md5.c
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上传日期:2007-10-30
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- /*
- * ** **************************************************************************
- * ** md5.c -- Implementation of MD5 Message Digest Algorithm **
- * ** Updated: 2/16/90 by Ronald L. Rivest **
- * ** (C) 1990 RSA Data Security, Inc. **
- * ** **************************************************************************
- */
- /*
- * ** To use MD5:
- * ** -- Include md5.h in your program
- * ** -- Declare an MDstruct MD to hold the state of the digest computation.
- * ** -- Initialize MD using MDbegin(&MD)
- * ** -- For each full block (64 bytes) X you wish to process, call
- * ** MDupdate(&MD,X,512)
- * ** (512 is the number of bits in a full block.)
- * ** -- For the last block (less than 64 bytes) you wish to process,
- * ** MDupdate(&MD,X,n)
- * ** where n is the number of bits in the partial block. A partial
- * ** block terminates the computation, so every MD computation should
- * ** terminate by processing a partial block, even if it has n = 0.
- * ** -- The message digest is available in MD.buffer[0] ... MD.buffer[3].
- * ** (Least-significant byte of each word should be output first.)
- * ** -- You can print out the digest using MDprint(&MD)
- */
- /*
- * Implementation notes:
- * ** This implementation assumes that ints are 32-bit quantities.
- * ** If the machine stores the least-significant byte of an int in the
- * ** least-addressed byte (eg., VAX and 8086), then LOWBYTEFIRST should be
- * ** set to TRUE. Otherwise (eg., SUNS), LOWBYTEFIRST should be set to
- * ** FALSE. Note that on machines with LOWBYTEFIRST FALSE the routine
- * ** MDupdate modifies has a side-effect on its input array (the order of bytes
- * ** in each word are reversed). If this is undesired a call to MDreverse(X) can
- * ** reverse the bytes of X back into order after each call to MDupdate.
- */
- /*
- * code uses WORDS_BIGENDIAN defined by configure now -- WH 9/27/95
- */
- /*
- * Compile-time includes
- */
- #include <net-snmp/net-snmp-config.h>
- #ifndef DISABLE_MD5
- #include <stdio.h>
- #include <sys/types.h>
- #if HAVE_STRING_H
- #include <string.h>
- #else
- #include <strings.h>
- #endif
- #if HAVE_WINSOCK_H
- #include <winsock.h>
- #endif
- #if HAVE_STDLIB_H
- #include <stdlib.h>
- #endif
- #include <net-snmp/utilities.h>
- #include <net-snmp/library/md5.h>
- /*
- * Compile-time declarations of MD5 ``magic constants''.
- */
- #define I0 0x67452301 /* Initial values for MD buffer */
- #define I1 0xefcdab89
- #define I2 0x98badcfe
- #define I3 0x10325476
- #define fs1 7 /* round 1 shift amounts */
- #define fs2 12
- #define fs3 17
- #define fs4 22
- #define gs1 5 /* round 2 shift amounts */
- #define gs2 9
- #define gs3 14
- #define gs4 20
- #define hs1 4 /* round 3 shift amounts */
- #define hs2 11
- #define hs3 16
- #define hs4 23
- #define is1 6 /* round 4 shift amounts */
- #define is2 10
- #define is3 15
- #define is4 21
- /*
- * Compile-time macro declarations for MD5.
- * ** Note: The ``rot'' operator uses the variable ``tmp''.
- * ** It assumes tmp is declared as unsigned int, so that the >>
- * ** operator will shift in zeros rather than extending the sign bit.
- */
- #define f(X,Y,Z) ((X&Y) | ((~X)&Z))
- #define g(X,Y,Z) ((X&Z) | (Y&(~Z)))
- #define h(X,Y,Z) (X^Y^Z)
- #define i_(X,Y,Z) (Y ^ ((X) | (~Z)))
- #define rot(X,S) (tmp=X,(tmp<<S) | (tmp>>(32-S)))
- #define ff(A,B,C,D,i,s,lp) A = rot((A + f(B,C,D) + X[i] + lp),s) + B
- #define gg(A,B,C,D,i,s,lp) A = rot((A + g(B,C,D) + X[i] + lp),s) + B
- #define hh(A,B,C,D,i,s,lp) A = rot((A + h(B,C,D) + X[i] + lp),s) + B
- #define ii(A,B,C,D,i,s,lp) A = rot((A + i_(B,C,D) + X[i] + lp),s) + B
- #ifdef STDC_HEADERS
- #define Uns(num) num##U
- #else
- #define Uns(num) num
- #endif /* STDC_HEADERS */
- void MDreverse(unsigned int *);
- static void MDblock(MDptr, unsigned int *);
- #ifdef SNMP_TESTING_CODE
- /*
- * MDprint(MDp)
- * ** Print message digest buffer MDp as 32 hexadecimal digits.
- * ** Order is from low-order byte of buffer[0] to high-order byte of buffer[3].
- * ** Each byte is printed with high-order hexadecimal digit first.
- * ** This is a user-callable routine.
- */
- void
- MDprint(MDptr MDp)
- {
- int i, j;
- for (i = 0; i < 4; i++)
- for (j = 0; j < 32; j = j + 8)
- printf("%02x", (MDp->buffer[i] >> j) & 0xFF);
- printf("n");
- fflush(stdout);
- }
- #endif /* SNMP_TESTING_CODE */
- /*
- * MDbegin(MDp)
- * ** Initialize message digest buffer MDp.
- * ** This is a user-callable routine.
- */
- void
- MDbegin(MDptr MDp)
- {
- int i;
- MDp->buffer[0] = I0;
- MDp->buffer[1] = I1;
- MDp->buffer[2] = I2;
- MDp->buffer[3] = I3;
- for (i = 0; i < 8; i++)
- MDp->count[i] = 0;
- MDp->done = 0;
- }
- /*
- * MDreverse(X)
- * ** Reverse the byte-ordering of every int in X.
- * ** Assumes X is an array of 16 ints.
- * ** The macro revx reverses the byte-ordering of the next word of X.
- */
- #define revx { t = (*X << 16) | (*X >> 16);
- *X++ = ((t & 0xFF00FF00) >> 8) | ((t & 0x00FF00FF) << 8); }
- void
- MDreverse(unsigned int *X)
- {
- register unsigned int t;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- revx;
- }
- /*
- * MDblock(MDp,X)
- * ** Update message digest buffer MDp->buffer using 16-word data block X.
- * ** Assumes all 16 words of X are full of data.
- * ** Does not update MDp->count.
- * ** This routine is not user-callable.
- */
- static void
- MDblock(MDptr MDp, unsigned int *X)
- {
- register unsigned int tmp, A, B, C, D; /* hpux sysv sun */
- #ifdef WORDS_BIGENDIAN
- MDreverse(X);
- #endif
- A = MDp->buffer[0];
- B = MDp->buffer[1];
- C = MDp->buffer[2];
- D = MDp->buffer[3];
- /*
- * Update the message digest buffer
- */
- ff(A, B, C, D, 0, fs1, Uns(3614090360)); /* Round 1 */
- ff(D, A, B, C, 1, fs2, Uns(3905402710));
- ff(C, D, A, B, 2, fs3, Uns(606105819));
- ff(B, C, D, A, 3, fs4, Uns(3250441966));
- ff(A, B, C, D, 4, fs1, Uns(4118548399));
- ff(D, A, B, C, 5, fs2, Uns(1200080426));
- ff(C, D, A, B, 6, fs3, Uns(2821735955));
