-/*
- Copyright (C) Andrew Tridgell 1996
- Copyright (C) Paul Mackerras 1996
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
+/*
+ * Routines to support checksumming of bytes.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2004-2020 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to dynamically link rsync with the OpenSSL and xxhash
+ * libraries when those libraries are being distributed in compliance
+ * with their license terms, and to distribute a dynamically linked
+ * combination of rsync and these libraries. This is also considered
+ * to be covered under the GPL's System Libraries exception.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
#include "rsync.h"
+#ifdef SUPPORT_XXHASH
+#include "xxhash.h"
+#endif
+#ifdef USE_OPENSSL
+#include "openssl/md4.h"
+#include "openssl/md5.h"
+#endif
-int csum_length=SUM_LENGTH;
-
-#define CSUM_CHUNK 64
+extern int am_server;
+extern int whole_file;
+extern int checksum_seed;
+extern int protocol_version;
+extern int proper_seed_order;
+extern char *checksum_choice;
+
+#define CSUM_NONE 0
+#define CSUM_MD4_ARCHAIC 1
+#define CSUM_MD4_BUSTED 2
+#define CSUM_MD4_OLD 3
+#define CSUM_MD4 4
+#define CSUM_MD5 5
+#define CSUM_XXH64 6
+
+struct name_num_obj valid_checksums = {
+ "checksum", NULL, NULL, 0, 0, {
+#ifdef SUPPORT_XXHASH
+ { CSUM_XXH64, "xxh64", NULL },
+ { CSUM_XXH64, "xxhash", NULL },
+#endif
+ { CSUM_MD5, "md5", NULL },
+ { CSUM_MD4, "md4", NULL },
+ { CSUM_NONE, "none", NULL },
+ { 0, NULL, NULL }
+ }
+};
+
+#ifndef USE_OPENSSL
+#define MD5_CTX md_context
+#define MD5_Init md5_begin
+#define MD5_Update md5_update
+#define MD5_Final(digest, cptr) md5_result(cptr, digest)
+#endif
-int checksum_seed = 0;
+int xfersum_type = 0; /* used for the file transfer checksums */
+int checksum_type = 0; /* used for the pre-transfer (--checksum) checksums */
-/*
- a simple 32 bit checksum that can be upadted from either end
- (inspired by Mark Adler's Adler-32 checksum)
- */
-uint32 get_checksum1(char *buf,int len)
+static int parse_csum_name(const char *name, int len)
{
- int i;
- uint32 s1, s2;
-
- s1 = s2 = 0;
- for (i = 0; i < (len-4); i+=4) {
- s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3];
- s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3]);
- }
- for (; i < len; i++) {
- s1 += buf[i]; s2 += s1;
- }
- return (s1 & 0xffff) + (s2 << 16);
-}
+ struct name_num_item *nni;
+
+ if (len < 0 && name)
+ len = strlen(name);
+
+ if (!name || (len == 4 && strncasecmp(name, "auto", 4) == 0)) {
+ if (protocol_version >= 30)
+ return CSUM_MD5;
+ if (protocol_version >= 27)
+ return CSUM_MD4_OLD;
+ if (protocol_version >= 21)
+ return CSUM_MD4_BUSTED;
+ return CSUM_MD4_ARCHAIC;
+ }
+
+ nni = get_nni_by_name(&valid_checksums, name, len);
+ if (!nni) {
+ rprintf(FERROR, "unknown checksum name: %s\n", name);
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
-static void sum_put(MDstruct *md,char *sum)
+ return nni->num;
+}
+
+static const char *checksum_name(int num)
{
- SIVAL(sum,0,md->buffer[0]);
- if (csum_length <= 4) return;
- SIVAL(sum,4,md->buffer[1]);
- if (csum_length <= 8) return;
- SIVAL(sum,8,md->buffer[2]);
- if (csum_length <= 12) return;
- SIVAL(sum,12,md->buffer[3]);
+ struct name_num_item *nni = get_nni_by_num(&valid_checksums, num);
+
+ return nni ? nni->name : num < CSUM_MD4 ? "MD4" : "UNKNOWN";
}
+void parse_checksum_choice(int final_call)
