libbb: split decode_base64 off read_base64

function                                             old     new   delta
decode_base64                                          -     182    +182
read_base64                                          378     255    -123
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 182/-123)           Total: 59 bytes

Signed-off-by: Leonid Lisovskiy <lly.dev@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Leonid Lisovskiy 2011-10-28 13:59:04 +02:00 committed by Denys Vlasenko
parent ec447c7f01
commit 328f27fe44
3 changed files with 200 additions and 29 deletions

View File

@ -1591,7 +1591,8 @@ enum {
/* Sign-extends to a value which never matches fgetc result: */ /* Sign-extends to a value which never matches fgetc result: */
BASE64_FLAG_NO_STOP_CHAR = 0x80, BASE64_FLAG_NO_STOP_CHAR = 0x80,
}; };
void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags); const char *decode_base64(char **pp_dst, const char *src) FAST_FUNC;
void read_base64(FILE *src_stream, FILE *dst_stream, int flags) FAST_FUNC;
typedef struct md5_ctx_t { typedef struct md5_ctx_t {
uint8_t wbuffer[64]; /* always correctly aligned for uint64_t */ uint8_t wbuffer[64]; /* always correctly aligned for uint64_t */

View File

@ -73,23 +73,23 @@ void FAST_FUNC bb_uuencode(char *p, const void *src, int length, const char *tbl
} }
/* /*
* Decode base64 encoded stream. * Decode base64 encoded string. Stops on '\0'.
* Can stop on EOF, specified char, or on uuencode-style "====" line: *
* flags argument controls it. * Returns: pointer to the undecoded part of source.
* If points to '\0', then the source was fully decoded.
* (*dst): advanced past the last written byte.
*/ */
void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags) const char* FAST_FUNC decode_base64(char **pp_dst, const char *src)
{ {
/* Note that EOF _can_ be passed as exit_char too */ char *dst = *pp_dst;
#define exit_char ((int)(signed char)flags) const char *src_tail;
#define uu_style_end (flags & BASE64_FLAG_UU_STOP)
int term_count = 0;
while (1) { while (1) {
unsigned char translated[4]; unsigned char translated[4];
int count = 0; int count = 0;
/* Process one group of 4 chars */ /* Process one group of 4 chars */
src_tail = src;
while (count < 4) { while (count < 4) {
char *table_ptr; char *table_ptr;
int ch; int ch;
@ -101,11 +101,20 @@ void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags)
* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n" * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n"
*/ */
do { do {
ch = fgetc(src_stream); ch = *src;
if (ch == exit_char && count == 0) if (ch == '\0') {
return; if (count == 0) {
if (ch == EOF) /* Example:
bb_error_msg_and_die("truncated base64 input"); * If we decode "QUJD <NUL>", we want
* to return ptr to NUL, not to ' ',
* because we did fully decode
* the string (to "ABC").
*/
src_tail = src;
}
goto ret;
}
src++;
table_ptr = strchr(bb_uuenc_tbl_base64, ch); table_ptr = strchr(bb_uuenc_tbl_base64, ch);
//TODO: add BASE64_FLAG_foo to die on bad char? //TODO: add BASE64_FLAG_foo to die on bad char?
//Note that then we may need to still allow '\r' (for mail processing) //Note that then we may need to still allow '\r' (for mail processing)
@ -114,21 +123,15 @@ void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags)
/* Convert encoded character to decimal */ /* Convert encoded character to decimal */
ch = table_ptr - bb_uuenc_tbl_base64; ch = table_ptr - bb_uuenc_tbl_base64;
if (ch == 65 /* '\n' */) { if (ch == 65) { /* '\n' */
/* Terminating "====" line? */
if (uu_style_end && term_count == 4)
return; /* yes */
term_count = 0;
continue; continue;
} }
/* ch is 64 if char was '=', otherwise 0..63 */ /* ch is 64 if char was '=', otherwise 0..63 */
translated[count] = ch & 63; /* 64 -> 0 */ translated[count] = ch & 63; /* 64 -> 0 */
if (ch == 64) { if (ch == 64) { /* '=' */
term_count++;
break; break;
} }
count++; count++;
term_count = 0;
} }
/* Merge 6 bit chars to 8 bit. /* Merge 6 bit chars to 8 bit.
@ -136,10 +139,82 @@ void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags)
* "eQ==" -> "y", not "y NUL NUL" * "eQ==" -> "y", not "y NUL NUL"
*/ */
if (count > 1) if (count > 1)
fputc(translated[0] << 2 | translated[1] >> 4, dst_stream); *dst++ = translated[0] << 2 | translated[1] >> 4;
if (count > 2) if (count > 2)
fputc(translated[1] << 4 | translated[2] >> 2, dst_stream); *dst++ = translated[1] << 4 | translated[2] >> 2;
if (count > 3) if (count > 3)
fputc(translated[2] << 6 | translated[3], dst_stream); *dst++ = translated[2] << 6 | translated[3];
} /* while (1) */ } /* while (1) */
ret:
*pp_dst = dst;
return src_tail;
}
/*
* Decode base64 encoded stream.
* Can stop on EOF, specified char, or on uuencode-style "====" line:
* flags argument controls it.
*/
void FAST_FUNC read_base64(FILE *src_stream, FILE *dst_stream, int flags)
{
/* Note that EOF _can_ be passed as exit_char too */
#define exit_char ((int)(signed char)flags)
#define uu_style_end (flags & BASE64_FLAG_UU_STOP)
/* uuencoded files have 61 byte lines. Use 64 byte buffer
* to process line at a time.
*/
enum { BUFFER_SIZE = 64 };
char in_buf[BUFFER_SIZE + 2];
char out_buf[BUFFER_SIZE / 4 * 3 + 2];
char *out_tail;
const char *in_tail;
int term_seen = 0;
int in_count = 0;
while (1) {
while (in_count < BUFFER_SIZE) {
int ch = fgetc(src_stream);
if (ch == exit_char) {
if (in_count == 0)
return;
term_seen = 1;
break;
}
if (ch == EOF) {
term_seen = 1;
break;
}
/* Prevent "====" line to be split: stop if we see '\n'.
* We can also skip other whitespace and skirt the problem
* of files with NULs by stopping on any control char or space:
*/
if (ch <= ' ')
break;
in_buf[in_count++] = ch;
}
in_buf[in_count] = '\0';
/* Did we encounter "====" line? */
if (uu_style_end && strcmp(in_buf, "====") == 0)
return;
out_tail = out_buf;
in_tail = decode_base64(&out_tail, in_buf);
fwrite(out_buf, (out_tail - out_buf), 1, dst_stream);
if (term_seen) {
/* Did we consume ALL characters? */
if (*in_tail == '\0')
return;
/* No */
bb_error_msg_and_die("truncated base64 input");
}
/* It was partial decode */
in_count = strlen(in_tail);
memmove(in_buf, in_tail, in_count);
}
} }

