src/signature.c

   1 /*
   2  * Copyright (C) 2009-2012 the libgit2 contributors
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "common.h"
   9 #include "signature.h"
  10 #include "repository.h"
  11 #include "git2/common.h"
  12
  13 void git_signature_free(git_signature *sig)
  14 {
  15         if (sig == NULL)
  16                 return;
  17
  18         git__free(sig->name);
  19         sig->name = NULL;
  20         git__free(sig->email);
  21         sig->email = NULL;
  22         git__free(sig);
  23 }
  24
  25 static const char *skip_leading_spaces(const char *buffer, const char *buffer_end)
  26 {
  27         while (*buffer == ' ' && buffer < buffer_end)
  28                 buffer++;
  29
  30         return buffer;
  31 }
  32
  33 static const char *skip_trailing_spaces(const char *buffer_start, const char *buffer_end)
  34 {
  35         while (*buffer_end == ' ' && buffer_end > buffer_start)
  36                 buffer_end--;
  37
  38         return buffer_end;
  39 }
  40
  41 static int signature_error(const char *msg)
  42 {
  43         giterr_set(GITERR_INVALID, "Failed to parse signature - %s", msg);
  44         return -1;
  45 }
  46
  47 static int process_trimming(const char *input, char **storage, const char *input_end, int fail_when_empty)
  48 {
  49         const char *left, *right;
  50         size_t trimmed_input_length;
  51
  52         assert(storage);
  53
  54         left = skip_leading_spaces(input, input_end);
  55         right = skip_trailing_spaces(input, input_end - 1);
  56
  57         if (right < left) {
  58                 if (fail_when_empty)
  59                         return signature_error("input is either empty of contains only spaces");
  60
  61                 right = left - 1;
  62         }
  63
  64         trimmed_input_length = right - left + 1;
  65
  66         *storage = git__malloc(trimmed_input_length + 1);
  67         GITERR_CHECK_ALLOC(*storage);
  68
  69         memcpy(*storage, left, trimmed_input_length);
  70         (*storage)[trimmed_input_length] = 0;
  71
  72         return 0;
  73 }
  74
  75 int git_signature_new(git_signature **sig_out, const char *name, const char *email, git_time_t time, int offset)
  76 {
  77         int error;
  78         git_signature *p = NULL;
  79
  80         assert(name && email);
  81
  82         *sig_out = NULL;
  83
  84         p = git__calloc(1, sizeof(git_signature));
  85         GITERR_CHECK_ALLOC(p);
  86
  87         if ((error = process_trimming(name, &p->name, name + strlen(name), 1)) < 0 ||
  88                 (error = process_trimming(email, &p->email, email + strlen(email), 1)) < 0)
  89         {
  90                 git_signature_free(p);
  91                 return error;
  92         }
  93
  94         p->when.time = time;
  95         p->when.offset = offset;
  96
  97         *sig_out = p;
  98
  99         return 0;
 100 }
 101
 102 git_signature *git_signature_dup(const git_signature *sig)
 103 {
 104         git_signature *new;
 105         if (git_signature_new(&new, sig->name, sig->email, sig->when.time, sig->when.offset) < 0)
 106                 return NULL;
 107         return new;
 108 }
 109
 110 int git_signature_now(git_signature **sig_out, const char *name, const char *email)
 111 {
 112         time_t now;
 113         time_t offset;
 114         struct tm *utc_tm, *local_tm;
 115         git_signature *sig;
 116         struct tm _utc, _local;
 117
 118         *sig_out = NULL;
 119
 120         time(&now);
 121
 122         utc_tm = p_gmtime_r(&now, &_utc);
 123         local_tm = p_localtime_r(&now, &_local);
 124
 125         offset = mktime(local_tm) - mktime(utc_tm);
 126         offset /= 60;
 127
 128         /* mktime takes care of setting tm_isdst correctly */
 129         if (local_tm->tm_isdst)
 130                 offset += 60;
 131
 132         if (git_signature_new(&sig, name, email, now, (int)offset) < 0)
 133                 return -1;
 134
 135         *sig_out = sig;
 136
 137         return 0;
 138 }
 139
 140 static int timezone_error(const char *msg)
 141 {
 142         giterr_set(GITERR_INVALID, "Failed to parse TZ offset - %s", msg);
 143         return -1;
 144 }
 145
 146 static int parse_timezone_offset(const char *buffer, int *offset_out)
 147 {
 148         int dec_offset;
 149         int mins, hours, offset;
 150
 151         const char *offset_start;
 152         const char *offset_end;
 153
 154         offset_start = buffer;
 155
 156         if (*offset_start == '\n') {
 157                 *offset_out = 0;
 158                 return 0;
 159         }
 160
 161         if (offset_start[0] != '-' && offset_start[0] != '+')
 162                 return timezone_error("does not start with '+' or '-'");
 163
 164         if (offset_start[1] < '0' || offset_start[1] > '9')
 165                 return timezone_error("expected initial digit");
 166
 167         if (git__strtol32(&dec_offset, offset_start + 1, &offset_end, 10) < 0)
 168                 return timezone_error("not a valid number");
 169
 170         if (offset_end - offset_start != 5)
 171                 return timezone_error("invalid length");
 172
 173         if (dec_offset > 1400)
