bit constant, written with the high-order digit first. This constant represents the square root of 2. The octal value of this constant is 013240474631. The value 6E..A1 is a hexadecimal 32-bit constant, written with the high-order digit first. This constant represents the square root of 3. The octal value of this constant is 015666365641. See Knuth, The Art of Programming, Volume 2 (Seminumerical Algo- rithms), Second Edition (1981), Addison-Wesley. Table 2, page 660. 3.5 Step 5. Output The message digest produced as output is A, B, C, D. That is, we be- gin with the low-order byte of A, and end with the high-order byte of D. This completes the description of MD4. A reference implementation in C is given in the Appendix. 4. Summary The MD4 message-digest algorithm is simple to implement, and provides a "fingerprint" or message digest of a message of arbitrary length. It is conjectured that the difficulty of coming up with two messages having the same message digest is on the order of 2^64 operations, and that the difficulty of coming up with any message having a given message digest is on the order of 2^128 operations. The MD4 algorithm has been carefully scrutinized for weaknesses. It is, however, a rel- atively new algorithm and further security analysis is of course jus- tified, as is the case with any new proposal of this sort. 5. Security Considerations The level of security discussed in this memo is considered to be suf- ficient for implementing very high security hybrid digital-signature schemes based on MD4 and a public-key cryptosystem. Rivest and Dusse [Page 6] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 References [1] Rivest, R.L., The MD4 Message Digest Algorithm (RFC 1186), Oc- tober 1990. [2] Rivest, R.L., The MD4 message digest algorithm, presented at CRYPTO '90 (Santa Barbara, CA, August 11-15, 1990). [3] CCITT, The Directory---Authentication Framework (Recommendation X.509), 1988. Authors' Addresses Ronald L. Rivest Massachusetts Institute of Technology Laboratory for Computer Science NE43-324 545 Technology Square Cambridge, MA 02139-1986 Phone: (617) 253-5880 EMail: rivest@theory.lcs.mit.edu Steve Dusse RSA Data Security, Inc. 10 Twin Dolphin Drive Redwood City, CA 94065 Phone: (415) 595-8782 EMail: dusse@rsa.com Rivest and Dusse [Page 7] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 APPENDIX - Reference Implementation This appendix contains the following files: md4.h -- header file for implementation of MD4 md4.c -- the source code for MD4 routines md4driver.c -- sample test routines session -- sample results of running md4driver The implementation of MD4 given in this appendix differs from the one given in RFC 1186 [1] and the CRYPTO '90 paper on MD4. The main dif- ference is that this version should compile and run correctly on more platforms than the other ones. We have sacrificed performance for portability. MD4 speeds given in RFC 1186 and the CRYPTO '90 paper are not necessarily the same as those one might obtain with this ref- erence implementation. However, it is not difficult to improve this implementation on particular platforms, an exercise left to the reader. Following are some suggestions: 1. Change MD4Update so that the context is not used at all if it is empty (mdi == 0) and 64 or more bytes remain (inLen >= 64). In other words, call Transform with inBuf in this case. (This requires that byte ordering is cor- rect in inBuf.) 