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Differential Revision: https://review.lighttpd.net/D6 From: Stefan Bühler <stbuehler@web.de> git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3053 152afb58-edef-0310-8abb-c4023f1b3aa9svn/tags/lighttpd-1.4.38
6 changed files with 265 additions and 132 deletions
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#include "base64.h" |
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/* reverse mapping:
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* >= 0: base64 value |
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* -1: invalid character |
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* -2: skip character (whitespace/control) |
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* -3: padding |
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*/ |
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/* BASE64_STANDARD: "A-Z a-z 0-9 + /" maps to 0-63, pad with "=" */ |
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static const char base64_standard_table[66] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="; |
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static const short base64_standard_reverse_table[128] = { |
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/* 0 1 2 3 4 5 6 7 8 9 A B C D E F */ |
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-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x00 - 0x0F */ |
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-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x10 - 0x1F */ |
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-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, /* 0x20 - 0x2F */ |
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -3, -1, -1, /* 0x30 - 0x3F */ |
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-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40 - 0x4F */ |
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, /* 0x50 - 0x5F */ |
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-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60 - 0x6F */ |
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41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 0x70 - 0x7F */ |
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}; |
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/* BASE64_URL: "A-Z a-z 0-9 - _" maps to 0-63, pad with "." */ |
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static const char base64_url_table[66] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_."; |
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static const short base64_url_reverse_table[128] = { |
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/* 0 1 2 3 4 5 6 7 8 9 A B C D E F */ |
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-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x00 - 0x0F */ |
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-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, /* 0x10 - 0x1F */ |
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-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -3, -1, /* 0x20 - 0x2F */ |
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, /* 0x30 - 0x3F */ |
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-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 0x40 - 0x4F */ |
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63, /* 0x50 - 0x5F */ |
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-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 0x60 - 0x6F */ |
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41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, /* 0x70 - 0x7F */ |
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}; |
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unsigned char* buffer_append_base64_decode(buffer *out, const char* in, size_t in_length, base64_charset charset) { |
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unsigned char *result; |
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size_t out_pos = 0; /* current output character (position) that is decoded. can contain partial result */ |
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unsigned int group = 0; /* how many base64 digits in the current group were decoded already. each group has up to 4 digits */ |
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size_t i; |
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const short* base64_reverse_table; |
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switch (charset) { |
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case BASE64_STANDARD: |
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base64_reverse_table = base64_standard_reverse_table; |
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break; |
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case BASE64_URL: |
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base64_reverse_table = base64_url_reverse_table; |
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break; |
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default: |
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return NULL; |
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} |
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result = (unsigned char *) buffer_string_prepare_append(out, 3*(in_length / 4) + 3); |
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/* run through the whole string, converting as we go */ |
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for (i = 0; i < in_length; i++) { |
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unsigned char c = (unsigned char) in[i]; |
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short ch; |
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if (c == '\0') break; |
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if (c >= 128) return NULL; /* only 7-bit characters allowed */ |
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ch = base64_reverse_table[c]; |
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if (-3 == ch) { |
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/* pad character; can only come after 2 base64 digits in a group */ |
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if (group < 2) return NULL; |
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break; |
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} else if (-2 == ch) { |
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continue; /* skip character */ |
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} else if (ch < 0) { |
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return NULL; /* invalid character, abort */ |
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} |
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switch(group) { |
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case 0: |
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result[out_pos] = ch << 2; |
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group = 1; |
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break; |
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case 1: |
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result[out_pos++] |= ch >> 4; |
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result[out_pos] = (ch & 0x0f) << 4; |
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group = 2; |
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break; |
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case 2: |
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result[out_pos++] |= ch >>2; |
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result[out_pos] = (ch & 0x03) << 6; |
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group = 3; |
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break; |
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case 3: |
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result[out_pos++] |= ch; |
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group = 0; |
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break; |
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} |
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} |
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switch(group) { |
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case 0: |
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/* ended on boundary */ |
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break; |
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case 1: |
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/* need at least 2 base64 digits per group */ |
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return NULL; |
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case 2: |
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/* have 2 base64 digits in last group => one real octect, two zeroes padded */ |
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case 3: |
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/* have 3 base64 digits in last group => two real octects, one zero padded */ |
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/* for both cases the current index already is on the first zero padded octet
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* - check it really is zero (overlapping bits) */ |
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if (0 != result[out_pos]) return NULL; |
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break; |
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} |
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buffer_commit(out, out_pos); |
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return result; |
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} |
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size_t li_to_base64_no_padding(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset) { |
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const size_t full_tuples = in_length / 3; |
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const size_t in_tuple_remainder = in_length % 3; |
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const size_t out_tuple_remainder = in_tuple_remainder ? 1 + in_tuple_remainder : 0; |
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const size_t require_space = 4 * full_tuples + out_tuple_remainder; |
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const char* base64_table; |
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size_t i; |
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size_t out_pos = 0; |
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switch (charset) { |
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case BASE64_STANDARD: |
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base64_table = base64_standard_table; |
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break; |
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case BASE64_URL: |
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base64_table = base64_url_table; |
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break; |
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default: |
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force_assert(0 && "invalid charset"); |
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} |
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/* check overflows */ |
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force_assert(full_tuples < 2*full_tuples); |
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force_assert(full_tuples < 4*full_tuples); |
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force_assert(4*full_tuples < 4*full_tuples + out_tuple_remainder); |
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force_assert(require_space <= out_length); |
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for (i = 2; i < in_length; i += 3) { |
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unsigned int v = (in[i-2] << 16) | (in[i-1] << 8) | in[i]; |
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out[out_pos+3] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+2] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+0] = base64_table[v & 0x3f]; |
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out_pos += 4; |
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} |
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switch (in_tuple_remainder) { |
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case 0: |
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break; |
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case 1: |
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{ |
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/* pretend in[i-1] = in[i] = 0, don't write last two (out_pos+3, out_pos+2) characters */ |
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unsigned int v = (in[i-2] << 4); |
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out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+0] = base64_table[v & 0x3f]; |
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out_pos += 2; |
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} |
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break; |
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case 2: |
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{ |
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/* pretend in[i] = 0, don't write last (out_pos+3) character */ |
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unsigned int v = (in[i-2] << 10) | (in[i-1] << 2); |
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out[out_pos+2] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+1] = base64_table[v & 0x3f]; v >>= 6; |
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out[out_pos+0] = base64_table[v & 0x3f]; |
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out_pos += 3; |
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} |
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break; |
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} |
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force_assert(out_pos <= out_length); |
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return out_pos; |
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} |
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size_t li_to_base64(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset) { |
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const size_t in_tuple_remainder = in_length % 3; |
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size_t padding_length = in_tuple_remainder ? 3 - in_tuple_remainder : 0; |
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char padding; |
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size_t out_pos; |
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switch (charset) { |
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case BASE64_STANDARD: |
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padding = base64_standard_table[64]; |
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break; |
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case BASE64_URL: |
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padding = base64_url_table[64]; |
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break; |
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default: |
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force_assert(0 && "invalid charset"); |
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} |
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force_assert(out_length >= padding_length); |
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out_pos = li_to_base64_no_padding(out, out_length - padding_length, in, in_length, charset); |
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while (padding_length > 0) { |
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out[out_pos++] = padding; |
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padding_length--; |
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} |
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force_assert(out_pos <= out_length); |
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return out_pos; |
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} |
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char* buffer_append_base64_encode_no_padding(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset) { |
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size_t reserve = 4*(in_length/3) + 4; |
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char* result = buffer_string_prepare_append(out, reserve); |
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size_t out_pos = li_to_base64_no_padding(result, reserve, in, in_length, charset); |
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buffer_commit(out, out_pos); |
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return result; |
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} |
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char* buffer_append_base64_encode(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset) { |
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size_t reserve = 4*(in_length/3) + 4; |
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char* result = buffer_string_prepare_append(out, reserve); |
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size_t out_pos = li_to_base64(result, reserve, in, in_length, charset); |
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buffer_commit(out, out_pos); |
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return result; |
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} |
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@ -0,0 +1,19 @@
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#ifndef _BASE64_H_ |
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#define _BASE64_H_ |
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#include "buffer.h" |
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typedef enum { |
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BASE64_STANDARD, |
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BASE64_URL, |
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} base64_charset; |
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unsigned char* buffer_append_base64_decode(buffer *out, const char* in, size_t in_length, base64_charset charset); |
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size_t li_to_base64_no_padding(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset); |
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size_t li_to_base64(char* out, size_t out_length, const unsigned char* in, size_t in_length, base64_charset charset); |
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char* buffer_append_base64_encode_no_padding(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset); |
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char* buffer_append_base64_encode(buffer *out, const unsigned char* in, size_t in_length, base64_charset charset); |
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#endif |
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