Replace base{32,64}_decode() with table-driven implementations. The new
code is less strict about padding, thus ensuring compatibility with implementations which do not understand padding, such as MIME::Base32. git-svn-id: svn+ssh://svn.openpam.org/svn/openpam/trunk@771 185d5e19-27fe-0310-9dcf-9bff6b9f3609
This commit is contained in:
Dag-Erling Smørgrav
parent
4645bc1762
commit
17144e7a5f
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@ -37,14 +37,36 @@
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#include <errno.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <security/oath.h>
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static const char b32[] =
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static const char b32enc[] =
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"ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
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static const uint8_t b32dec[256] = {
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['A'] = 0, ['B'] = 1, ['C'] = 2, ['D'] = 3,
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['E'] = 4, ['F'] = 5, ['G'] = 6, ['H'] = 7,
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['I'] = 8, ['J'] = 9, ['K'] = 10, ['L'] = 11,
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['M'] = 12, ['N'] = 13, ['O'] = 14, ['P'] = 15,
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['Q'] = 16, ['R'] = 17, ['S'] = 18, ['T'] = 19,
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['U'] = 20, ['V'] = 21, ['W'] = 22, ['X'] = 23,
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['Y'] = 24, ['Z'] = 25,
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['a'] = 0, ['b'] = 1, ['c'] = 2, ['d'] = 3,
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['e'] = 4, ['f'] = 5, ['g'] = 6, ['h'] = 7,
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['i'] = 8, ['j'] = 9, ['k'] = 10, ['l'] = 11,
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['m'] = 12, ['n'] = 13, ['o'] = 14, ['p'] = 15,
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['q'] = 16, ['r'] = 17, ['s'] = 18, ['t'] = 19,
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['u'] = 20, ['v'] = 21, ['w'] = 22, ['x'] = 23,
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['y'] = 24, ['z'] = 25,
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['2'] = 26, ['3'] = 27, ['4'] = 28, ['5'] = 29,
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['6'] = 30, ['7'] = 31,
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};
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/*
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* Encode data in RFC 3548 base 32 representation. The target buffer must
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* Encode data in RFC 4648 base 32 representation. The target buffer must
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* have room for base32_enclen(len) characters and a terminating NUL.
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*/
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int
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@ -52,8 +74,10 @@ base32_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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{
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uint64_t bits;
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if (*olen <= base32_enclen(ilen))
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if (*olen <= base32_enclen(ilen)) {
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errno = ENOSPC;
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return (-1);
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}
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*olen = 0;
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while (ilen >= 5) {
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bits = 0;
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@ -64,14 +88,14 @@ base32_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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bits |= (uint64_t)in[4];
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ilen -= 5;
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in += 5;
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out[0] = b32[bits >> 35 & 0x1f];
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out[1] = b32[bits >> 30 & 0x1f];
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out[2] = b32[bits >> 25 & 0x1f];
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out[3] = b32[bits >> 20 & 0x1f];
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out[4] = b32[bits >> 15 & 0x1f];
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out[5] = b32[bits >> 10 & 0x1f];
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out[6] = b32[bits >> 5 & 0x1f];
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out[7] = b32[bits & 0x1f];
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out[0] = b32enc[bits >> 35 & 0x1f];
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out[1] = b32enc[bits >> 30 & 0x1f];
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out[2] = b32enc[bits >> 25 & 0x1f];
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out[3] = b32enc[bits >> 20 & 0x1f];
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out[4] = b32enc[bits >> 15 & 0x1f];
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out[5] = b32enc[bits >> 10 & 0x1f];
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out[6] = b32enc[bits >> 5 & 0x1f];
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out[7] = b32enc[bits & 0x1f];
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*olen += 8;
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out += 8;
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}
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@ -87,13 +111,13 @@ base32_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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case 1:
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bits |= (uint64_t)in[0] << 32;
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}
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out[0] = b32[bits >> 35 & 0x1f];
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out[1] = b32[bits >> 30 & 0x1f];
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out[2] = ilen > 1 ? b32[bits >> 25 & 0x1f] : '=';
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out[3] = ilen > 1 ? b32[bits >> 20 & 0x1f] : '=';
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out[4] = ilen > 2 ? b32[bits >> 15 & 0x1f] : '=';
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out[5] = ilen > 3 ? b32[bits >> 10 & 0x1f] : '=';
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out[6] = ilen > 3 ? b32[bits >> 5 & 0x1f] : '=';
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out[0] = b32enc[bits >> 35 & 0x1f];
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out[1] = b32enc[bits >> 30 & 0x1f];
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out[2] = ilen > 1 ? b32enc[bits >> 25 & 0x1f] : '=';
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out[3] = ilen > 1 ? b32enc[bits >> 20 & 0x1f] : '=';
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out[4] = ilen > 2 ? b32enc[bits >> 15 & 0x1f] : '=';
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out[5] = ilen > 3 ? b32enc[bits >> 10 & 0x1f] : '=';
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out[6] = ilen > 3 ? b32enc[bits >> 5 & 0x1f] : '=';
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out[7] = '=';
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*olen += 8;
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out += 8;
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@ -104,10 +128,15 @@ base32_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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}
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/*
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* Decode data in RFC 2548 base 32 representation, stopping at the
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* Decode data in RFC 4648 base 32 representation, stopping at the
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* terminating NUL, the first invalid (non-base32, non-whitespace)
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* character or after len characters, whichever comes first.