2. Implement a procedure MD4UpdateLong modeled after MD4Update where inBuf is UINT4 * instead of unsigned char *. MD4UpdateLong would call Transform directly with 16 word blocks from inBuf. Call this instead of MD4Update in general. This works well if you have an I/O procedure that can read long words from a file. 3. On "little-endian" platforms where the lowest-address byte in a long word is the least significant (and there are no alignment restrictions), change MD4Update to call Transform directly with 64-byte blocks from inBuf (typecast to a UINT4 *). Rivest and Dusse [Page 8] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 /* *********************************************************************** ** md4.h -- header file for implementation of MD4 ** ** RSA Data Security, Inc. MD4 Message-Digest Algorithm ** ** Created: 2/17/90 RLR ** ** Revised: 12/27/90 SRD,AJ,BSK,JT Reference C version ** *********************************************************************** */ /* *********************************************************************** ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. ** ** ** ** License to copy and use this software is granted provided that ** ** it is identified as the "RSA Data Security, Inc. MD4 Message- ** ** Digest Algorithm" in all material mentioning or referencing this ** ** software or this function. ** ** ** ** License is also granted to make and use derivative works ** ** provided that such works are identified as "derived from the RSA ** ** Data Security, Inc. MD4 Message-Digest Algorithm" in all ** ** material mentioning or referencing the derived work. ** ** ** ** RSA Data Security, Inc. makes no representations concerning ** ** either the merchantability of this software or the suitability ** ** of this software for any particular purpose. It is provided "as ** ** is" without express or implied warranty of any kind. ** ** ** ** These notices must be retained in any copies of any part of this ** ** documentation and/or software. ** *********************************************************************** */ /* typedef a 32-bit type */ typedef unsigned long int UINT4; /* Data structure for MD4 (Message-Digest) computation */ typedef struct { UINT4 i[2]; /* number of _bits_ handled mod 2^64 */ UINT4 buf[4]; /* scratch buffer */ unsigned char in[64]; /* input buffer */ unsigned char digest[16]; /* actual digest after MD4Final call */ } MD4_CTX; void MD4Init (); void MD4Update (); void MD4Final (); /* *********************************************************************** ** End of md4.h ** ******************************** (cut) ******************************** Rivest and Dusse [Page 9] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 */ Rivest and Dusse [Page 10] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 /* *********************************************************************** ** md4.c -- the source code for MD4 routines ** ** RSA Data Security, Inc. MD4 Message-Digest Algorithm ** ** Created: 2/17/90 RLR ** ** Revised: 1/91 SRD,AJ,BSK,JT Reference C Version ** *********************************************************************** */ /* *********************************************************************** ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. ** ** ** ** License to copy and use this software is granted provided that ** ** it is identified as the "RSA Data Security, Inc. MD4 Message- ** ** Digest Algorithm" in all material mentioning or referencing this ** ** software or this function. ** ** ** ** License is also granted to make and use derivative works ** ** provided that such works are identified as "derived from the RSA ** ** Data Security, Inc. MD4 Message-Digest Algorithm" in all ** ** material mentioning or referencing the derived work. ** ** ** ** RSA Data Security, Inc. makes no representations concerning ** ** either the merchantability of this software or the suitability ** ** of this software for any particular purpose. It is provided "as ** ** is" without express or implied warranty of any kind. ** ** ** ** These notices must be retained in any copies of any part of this ** ** documentation and/or software. ** *********************************************************************** */ #include "md4.h" /* *********************************************************************** ** Message-digest routines: ** ** To form the message digest for a message M ** ** (1) Initialize a context buffer mdContext using MD4Init ** ** (2) Call MD4Update on mdContext and M ** ** (3) Call MD4Final on mdContext ** ** The message digest is now in