+{
+ if (valid_checksums.negotiated_name)
+ xfersum_type = checksum_type = valid_checksums.negotiated_num;
+ else {
+ char *cp = checksum_choice ? strchr(checksum_choice, ',') : NULL;
+ if (cp) {
+ xfersum_type = parse_csum_name(checksum_choice, cp - checksum_choice);
+ checksum_type = parse_csum_name(cp+1, -1);
+ } else
+ xfersum_type = checksum_type = parse_csum_name(checksum_choice, -1);
+ }
+
+ if (xfersum_type == CSUM_NONE)
+ whole_file = 1;
+
+ if (final_call && DEBUG_GTE(NSTR, am_server ? 3 : 1)) {
+ const char *c_s = am_server ? "Server" : "Client";
+ if (valid_checksums.negotiated_name)
+ rprintf(FINFO, "%s negotiated checksum: %s\n", c_s, valid_checksums.negotiated_name);
+ else if (xfersum_type == checksum_type) {
+ rprintf(FINFO, "%s %s checksum: %s\n", c_s,
+ checksum_choice ? "chosen" : "protocol-based",
+ checksum_name(xfersum_type));
+ } else {
+ rprintf(FINFO, "%s chosen transfer checksum: %s\n", c_s, checksum_name(xfersum_type));
+ rprintf(FINFO, "%s chosen pre-transfer checksum: %s\n", c_s, checksum_name(checksum_type));
+ }
+ }
+}
-void get_checksum2(char *buf,int len,char *sum)
+int csum_len_for_type(int cst, BOOL flist_csum)
{
- int i;
- MDstruct MD;
- static char *buf1 = NULL;
- static int len1 = 0;
-
- if (len > len1) {
- if (buf1) free(buf1);
- buf1 = (char *)malloc(len+4);
- len1 = len;
- if (!buf1) out_of_memory("get_checksum2");
- }
-
- MDbegin(&MD);
-
- bcopy(buf,buf1,len);
- if (checksum_seed) {
- SIVAL(buf1,len,checksum_seed);
- len += 4;
- }
-
- for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
- MDupdate(&MD, buf1+i, CSUM_CHUNK*8);
- }
- if (len - i > 0)
- MDupdate(&MD, buf1+i, (len-i)*8);
-
- sum_put(&MD,sum);
+ switch (cst) {
+ case CSUM_NONE:
+ return 1;
+ case CSUM_MD4_ARCHAIC:
+ /* The oldest checksum code is rather weird: the file-list code only sent
+ * 2-byte checksums, but all other checksums were full MD4 length. */
+ return flist_csum ? 2 : MD4_DIGEST_LEN;
+ case CSUM_MD4:
+ case CSUM_MD4_OLD:
+ case CSUM_MD4_BUSTED:
+ return MD4_DIGEST_LEN;
+ case CSUM_MD5:
+ return MD5_DIGEST_LEN;
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64:
+ return 64/8;
+#endif
+ default: /* paranoia to prevent missing case values */
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
+ return 0;
}
+int canonical_checksum(int csum_type)
+{
+ return csum_type >= CSUM_MD4 ? 1 : 0;
+}
-void file_checksum(char *fname,char *sum,off_t size)
+#ifndef HAVE_SIMD /* See simd-checksum-*.cpp. */
+/*
+ a simple 32 bit checksum that can be updated from either end
+ (inspired by Mark Adler's Adler-32 checksum)
+ */
+uint32 get_checksum1(char *buf1, int32 len)
{
- int i;
- MDstruct MD;
- struct map_struct *buf;
- int fd;
- int len = size;
- char tmpchunk[CSUM_CHUNK];
+ int32 i;
+ uint32 s1, s2;
+ schar *buf = (schar *)buf1;
+
+ s1 = s2 = 0;
+ for (i = 0; i < (len-4); i+=4) {
+ s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3] + 10*CHAR_OFFSET;
+ s1 += (buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3] + 4*CHAR_OFFSET);
+ }
+ for (; i < len; i++) {
+ s1 += (buf[i]+CHAR_OFFSET); s2 += s1;
+ }
+ return (s1 & 0xffff) + (s2 << 16);
+}
+#endif
- bzero(sum,csum_length);
+void get_checksum2(char *buf, int32 len, char *sum)
+{
+ switch (xfersum_type) {
+ case CSUM_MD5: {
+ MD5_CTX m5;
+ uchar seedbuf[4];
+ MD5_Init(&m5);
+ if (proper_seed_order) {
+ if (checksum_seed) {
+ SIVALu(seedbuf, 0, checksum_seed);
+ MD5_Update(&m5, seedbuf, 4);
+ }
+ MD5_Update(&m5, (uchar *)buf, len);
+ } else {
+ MD5_Update(&m5, (uchar *)buf, len);
+ if (checksum_seed) {
+ SIVALu(seedbuf, 0, checksum_seed);
+ MD5_Update(&m5, seedbuf, 4);
+ }
+ }
+ MD5_Final((uchar *)sum, &m5);
+ break;
+ }
+ case CSUM_MD4:
+#ifdef USE_OPENSSL
+ {
+ MD4_CTX m4;
+ MD4_Init(&m4);
+ MD4_Update(&m4, (uchar *)buf, len);
+ if (checksum_seed) {
+ uchar seedbuf[4];
+ SIVALu(seedbuf, 0, checksum_seed);
+ MD4_Update(&m4, seedbuf, 4);
+ }
+ MD4_Final((uchar *)sum, &m4);
+ break;
+ }
+#endif
+ case CSUM_MD4_OLD:
+ case CSUM_MD4_BUSTED:
+ case CSUM_MD4_ARCHAIC: {
+ md_context m;
+ int32 i;
+ static char *buf1;
+ static int32 len1;
+
+ mdfour_begin(&m);
+
+ if (len > len1) {
+ if (buf1)
+ free(buf1);
+ buf1 = new_array(char, len+4);
+ len1 = len;
+ if (!buf1)
+ out_of_memory("get_checksum2");
+ }
+
+ memcpy(buf1, buf, len);
+ if (checksum_seed) {
+ SIVAL(buf1,len,checksum_seed);
+ len += 4;
+ }
+
+ for (i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK)
+ mdfour_update(&m, (uchar *)(buf1+i), CSUM_CHUNK);
+
+ /*
+ * Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes.
+ */
+ if (len - i > 0 || xfersum_type > CSUM_MD4_BUSTED)
+ mdfour_update(&m, (uchar *)(buf1+i), len-i);
+
+ mdfour_result(&m, (uchar *)sum);
+ break;
+ }
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64:
+ SIVAL64(sum, 0, XXH64(buf, len, checksum_seed));
+ break;
+#endif
+ default: /* paranoia to prevent missing case values */
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
+}
- fd = open(fname,O_RDONLY);
- if (fd == -1) return;
+void file_checksum(const char *fname, const STRUCT_STAT *st_p, char *sum)
+{
+ struct map_struct *buf;
+ OFF_T i, len = st_p->st_size;
+ int32 remainder;
+ int fd;
- buf = map_file(fd,size);
+ memset(sum, 0, MAX_DIGEST_LEN);
- MDbegin(&MD);
+ fd = do_open(fname, O_RDONLY, 0);
+ if (fd == -1)
+ return;
- for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
- bcopy(map_ptr(buf,i,CSUM_CHUNK),tmpchunk,CSUM_CHUNK);
- MDupdate(&MD, tmpchunk, CSUM_CHUNK*8);
- }
+ buf = map_file(fd, len, MAX_MAP_SIZE, CHUNK_SIZE);
- if (len - i > 0) {
- bcopy(map_ptr(buf,i,len-i),tmpchunk,len-i);
- MDupdate(&MD, tmpchunk, (len-i)*8);
- }
+ switch (checksum_type) {
+ case CSUM_MD5: {
+ MD5_CTX m5;
- sum_put(&MD,sum);
+ MD5_Init(&m5);
- close(fd);
- unmap_file(buf);
-}
+ for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE)
+ MD5_Update(&m5, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);
+ remainder = (int32)(len - i);
+ if (remainder > 0)
+ MD5_Update(&m5, (uchar *)map_ptr(buf, i, remainder), remainder);
-void checksum_init(void)
-{
-}
+ MD5_Final((uchar *)sum, &m5);
+ break;
+ }
+ case CSUM_MD4:
+#ifdef USE_OPENSSL
+ {
+ MD4_CTX m4;
+ MD4_Init(&m4);
+ for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE)
+ MD4_Update(&m4, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);
-static MDstruct sumMD;
-static int sumresidue;
-static char sumrbuf[CSUM_CHUNK];
+ remainder = (int32)(len - i);
+ if (remainder > 0)
+ MD4_Update(&m4, (uchar *)map_ptr(buf, i, remainder), remainder);
-void sum_init(void)
-{
- MDbegin(&sumMD);
- sumresidue=0;
+ MD4_Final((uchar *)sum, &m4);
+ break;
+ }
+#endif
+ case CSUM_MD4_OLD:
+ case CSUM_MD4_BUSTED:
+ case CSUM_MD4_ARCHAIC: {
+ md_context m;
+
+ mdfour_begin(&m);
+
+ for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE)
