summaryrefslogtreecommitdiffstats
path: root/mysys/base64.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--mysys/base64.c443
1 files changed, 443 insertions, 0 deletions
diff --git a/mysys/base64.c b/mysys/base64.c
new file mode 100644
index 00000000..d46c9a22
--- /dev/null
+++ b/mysys/base64.c
@@ -0,0 +1,443 @@
+/* Copyright (c) 2003, 2010, Oracle and/or its affiliates.
+ Copyright (c) 2013, MariaDB Foundation.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#include <my_global.h>
+#include <m_string.h> /* strchr() */
+#include <m_ctype.h> /* my_isspace() */
+
+#ifndef MAIN
+
+static char base64_table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz"
+ "0123456789+/";
+
+/**
+ * Maximum length my_base64_needed_encoded_length()
+ * can handle without signed integer overflow.
+ */
+int
+my_base64_encode_max_arg_length()
+{
+ /*
+ my_base64_needed_encoded_length(1589695686) -> 2147483646 (7FFFFFFE)
+ my_base64_needed_encoded_length(1589695687) -> -2147483645
+ */
+ return 0x5EC0D4C6; /* 1589695686 */
+}
+
+
+int
+my_base64_needed_encoded_length(int length_of_data)
+{
+ int nb_base64_chars;
+ nb_base64_chars= (length_of_data + 2) / 3 * 4;
+
+ return
+ nb_base64_chars + /* base64 char incl padding */
+ (nb_base64_chars - 1)/ 76 + /* newlines */
+ 1; /* NUL termination of string */
+}
+
+
+/**
+ * Maximum length supported by my_base64_decode().
+ */
+int
+my_base64_decode_max_arg_length()
+{
+ return 0x7FFFFFFF;
+}
+
+
+int
+my_base64_needed_decoded_length(int length_of_encoded_data)
+{
+ return (int) ((longlong) length_of_encoded_data + 3) / 4 * 3;
+}
+
+
+/*
+ Encode a data as base64.
+
+ Note: We require that dst is pre-allocated to correct size.
+ See my_base64_needed_encoded_length().
+
+ Note: We add line separators every 76 characters.
+
+ Note: The output string is properly padded with the '=' character,
+ so the length of the output string is always divisable by 4.
+*/
+
+int
+my_base64_encode(const void *src, size_t src_len, char *dst)
+{
+ const unsigned char *s= (const unsigned char*)src;
+ size_t i= 0;
+ size_t len= 0;
+
+ for (; i < src_len; len += 4)
+ {
+ unsigned c;
+
+ if (len == 76)
+ {
+ len= 0;
+ *dst++= '\n';
+ }
+
+ c= s[i++];
+ c <<= 8;
+
+ if (i < src_len)
+ c += s[i];
+ c <<= 8;
+ i++;
+
+ if (i < src_len)
+ c += s[i];
+ i++;
+
+ *dst++= base64_table[(c >> 18) & 0x3f];
+ *dst++= base64_table[(c >> 12) & 0x3f];
+
+ if (i > (src_len + 1))
+ *dst++= '=';
+ else
+ *dst++= base64_table[(c >> 6) & 0x3f];
+
+ if (i > src_len)
+ *dst++= '=';
+ else
+ *dst++= base64_table[(c >> 0) & 0x3f];
+ }
+ *dst= '\0';
+
+ return 0;
+}
+
+
+/*
+ Base64 decoder stream
+*/
+typedef struct my_base64_decoder_t
+{
+ const char *src; /* Pointer to the current input position */
+ const char *end; /* Pointer to the end of input buffer */
+ uint c; /* Collect bits into this number */
+ int error; /* Error code */
+ uchar state; /* Character number in the current group of 4 */
+ uchar mark; /* Number of padding marks in the current group */
+} MY_BASE64_DECODER;
+
+
+/*
+ Helper table for decoder.
+ -2 means "space character"
+ -1 means "bad character"
+ Non-negative values mean valid base64 encoding character.