- ff(B, C, D, A, 7, fs4, Uns(4249261313));
- ff(A, B, C, D, 8, fs1, Uns(1770035416));
- ff(D, A, B, C, 9, fs2, Uns(2336552879));
- ff(C, D, A, B, 10, fs3, Uns(4294925233));
- ff(B, C, D, A, 11, fs4, Uns(2304563134));
- ff(A, B, C, D, 12, fs1, Uns(1804603682));
- ff(D, A, B, C, 13, fs2, Uns(4254626195));
- ff(C, D, A, B, 14, fs3, Uns(2792965006));
- ff(B, C, D, A, 15, fs4, Uns(1236535329));
- gg(A, B, C, D, 1, gs1, Uns(4129170786)); /* Round 2 */
- gg(D, A, B, C, 6, gs2, Uns(3225465664));
- gg(C, D, A, B, 11, gs3, Uns(643717713));
- gg(B, C, D, A, 0, gs4, Uns(3921069994));
- gg(A, B, C, D, 5, gs1, Uns(3593408605));
- gg(D, A, B, C, 10, gs2, Uns(38016083));
- gg(C, D, A, B, 15, gs3, Uns(3634488961));
- gg(B, C, D, A, 4, gs4, Uns(3889429448));
- gg(A, B, C, D, 9, gs1, Uns(568446438));
- gg(D, A, B, C, 14, gs2, Uns(3275163606));
- gg(C, D, A, B, 3, gs3, Uns(4107603335));
- gg(B, C, D, A, 8, gs4, Uns(1163531501));
- gg(A, B, C, D, 13, gs1, Uns(2850285829));
- gg(D, A, B, C, 2, gs2, Uns(4243563512));
- gg(C, D, A, B, 7, gs3, Uns(1735328473));
- gg(B, C, D, A, 12, gs4, Uns(2368359562));
- hh(A, B, C, D, 5, hs1, Uns(4294588738)); /* Round 3 */
- hh(D, A, B, C, 8, hs2, Uns(2272392833));
- hh(C, D, A, B, 11, hs3, Uns(1839030562));
- hh(B, C, D, A, 14, hs4, Uns(4259657740));
- hh(A, B, C, D, 1, hs1, Uns(2763975236));
- hh(D, A, B, C, 4, hs2, Uns(1272893353));
- hh(C, D, A, B, 7, hs3, Uns(4139469664));
- hh(B, C, D, A, 10, hs4, Uns(3200236656));
- hh(A, B, C, D, 13, hs1, Uns(681279174));
- hh(D, A, B, C, 0, hs2, Uns(3936430074));
- hh(C, D, A, B, 3, hs3, Uns(3572445317));
- hh(B, C, D, A, 6, hs4, Uns(76029189));
- hh(A, B, C, D, 9, hs1, Uns(3654602809));
- hh(D, A, B, C, 12, hs2, Uns(3873151461));
- hh(C, D, A, B, 15, hs3, Uns(530742520));
- hh(B, C, D, A, 2, hs4, Uns(3299628645));
- ii(A, B, C, D, 0, is1, Uns(4096336452)); /* Round 4 */
- ii(D, A, B, C, 7, is2, Uns(1126891415));
- ii(C, D, A, B, 14, is3, Uns(2878612391));
- ii(B, C, D, A, 5, is4, Uns(4237533241));
- ii(A, B, C, D, 12, is1, Uns(1700485571));
- ii(D, A, B, C, 3, is2, Uns(2399980690));
- ii(C, D, A, B, 10, is3, Uns(4293915773));
- ii(B, C, D, A, 1, is4, Uns(2240044497));
- ii(A, B, C, D, 8, is1, Uns(1873313359));
- ii(D, A, B, C, 15, is2, Uns(4264355552));
- ii(C, D, A, B, 6, is3, Uns(2734768916));
- ii(B, C, D, A, 13, is4, Uns(1309151649));
- ii(A, B, C, D, 4, is1, Uns(4149444226));
- ii(D, A, B, C, 11, is2, Uns(3174756917));
- ii(C, D, A, B, 2, is3, Uns(718787259));
- ii(B, C, D, A, 9, is4, Uns(3951481745));
- MDp->buffer[0] += A;
- MDp->buffer[1] += B;
- MDp->buffer[2] += C;
- MDp->buffer[3] += D;
- #ifdef WORDS_BIGENDIAN
- MDreverse(X);
- #endif
- }
- /*
- * MDupdate(MDp,X,count)
- * ** Input: MDp -- an MDptr
- * ** X -- a pointer to an array of unsigned characters.
