hacking the server

diff --git a/server/src/main.c b/server/src/main.c
index c4e0846..a3174d1 100644 (file)
--- a/server/src/main.c
+++ b/server/src/main.c
@@ -2,8 +2,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>

+#include <time.h>

 #include "repo.h"
 
 #include "repo.h"
 

+#include "md5.h"
+

 static const char *guess_repo_name(const char *path);
 static int parse_args(int argc, char **argv);
 
 static const char *guess_repo_name(const char *path);
 static int parse_args(int argc, char **argv);
 

@@ -30,9 +33,13 @@ int main(int argc, char **argv)
 
        /* DBG */
        {
 
        /* DBG */
        {

+               struct md5_state sum;

                int i, count = repo_num_files();
                for(i=0; i<count; i++) {
                int i, count = repo_num_files();
                for(i=0; i<count; i++) {

-                       printf("%s\n", repo_file(i));
+                       struct repo_file *file = repo_file(i);
+                       memcpy(sum.sum, file->chksum, sizeof sum.sum);
+                       printf("%s\tmd5:%s size:%lu mtime:%s", file->path, md5_sumstr(&sum),
+                                       (unsigned long)file->size, ctime(&file->mtime));

                }
        }
 
                }
        }
 

diff --git a/server/src/md5.c b/server/src/md5.c
new file mode 100644 (file)
index 0000000..6b45070
--- /dev/null
+++ b/server/src/md5.c
@@ -0,0 +1,156 @@
+/* MD5 message digest
+ * Author: John Tsiombikas <nuclear@member.fsf.org>
+ *
+ * This software is public domain. Feel free to use it any way you like.
+ *
+ * If public domain is not applicable in your part of the world, you may use
+ * this under the terms of the Creative Commons CC-0 license:
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+#include <stdio.h>
+#include <string.h>
+#include "md5.h"
+
+#define BLOCKSZ 64
+
+static const int shifttab[] = {
+       7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
+       5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
+       4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
+       6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21
+};
+
+static const uint32_t sintab[] = {
+       0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
+       0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
+       0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+       0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
+       0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
+       0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
+       0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
+       0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
+       0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
+       0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
+       0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
+       0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+       0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
+       0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
+       0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+       0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
+};
+
+static void sum_block(uint32_t *blk, uint32_t *sum);
+static uint32_t rol(uint32_t x, int s);
+
+void md5_begin(struct md5_state *md)
+{
+       md->sum[0] = 0x67452301;
+       md->sum[1] = 0xefcdab89;
+       md->sum[2] = 0x98badcfe;
+       md->sum[3] = 0x10325476;
+       md->len = 0;
+       md->bblen = 0;
+}
+
+void md5_msg(struct md5_state *md, void *msg, int msg_size)
+{
+       int pending, sz;
+
+       while(msg_size) {
+               pending = BLOCKSZ - md->bblen;
+               sz = msg_size > pending ? pending : msg_size;
+
+               memcpy(md->blockbuf + md->bblen, msg, sz);
+               msg = (char*)msg + sz;
+               md->bblen += sz;
+               msg_size -= sz;
+
+               if(md->bblen >= BLOCKSZ) {
+                       sum_block((uint32_t*)md->blockbuf, md->sum);
+                       md->bblen = 0;
+                       md->len += BLOCKSZ * 8;
+               }
+       }
+}
+
+static void sum_block(uint32_t *blk, uint32_t *sum)
+{
+       int i, f, g;
+       int a = sum[0];
+       int b = sum[1];
+       int c = sum[2];
+       int d = sum[3];
+
+       for(i=0; i<64; i++) {
+               switch(i >> 4) {
+               case 0:
+                       f = d ^ (b & (c ^ d));
+                       g = i;
+                       break;
+
+               case 1:
+                       f = c ^ (d & (b ^ c));
+                       g = (i * 5 + 1) & 0xf;
+                       break;
+
+               case 2:
+                       f = b ^ c ^ d;
+                       g = (i * 3 + 5) & 0xf;
+                       break;
+
+               case 3:
+                       f = c ^ (b | ~d);
+                       g = (i * 7) & 0xf;
+               }
+
+               f += a + sintab[i] + blk[g];
+               a = d;
+               d = c;
+               c = b;
+               b += rol(f, shifttab[i]);
+       }
+
+       sum[0] += a;
+       sum[1] += b;
+       sum[2] += c;
+       sum[3] += d;
+}
+
+static uint32_t rol(uint32_t x, int s)
+{
+       return (x << s) | (x >> (32 - s));
+}
+
+void md5_end(struct md5_state *md)
+{
+       md->len += md->bblen * 8;
+       md->blockbuf[md->bblen++] = 0x80;       /* append 1-bit plus 8 zeros padding */
+
+       if(md->bblen > BLOCKSZ - 8) {
+               /* pad to BLOCKSZ, sum, then continue with further padding */
+               memset(md->blockbuf + md->bblen, 0, BLOCKSZ - md->bblen);
+               sum_block((uint32_t*)md->blockbuf, md->sum);
+               md->bblen = 0;
+       }
+
+       /* pad to BLOCKSZ - 8 */
+       memset(md->blockbuf + md->bblen, 0, BLOCKSZ - 8 - md->bblen);
+
+       /* add the length */
+       *(uint64_t*)(md->blockbuf + BLOCKSZ - 8) = md->len;
+
+       /* then sum for the last time */
+       sum_block((uint32_t*)md->blockbuf, md->sum);
+}
+
+const char *md5_sumstr(struct md5_state *md)
+{
+       int i;
+       unsigned char *sum = (unsigned char*)md->sum;
+       char *s = (char*)md->blockbuf;
+
+       for(i=0; i<16; i++) {
+               s += sprintf(s, "%02x", sum[i]);
+       }
+       return (char*)md->blockbuf;
+}

