diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | fsck-cache.c | 39 | ||||
| -rw-r--r-- | git-mktag.c | 125 |
3 files changed, 165 insertions, 1 deletions
@@ -16,7 +16,7 @@ AR=ar PROG= update-cache show-diff init-db write-tree read-tree commit-tree \ cat-file fsck-cache checkout-cache diff-tree rev-tree show-files \ check-files ls-tree merge-base merge-cache unpack-file git-export \ - diff-cache convert-cache http-pull rpush rpull rev-list + diff-cache convert-cache http-pull rpush rpull rev-list git-mktag all: $(PROG) diff --git a/fsck-cache.c b/fsck-cache.c index e3c41d48e..12443b165 100644 --- a/fsck-cache.c +++ b/fsck-cache.c @@ -69,6 +69,42 @@ static int fsck_blob(unsigned char *sha1, void *data, unsigned long size) return 0; } +static int fsck_tag(unsigned char *sha1, void *data, unsigned long size) +{ + int typelen, taglen; + unsigned char object[20]; + const char *type_line, *tag_line, *sig_line; + + if (size < 64) + return -1; + if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object)) + return -1; + + type_line = data + 48; + if (memcmp("\ntype ", type_line-1, 6)) + return -1; + + tag_line = strchr(type_line, '\n'); + if (!tag_line || memcmp("tag ", ++tag_line, 4)) + return -1; + + sig_line = strchr(tag_line, '\n'); + if (!sig_line) + return -1; + sig_line++; + + typelen = tag_line - type_line - strlen("type \n"); + if (typelen >= 20) + return -1; + taglen = sig_line - tag_line - strlen("tag \n"); + + printf("tagged %.*s %s (%.*s)\n", + typelen, type_line + 5, + sha1_to_hex(object), + taglen, tag_line + 4); + return 0; +} + static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size) { @@ -81,6 +117,9 @@ static int fsck_entry(unsigned char *sha1, char *tag, void *data, } else if (!strcmp(tag, "commit")) { if (fsck_commit(sha1, data, size) < 0) return -1; + } else if (!strcmp(tag, "tag")) { + if (fsck_tag(sha1, data, size) < 0) + return -1; } else return -1; return 0; diff --git a/git-mktag.c b/git-mktag.c new file mode 100644 index 000000000..5d2830dc2 --- /dev/null +++ b/git-mktag.c @@ -0,0 +1,125 @@ +#include "cache.h" + +/* + * A signature file has a very simple fixed format: three lines + * of "object <sha1>" + "type <typename>" + "tag <tagname>", + * followed by some free-form signature that git itself doesn't + * care about, but that can be verified with gpg or similar. + * + * The first three lines are guaranteed to be at least 63 bytes: + * "object <sha1>\n" is 48 bytes, "type tag\n" at 9 bytes is the + * shortest possible type-line, and "tag .\n" at 6 bytes is the + * shortest single-character-tag line. + * + * We also artificially limit the size of the full object to 8kB. + * Just because I'm a lazy bastard, and if you can't fit a signature + * in that size, you're doing something wrong. + */ + +// Some random size +#define MAXSIZE (8192) + +/* + * We refuse to tag something we can't verify. Just because. + */ +static int verify_object(unsigned char *sha1, const char *expected_type) +{ + int ret = -1; + unsigned long mapsize; + void *map = map_sha1_file(sha1, &mapsize); + + if (map) { + char type[100]; + unsigned long size; + void *buffer = unpack_sha1_file(map, mapsize, type, &size); + + if (buffer) { + if (!strcmp(type, expected_type)) + ret = check_sha1_signature(sha1, buffer, size, type); + free(buffer); + } + munmap(map, mapsize); + } + return ret; +} + +static int verify_tag(char *buffer, unsigned long size) +{ + int typelen; + char type[20]; + unsigned char sha1[20]; + const char *object, *type_line, *tag_line; + + if (size < 64 || size > MAXSIZE-1) + return -1; + buffer[size] = 0; + + /* Verify object line */ + object = buffer; + if (memcmp(object, "object ", 7)) + return -1; + if (get_sha1_hex(object + 7, sha1)) + return -1; + + /* Verify type line */ + type_line = object + 48; + if (memcmp(type_line - 1, "\ntype ", 6)) + return -1; + + /* Verify tag-line */ + tag_line = strchr(type_line, '\n'); + if (!tag_line) + return -1; + tag_line++; + if (memcmp(tag_line, "tag ", 4) || tag_line[4] == '\n') + return -1; + + /* Get the actual type */ + typelen = tag_line - type_line - strlen("type \n"); + if (typelen >= sizeof(type)) + return -1; + memcpy(type, type_line+5, typelen); + type[typelen] = 0; + + /* Verify that the object matches */ + if (get_sha1_hex(object + 7, sha1)) + return -1; + if (verify_object(sha1, type)) + return -1; + + /* Verify the tag-name: we don't allow control characters or spaces in it */ + tag_line += 4; + for (;;) { + unsigned char c = *tag_line++; + if (c == '\n') + break; + if (c > ' ') + continue; + return -1; + } + + /* The actual stuff afterwards we don't care about.. */ + return 0; +} + +int main(int argc, char **argv) +{ + unsigned long size; + char buffer[MAXSIZE]; + unsigned char result_sha1[20]; + + if (argc != 1) + usage("cat <signaturefile> | git-mktag"); + + // Read the signature + size = read(0, buffer, MAXSIZE); + + // Verify it for some basic sanity: it needs to start with "object <sha1>\ntag " + if (verify_tag(buffer, size) < 0) + die("invalid tag signature file"); + + if (write_sha1_file(buffer, size, "tag", result_sha1) < 0) + die("unable to write tag file"); + printf("%s\n", sha1_to_hex(result_sha1)); + return 0; +} |