- * ** count -- the number of bits of X to use.
- * ** (if not a multiple of 8, uses high bits of last byte.)
- * ** Update MDp using the number of bits of X given by count.
- * ** This is the basic input routine for an MD5 user.
- * ** The routine completes the MD computation when count < 512, so
- * ** every MD computation should end with one call to MDupdate with a
- * ** count less than 512. A call with count 0 will be ignored if the
- * ** MD has already been terminated (done != 0), so an extra call with count
- * ** 0 can be given as a ``courtesy close'' to force termination if desired.
- * ** Returns : 0 if processing succeeds or was already done;
- * ** -1 if processing was already done
- * ** -2 if count was too large
- */
- int
- MDupdate(MDptr MDp, unsigned char *X, unsigned int count)
- {
- unsigned int i, tmp, bit, byte, mask;
- unsigned char XX[64];
- unsigned char *p;
- /*
- * return with no error if this is a courtesy close with count
- * ** zero and MDp->done is true.
- */
- if (count == 0 && MDp->done)
- return 0;
- /*
- * check to see if MD is already done and report error
- */
- if (MDp->done) {
- return -1;
- }
- /*
- * if (MDp->done) { fprintf(stderr,"nError: MDupdate MD already done."); return; }
- */
- /*
- * Add count to MDp->count
- */
- tmp = count;
- p = MDp->count;
- while (tmp) {
- tmp += *p;
- *p++ = tmp;
- tmp = tmp >> 8;
- }
- /*
- * Process data
- */
- if (count == 512) { /* Full block of data to handle */
- MDblock(MDp, (unsigned int *) X);
- } else if (count > 512) /* Check for count too large */
- return -2;
- /*
- * { fprintf(stderr,"nError: MDupdate called with illegal count value %d.",count);
- * return;
- * }
- */
- else { /* partial block -- must be last block so finish up */
- /*
- * Find out how many bytes and residual bits there are
- */
- int copycount;
- byte = count >> 3;
- bit = count & 7;
- copycount = byte;
- if (bit)
- copycount++;
- /*
- * Copy X into XX since we need to modify it
- */
- memset(XX, 0, sizeof(XX));
- memcpy(XX, X, copycount);
- /*
- * Add padding '1' bit and low-order zeros in last byte
- */
- mask = ((unsigned long) 1) << (7 - bit);
- XX[byte] = (XX[byte] | mask) & ~(mask - 1);
- /*
- * If room for bit count, finish up with this block
- */
- if (byte <= 55) {
- for (i = 0; i < 8; i++)
- XX[56 + i] = MDp->count[i];
- MDblock(MDp, (unsigned int *) XX);
- } else { /* need to do two blocks to finish up */
- MDblock(MDp, (unsigned int *) XX);
- for (i = 0; i < 56; i++)
- XX[i] = 0;
- for (i = 0; i < 8; i++)
- XX[56 + i] = MDp->count[i];
- MDblock(MDp, (unsigned int *) XX);
- }
- /*
- * Set flag saying we're done with MD computation
- */
- MDp->done = 1;
- }
- return 0;
- }
- /*
- * MDchecksum(data, len, MD5): do a checksum on an arbirtrary amount of data
- */
- int
- MDchecksum(u_char * data, size_t len, u_char * mac, size_t maclen)
- {
- MDstruct md;
- MDstruct *MD = &md;
- int rc = 0;
- MDbegin(MD);
- while (len >= 64) {
- rc = MDupdate(MD, data, 64 * 8);
- if (rc)
- goto check_end;
- data += 64;
- len -= 64;
- }
- rc = MDupdate(MD, data, len * 8);
- if (rc)
- goto check_end;
- /*
- * copy the checksum to the outgoing data (all of it that is requested).
