diff options
Diffstat (limited to 'src/lib/zlib/crc32.c')
-rw-r--r-- | src/lib/zlib/crc32.c | 486 |
1 files changed, 243 insertions, 243 deletions
diff --git a/src/lib/zlib/crc32.c b/src/lib/zlib/crc32.c index 988ac6d4180..b6b09915adf 100644 --- a/src/lib/zlib/crc32.c +++ b/src/lib/zlib/crc32.c @@ -37,10 +37,10 @@ # define BYFOUR #endif #ifdef BYFOUR - local unsigned long crc32_little OF((unsigned long, - const unsigned char FAR *, unsigned)); - local unsigned long crc32_big OF((unsigned long, - const unsigned char FAR *, unsigned)); + local unsigned long crc32_little OF((unsigned long, + const unsigned char FAR *, unsigned)); + local unsigned long crc32_big OF((unsigned long, + const unsigned char FAR *, unsigned)); # define TBLS 8 #else # define TBLS 1 @@ -48,7 +48,7 @@ /* Local functions for crc concatenation */ local unsigned long gf2_matrix_times OF((unsigned long *mat, - unsigned long vec)); + unsigned long vec)); local void gf2_matrix_square OF((unsigned long *square, unsigned long *mat)); local uLong crc32_combine_ OF((uLong crc1, uLong crc2, z_off64_t len2)); @@ -59,7 +59,7 @@ local volatile int crc_table_empty = 1; local z_crc_t FAR crc_table[TBLS][256]; local void make_crc_table OF((void)); #ifdef MAKECRCH - local void write_table OF((FILE *, const z_crc_t FAR *)); + local void write_table OF((FILE *, const z_crc_t FAR *)); #endif /* MAKECRCH */ /* Generate tables for a byte-wise 32-bit CRC calculation on the polynomial: @@ -89,91 +89,91 @@ local void make_crc_table OF((void)); */ local void make_crc_table() { - z_crc_t c; - int n, k; - z_crc_t poly; /* polynomial exclusive-or pattern */ - /* terms of polynomial defining this crc (except x^32): */ - static volatile int first = 1; /* flag to limit concurrent making */ - static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; - - /* See if another task is already doing this (not thread-safe, but better - than nothing -- significantly reduces duration of vulnerability in - case the advice about DYNAMIC_CRC_TABLE is ignored) */ - if (first) { - first = 0; - - /* make exclusive-or pattern from polynomial (0xedb88320UL) */ - poly = 0; - for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++) - poly |= (z_crc_t)1 << (31 - p[n]); - - /* generate a crc for every 8-bit value */ - for (n = 0; n < 256; n++) { - c = (z_crc_t)n; - for (k = 0; k < 8; k++) - c = c & 1 ? poly ^ (c >> 1) : c >> 1; - crc_table[0][n] = c; - } + z_crc_t c; + int n, k; + z_crc_t poly; /* polynomial exclusive-or pattern */ + /* terms of polynomial defining this crc (except x^32): */ + static volatile int first = 1; /* flag to limit concurrent making */ + static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; + + /* See if another task is already doing this (not thread-safe, but better + than nothing -- significantly reduces duration of vulnerability in + case the advice about DYNAMIC_CRC_TABLE is ignored) */ + if (first) { + first = 0; + + /* make exclusive-or pattern from polynomial (0xedb88320UL) */ + poly = 0; + for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++) + poly |= (z_crc_t)1 << (31 - p[n]); + + /* generate a crc for every 8-bit value */ + for (n = 0; n < 256; n++) { + c = (z_crc_t)n; + for (k = 0; k < 8; k++) + c = c & 1 ? poly ^ (c >> 1) : c >> 1; + crc_table[0][n] = c; + } #ifdef BYFOUR - /* generate crc for each value followed by one, two, and three zeros, - and then the byte reversal of those as well as the first table */ - for (n = 0; n < 256; n++) { - c = crc_table[0][n]; - crc_table[4][n] = ZSWAP32(c); - for (k = 1; k < 4; k++) { - c = crc_table[0][c & 0xff] ^ (c >> 8); - crc_table[k][n] = c; - crc_table[k + 4][n] = ZSWAP32(c); - } - } + /* generate crc for each value followed by one, two, and three zeros, + and then the byte reversal of those as well as the first table */ + for (n = 0; n < 256; n++) { + c = crc_table[0][n]; + crc_table[4][n] = ZSWAP32(c); + for (k = 1; k < 4; k++) { + c = crc_table[0][c & 0xff] ^ (c >> 8); + crc_table[k][n] = c; + crc_table[k + 4][n] = ZSWAP32(c); + } + } #endif /* BYFOUR */ - crc_table_empty = 0; - } - else { /* not first */ - /* wait for the other guy to finish (not efficient, but rare) */ - while (crc_table_empty) - ; - } + crc_table_empty = 0; + } + else { /* not first */ + /* wait for the other guy to finish (not efficient, but rare) */ + while (crc_table_empty) + ; + } #ifdef MAKECRCH - /* write out CRC tables to crc32.h */ - { - FILE *out; - - out = fopen("crc32.h", "w"); - if (out == NULL) return; - fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n"); - fprintf(out, " * Generated automatically by crc32.c\n */\n\n"); - fprintf(out, "local const z_crc_t FAR "); - fprintf(out, "crc_table[TBLS][256] =\n{\n {\n"); - write_table(out, crc_table[0]); + /* write out CRC tables to crc32.h */ + { + FILE *out; + + out = fopen("crc32.h", "w"); + if (out == NULL) return; + fprintf(out, "/* crc32.h -- tables for rapid CRC calculation\n"); + fprintf(out, " * Generated automatically by crc32.c\n */\n\n"); + fprintf(out, "local const z_crc_t FAR "); + fprintf(out, "crc_table[TBLS][256] =\n{\n {\n"); + write_table(out, crc_table[0]); # ifdef BYFOUR - fprintf(out, "#ifdef BYFOUR\n"); - for (k = 1; k < 8; k++) { - fprintf(out, " },\n {\n"); - write_table(out, crc_table[k]); - } - fprintf(out, "#endif\n"); + fprintf(out, "#ifdef BYFOUR\n"); + for (k = 1; k < 8; k++) { + fprintf(out, " },\n {\n"); + write_table(out, crc_table[k]); + } + fprintf(out, "#endif\n"); # endif /* BYFOUR */ - fprintf(out, " }\n};\n"); - fclose(out); - } + fprintf(out, " }\n};\n"); + fclose(out); + } #endif /* MAKECRCH */ } #ifdef MAKECRCH local void write_table(out, table) - FILE *out; - const z_crc_t FAR *table; + FILE *out; + const z_crc_t FAR *table; { - int n; + int n; - for (n = 0; n < 256; n++) - fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : " ", - (unsigned long)(table[n]), - n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", ")); + for (n = 0; n < 256; n++) + fprintf(out, "%s0x%08lxUL%s", n % 5 ? "" : " ", + (unsigned long)(table[n]), + n == 255 ? "\n" : (n % 5 == 4 ? ",\n" : ", ")); } #endif /* MAKECRCH */ @@ -190,10 +190,10 @@ local void write_table(out, table) const z_crc_t FAR * ZEXPORT get_crc_table() { #ifdef DYNAMIC_CRC_TABLE - if (crc_table_empty) - make_crc_table(); + if (crc_table_empty) + make_crc_table(); #endif /* DYNAMIC_CRC_TABLE */ - return (const z_crc_t FAR *)crc_table; + return (const z_crc_t FAR *)crc_table; } /* ========================================================================= */ @@ -202,121 +202,121 @@ const z_crc_t FAR * ZEXPORT get_crc_table() /* ========================================================================= */ unsigned long ZEXPORT crc32(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - uInt len; + unsigned long crc; + const unsigned char FAR *buf; + uInt len; { - if (buf == Z_NULL) return 0UL; + if (buf == Z_NULL) return 0UL; #ifdef DYNAMIC_CRC_TABLE - if (crc_table_empty) - make_crc_table(); + if (crc_table_empty) + make_crc_table(); #endif /* DYNAMIC_CRC_TABLE */ #ifdef BYFOUR - if (sizeof(void *) == sizeof(ptrdiff_t)) { - z_crc_t endian; - - endian = 1; - if (*((unsigned char *)(&endian))) - return crc32_little(crc, buf, len); - else - return crc32_big(crc, buf, len); - } + if (sizeof(void *) == sizeof(ptrdiff_t)) { + z_crc_t endian; + + endian = 1; + if (*((unsigned char *)(&endian))) + return crc32_little(crc, buf, len); + else + return crc32_big(crc, buf, len); + } #endif /* BYFOUR */ - crc = crc ^ 0xffffffffUL; - while (len >= 8) { - DO8; - len -= 8; - } - if (len) do { - DO1; - } while (--len); - return crc ^ 0xffffffffUL; + crc = crc ^ 0xffffffffUL; + while (len >= 8) { + DO8; + len -= 8; + } + if (len) do { + DO1; + } while (--len); + return crc ^ 0xffffffffUL; } #ifdef