+*/
+static int8
+from_base64_table[]=
+{
+/*00*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-2,-2,-2,-2,-2,-1,-1,
+/*10*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*20*/ -2,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63, /* !"#$%&'()*+,-./ */
+/*30*/ 52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1, /* 0123456789:;<=>? */
+/*40*/ -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14, /* @ABCDEFGHIJKLMNO */
+/*50*/ 15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1, /* PQRSTUVWXYZ[\]^_ */
+/*60*/ -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40, /* `abcdefghijklmno */
+/*70*/ 41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1, /* pqrstuvwxyz{|}~ */
+/*80*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*90*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*A0*/ -2,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*B0*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*C0*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*D0*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*E0*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
+/*F0*/ -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+};
+
+
+/**
+ * Skip leading spaces in a base64 encoded stream
+ * and stop on the first non-space character.
+ * decoder->src will point to the first non-space character,
+ * or to the end of the input string.
+ * In case when end-of-input met on unexpected position,
+ * decoder->error is also set to 1.
+ *
+ * See http://en.wikipedia.org/wiki/Base64 for the base64 encoding details
+ *
+ * @param decoder Pointer to MY_BASE64_DECODER
+ *
+ * @return
+ * FALSE on success (there are some more non-space input characters)
+ * TRUE on error (end-of-input found)
+ */
+
+static inline my_bool
+my_base64_decoder_skip_spaces(MY_BASE64_DECODER *decoder)
+{
+ for ( ; decoder->src < decoder->end; decoder->src++)
+ {
+ if (from_base64_table[(uchar) *decoder->src] != -2)
+ return FALSE;
+ }
+ if (decoder->state > 0)
+ decoder->error= 1; /* Unexpected end-of-input found */
+ return TRUE;
+}
+
+
+/**
+ * Convert the next character in a base64 encoded stream
+ * to a number in the range [0..63]
+ * and mix it with the previously collected value in decoder->c.
+ *
+ * @param decode base64 decoding stream
+ *
+ * @return
+ * FALSE on success
+ * TRUE on error (invalid base64 character found)
+ */
+static inline my_bool
+my_base64_add(MY_BASE64_DECODER *decoder)
+{
+ int res;
+ decoder->c <<= 6;
+ if ((res= from_base64_table[(uchar) *decoder->src++]) < 0)
+ return (decoder->error= TRUE);
+ decoder->c+= (uint) res;
+ return FALSE;
+}
+
+
+/**
+ * Get the next character from a base64 encoded stream.
+ * Skip spaces, then scan the next base64 character or a pad character
+ * and collect bits into decoder->c.
+ *
+ * @param decoder Pointer to MY_BASE64_DECODER
+ * @return
+ * FALSE on success (a valid base64 encoding character found)
+ * TRUE on error (unexpected character or unexpected end-of-input found)
+ */
+static my_bool
+my_base64_decoder_getch(MY_BASE64_DECODER *decoder)
+{
+ if (my_base64_decoder_skip_spaces(decoder))
+ return TRUE; /* End-of-input */
+
+ if (!my_base64_add(decoder)) /* Valid base64 character found */
+ {
+ if (decoder->mark)
+ {
+ /* If we have scanned '=' already, then only '=' is valid */
+ DBUG_ASSERT(decoder->state == 3);
+ decoder->error= 1;
+ decoder->src--;
+ return TRUE; /* expected '=', but encoding character found */
+ }
+ decoder->state++;
+ return FALSE;
+ }
+
+ /* Process error */
+ switch (decoder->state)
+ {
+ case 0:
+ case 1:
+ decoder->src--;
+ return TRUE; /* base64 character expected */
+ break;
+
+ case 2:
+ case 3:
+ if (decoder->src[-1] == '=')
+ {
+ decoder->error= 0; /* Not an error - it's a pad character */
+ decoder->mark++;
+ }
+ else
+ {
+ decoder->src--;
+ return TRUE; /* base64 character or '=' expected */
+ }
+ break;
+
+ default:
+ DBUG_ASSERT(0);
+ return TRUE; /* Wrong state, should not happen */
+ }
+
+ decoder->state++;
+ return FALSE;
+}
+
+
+/**
+ * Decode a base64 string
+ * The base64-encoded data in the range ['src','*end_ptr') will be
+ * decoded and stored starting at 'dst'. The decoding will stop
+ * after 'len' characters have been read from 'src', or when padding
+ * occurs in the base64-encoded data. In either case: if 'end_ptr' is
+ * non-null, '*end_ptr' will be set to point to the character after
+ * the last read character, even in the presence of error.
+ *
+ * Note: 'dst' must have sufficient space to store the decoded data.