+ mdfour_update(&m, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);
+
+ /* Prior to version 27 an incorrect MD4 checksum was computed
+ * by failing to call mdfour_tail() for block sizes that
+ * are multiples of 64. This is fixed by calling mdfour_update()
+ * even when there are no more bytes. */
+ remainder = (int32)(len - i);
+ if (remainder > 0 || checksum_type > CSUM_MD4_BUSTED)
+ mdfour_update(&m, (uchar *)map_ptr(buf, i, remainder), remainder);
+
+ mdfour_result(&m, (uchar *)sum);
+ break;
+ }
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64: {
+ XXH64_state_t* state = XXH64_createState();
+ if (state == NULL)
+ out_of_memory("file_checksum XXH64");
+
+ if (XXH64_reset(state, 0) == XXH_ERROR) {
+ rprintf(FERROR, "error resetting XXH64 seed");
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ for (i = 0; i + CHUNK_SIZE <= len; i += CHUNK_SIZE) {
+ XXH_errorcode const updateResult =
+ XXH64_update(state, (uchar *)map_ptr(buf, i, CHUNK_SIZE), CHUNK_SIZE);
+ if (updateResult == XXH_ERROR) {
+ rprintf(FERROR, "error computing XXH64 hash");
+ exit_cleanup(RERR_STREAMIO);
+ }
+ }
+
+ remainder = (int32)(len - i);
+ if (remainder > 0)
+ XXH64_update(state, (uchar *)map_ptr(buf, i, remainder), remainder);
+ SIVAL64(sum, 0, XXH64_digest(state));
+
+ XXH64_freeState(state);
+ break;
+ }
+#endif
+ default:
+ rprintf(FERROR, "Invalid checksum-choice for --checksum: %s (%d)\n",
+ checksum_name(checksum_type), checksum_type);
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
+
+ close(fd);
+ unmap_file(buf);
}
-void sum_update(char *p,int len)
+static int32 sumresidue;
+static union {
+ md_context md;
+#ifdef USE_OPENSSL
+ MD4_CTX m4;
+#endif
+ MD5_CTX m5;
+} ctx;
+#ifdef SUPPORT_XXHASH
+static XXH64_state_t* xxh64_state;
+#endif
+static int cursum_type;
+
+void sum_init(int csum_type, int seed)
{
- int i;
- if (sumresidue) {
- i = MIN(CSUM_CHUNK-sumresidue,len);
- bcopy(p,sumrbuf+sumresidue,i);
- MDupdate(&sumMD, sumrbuf, (i+sumresidue)*8);
- len -= i;
- p += i;
- }
-
- for(i = 0; i + CSUM_CHUNK <= len; i += CSUM_CHUNK) {
- bcopy(p+i,sumrbuf,CSUM_CHUNK);
- MDupdate(&sumMD, sumrbuf, CSUM_CHUNK*8);
- }
-
- if (len - i > 0) {
- sumresidue = len-i;
- bcopy(p+i,sumrbuf,sumresidue);
- } else {
- sumresidue = 0;
- }
+ char s[4];
+
+ if (csum_type < 0)
+ csum_type = parse_csum_name(NULL, 0);
+ cursum_type = csum_type;
+
+ switch (csum_type) {
+ case CSUM_MD5:
+ MD5_Init(&ctx.m5);
+ break;
+ case CSUM_MD4:
+#ifdef USE_OPENSSL
+ MD4_Init(&ctx.m4);
+#else
+ mdfour_begin(&ctx.md);
+ sumresidue = 0;
+#endif
+ break;
+ case CSUM_MD4_OLD:
+ case CSUM_MD4_BUSTED:
+ case CSUM_MD4_ARCHAIC:
+ mdfour_begin(&ctx.md);
+ sumresidue = 0;
+ SIVAL(s, 0, seed);
+ sum_update(s, 4);
+ break;
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64:
+ if (xxh64_state == NULL) {
+ xxh64_state = XXH64_createState();
+ if (xxh64_state == NULL)
+ out_of_memory("sum_init xxh64");
+ }
+ if (XXH64_reset(xxh64_state, 0) == XXH_ERROR) {
+ rprintf(FERROR, "error resetting XXH64 state");
+ exit_cleanup(RERR_STREAMIO);
+ }
+ break;
+#endif
+ case CSUM_NONE:
+ break;
+ default: /* paranoia to prevent missing case values */
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
}
-void sum_end(char *sum)
+/**
+ * Feed data into an MD4 accumulator, md. The results may be
+ * retrieved using sum_end(). md is used for different purposes at
+ * different points during execution.
