From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEtD7-0006GS-RF for barebox@lists.infradead.org; Fri, 12 Apr 2019 10:15:09 +0000 From: Sascha Hauer Date: Fri, 12 Apr 2019 12:14:57 +0200 Message-Id: <20190412101502.11904-3-s.hauer@pengutronix.de> In-Reply-To: <20190412101502.11904-1-s.hauer@pengutronix.de> References: <20190412101502.11904-1-s.hauer@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 2/7] lib: add base64 helpers To: Barebox List Cc: Steffen Trumtrar From: Steffen Trumtrar Import the busybox-1.23.1 uuencode/base64 helper functions. Signed-off-by: Steffen Trumtrar Signed-off-by: Sascha Hauer --- include/base64.h | 9 +++ lib/Kconfig | 3 + lib/Makefile | 1 + lib/base64.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 167 insertions(+) create mode 100644 include/base64.h create mode 100644 lib/base64.c diff --git a/include/base64.h b/include/base64.h new file mode 100644 index 0000000000..0df510281d --- /dev/null +++ b/include/base64.h @@ -0,0 +1,9 @@ +#ifndef __BASE64_H +#define __BASE64_H + +void uuencode(char *p, const char *src, int length); +int decode_base64(char *dst, int dst_len, const char *src); + +#define BASE64_LENGTH(len) (4 * (((len) + 2) / 3)) + +#endif /* __BASE64_H */ diff --git a/lib/Kconfig b/lib/Kconfig index 27f62461f0..35f208cbc1 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -57,6 +57,9 @@ config XZ_DEC_SPARC config REED_SOLOMON bool +config BASE64 + bool "include base64 encode/decode support" + config GENERIC_FIND_NEXT_BIT def_bool n diff --git a/lib/Makefile b/lib/Makefile index 8dabf4ae77..31e66de33f 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_LZ4_DECOMPRESS) += decompress_unlz4.o obj-$(CONFIG_PROCESS_ESCAPE_SEQUENCE) += process_escape_sequence.o obj-$(CONFIG_UNCOMPRESS) += uncompress.o obj-$(CONFIG_BCH) += bch.o +obj-$(CONFIG_BASE64) += base64.o obj-$(CONFIG_BITREV) += bitrev.o obj-$(CONFIG_QSORT) += qsort.o obj-$(CONFIG_LIBSCAN) += libscan.o diff --git a/lib/base64.c b/lib/base64.c new file mode 100644 index 0000000000..ac165ab168 --- /dev/null +++ b/lib/base64.c @@ -0,0 +1,154 @@ +/* + * Code based on busybox-1.23.2 + * + * Copyright 2003, Glenn McGrath + * Copyright 2006, Rob Landley + * Copyright 2010, Denys Vlasenko + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include +#include + +/* Conversion table. for base 64 */ +static const char uuenc_tbl_base64[65 + 1] = { + 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', + 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', + 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', + 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', + 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', + 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', + 'w', 'x', 'y', 'z', '0', '1', '2', '3', + '4', '5', '6', '7', '8', '9', '+', '/', + '=' /* termination character */, + '\0' /* needed for uudecode.c only */ +}; + +/* + * Encode bytes at S of length LENGTH to uuencode or base64 format and place it + * to STORE. STORE will be 0-terminated, and must point to a writable + * buffer of at least 1+BASE64_LENGTH(length) bytes. + * where BASE64_LENGTH(len) = (4 * ((LENGTH + 2) / 3)) + */ +void uuencode(char *p, const char *src, int length) +{ + const unsigned char *s = src; + const char *tbl = uuenc_tbl_base64; + + /* Transform the 3x8 bits to 4x6 bits */ + while (length > 0) { + unsigned s1, s2; + + /* Are s[1], s[2] valid or should be assumed 0? */ + s1 = s2 = 0; + length -= 3; /* can be >=0, -1, -2 */ + if (length >= -1) { + s1 = s[1]; + if (length >= 0) + s2 = s[2]; + } + *p++ = tbl[s[0] >> 2]; + *p++ = tbl[((s[0] & 3) << 4) + (s1 >> 4)]; + *p++ = tbl[((s1 & 0xf) << 2) + (s2 >> 6)]; + *p++ = tbl[s2 & 0x3f]; + s += 3; + } + /* Zero-terminate */ + *p = '\0'; + /* If length is -2 or -1, pad last char or two */ + while (length) { + *--p = tbl[64]; + length++; + } +} +EXPORT_SYMBOL(uuencode); + +/* + * Decode base64 encoded string. Stops on '\0'. + * + */ +int decode_base64(char *p_dst, int dst_len, const char *src) +{ + const char *src_tail; + char *dst = p_dst; + int length = 0; + + while (dst_len > 0) { + unsigned char six_bit[4]; + int count = 0; + + /* Fetch up to four 6-bit values */ + src_tail = src; + while (count < 4) { + const char *table_ptr; + int ch; + + /* + * Get next _valid_ character. + * uuenc_tbl_base64[] contains this string: + * 0 1 2 3 4 5 6 + * 01234567890123456789012345678901234567890123456789012345678901234 + * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=" + */ + do { + ch = *src; + if (ch == '\0') { + /* + * Example: + * If we decode "QUJD ", we want + * to return ptr to NUL, not to ' ', + * because we did fully decode + * the string (to "ABC"). + */ + if (count == 0) + src_tail = src; + goto ret; + } + src++; + table_ptr = strchr(uuenc_tbl_base64, ch); + } while (!table_ptr); + + /* Convert encoded character to decimal */ + ch = table_ptr - uuenc_tbl_base64; + + /* ch is 64 if char was '=', otherwise 0..63 */ + if (ch == 64) + break; + + six_bit[count] = ch; + count++; + } + + /* + * Transform 6-bit values to 8-bit ones. + * count can be < 4 when we decode the tail: + * "eQ==" -> "y", not "y NUL NUL". + * Note that (count > 1) is always true, + * "x===" encoding is not valid: + * even a single zero byte encodes as "AA==". + * However, with current logic we come here with count == 1 + * when we decode "==" tail. + */ + if (count > 1) + *dst++ = six_bit[0] << 2 | six_bit[1] >> 4; + if (count > 2) + *dst++ = six_bit[1] << 4 | six_bit[2] >> 2; + if (count > 3) + *dst++ = six_bit[2] << 6 | six_bit[3]; + /* + * Note that if we decode "AA==" and ate first '=', + * we just decoded one char (count == 2) and now we'll + * do the loop once more to decode second '='. + */ + dst_len -= count-1; + /* last character was "=" */ + if (count != 0) + length += count - 1; + } +ret: + p_dst = dst; + + return length; +} +EXPORT_SYMBOL(decode_base64); -- 2.20.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox