Rename occurrences of USE_ to HAVE_ (again)

[s-mailx.git] / md5.c

/*@ S-nail - a mail user agent derived from Berkeley Mail.
 *@ MD5 / HMAC-MD5 algorithm implementation. 
 *
 * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
 * Copyright (c) 2012 - 2013 Steffen "Daode" Nurpmeso <sdaoden@users.sf.net>.
 */
/*
 * The MD5_CTX algorithm is derived from RFC 1321:
 */
/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 */
/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
rights reserved.

License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 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. MD5 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.
 */

/* hmac_md5() is derived from:

Network Working Group                                       H. Krawczyk
Request for Comments: 2104                                          IBM
Category: Informational                                      M. Bellare
                                                                   UCSD
                                                             R. Canetti
                                                                    IBM
                                                          February 1997


             HMAC: Keyed-Hashing for Message Authentication

Status of This Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Appendix -- Sample Code

   For the sake of illustration we provide the following sample code for
   the implementation of HMAC-MD5 as well as some corresponding test
   vectors (the code is based on MD5 code as described in [MD5]).
*/

#include "rcv.h"

#ifndef HAVE_MD5
typedef int avoid_empty_file_compiler_warning;
#else
#include "md5.h"

#define UINT4B_MAX      0xFFFFFFFFul

/*
 * Constants for MD5Transform routine.
 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
#define F(x,y,z)        (((x) & (y))  |  ((~(x)) & (z)))
#define G(x,y,z)        (((x) & (z))  |  ((y) & (~(z))))
*/

/* As pointed out by Wei Dai <weidai@eskimo.com>, the above can be
 * simplified to the code below.  Wei attributes these optimizations
 * to Peter Gutmann's SHS code, and he attributes it to Rich Schroeppel.
 */
#define F(b,c,d)        ((((c) ^ (d)) & (b)) ^ (d))
#define G(b,c,d)        ((((b) ^ (c)) & (d)) ^ (c))
#define H(b,c,d)        ((b) ^ (c) ^ (d))
#define I(b,c,d)        (((~(d) & UINT4B_MAX) | (b)) ^ (c))

/*
 * ROTATE_LEFT rotates x left n bits.
 */
#define ROTATE_LEFT(x, n) ((((x) << (n)) & UINT4B_MAX) | ((x) >> (32 - (n))))

/*
 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
 * Rotation is separate from addition to prevent recomputation.
 */
#define FF(a, b, c, d, x, s, ac) { \
        (a) = ((a) + F(b, c, d) + (x) + ((ac) & UINT4B_MAX)) & UINT4B_MAX; \
        (a) = ROTATE_LEFT((a), (s)); \
        (a) = ((a) + (b)) & UINT4B_MAX; \
}

#define GG(a, b, c, d, x, s, ac) { \
        (a) = ((a) + G(b, c, d) + (x) + ((ac) & UINT4B_MAX)) & UINT4B_MAX; \
        (a) = ROTATE_LEFT((a), (s)); \
        (a) = ((a) + (b)) & UINT4B_MAX; \
}

#define HH(a, b, c, d, x, s, ac) { \
        (a) = ((a) + H(b, c, d) + (x) + ((ac) & UINT4B_MAX)) & UINT4B_MAX; \
        (a) = ROTATE_LEFT((a), (s)); \
        (a) = ((a) + (b)) & UINT4B_MAX; \
}

#define II(a, b, c, d, x, s, ac) { \
        (a) = ((a) + I(b, c, d) + (x) + ((ac) & UINT4B_MAX)) & UINT4B_MAX; \
        (a) = ROTATE_LEFT((a), (s)); \
        (a) = ((a) + (b)) & UINT4B_MAX; \
}

static void * ( *volatile _volatile_memset)(void*, int, size_t) = &(memset);

static void Encode(unsigned char *output, md5_type *input, unsigned int len);
static void Decode(md5_type *output, unsigned char *input, unsigned int len);
static void MD5Transform(md5_type state[], unsigned char block[]);

/*
 * Encodes input (md5_type) into output (unsigned char). Assumes len is
 * a multiple of 4.
 */
static void
Encode(unsigned char *output, md5_type *input, unsigned int len)
{
        unsigned int i, j;

        for (i = 0, j = 0; j < len; i++, j += 4) {
                output[j] = input[i] & 0xff;
                output[j+1] = (input[i] >> 8) & 0xff;
                output[j+2] = (input[i] >> 16) & 0xff;
                output[j+3] = (input[i] >> 24) & 0xff;
        }
}

/*
 * Decodes input (unsigned char) into output (md5_type). Assumes len is
 * a multiple of 4.
 */
static void
Decode(md5_type *output, unsigned char *input, unsigned int len)
{
        unsigned int    i, j;

        for (i = 0, j = 0; j < len; i++, j += 4)
                output[i] = ((md5_type)input[j] |
                        (md5_type)input[j+1] << 8 |
                        (md5_type)input[j+2] << 16 |
                        (md5_type)input[j+3] << 24) & UINT4B_MAX;
}

/* MD5 basic transformation. Transforms state based on block. */
static void
MD5Transform(md5_type state[4], unsigned char block[64])
{
        md5_type a = state[0], b = state[1], c = state[2], d = state[3],
                x[16];

        Decode(x, block, 64);

        /* Round 1 */
        FF(a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
        FF(d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
        FF(c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
        FF(b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
        FF(a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
        FF(d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
        FF(c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
        FF(b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
        FF(a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
        FF(d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
        FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
        FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
        FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
        FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
        FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
        FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

        /* Round 2 */
        GG(a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
        GG(d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
        GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
        GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
        GG(a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
        GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
        GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
        GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
        GG(a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
        GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
        GG(c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
        GG(b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
        GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
        GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
        GG(c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
        GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