+ *
+ * @todo Perhaps get rid of md and just pass in the address each time.
+ * Very slightly clearer and slower.
+ **/
+void sum_update(const char *p, int32 len)
{
- if (sumresidue)
- MDupdate(&sumMD, sumrbuf, sumresidue*8);
-
- SIVAL(sum,0,sumMD.buffer[0]);
- SIVAL(sum,4,sumMD.buffer[1]);
- SIVAL(sum,8,sumMD.buffer[2]);
- SIVAL(sum,12,sumMD.buffer[3]);
+ switch (cursum_type) {
+ case CSUM_MD5:
+ MD5_Update(&ctx.m5, (uchar *)p, len);
+ break;
+ case CSUM_MD4:
+#ifdef USE_OPENSSL
+ MD4_Update(&ctx.m4, (uchar *)p, len);
+ break;
+#endif
+ case CSUM_MD4_OLD:
+ case CSUM_MD4_BUSTED:
+ case CSUM_MD4_ARCHAIC:
+ if (len + sumresidue < CSUM_CHUNK) {
+ memcpy(ctx.md.buffer + sumresidue, p, len);
+ sumresidue += len;
+ break;
+ }
+
+ if (sumresidue) {
+ int32 i = CSUM_CHUNK - sumresidue;
+ memcpy(ctx.md.buffer + sumresidue, p, i);
+ mdfour_update(&ctx.md, (uchar *)ctx.md.buffer, CSUM_CHUNK);
+ len -= i;
+ p += i;
+ }
+
+ while (len >= CSUM_CHUNK) {
+ mdfour_update(&ctx.md, (uchar *)p, CSUM_CHUNK);
+ len -= CSUM_CHUNK;
+ p += CSUM_CHUNK;
+ }
+
+ sumresidue = len;
+ if (sumresidue)
+ memcpy(ctx.md.buffer, p, sumresidue);
+ break;
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64:
+ if (XXH64_update(xxh64_state, p, len) == XXH_ERROR) {
+ rprintf(FERROR, "error computing XXH64 hash");
+ exit_cleanup(RERR_STREAMIO);
+ }
+ break;
+#endif
+ case CSUM_NONE:
+ break;
+ default: /* paranoia to prevent missing case values */
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
}
-
-#ifdef CHECKSUM_MAIN
- int main(int argc,char *argv[])
+/* NOTE: all the callers of sum_end() pass in a pointer to a buffer that is
+ * MAX_DIGEST_LEN in size, so even if the csum-len is shorter that that (i.e.
+ * CSUM_MD4_ARCHAIC), we don't have to worry about limiting the data we write
+ * into the "sum" buffer. */
+int sum_end(char *sum)
{
- char sum[SUM_LENGTH];
- int i,j;
-
- checksum_init();
-
- for (i=1;i<argc;i++) {
- struct stat st;
- if (stat(argv[i],&st) == 0) {
- file_checksum(argv[i],sum,st.st_size);
- for (j=0;j<SUM_LENGTH;j++)
- printf("%02X",(unsigned char)sum[j]);
- printf(" %s\n",argv[i]);
- }
- }
-}
+ switch (cursum_type) {
+ case CSUM_MD5:
+ MD5_Final((uchar *)sum, &ctx.m5);
+ break;
+ case CSUM_MD4:
+#ifdef USE_OPENSSL
+ MD4_Final((uchar *)sum, &ctx.m4);
+ break;
+#endif
+ case CSUM_MD4_OLD:
+ mdfour_update(&ctx.md, (uchar *)ctx.md.buffer, sumresidue);
+ mdfour_result(&ctx.md, (uchar *)sum);
+ break;
+ case CSUM_MD4_BUSTED:
+ case CSUM_MD4_ARCHAIC:
+ if (sumresidue)
+ mdfour_update(&ctx.md, (uchar *)ctx.md.buffer, sumresidue);
+ mdfour_result(&ctx.md, (uchar *)sum);
+ break;
+#ifdef SUPPORT_XXHASH
+ case CSUM_XXH64:
+ SIVAL64(sum, 0, XXH64_digest(xxh64_state));
+ break;
#endif
+ case CSUM_NONE:
+ *sum = '\0';
+ break;
+ default: /* paranoia to prevent missing case values */
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
+
+ return csum_len_for_type(cursum_type, 0);
+}