[PATCH] md5sum, sha*sum: add --base32 option (original) (raw)

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From: Noah Levitt
Subject: [PATCH] md5sum, sha*sum: add --base32 option
Date: Fri, 13 Nov 2009 20:52:19 -0800
User-agent: Thunderbird 2.0.0.23 (X11/20090817)

Hello,

Here is a patch to add a --base32 option to md5sum and sha*sum.

The Internet Archive's web crawler Heritrix records digests of crawled content in base32. With *sum --base32 it will be much easier to work with those digests.

Noah

From 39d0fbc760686d6bcc9110404d33115d3f5e38f5 Mon Sep 17 00:00:00 2001 From: Noah Levitt <address@hidden(none)> Date: Fri, 13 Nov 2009 20:12:10 -0800 Subject: [PATCH] md5sum, sha*sum: add --base32 option

doc/coreutils.texi | 7 ++ src/md5sum.c | 191 ++++++++++++++++++++++++++++++++++++++++++---------- 2 files changed, 162 insertions(+), 36 deletions(-)

diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 3721bee..f9fe5f2 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -3454,6 +3454,13 @@ the MD5 checksum is unaffected. This option is the default on systems like MS-DOS that distinguish between binary and text files, except for reading standard input when standard input is a terminal. address@hidden --base32 +When printing checksums, print in base32 encoding, rather than +hexadecimal. When verifying checksums, expect them in base32. See address@hidden://tools.ietf.org/html/rfc4648, RFC 4648} for the definition +of base32. Note that @command{md5sum} uses the standard base32 alphabet +(not the ``extended hex'' version). + @item -c @itemx --check Read file names and checksum information (not data) from each diff --git a/src/md5sum.c b/src/md5sum.c index b7db03e..0adee76 100644 --- a/src/md5sum.c +++ b/src/md5sum.c @@ -87,6 +87,7 @@ #endif #define DIGEST_HEX_BYTES (DIGEST_BITS / 4) +#define DIGEST_BASE32_BYTES ((DIGEST_BITS + 4) / 5) #define DIGEST_BIN_BYTES (DIGEST_BITS / 8) #define AUTHORS
@@ -96,10 +97,14 @@ /* The minimum length of a valid digest line. This length does not include any newline character at the end of a line. / -#define MIN_DIGEST_LINE_LENGTH
+#define MIN_HEX_DIGEST_LINE_LENGTH
(DIGEST_HEX_BYTES / length of hexadecimal message digest /
+ 2 / blank and binary indicator /
+ 1 / minimum filename length / ) +#define MIN_BASE32_DIGEST_LINE_LENGTH
+ (DIGEST_BASE32_BYTES / length of base32 message digest /
+ + 2 / blank and binary indicator /
+ + 1 / minimum filename length / ) / True if any of the files read were the standard input. / static bool have_read_stdin; @@ -107,8 +112,12 @@ static bool have_read_stdin; / The minimum length of a valid checksum line for the selected algorithm. / static size_t min_digest_line_length; -/ Set to the length of a digest hex string for the selected algorithm. / -static size_t digest_hex_bytes; +/ Set to the length of a digest string for the selected algorithm and base + * (hex or base32). / +static size_t digest_string_bytes; + +/ Base32 digits as specified by RFC 4648. / +static char base32_chars[] = "abcdefghijklmnopqrstuvwxyz234567"; / With --check, don't generate any output. The exit code indicates success or failure. */ @@ -137,6 +146,7 @@ static struct option const long_options[] = { "status", no_argument, NULL, STATUS_OPTION }, { "text", no_argument, NULL, 't' }, { "warn", no_argument, NULL, 'w' }, + { "base32", no_argument, NULL, '3' }, { GETOPT_HELP_OPTION_DECL }, { GETOPT_VERSION_OPTION_DECL }, { NULL, 0, NULL, 0 } @@ -178,6 +188,9 @@ With no FILE, or when FILE is -, read standard input.\n
fputs (("
-t, --text read in text mode (default)\n
"), stdout); + printf (("
+ --base32 print or check %s sums in base32 (RFC 4648)\n"), + DIGEST_TYPE_STRING); fputs (_("