mdContext->digest[0...15] ** *********************************************************************** */ /* forward declaration */ static void Transform (); static unsigned char PADDING[64] = { 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, Rivest and Dusse [Page 11] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; /* F, G and H are basic MD4 functions: selection, majority, parity */ #define F(x, y, z) (((x) & (y)) | ((~x) & (z))) #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z))) #define H(x, y, z) ((x) ^ (y) ^ (z)) /* ROTATE_LEFT rotates x left n bits */ #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n)))) /* FF, GG and HH are MD4 transformations for rounds 1, 2 and 3 */ /* Rotation is separate from addition to prevent recomputation */ #define FF(a, b, c, d, x, s) \ {(a) += F ((b), (c), (d)) + (x); \ (a) = ROTATE_LEFT ((a), (s));} #define GG(a, b, c, d, x, s) \ {(a) += G ((b), (c), (d)) + (x) + (UINT4)0x5A827999; \ (a) = ROTATE_LEFT ((a), (s));} #define HH(a, b, c, d, x, s) \ {(a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ED9EBA1; \ (a) = ROTATE_LEFT ((a), (s));} /* The routine MD4Init initializes the message-digest context mdContext. All fields are set to zero. */ void MD4Init (mdContext) MD4_CTX *mdContext; { mdContext->i[0] = mdContext->i[1] = (UINT4)0; /* Load magic initialization constants. */ mdContext->buf[0] = (UINT4)0x67452301; mdContext->buf[1] = (UINT4)0xefcdab89; mdContext->buf[2] = (UINT4)0x98badcfe; mdContext->buf[3] = (UINT4)0x10325476; } /* The routine MD4Update updates the message-digest context to account for the presence of each of the characters inBuf[0..inLen-1] in the message whose digest is being computed. */ void MD4Update (mdContext, inBuf, inLen) MD4_CTX *mdContext; unsigned char *inBuf; unsigned int inLen; Rivest and Dusse [Page 12] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 { UINT4 in[16]; int mdi; unsigned int i, ii; /* compute number of bytes mod 64 */ mdi = (int)((mdContext->i[0] >> 3) & 0x3F); /* update number of bits */ if ((mdContext->i[0] + ((UINT4)inLen << 3)) < mdContext->i[0]) mdContext->i[1]++; mdContext->i[0] += ((UINT4)inLen << 3); mdContext->i[1] += ((UINT4)inLen >> 29); while (inLen--) { /* add new character to buffer, increment mdi */ mdContext->in[mdi++] = *inBuf++; /* transform if necessary */ if (mdi == 0x40) { for (i = 0, ii = 0; i < 16; i++, ii += 4) in[i] = (((UINT4)mdContext->in[ii+3]) << 24) | (((UINT4)mdContext->in[ii+2]) << 16) | (((UINT4)mdContext->in[ii+1]) << 8) | ((UINT4)mdContext->in[ii]); Transform (mdContext->buf, in); mdi = 0; } } } /* The routine MD4Final terminates the message-digest computation and ends with the desired message digest in mdContext->digest[0...15]. */ void MD4Final (mdContext) MD4_CTX *mdContext; { UINT4 in[16]; int mdi; unsigned int i, ii; unsigned int padLen; /* save number of bits */ in[14] = mdContext->i[0]; in[15] = mdContext->i[1]; /* compute number of bytes mod 64 */ mdi = (int)((mdContext->i[0] >> 3) & 0x3F); /* pad out to 56 mod 64 */ padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi); MD4Update (mdContext, PADDING, padLen); Rivest and Dusse [Page 13] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 /* append length in bits and transform */ for (i = 0, ii = 0; i < 14; i++, ii += 4) in[i] = (((UINT4)mdContext->in[ii+3]) << 24) | (((UINT4)mdContext->in[ii+2]) << 16) | (((UINT4)mdContext->in[ii+1]) << 8) | ((UINT4)mdContext->in[ii]); Transform (mdContext->buf, in); /* store buffer in digest */ for (i = 0, ii = 0; i < 4; i++, ii += 4) { mdContext->digest[ii] = (unsigned char)(mdContext->buf[i] & 0xFF); mdContext->digest[ii+1] = (unsigned char)((mdContext->buf[i] >> 8) & 0xFF); mdContext->digest[ii+2] = (unsigned char)((mdContext->buf[i] >> 16) & 0xFF); mdContext->digest[ii+3] = (unsigned char)((mdContext->buf[i] >> 24) & 0xFF); } } /* Basic MD4 step. Transforms buf based on in. */ static void Transform (buf, in) UINT4 *buf; UINT4 *in; { UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3]; /* Round 1 */ FF (a, b, c, d, in[ 0], 3); FF (d, a, b, c, in[ 1], 7); FF (c, d, a, b, in[ 2], 11); FF (b, c, d, a, in[ 3], 19); FF (a, b, c, d, in[ 4], 3); FF (d, a, b, c, in[ 5], 7); FF (c, d, a, b, in[ 6], 11); FF (b, c, d, a, in[ 7], 19); FF (a, b, c, d, in[ 8], 3); FF (d, a, b, c, in[ 9], 7); FF (c, d, a, b, in[10], 11); FF (b, c, d, a, in[11], 19); FF (a, b, c, d, in[12], 3); FF (d, a, b, c, in[13], 7); FF (c, d, a, b, in[14], 11); FF (b, c, d, a, in[15], 19); /* Round 2 */ GG (a, b, c, d, in[ 0], 3); GG (d, a, b, c, in[ 4], 5); GG (c, d, a, b, in[ 8], 9); GG (b, c, d, a, in[12], 13); Rivest and Dusse [Page 14] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 GG (a, b, c, d, in[ 1], 3); GG (d, a, b, c, in[ 5], 5); GG (c, d, a, b, in[ 9], 9); GG (b, c, d, a, in[13], 13); GG (a, b, c, d, in[ 2], 3); GG (d, a, b, c, in[ 6], 5); GG (c, d, a, b, in[10], 9); GG (b, c, d, a, in[14], 13); GG (a, b, c, d, in[ 3], 3); GG (d, a, b, c, in[ 7], 5); GG (c, d, a, b, in[11], 9); GG (b, c, d, a, in[15], 13); /* Round 3 */ HH (a, b, c, d, in[ 0], 3); HH (d, a, b, c, in[ 8], 9); HH (c, d, a, b, in[ 4], 11); HH (b, c, d, a, in[12], 15); HH (a, b, c, d, in[ 2], 3); HH (d, a, b, c, in[10], 9); HH (c, d, a, b, in[ 6], 11); HH (b, c, d, a, in[14], 15); HH (a, b, c, d, in[ 1], 3); HH (d, a, b, c, in[ 9], 9); HH (c, d, a, b, in[ 5], 11); HH (b, c, d, a, in[13], 15); HH (a, b, c, d, in[ 3], 3); HH (d, a, b, c, in[11], 9); HH (c, d, a, b, in[ 7], 11); HH (b, c, d, a, in[15], 15); buf[0] += a; buf[1] += b; buf[2] += c; buf[3] += d; } /* *********************************************************************** ** End of md4.c ** ******************************** (cut) ******************************** */ Rivest and Dusse [Page 15] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 /* *********************************************************************** ** md4driver.c -- sample test routines ** ** RSA Data Security, Inc. MD4 Message-Digest Algorithm ** ** Created: 2/16/90 RLR ** ** Updated: 1/91 SRD ** *********************************************************************** */ /* *********************************************************************** ** Copyright (C) 1990, RSA Data Security, Inc. All rights reserved. ** ** ** ** RSA Data Security, Inc. makes no representations concerning ** ** either the merchantability of this software or the suitability ** ** of this software for any particular purpose. It is provided "as ** ** is" without express or implied warranty of any kind. ** ** ** ** These notices must be retained in any copies of any part of this ** ** documentation and/or software. ** *********************************************************************** */ #include #include #include #include #include "md4.h" /* Prints message digest buffer in mdContext as 32 hexadecimal digits. Order is from low-order byte to high-order byte of digest. Each byte is printed with high-order hexadecimal digit first. */ static void MDPrint (mdContext) MD4_CTX *mdContext; { int i; for (i = 0; i < 16; i++) printf ("%02x", mdContext->digest[i]); } /* size of test block */ #define TEST_BLOCK_SIZE 1000 /* number of blocks to process */ #define TEST_BLOCKS 10000 /* number of test bytes = TEST_BLOCK_SIZE * TEST_BLOCKS */ static long TEST_BYTES = (long)TEST_BLOCK_SIZE * (long)TEST_BLOCKS; /* A time trial routine, to measure the speed of MD4. Rivest and Dusse [Page 16] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 Measures wall time required to digest TEST_BLOCKS * TEST_BLOCK_SIZE characters. */ static void MDTimeTrial () { MD4_CTX mdContext; time_t endTime, startTime; unsigned char data[TEST_BLOCK_SIZE]; unsigned int i; /* initialize test data */ for (i = 0; i < TEST_BLOCK_SIZE; i++) data[i] = (unsigned char)(i & 0xFF); /* start timer */ printf ("MD4 time trial. Processing %ld characters...\n", TEST_BYTES); time (&startTime); /* digest data in TEST_BLOCK_SIZE byte blocks */ MD4Init (&mdContext); for (i = TEST_BLOCKS; i > 0; i--) MD4Update (&mdContext, data, TEST_BLOCK_SIZE); MD4Final (&mdContext); /* stop timer, get time difference */ time (&endTime); MDPrint (&mdContext); printf (" is digest of test input.