diff --git a/server/src/md5.h b/server/src/md5.h
new file mode 100644 (file)
index 0000000..8f6ef38
--- /dev/null
+++ b/server/src/md5.h
@@ -0,0 +1,55 @@
+/* MD5 message digest
+ * Author: John Tsiombikas <nuclear@member.fsf.org>
+ *
+ * This software is public domain. Feel free to use it any way you like.
+ *
+ * If public domain is not applicable in your part of the world, you may use
+ * this under the terms of the Creative Commons CC-0 license:
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ *
+ *
+ * usage example 1: compute the md5 sum of the string "hello world"
+ *
+ *    struct md5_state md;
+ *    md5_begin(&md);
+ *    md5_msg(&md, "hello world", 11);
+ *    md5_end(&md);
+ *
+ * md5 sum in: md5_state.sum[0..4]
+ * To print it you may use the helper function md5_sumstr:
+ *    printf("%s\n", md5_sumstr(&md));
+ *
+ * usage example 2: comput the md5 sum of whatever comes through stdin
+ *
+ *     int sz;
+ *     struct md5_state md;
+ *     char buf[1024];
+ *
+ *     md5_begin(&md);
+ *     while((sz = fread(buf, 1, sizeof buf, stdin)) > 0) {
+ *         md5_msg(&md, buf, sz);
+ *     }
+ *     md5_end(&md);
+ */
+#ifndef NUCLEAR_DROPCODE_MD5_H_
+#define NUCLEAR_DROPCODE_MD5_H_
+
+#include <stdint.h>
+
+struct md5_state {
+       uint32_t sum[4];
+       uint64_t len;
+       unsigned char blockbuf[64];
+       int bblen;
+};
+
+void md5_begin(struct md5_state *md);
+void md5_msg(struct md5_state *md, void *msg, int msg_size);
+void md5_end(struct md5_state *md);
+
+/* after computing the md5 sum, you may use this function to get a pointer
+ * to a canonical string representation of the sum (identical to GNU md5sum)
+ */
+const char *md5_sumstr(struct md5_state *md);
+
+#endif /* NUCLEAR_DROPCODE_MD5_H_ */

diff --git a/server/src/repo.c b/server/src/repo.c
index fee52e8..6f81d90 100644 (file)
--- a/server/src/repo.c
+++ b/server/src/repo.c
@@ -1,22 +1,25 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