\n
The following three options are useful only when verifying checksums:\n
@@ -244,12 +257,12 @@ bsd_split_3 (char *s, size_t s_len, unsigned char **hex_digest, char *file_name } / Split the string S (of length S_LEN) into three parts: - a hexadecimal digest, binary flag, and the file name. + a digest string, binary flag, and the file name. S is modified. Return true if successful. */ static bool split_3 (char *s, size_t s_len, - unsigned char **hex_digest, int *binary, char **file_name) + unsigned char **digest, int *binary, char **file_name) { bool escaped_filename = false; size_t algo_name_len; @@ -269,7 +282,7 @@ split_3 (char *s, size_t s_len, *binary = 0; return bsd_split_3 (s + i + algo_name_len + 1, s_len - (i + algo_name_len + 1), - hex_digest, file_name); + digest, file_name); } } @@ -285,12 +298,12 @@ split_3 (char *s, size_t s_len, ++i; escaped_filename = true; } - *hex_digest = (unsigned char *) &s[i]; + *digest = (unsigned char ) &s[i]; / The first field has to be the n-character hexadecimal representation of the message digest. If it is not followed immediately by a white space it's an error. */ - i += digest_hex_bytes; + i += digest_string_bytes; if (!ISWHITE (s[i])) return false; @@ -357,7 +370,7 @@ static bool hex_digits (unsigned char const *s) { unsigned int i; - for (i = 0; i < digest_hex_bytes; i++) + for (i = 0; i < DIGEST_HEX_BYTES; i++) { if (!isxdigit (*s)) return false; @@ -366,6 +379,21 @@ hex_digits (unsigned char const *s) return *s == '\0'; } +/* Return true if S is a NUL-terminated string of DIGEST_HEX_BYTES hex digits. + Otherwise, return false. */ +static bool +base32_digits (unsigned char const *s) +{ + unsigned int i; + for (i = 0; i < DIGEST_BASE32_BYTES; i++) + { + if (! strchr (base32_chars, tolower (*s))) + return false; + ++s; + } + return *s == '\0'; +} + /* An interface to the function, DIGEST_STREAM. Operate on FILENAME (it may be "-"). @@ -425,7 +453,89 @@ digest_file (const char *filename, int *binary, unsigned char *bin_result) } static bool -digest_check (const char *checkfile_name) +hex_digest_matches (unsigned char const *bin_buffer, + char const *purported_digest) +{ + static const char bin2hex[] = { '0', '1', '2', '3', + '4', '5', '6', '7', + '8', '9', 'a', 'b', + 'c', 'd', 'e', 'f' }; + size_t digest_bin_bytes = DIGEST_HEX_BYTES / 2; + size_t cnt; + + /* Compare generated binary number with text representation + in check file. Ignore case of hex digits. */ + for (cnt = 0; cnt < digest_bin_bytes; ++cnt) + { + if (tolower (purported_digest[2 * cnt]) != bin2hex[bin_buffer[cnt] >> 4] + || (tolower (purported_digest[2 * cnt + 1]) != (bin2hex[bin_buffer[cnt] & 0xf]))) + return false; + } + + return true; +} + +static bool +print_or_check_base32 (unsigned char const *bin_buffer, + char const *purported_digest, + FILE out) +{ + / based on public domain code from bitzi by way of heritrix */ + int i = 0, index = 0, digit = 0; + size_t cnt = 0; + unsigned char currByte, nextByte; + + for (i = 0; i < DIGEST_BASE32_BYTES; i++) + { + currByte = bin_buffer[cnt]; + + /* Is the current digit going to span a byte boundary? */ + if (index > 3) + { + if (cnt + 1 < DIGEST_BIN_BYTES) + nextByte = bin_buffer[cnt+1]; + else + nextByte = 0; + + digit = currByte & (0xFF >> index); + index = (index + 5) % 8; + digit <<= index; + digit |= nextByte >> (8 - index); + cnt++; + } + else + { + digit = (currByte >> (8 - (index + 5))) & 0x1F; + index = (index + 5) % 8; + if (index == 0) + cnt++; + } + + if (purported_digest != NULL + && base32_chars[digit] != tolower (purported_digest[i])) + return false; + else if (out) + fputc (base32_chars[digit], out); + } + + return true; +} + +static void +print_base32_digest (const unsigned char *bin_buffer) +{ + print_or_check_base32 (bin_buffer, NULL, stdout); +} + +static bool +base32_digest_matches (const unsigned char *bin_buffer, + const char *purported_digest) +{ + return print_or_check_base32 (bin_buffer, purported_digest, NULL); +} + +static bool +digest_check (const char *checkfile_name, bool base32) { FILE *checkfile_stream; uintmax_t n_properly_formatted_lines = 0; @@ -462,7 +572,7 @@ digest_check (const char *checkfile_name) { char *filename IF_LINT (= NULL); int binary; - unsigned char *hex_digest IF_LINT (= NULL); + unsigned char *purported_digest IF_LINT (= NULL); ssize_t line_length; ++line_number; @@ -482,9 +592,11 @@ digest_check (const char *checkfile_name) if (line[line_length - 1] == '\n') line[--line_length] = '\0'; - if (! (split_3 (line, line_length, &hex_digest, &binary, &filename) + if (! (split_3 (line, line_length, &purported_digest, &binary, &filename) && ! (is_stdin && STREQ (filename, "-")) - && hex_digits (hex_digest))) + && (base32 && base32_digits (purported_digest) + || ! base32 && hex_digits (purported_digest)))) + { if (warn) { @@ -497,10 +609,6 @@ digest_check (const char *checkfile_name) } else { - static const char bin2hex[] = { '0', '1', '2', '3', - '4', '5', '6', '7', - '8', '9', 'a', 'b', - 'c', 'd', 'e', 'f' }; bool ok; ++n_properly_formatted_lines; @@ -517,24 +625,20 @@ digest_check (const char checkfile_name) } else { - size_t digest_bin_bytes = digest_hex_bytes / 2; - size_t cnt; - / Compare generated binary number with text representation - in check file. Ignore case of hex digits. */ - for (cnt = 0; cnt < digest_bin_bytes; ++cnt) - { - if (tolower (hex_digest[2 * cnt]) - != bin2hex[bin_buffer[cnt] >> 4] - || (tolower (hex_digest[2 * cnt + 1]) - != (bin2hex[bin_buffer[cnt] & 0xf]))) - break; - } - if (cnt != digest_bin_bytes) + bool digest_matches; + if (base32) + digest_matches = base32_digest_matches (bin_buffer, + purported_digest); + else + digest_matches = hex_digest_matches (bin_buffer, + purported_digest); + + if (!digest_matches) ++n_mismatched_checksums; if (!status_only) { - if (cnt != digest_bin_bytes) + if (!digest_matches) printf ("%s: %s\n", filename, _("FAILED")); else if (!quiet) printf ("%s: %s\n", filename, _("OK")); @@ -607,6 +711,7 @@ main (int argc, char *argv) int opt; bool ok = true; int binary = -1; + bool base32 = false; / Setting values of global variables. */ initialize_main (&argc, &argv); @@ -630,6 +735,9 @@ main (int argc, char **argv) case 'c': do_check = true; break; + case '3': + base32 = true; + break; case STATUS_OPTION: status_only = true; warn = false; @@ -654,8 +762,16 @@ main (int argc, char **argv) usage (EXIT_FAILURE); } - min_digest_line_length = MIN_DIGEST_LINE_LENGTH; - digest_hex_bytes = DIGEST_HEX_BYTES; + if (base32) + { + digest_string_bytes = DIGEST_BASE32_BYTES; + min_digest_line_length = MIN_BASE32_DIGEST_LINE_LENGTH; + } + else + { + digest_string_bytes = DIGEST_HEX_BYTES; + min_digest_line_length = MIN_HEX_DIGEST_LINE_LENGTH; + } if (0 <= binary && do_check) { @@ -696,7 +812,7 @@ main (int argc, char **argv) char *file = argv[optind]; if (do_check) - ok &= digest_check (file); + ok &= digest_check (file, base32); else { int file_is_binary = binary; @@ -712,8 +828,11 @@ main (int argc, char **argv) if (strchr (file, '\n') || strchr (file, '\')) putchar ('\'); - for (i = 0; i < (digest_hex_bytes / 2); ++i) - printf ("%02x", bin_buffer[i]); + if (base32) + print_base32_digest (bin_buffer); + else + for (i = 0; i < (DIGEST_HEX_BYTES / 2); ++i) + printf ("%02x", bin_buffer[i]); putchar (' '); if (file_is_binary)

1.6.3.3

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