\n"); printf ("Seconds to process test input: %ld\n", (long)(endTime-startTime)); printf ("Characters processed per second: %ld\n", TEST_BYTES/(endTime-startTime)); } /* Computes the message digest for string inString. Prints out message digest, a space, the string (in quotes) and a carriage return. */ static void MDString (inString) char *inString; { MD4_CTX mdContext; unsigned int len = strlen (inString); MD4Init (&mdContext); MD4Update (&mdContext, inString, len); MD4Final (&mdContext); MDPrint (&mdContext); printf (" \"%s\"\n", inString); } Rivest and Dusse [Page 17] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 /* Computes the message digest for a specified file. Prints out message digest, a space, the file name, and a carriage return. */ static void MDFile (filename) char *filename; { FILE *inFile = fopen (filename, "rb"); MD4_CTX mdContext; int bytes; unsigned char data[1024]; if (inFile == NULL) { printf ("%s can't be opened.\n", filename); return; } MD4Init (&mdContext); while ((bytes = fread (data, 1, 1024, inFile)) != 0) MD4Update (&mdContext, data, bytes); MD4Final (&mdContext); MDPrint (&mdContext); printf (" %s\n", filename); fclose (inFile); } /* Writes the message digest of the data from stdin onto stdout, followed by a carriage return. */ static void MDFilter () { MD4_CTX mdContext; int bytes; unsigned char data[16]; MD4Init (&mdContext); while ((bytes = fread (data, 1, 16, stdin)) != 0) MD4Update (&mdContext, data, bytes); MD4Final (&mdContext); MDPrint (&mdContext); printf ("\n"); } /* Runs a standard suite of test data. */ static void MDTestSuite () { printf ("MD4 test suite results:\n"); MDString (""); MDString ("a"); MDString ("abc"); MDString ("message digest"); Rivest and Dusse [Page 18] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 MDString ("abcdefghijklmnopqrstuvwxyz"); MDString ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"); MDString ("1234567890123456789012345678901234567890\ 1234567890123456789012345678901234567890"); /* Contents of file foo are "abc" */ MDFile ("foo"); } void main (argc, argv) int argc; char *argv[]; { int i; /* For each command line argument in turn: ** filename -- prints message digest and name of file ** -sstring -- prints message digest and contents of string ** -t -- prints time trial statistics for 10M characters ** -x -- execute a standard suite of test data ** (no args) -- writes messages digest of stdin onto stdout */ if (argc == 1) MDFilter (); else for (i = 1; i < argc; i++) if (argv[i][0] == '-' && argv[i][1] == 's') MDString (argv[i] + 2); else if (strcmp (argv[i], "-t") == 0) MDTimeTrial (); else if (strcmp (argv[i], "-x") == 0) MDTestSuite (); else MDFile (argv[i]); } /* *********************************************************************** ** End of md4driver.c ** ******************************** (cut) ******************************** */ Rivest and Dusse [Page 19] INTERNET-DRAFT The MD4 Message-Digest Algorithm 1 July 1991 ------------------------------------------------------------------------ -- Sample session output obtained by running md4driver test suite -- ------------------------------------------------------------------------ MD4 test suite results: 31d6cfe0d16ae931b73c59d7e0c089c0 "" bde52cb31de33e46245e05fbdbd6fb24 "a" a448017aaf21d8525fc10ae87aa6729d "abc" d9130a8164549fe818874806e1c7014b "message digest" d79e1c308aa5bbcdeea8ed63df412da9 "abcdefghijklmnopqrstuvwxyz" 043f8582f241db351ce627e153e7f0e4 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijk\ lmnopqrstuvwxyz0123456789" e33b4ddc9c38f2199c3e7b164fcc0536 "1234567890123456789012345678901234567\ 8901234567890123456789012345678901234567890" a448017aaf21d8525fc10ae87aa6729d foo ------------------------------------------------------------------------ -- End of sample session -- -------------------------------- (cut) --------------------------------- Rivest and Dusse [Page 20]