 174                 return timezone_error("value too large");
 175
 176         hours = dec_offset / 100;
 177         mins = dec_offset % 100;
 178
 179         if (hours > 14) // see http://www.worldtimezone.com/faq.html
 180                 return timezone_error("hour value too large");
 181
 182         if (mins > 59)
 183                 return timezone_error("minutes value too large");
 184
 185         offset = (hours * 60) + mins;
 186
 187         if (offset_start[0] == '-')
 188                 offset *= -1;
 189
 190         *offset_out = offset;
 191
 192         return 0;
 193 }
 194
 195 static int process_next_token(const char **buffer_out, char **storage,
 196         const char *token_end, const char *right_boundary)
 197 {
 198         int error = process_trimming(*buffer_out, storage, token_end, 0);
 199         if (error < 0)
 200                 return error;
 201
 202         *buffer_out = token_end + 1;
 203
 204         if (*buffer_out > right_boundary)
 205                 return signature_error("signature is too short");
 206
 207         return 0;
 208 }
 209
 210 static const char *scan_for_previous_token(const char *buffer, const char *left_boundary)
 211 {
 212         const char *start;
 213
 214         if (buffer <= left_boundary)
 215                 return NULL;
 216
 217         start = skip_trailing_spaces(left_boundary, buffer);
 218
 219         /* Search for previous occurence of space */
 220         while (start[-1] != ' ' && start > left_boundary)
 221                 start--;
 222
 223         return start;
 224 }
 225
 226 static int parse_time(git_time_t *time_out, const char *buffer)
 227 {
 228         int time;
 229         int error;
 230
 231         if (*buffer == '+' || *buffer == '-') {
 232                 giterr_set(GITERR_INVALID, "Failed while parsing time. '%s' actually looks like a timezone offset.", buffer);
 233                 return -1;
 234         }
 235
 236         error = git__strtol32(&time, buffer, &buffer, 10);
 237
 238         if (!error)
 239                 *time_out = (git_time_t)time;
 240
 241         return error;
 242 }
 243
 244 int git_signature__parse(git_signature *sig, const char **buffer_out,
 245                 const char *buffer_end, const char *header, char ender)
 246 {
 247         const char *buffer = *buffer_out;
 248         const char *line_end, *name_end, *email_end, *tz_start, *time_start;
 249         int error = 0;
 250
 251         memset(sig, 0x0, sizeof(git_signature));
 252
 253         if ((line_end = memchr(buffer, ender, buffer_end - buffer)) == NULL)
 254                 return signature_error("no newline given");
 255
 256         if (header) {
 257                 const size_t header_len = strlen(header);
 258
 259                 if (memcmp(buffer, header, header_len) != 0)
 260                         return signature_error("expected prefix doesn't match actual");
 261
 262                 buffer += header_len;
 263         }
 264
 265         if (buffer > line_end)
 266                 return signature_error("signature too short");
 267
 268         if ((name_end = strchr(buffer, '<')) == NULL)
 269                 return signature_error("character '<' not allowed in signature");
 270
 271         if ((email_end = strchr(name_end, '>')) == NULL)
 272                 return signature_error("character '>' not allowed in signature");
 273
 274         if (email_end < name_end)
 275                 return signature_error("malformed e-mail");
 276
 277         error = process_next_token(&buffer, &sig->name, name_end, line_end);
 278         if (error < 0)
 279                 return error;
 280
 281         error = process_next_token(&buffer, &sig->email, email_end, line_end);
 282         if (error < 0)
 283                 return error;
 284
 285         tz_start = scan_for_previous_token(line_end - 1, buffer);
 286
 287         if (tz_start == NULL)
 288                 goto clean_exit;        /* No timezone nor date */
 289
 290         time_start = scan_for_previous_token(tz_start - 1, buffer);
 291         if (time_start == NULL || parse_time(&sig->when.time, time_start) < 0) {
 292                 /* The tz_start might point at the time */
 293                 parse_time(&sig->when.time, tz_start);
 294                 goto clean_exit;
 295         }
 296
 297         if (parse_timezone_offset(tz_start, &sig->when.offset) < 0) {
 298                 sig->when.time = 0; /* Bogus timezone, we reset the time */
 299         }
 300
 301 clean_exit:
 302         *buffer_out = line_end + 1;
 303         return 0;
 304 }
 305
 306 void git_signature__writebuf(git_buf *buf, const char *header, const git_signature *sig)
 307 {
 308         int offset, hours, mins;
 309         char sign;
 310
 311         offset = sig->when.offset;
 312         sign = (sig->when.offset < 0) ? '-' : '+';
 313
 314         if (offset < 0)
 315                 offset = -offset;
 316
 317         hours = offset / 60;
 318         mins = offset % 60;
 319
 320         git_buf_printf(buf, "%s%s <%s> %u %c%02d%02d\n",
 321                         header ? header : "", sig->name, sig->email,
 322                         (unsigned)sig->when.time, sign, hours, mins);
 323 }
 324