+#include <errno.h>
+#include <sys/stat.h>

 #include <git2.h>
 #include <git2.h>

+#include "repo.h"
+#include "md5.h"

 
 

-struct repofile {
-       char *path;
-};
-
+static int add_file(const char *name, const char *path);
+static void calc_chksum(FILE *fp, uint32_t *sum);

 static int proc_tree(git_repository *repo, git_tree *tree, const char *path);
 
 static int proc_tree(git_repository *repo, git_tree *tree, const char *path);
 

-static struct repofile *files;
+static struct repo_file *files;

 static int num_files, max_files;
 static int num_files, max_files;

+static const char *repo_path;

 
 int repo_init(const char *path)
 {
        int res = -1;
        git_repository *repo = 0;
 
 int repo_init(const char *path)
 {
        int res = -1;
        git_repository *repo = 0;

-       git_tree *tree;
+       git_object *tree;

 
        git_libgit2_init();
 
 
        git_libgit2_init();
 

@@ -28,14 +31,16 @@ int repo_init(const char *path)
 
        files = 0;
        num_files = max_files = 0;
 
        files = 0;
        num_files = max_files = 0;

+       repo_path = path;

 
 

-       if(git_revparse_single((git_object**)&tree, repo, "HEAD^{tree}") != 0) {
+       if(git_revparse_single(&tree, repo, "HEAD^{tree}") != 0) {

                fprintf(stderr, "repo_init: %s\n", git_error_last()->message);
                goto end;
        }
                fprintf(stderr, "repo_init: %s\n", git_error_last()->message);
                goto end;
        }

-       if(proc_tree(repo, tree, 0) == -1) {
+       if(proc_tree(repo, (git_tree*)tree, 0) == -1) {

                goto end;
        }
                goto end;
        }

+       git_object_free(tree);

 
        res = 0;
 end:
 
        res = 0;
 end:

@@ -51,6 +56,10 @@ end:
 
 void repo_cleanup(void)
 {
 
 void repo_cleanup(void)
 {

+       int i;
+       for(i=0; i<num_files; i++) {
+               free(files[i].fullpath);
+       }

        free(files);
        files = 0;
        num_files = max_files = 0;
        free(files);
        files = 0;
        num_files = max_files = 0;

@@ -61,16 +70,18 @@ int repo_num_files(void)
        return num_files;
 }
 
        return num_files;
 }
 

-const char *repo_file(int idx)
+struct repo_file *repo_file(int idx)

 {
        if(idx < 0 || idx >= num_files) return 0;
 {
        if(idx < 0 || idx >= num_files) return 0;

-       return files[idx].path;
+       return files + idx;

 }
 
 static int add_file(const char *name, const char *path)
 {
 }
 
 static int add_file(const char *name, const char *path)
 {

-       struct repofile *file;
+       struct repo_file *file;

        int pathlen;
        int pathlen;

+       struct stat st;
+       FILE *fp;

 
        if(num_files >= max_files) {
                int newmax = max_files ? max_files * 2 : 16;
 
        if(num_files >= max_files) {
                int newmax = max_files ? max_files * 2 : 16;

@@ -83,26 +94,59 @@ static int add_file(const char *name, const char *path)
                max_files = newmax;
        }
 
                max_files = newmax;
        }
 

-       pathlen = strlen(name);
+       pathlen = strlen(repo_path) + strlen(name) + 1;

        if(path) {
                pathlen += strlen(path) + 1;
        }
 
        file = files + num_files;
        if(path) {
                pathlen += strlen(path) + 1;
        }
 
        file = files + num_files;