+ * Use my_base64_needed_decoded_length() to calculate the correct space size.
+ *
+ * Note: we allow spaces and line separators at any position.
+ *
+ * @param src Pointer to base64-encoded string
+ * @param len Length of string at 'src'
+ * @param dst Pointer to location where decoded data will be stored
+ * @param end_ptr Pointer to variable that will refer to the character
+ * after the end of the encoded data that were decoded.
+ * Can be NULL.
+ * @flags flags e.g. allow multiple chunks
+ * @return Number of bytes written at 'dst', or -1 in case of failure
+ */
+int
+my_base64_decode(const char *src_base, size_t len,
+ void *dst, const char **end_ptr, int flags)
+{
+ char *d= (char*) dst;
+ MY_BASE64_DECODER decoder;
+
+ decoder.src= src_base;
+ decoder.end= src_base + len;
+ decoder.error= 0;
+ decoder.mark= 0;
+
+ for ( ; ; )
+ {
+ decoder.c= 0;
+ decoder.state= 0;
+
+ if (my_base64_decoder_getch(&decoder) ||
+ my_base64_decoder_getch(&decoder) ||
+ my_base64_decoder_getch(&decoder) ||
+ my_base64_decoder_getch(&decoder))
+ break;
+
+ *d++= (decoder.c >> 16) & 0xff;
+ *d++= (decoder.c >> 8) & 0xff;
+ *d++= (decoder.c >> 0) & 0xff;
+
+ if (decoder.mark)
+ {
+ d-= decoder.mark;
+ if (!(flags & MY_BASE64_DECODE_ALLOW_MULTIPLE_CHUNKS))
+ break;
+ decoder.mark= 0;
+ }
+ }
+
+ /* Return error if there are more non-space characters */
+ decoder.state= 0;
+ if (!my_base64_decoder_skip_spaces(&decoder))
+ decoder.error= 1;
+
+ if (end_ptr != NULL)
+ *end_ptr= decoder.src;
+
+ return decoder.error ? -1 : (int) (d - (char*) dst);
+}
+
+
+#else /* MAIN */
+
+#define require(b) { \
+ if (!(b)) { \
+ printf("Require failed at %s:%d\n", __FILE__, __LINE__); \
+ abort(); \
+ } \
+}
+
+
+int
+main(void)
+{
+ int i;
+ size_t j;
+ size_t k, l;
+ size_t dst_len;
+ size_t needed_length;
+
+ for (i= 0; i < 500; i++)
+ {
+ /* Create source data */
+ const size_t src_len= rand() % 1000 + 1;
+
+ char * src= (char *) malloc(src_len);
+ char * s= src;
+ char * str;
+ char * dst;
+
+ require(src);
+ for (j= 0; j<src_len; j++)
+ {
+ char c= rand();
+ *s++= c;
+ }
+
+ /* Encode */
+ needed_length= my_base64_needed_encoded_length(src_len);
+ str= (char *) malloc(needed_length);
+ require(str);
+ for (k= 0; k < needed_length; k++)
+ str[k]= 0xff; /* Fill memory to check correct NUL termination */
+ require(my_base64_encode(src, src_len, str) == 0);
+ require(needed_length == strlen(str) + 1);
+
+ /* Decode */
+ dst= (char *) malloc(my_base64_needed_decoded_length(strlen(str)));
+ require(dst);
+ dst_len= my_base64_decode(str, strlen(str), dst, NULL);
+ require(dst_len == src_len);
+
+ if (memcmp(src, dst, src_len) != 0)
+ {
+ printf(" --------- src --------- --------- dst ---------\n");
+ for (k= 0; k<src_len; k+=8)
+ {
+ printf("%.4x ", (uint) k);
+ for (l=0; l<8 && k+l<src_len; l++)
+ {
+ unsigned char c= src[k+l];
+ printf("%.2x ", (unsigned)c);
+ }
+
+ printf(" ");
+
+ for (l=0; l<8 && k+l<dst_len; l++)
+ {
+ unsigned char c= dst[k+l];
+ printf("%.2x ", (unsigned)c);
+ }
+ printf("\n");
+ }
+ printf("src length: %.8x, dst length: %.8x\n",
+ (uint) src_len, (uint) dst_len);
+ require(0);
+ }
+ }
+ printf("Test succeeded.\n");
+ return 0;
+}
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 19:12:18 +0000