From 5ec6074f0633939fd17d94111d10c6c6b062978c Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 11:49:36 +0200 Subject: Adding upstream version 1:2.30.2. Signed-off-by: Daniel Baumann --- builtin/mktag.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 builtin/mktag.c (limited to 'builtin/mktag.c') diff --git a/builtin/mktag.c b/builtin/mktag.c new file mode 100644 index 0000000..4982d3a --- /dev/null +++ b/builtin/mktag.c @@ -0,0 +1,179 @@ +#include "builtin.h" +#include "tag.h" +#include "replace-object.h" +#include "object-store.h" + +/* + * A signature file has a very simple fixed format: four lines + * of "object " + "type " + "tag " + + * "tagger ", followed by a blank line, a free-form tag + * message and a signature block that git itself doesn't care about, + * but that can be verified with gpg or similar. + * + * The first four lines are guaranteed to be at least 83 bytes: + * "object \n" is 48 bytes, "type tag\n" at 9 bytes is the + * shortest possible type-line, "tag .\n" at 6 bytes is the shortest + * single-character-tag line, and "tagger . <> 0 +0000\n" at 20 bytes is + * the shortest possible tagger-line. + */ + +/* + * We refuse to tag something we can't verify. Just because. + */ +static int verify_object(const struct object_id *oid, const char *expected_type) +{ + int ret = -1; + enum object_type type; + unsigned long size; + void *buffer = read_object_file(oid, &type, &size); + const struct object_id *repl = lookup_replace_object(the_repository, oid); + + if (buffer) { + if (type == type_from_string(expected_type)) { + ret = check_object_signature(the_repository, repl, + buffer, size, + expected_type); + } + free(buffer); + } + return ret; +} + +static int verify_tag(char *buffer, unsigned long size) +{ + int typelen; + char type[20]; + struct object_id oid; + const char *object, *type_line, *tag_line, *tagger_line, *lb, *rb, *p; + size_t len; + + if (size < 84) + return error("wanna fool me ? you obviously got the size wrong !"); + + buffer[size] = 0; + + /* Verify object line */ + object = buffer; + if (memcmp(object, "object ", 7)) + return error("char%d: does not start with \"object \"", 0); + + if (parse_oid_hex(object + 7, &oid, &p)) + return error("char%d: could not get SHA1 hash", 7); + + /* Verify type line */ + type_line = p + 1; + if (memcmp(type_line - 1, "\ntype ", 6)) + return error("char%d: could not find \"\\ntype \"", 47); + + /* Verify tag-line */ + tag_line = strchr(type_line, '\n'); + if (!tag_line) + return error("char%"PRIuMAX": could not find next \"\\n\"", + (uintmax_t) (type_line - buffer)); + tag_line++; + if (memcmp(tag_line, "tag ", 4) || tag_line[4] == '\n') + return error("char%"PRIuMAX": no \"tag \" found", + (uintmax_t) (tag_line - buffer)); + + /* Get the actual type */ + typelen = tag_line - type_line - strlen("type \n"); + if (typelen >= sizeof(type)) + return error("char%"PRIuMAX": type too long", + (uintmax_t) (type_line+5 - buffer)); + + memcpy(type, type_line+5, typelen); + type[typelen] = 0; + + /* Verify that the object matches */ + if (verify_object(&oid, type)) + return error("char%d: could not verify object %s", 7, oid_to_hex(&oid)); + + /* 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 error("char%"PRIuMAX": could not verify tag name", + (uintmax_t) (tag_line - buffer)); + } + + /* Verify the tagger line */ + tagger_line = tag_line; + + if (memcmp(tagger_line, "tagger ", 7)) + return error("char%"PRIuMAX": could not find \"tagger \"", + (uintmax_t) (tagger_line - buffer)); + + /* + * Check for correct form for name and email + * i.e. " <" followed by "> " on _this_ line + * No angle brackets within the name or email address fields. + * No spaces within the email address field. + */ + tagger_line += 7; + if (!(lb = strstr(tagger_line, " <")) || !(rb = strstr(lb+2, "> ")) || + strpbrk(tagger_line, "<>\n") != lb+1 || + strpbrk(lb+2, "><\n ") != rb) + return error("char%"PRIuMAX": malformed tagger field", + (uintmax_t) (tagger_line - buffer)); + + /* Check for author name, at least one character, space is acceptable */ + if (lb == tagger_line) + return error("char%"PRIuMAX": missing tagger name", + (uintmax_t) (tagger_line - buffer)); + + /* timestamp, 1 or more digits followed by space */ + tagger_line = rb + 2; + if (!(len = strspn(tagger_line, "0123456789"))) + return error("char%"PRIuMAX": missing tag timestamp", + (uintmax_t) (tagger_line - buffer)); + tagger_line += len; + if (*tagger_line != ' ') + return error("char%"PRIuMAX": malformed tag timestamp", + (uintmax_t) (tagger_line - buffer)); + tagger_line++; + + /* timezone, 5 digits [+-]hhmm, max. 1400 */ + if (!((tagger_line[0] == '+' || tagger_line[0] == '-') && + strspn(tagger_line+1, "0123456789") == 4 && + tagger_line[5] == '\n' && atoi(tagger_line+1) <= 1400)) + return error("char%"PRIuMAX": malformed tag timezone", + (uintmax_t) (tagger_line - buffer)); + tagger_line += 6; + + /* Verify the blank line separating the header from the body */ + if (*tagger_line != '\n') + return error("char%"PRIuMAX": trailing garbage in tag header", + (uintmax_t) (tagger_line - buffer)); + + /* The actual stuff afterwards we don't care about.. */ + return 0; +} + +int cmd_mktag(int argc, const char **argv, const char *prefix) +{ + struct strbuf buf = STRBUF_INIT; + struct object_id result; + + if (argc != 1) + usage("git mktag"); + + if (strbuf_read(&buf, 0, 4096) < 0) { + die_errno("could not read from stdin"); + } + + /* Verify it for some basic sanity: it needs to start with + "object \ntype\ntagger " */ + if (verify_tag(buf.buf, buf.len) < 0) + die("invalid tag signature file"); + + if (write_object_file(buf.buf, buf.len, tag_type, &result) < 0) + die("unable to write tag file"); + + strbuf_release(&buf); + printf("%s\n", oid_to_hex(&result)); + return 0; +} -- cgit v1.2.3