        /* Round 3 */
        HH(a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
        HH(d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
        HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
        HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
        HH(a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
        HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
        HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
        HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
        HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
        HH(d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
        HH(c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
        HH(b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
        HH(a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
        HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
        HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
        HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

        /* Round 4 */
        II(a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
        II(d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
        II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
        II(b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
        II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
        II(d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
        II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
        II(b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
        II(a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
        II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
        II(c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
        II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
        II(a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
        II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
        II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
        II(b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

        state[0] = (state[0] + a) & UINT4B_MAX;
        state[1] = (state[1] + b) & UINT4B_MAX;
        state[2] = (state[2] + c) & UINT4B_MAX;
        state[3] = (state[3] + d) & UINT4B_MAX;

        /*
         * Zeroize sensitive information.
         */
        (*_volatile_memset)(x, 0, sizeof x);
}

/*
 * MD5 initialization. Begins an MD5 operation, writing a new context.
 */
void
MD5Init (
    MD5_CTX *context    /* context */
)
{
        context->count[0] = context->count[1] = 0;
        /*
         * Load magic initialization constants.
         */
        context->state[0] = 0x67452301;
        context->state[1] = 0xefcdab89;
        context->state[2] = 0x98badcfe;
        context->state[3] = 0x10325476;
}

/*
 * MD5 block update operation. Continues an MD5 message-digest
 * operation, processing another message block, and updating the
 * context.
 */
void
MD5Update (
    MD5_CTX *context,           /* context */
    unsigned char *input,               /* input block */
    unsigned int inputLen               /* length of input block */
)
{
        unsigned int i, index, partLen;

        /* Compute number of bytes mod 64 */
        index = context->count[0]>>3 & 0x3F;

        /* Update number of bits */
        if ((context->count[0] = (context->count[0] + (inputLen<<3)) &
                                        UINT4B_MAX)
                        < ((inputLen << 3) & UINT4B_MAX))
        context->count[1] = (context->count[1] + 1) & UINT4B_MAX;
        context->count[1] = (context->count[1] + (inputLen >> 29)) & UINT4B_MAX;

        partLen = 64 - index;

        /*
         * Transform as many times as possible.
         */
        if (inputLen >= partLen) {
                memcpy(&context->buffer[index], input, partLen);
                MD5Transform(context->state, context->buffer);

                for (i = partLen; i + 63 < inputLen; i += 64)
                        MD5Transform(context->state, &input[i]);

                index = 0;
        } else
                i = 0;

        /* Buffer remaining input */
        memcpy(&context->buffer[index], &input[i], inputLen-i);
}

/*
 * MD5 finalization. Ends an MD5 message-digest operation, writing the
 * the message digest and zeroizing the context.
 */
void
MD5Final (
    unsigned char digest[16],   /* message digest */
    MD5_CTX *context            /* context */
)
{
        unsigned char   bits[8];
        unsigned int    index, padLen;

        /* Save number of bits */
        Encode(bits, context->count, 8);

        /*
         * Pad out to 56 mod 64.
         */
        index = context->count[0]>>3 & 0x3f;
        padLen = index < 56 ? 56 - index : 120 - index;
        MD5Update(context, PADDING, padLen);

        /* Append length (before padding) */
        MD5Update(context, bits, 8);
        /* Store state in digest */
        Encode(digest, context->state, 16);

        /*
         * Zeroize sensitive information.
         */
        (*_volatile_memset)(context, 0, sizeof *context);
}

void
hmac_md5 (
    unsigned char *text,        /* pointer to data stream */
    int text_len,               /* length of data stream */
    unsigned char *key,         /* pointer to authentication key */
    int key_len,                /* length of authentication key */
    void *digest                /* caller digest to be filled in */
)
{
        MD5_CTX context;
        unsigned char k_ipad[65];    /* inner padding -
                                      * key XORd with ipad
                                      */
        unsigned char k_opad[65];    /* outer padding -
                                      * key XORd with opad
                                      */
        unsigned char tk[16];
        int i;
        /* if key is longer than 64 bytes reset it to key=MD5(key) */
        if (key_len > 64) {

                MD5_CTX      tctx;

                MD5Init(&tctx);
                MD5Update(&tctx, key, key_len);
                MD5Final(tk, &tctx);

                key = tk;
                key_len = 16;
        }

        /*
         * the HMAC_MD5 transform looks like:
         *
         * MD5(K XOR opad, MD5(K XOR ipad, text))
         *
         * where K is an n byte key
         * ipad is the byte 0x36 repeated 64 times
         * opad is the byte 0x5c repeated 64 times
         * and text is the data being protected
         */

        /* start out by storing key in pads */
        memset(k_ipad, 0, sizeof k_ipad);
        memset(k_opad, 0, sizeof k_opad);
        memcpy(k_ipad, key, key_len);
        memcpy(k_opad, key, key_len);

        /* XOR key with ipad and opad values */
        for (i=0; i<64; i++) {
                k_ipad[i] ^= 0x36;
                k_opad[i] ^= 0x5c;
        }
        /*
         * perform inner MD5
         */
        MD5Init(&context);                   /* init context for 1st
                                              * pass */
        MD5Update(&context, k_ipad, 64);             /* start with inner pad */
        MD5Update(&context, text, text_len); /* then text of datagram */
        MD5Final(digest, &context);          /* finish up 1st pass */
        /*
         * perform outer MD5
         */
        MD5Init(&context);                   /* init context for 2nd
                                              * pass */
        MD5Update(&context, k_opad, 64);     /* start with outer pad */
        MD5Update(&context, digest, 16);     /* then results of 1st
                                              * hash */
        MD5Final(digest, &context);          /* finish up 2nd pass */
}
#endif /* HAVE_MD5 */