BYFOUR /* ========================================================================= */ #define DOLIT4 c ^= *buf4++; \ - c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \ - crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24] + c = crc_table[3][c & 0xff] ^ crc_table[2][(c >> 8) & 0xff] ^ \ + crc_table[1][(c >> 16) & 0xff] ^ crc_table[0][c >> 24] #define DOLIT32 DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4; DOLIT4 /* ========================================================================= */ local unsigned long crc32_little(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - unsigned len; + unsigned long crc; + const unsigned char FAR *buf; + unsigned len; { - register z_crc_t c; - register const z_crc_t FAR *buf4; - - c = (z_crc_t)crc; - c = ~c; - while (len && ((ptrdiff_t)buf & 3)) { - c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); - len--; - } - - buf4 = (const z_crc_t FAR *)(const void FAR *)buf; - while (len >= 32) { - DOLIT32; - len -= 32; - } - while (len >= 4) { - DOLIT4; - len -= 4; - } - buf = (const unsigned char FAR *)buf4; - - if (len) do { - c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); - } while (--len); - c = ~c; - return (unsigned long)c; + register z_crc_t c; + register const z_crc_t FAR *buf4; + + c = (z_crc_t)crc; + c = ~c; + while (len && ((ptrdiff_t)buf & 3)) { + c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); + len--; + } + + buf4 = (const z_crc_t FAR *)(const void FAR *)buf; + while (len >= 32) { + DOLIT32; + len -= 32; + } + while (len >= 4) { + DOLIT4; + len -= 4; + } + buf = (const unsigned char FAR *)buf4; + + if (len) do { + c = crc_table[0][(c ^ *buf++) & 0xff] ^ (c >> 8); + } while (--len); + c = ~c; + return (unsigned long)c; } /* ========================================================================= */ #define DOBIG4 c ^= *++buf4; \ - c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \ - crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24] + c = crc_table[4][c & 0xff] ^ crc_table[5][(c >> 8) & 0xff] ^ \ + crc_table[6][(c >> 16) & 0xff] ^ crc_table[7][c >> 24] #define DOBIG32 DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4; DOBIG4 /* ========================================================================= */ local unsigned long crc32_big(crc, buf, len) - unsigned long crc; - const unsigned char FAR *buf; - unsigned len; + unsigned long crc; + const unsigned char FAR *buf; + unsigned len; { - register z_crc_t c; - register const z_crc_t FAR *buf4; - - c = ZSWAP32((z_crc_t)crc); - c = ~c; - while (len && ((ptrdiff_t)buf & 3)) { - c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); - len--; - } - - buf4 = (const z_crc_t FAR *)(const void FAR *)buf; - buf4--; - while (len >= 32) { - DOBIG32; - len -= 32; - } - while (len >= 4) { - DOBIG4; - len -= 4; - } - buf4++; - buf = (const unsigned char FAR *)buf4; - - if (len) do { - c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); - } while (--len); - c = ~c; - return (unsigned long)(ZSWAP32(c)); + register z_crc_t c; + register const z_crc_t FAR *buf4; + + c = ZSWAP32((z_crc_t)crc); + c = ~c; + while (len && ((ptrdiff_t)buf & 3)) { + c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); + len--; + } + + buf4 = (const z_crc_t FAR *)(const void FAR *)buf; + buf4--; + while (len >= 32) { + DOBIG32; + len -= 32; + } + while (len >= 4) { + DOBIG4; + len -= 4; + } + buf4++; + buf = (const unsigned char FAR *)buf4; + + if (len) do { + c = crc_table[4][(c >> 24) ^ *buf++] ^ (c << 8); + } while (--len); + c = ~c; + return (unsigned long)(ZSWAP32(c)); } #endif /* BYFOUR */ @@ -325,105 +325,105 @@ local unsigned long crc32_big(crc, buf, len) /* ========================================================================= */ local unsigned long gf2_matrix_times(mat, vec) - unsigned long *mat; - unsigned long vec; + unsigned long *mat; + unsigned long