- */
- MDget(MD, mac, maclen);
- check_end:
- memset(&md, 0, sizeof(md));
- return rc;
- }
- /*
- * MDsign(data, len, MD5): do a checksum on an arbirtrary amount
- * of data, and prepended with a secret in the standard fashion
- */
- int
- MDsign(u_char * data, size_t len, u_char * mac, size_t maclen,
- u_char * secret, size_t secretlen)
- {
- #define HASHKEYLEN 64
- MDstruct MD;
- u_char K1[HASHKEYLEN];
- u_char K2[HASHKEYLEN];
- u_char extendedAuthKey[HASHKEYLEN];
- u_char buf[HASHKEYLEN];
- size_t i;
- u_char *cp, *newdata = 0;
- int rc = 0;
- /*
- * memset(K1,0,HASHKEYLEN);
- * memset(K2,0,HASHKEYLEN);
- * memset(buf,0,HASHKEYLEN);
- * memset(extendedAuthKey,0,HASHKEYLEN);
- */
- if (secretlen != 16 || secret == NULL || mac == NULL || data == NULL ||
- len <= 0 || maclen <= 0) {
- /*
- * DEBUGMSGTL(("md5","MD5 signing not properly initialized"));
- */
- return -1;
- }
- memset(extendedAuthKey, 0, HASHKEYLEN);
- memcpy(extendedAuthKey, secret, secretlen);
- for (i = 0; i < HASHKEYLEN; i++) {
- K1[i] = extendedAuthKey[i] ^ 0x36;
- K2[i] = extendedAuthKey[i] ^ 0x5c;
- }
- MDbegin(&MD);
- rc = MDupdate(&MD, K1, HASHKEYLEN * 8);
- if (rc)
- goto update_end;
- i = len;
- if (((unsigned int) data) % sizeof(long) != 0) {
- /*
- * this relies on the ability to use integer math and thus we
- * must rely on data that aligns on 32-bit-word-boundries
- */
- memdup(&newdata, data, len);
- cp = newdata;
- } else {
- cp = data;
- }
- while (i >= 64) {
- rc = MDupdate(&MD, cp, 64 * 8);
- if (rc)
- goto update_end;
- cp += 64;
- i -= 64;
- }
- rc = MDupdate(&MD, cp, i * 8);
- if (rc)
- goto update_end;
- memset(buf, 0, HASHKEYLEN);
- MDget(&MD, buf, HASHKEYLEN);
- MDbegin(&MD);
- rc = MDupdate(&MD, K2, HASHKEYLEN * 8);
- if (rc)
- goto update_end;
- rc = MDupdate(&MD, buf, 16 * 8);
- if (rc)
- goto update_end;
- /*
- * copy the sign checksum to the outgoing pointer
- */
- MDget(&MD, mac, maclen);
- update_end:
- memset(buf, 0, HASHKEYLEN);
- memset(K1, 0, HASHKEYLEN);
- memset(K2, 0, HASHKEYLEN);
- memset(extendedAuthKey, 0, HASHKEYLEN);
- memset(&MD, 0, sizeof(MD));
- if (newdata)
- free(newdata);
- return rc;
- }
- void
- MDget(MDstruct * MD, u_char * buf, size_t buflen)
- {
- int i, j;
- /*
- * copy the checksum to the outgoing data (all of it that is requested).
- */
- for (i = 0; i < 4 && i * 4 < (int) buflen; i++)
- for (j = 0; j < 4 && i * 4 + j < (int) buflen; j++)
- buf[i * 4 + j] = (MD->buffer[i] >> j * 8) & 0xff;
- }
- /*
- * ** End of md5.c
- * ****************************(cut)****************************************
- */
- #endif /* DISABLE_MD5 */