View File

@ -8,9 +8,9 @@
. ./testing.sh . ./testing.sh
# testing "test name" "options" "expected result" "file input" "stdin" # testing "test name" "command(s)" "expected result" "file input" "stdin"
# file input will be file called "input" # file input will be file called "input"
# test can create a file "actual" instead of writing to stdout # test can create a file "actual" instead of writing to stdout
# Test setup of standard input # Test setup of standard input
umask 0 umask 0
@ -24,4 +24,99 @@ testing "uuencode correct encoding" "uuencode bb_uuenc_test.out" \
testing "uuencode correct base64 encoding" "uuencode -m bb_uuenc_test.out" \ testing "uuencode correct base64 encoding" "uuencode -m bb_uuenc_test.out" \
"begin-base64 644 bb_uuenc_test.out\nVGhlIGZhc3QgZ3JleSBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgYnJvd24g\nZG9nLgo=\n====\n" \ "begin-base64 644 bb_uuenc_test.out\nVGhlIGZhc3QgZ3JleSBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgYnJvd24g\nZG9nLgo=\n====\n" \
"" "The fast grey fox jumped over the lazy brown dog.\n" "" "The fast grey fox jumped over the lazy brown dog.\n"
testing "uuencode empty file" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
`
end
' "" ""
testing "uuencode -m empty file" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
====
' "" ""
testing "uuencode file 'A'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
!00``
`
end
A' "" "A"
testing "uuencode -m file 'A'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QQ==
====
A' "" "A"
testing "uuencode file 'AB'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
"04(`
`
end
AB' "" "AB"
testing "uuencode -m file 'AB'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QUI=
====
AB' "" "AB"
testing "uuencode file 'ABC'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
#04)#
`
end
ABC' "" "ABC"
testing "uuencode -m file 'ABC'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QUJD
====
ABC' "" "ABC"
testing "uuencode file 'ABCD'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
$04)#1```
`
end
ABCD' "" "ABCD"
testing "uuencode -m file 'ABCD'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QUJDRA==
====
ABCD' "" "ABCD"
testing "uuencode file 'ABCDE'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
%04)#1$4`
`
end
ABCDE' "" "ABCDE"
testing "uuencode -m file 'ABCDE'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QUJDREU=
====
ABCDE' "" "ABCDE"
testing "uuencode file 'ABCDEF'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
&04)#1$5&
`
end
ABCDEF' "" "ABCDEF"
testing "uuencode -m file 'ABCDEF'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QUJDREVG
====
ABCDEF' "" "ABCDEF"
testing "uuencode file 'A<NUL><0xff>Z'" 'r=`uuencode FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin 644 FILE
$00#_6@``
`
end
A\x0\xffZ' "" "A\x0\xffZ"
testing "uuencode -m file 'A<NUL><0xff>Z'" 'r=`uuencode -m FILE`; echo "$r"; echo "$r" | uudecode -o -;' \
'begin-base64 644 FILE
QQD/Wg==
====
A\x0\xffZ' "" "A\x0\xffZ"
exit $FAILCOUNT exit $FAILCOUNT