vec; { - unsigned long sum; - - sum = 0; - while (vec) { - if (vec & 1) - sum ^= *mat; - vec >>= 1; - mat++; - } - return sum; + unsigned long sum; + + sum = 0; + while (vec) { + if (vec & 1) + sum ^= *mat; + vec >>= 1; + mat++; + } + return sum; } /* ========================================================================= */ local void gf2_matrix_square(square, mat) - unsigned long *square; - unsigned long *mat; + unsigned long *square; + unsigned long *mat; { - int n; + int n; - for (n = 0; n < GF2_DIM; n++) - square[n] = gf2_matrix_times(mat, mat[n]); + for (n = 0; n < GF2_DIM; n++) + square[n] = gf2_matrix_times(mat, mat[n]); } /* ========================================================================= */ local uLong crc32_combine_(crc1, crc2, len2) - uLong crc1; - uLong crc2; - z_off64_t len2; + uLong crc1; + uLong crc2; + z_off64_t len2; { - int n; - unsigned long row; - unsigned long even[GF2_DIM]; /* even-power-of-two zeros operator */ - unsigned long odd[GF2_DIM]; /* odd-power-of-two zeros operator */ - - /* degenerate case (also disallow negative lengths) */ - if (len2 <= 0) - return crc1; - - /* put operator for one zero bit in odd */ - odd[0] = 0xedb88320UL; /* CRC-32 polynomial */ - row = 1; - for (n = 1; n < GF2_DIM; n++) { - odd[n] = row; - row <<= 1; - } - - /* put operator for two zero bits in even */ - gf2_matrix_square(even, odd); - - /* put operator for four zero bits in odd */ - gf2_matrix_square(odd, even); - - /* apply len2 zeros to crc1 (first square will put the operator for one - zero byte, eight zero bits, in even) */ - do { - /* apply zeros operator for this bit of len2 */ - gf2_matrix_square(even, odd); - if (len2 & 1) - crc1 = gf2_matrix_times(even, crc1); - len2 >>= 1; - - /* if no more bits set, then done */ - if (len2 == 0) - break; - - /* another iteration of the loop with odd and even swapped */ - gf2_matrix_square(odd, even); - if (len2 & 1) - crc1 = gf2_matrix_times(odd, crc1); - len2 >>= 1; - - /* if no more bits set, then done */ - } while (len2 != 0); - - /* return combined crc */ - crc1 ^= crc2; - return crc1; + int n; + unsigned long row; + unsigned long even[GF2_DIM]; /* even-power-of-two zeros operator */ + unsigned long odd[GF2_DIM]; /* odd-power-of-two zeros operator */ + + /* degenerate case (also disallow negative lengths) */ + if (len2 <= 0) + return crc1; + + /* put operator for one zero bit in odd */ + odd[0] = 0xedb88320UL; /* CRC-32 polynomial */ + row = 1; + for (n = 1; n < GF2_DIM; n++) { + odd[n] = row; + row <<= 1; + } + + /* put operator for two zero bits in even */ + gf2_matrix_square(even, odd); + + /* put operator for four zero bits in odd */ + gf2_matrix_square(odd, even); + + /* apply len2 zeros to crc1 (first square will put the operator for one + zero byte, eight zero bits, in even) */ + do { + /* apply zeros operator for this bit of len2 */ + gf2_matrix_square(even, odd); + if (len2 & 1) + crc1 = gf2_matrix_times(even, crc1); + len2 >>= 1; + + /* if no more bits set, then done */ + if (len2 == 0) + break; + + /* another iteration of the loop with odd and even swapped */ + gf2_matrix_square(odd, even); + if (len2 & 1) + crc1 = gf2_matrix_times(odd, crc1); + len2 >>= 1; + + /* if no more bits set, then done */ + } while (len2 != 0); + + /* return combined crc */ + crc1 ^= crc2; + return crc1; } /* ========================================================================= */ uLong ZEXPORT crc32_combine(crc1, crc2, len2) - uLong crc1; - uLong crc2; - z_off_t len2; + uLong crc1; + uLong crc2; + z_off_t len2; { - return crc32_combine_(crc1, crc2, len2); + return crc32_combine_(crc1, crc2, len2); } #ifdef Z_LARGE64 uLong ZEXPORT crc32_combine64(crc1, crc2, len2) - uLong crc1; - uLong crc2; - z_off64_t len2; + uLong crc1; + uLong crc2; + z_off64_t len2; { - return crc32_combine_(crc1, crc2, len2); + return crc32_combine_(crc1, crc2, len2); } #endif |