-       if(!(file->path = malloc(pathlen + 1))) {
+       if(!(file->fullpath = malloc(pathlen + 1))) {

                fprintf(stderr, "repo_init: failed to allocate file path buffer\n");
                return -1;
        }
        if(path) {
                fprintf(stderr, "repo_init: failed to allocate file path buffer\n");
                return -1;
        }
        if(path) {

-               sprintf(file->path, "%s/%s", path, name);
+               sprintf(file->fullpath, "%s/%s/%s", repo_path, path, name);

        } else {
        } else {

-               strcpy(file->path, name);
+               sprintf(file->fullpath, "%s/%s", repo_path, name);

        }
        }

+       file->path = file->fullpath + strlen(repo_path) + 1;
+
+       /* attempt to open the file */
+       if(!(fp = fopen(file->fullpath, "rb"))) {
+               fprintf(stderr, "repo_init: failed to open file: %s: %s\n", file->fullpath, strerror(errno));
+               free(file->fullpath);
+               return -1;
+       }
+
+       /* get size & modification time */
+       fstat(fileno(fp), &st);
+       file->size = st.st_size;
+       file->mtime = st.st_mtime;
+
+       /* calculate md5 checksum */
+       calc_chksum(fp, file->chksum);
+
+       fclose(fp);

 
        num_files++;
        return 0;
 }
 
 
        num_files++;
        return 0;
 }
 

+static void calc_chksum(FILE *fp, uint32_t *sum)
+{
+       static char buf[4096];
+       int sz;
+       struct md5_state md;
+
+       md5_begin(&md);
+       while((sz = fread(buf, 1, sizeof buf, fp)) > 0) {
+               md5_msg(&md, buf, sz);
+       }
+       md5_end(&md);
+
+       memcpy(sum, md.sum, sizeof md.sum);
+}
+

 static int proc_tree(git_repository *repo, git_tree *tree, const char *path)
 {
        int i, count = git_tree_entrycount(tree);
 static int proc_tree(git_repository *repo, git_tree *tree, const char *path)
 {
        int i, count = git_tree_entrycount(tree);

@@ -126,7 +170,7 @@ static int proc_tree(git_repository *repo, git_tree *tree, const char *path)
                case GIT_OBJECT_TREE:
                        git_tree_entry_to_object(&obj, repo, ent);
                        if(path) {
                case GIT_OBJECT_TREE:
                        git_tree_entry_to_object(&obj, repo, ent);
                        if(path) {

-                               char *pathbuf = malloc(strlen(path) + strlen(name) + 1);
+                               char *pathbuf = malloc(strlen(path) + strlen(name) + 2);

                                if(!pathbuf) {
                                        fprintf(stderr, "repo_init: failed to allocate memory\n");
                                        return -1;
                                if(!pathbuf) {
                                        fprintf(stderr, "repo_init: failed to allocate memory\n");
                                        return -1;

diff --git a/server/src/repo.h b/server/src/repo.h
index 3e8643d..fb2c977 100644 (file)
--- a/server/src/repo.h
+++ b/server/src/repo.h
@@ -1,10 +1,20 @@
 #ifndef REPO_H_
 #define REPO_H_
 
 #ifndef REPO_H_
 #define REPO_H_
 

+#include <stdint.h>
+
+struct repo_file {
+       char *path;
+       char *fullpath;
+       size_t size;
+       time_t mtime;
+       uint32_t chksum[4];
+};
+

 int repo_init(const char *path);
 void repo_cleanup(void);
 
 int repo_num_files(void);
 int repo_init(const char *path);
 void repo_cleanup(void);
 
 int repo_num_files(void);

-const char *repo_file(int idx);
+struct repo_file *repo_file(int idx);

 
 #endif /* REPO_H_ */
 
 #endif /* REPO_H_ */