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*
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* Padding is handled sloppily: any padding character following the data
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* is silently consumed. This not only simplifies the code but ensures
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* compatibility with implementations which do not emit or understand
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* padding.
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*
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* The olen argument is used by the caller to pass the size of the buffer
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* and by base32_dec() to return the amount of data successfully decoded.
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* If the buffer is too small, base32_dec() discards the excess data, but
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@ -117,90 +146,40 @@ int
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base32_dec(const char *in, size_t ilen, uint8_t *out, size_t *olen)
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{
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size_t len;
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uint64_t bits;
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int shift;
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int bits, shift, padding;
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for (len = 0, bits = 0, shift = 40; ilen && *in && *in != '='; --ilen, ++in) {
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n') {
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for (bits = shift = padding = len = 0; ilen && *in; --ilen, ++in) {
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n' ||
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(padding && *in == '=')) {
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/* consume */
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continue;
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} else if (*in >= 'A' && *in <= 'Z') {
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shift -= 5;
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bits |= (uint64_t)(*in - 'A') << shift;
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} else if (*in >= 'a' && *in <= 'z') {
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shift -= 5;
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bits |= (uint64_t)(*in - 'a') << shift;
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} else if (*in >= '2' && *in <= '7') {
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shift -= 5;
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bits |= (uint64_t)(*in - '2' + 26) << shift;
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} else if (*in == '=') {
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/* handled below */
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break;
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} else if (!padding && b32dec[(int)*in]) {
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/* shift into accumulator */
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shift += 5;
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bits = bits << 5 | b32dec[(int)*in];
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} else if (!padding && shift && *in == '=') {
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/* final byte */
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shift = 0;
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padding = 1;
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} else {
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goto bad;
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/* error */
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*olen = 0;
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errno = EINVAL;
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return (-1);
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}
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if (shift == 0) {
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if ((len += 5) <= *olen) {
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*out++ = (bits >> 32) & 0xff;
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*out++ = (bits >> 24) & 0xff;
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*out++ = (bits >> 16) & 0xff;
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*out++ = (bits >> 8) & 0xff;
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*out++ = bits & 0xff;
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}
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bits = 0;
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shift = 40;
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if (shift >= 8) {
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/* output accumulated byte */
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shift -= 8;
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if (len++ < *olen)
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*out++ = (bits >> shift) & 0xff;
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}
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}
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if (ilen && *in == '=' &&
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(shift == 30 || shift == 20 || shift == 15 || shift == 5)) {
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/*
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* Padding:
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*
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* 00 8 AA====== 30
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* 00 00 16 AAAA==== 20
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* 00 00 00 24 AAAAA=== 15
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* 00 00 00 00 32 AAAAAAA= 5
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*
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* XXX We should check that the last few bits before the
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* padding starts are zero.
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*/
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switch (shift) {
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case 5:
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if (++len <= *olen)
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*out++ = (bits >> 32) & 0xff;
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bits <<= 8;
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case 15:
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if (++len <= *olen)
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*out++ = (bits >> 32) & 0xff;
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bits <<= 8;
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case 20:
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if (++len <= *olen)
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*out++ = (bits >> 32) & 0xff;
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bits <<= 8;
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case 30:
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if (++len <= *olen)
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*out++ = (bits >> 32) & 0xff;
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bits <<= 8;
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break;
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default:
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goto bad;
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}
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/* consume remaining padding and whitespace */
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for (; ilen && *in; --ilen, ++in) {
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n')
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continue;
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else if (*in == '=' && shift)
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shift -= 5;
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else
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goto bad;
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}
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}
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if (ilen)
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goto bad;
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/* report decoded length */
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*olen = len;
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if (len > *olen)
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if (len > *olen) {
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/* overflow */
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errno = ENOSPC;
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return (-1);
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}
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return (0);
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bad:
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*olen = 0;
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return (-1);
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}
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@ -40,13 +40,32 @@
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#include <security/oath.h>
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static const char b64[] =
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static const char b64enc[] =
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"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
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"abcdefghijklmnopqrstuvwxyz"
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"0123456789+/";
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static const uint8_t b64dec[256] = {
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['A'] = 0, ['B'] = 1, ['C'] = 2, ['D'] = 3,
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['E'] = 4, ['F'] = 5, ['G'] = 6, ['H'] = 7,
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['I'] = 8, ['J'] = 9, ['K'] = 10, ['L'] = 11,
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['M'] = 12, ['N'] = 13, ['O'] = 14, ['P'] = 15,
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['Q'] = 16, ['R'] = 17, ['S'] = 18, ['T'] = 19,
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['U'] = 20, ['V'] = 21, ['W'] = 22, ['X'] = 23,
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['Y'] = 24, ['Z'] = 25, ['a'] = 26, ['b'] = 27,
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['c'] = 28, ['d'] = 29, ['e'] = 30, ['f'] = 31,
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['g'] = 32, ['h'] = 33, ['i'] = 34, ['j'] = 35,
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['k'] = 36, ['l'] = 37, ['m'] = 38, ['n'] = 39,
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['o'] = 40, ['p'] = 41, ['q'] = 42, ['r'] = 43,
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['s'] = 44, ['t'] = 45, ['u'] = 46, ['v'] = 47,
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['w'] = 48, ['x'] = 49, ['y'] = 50, ['z'] = 51,
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['0'] = 52, ['1'] = 53, ['2'] = 54, ['3'] = 55,
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['4'] = 56, ['5'] = 57, ['6'] = 58, ['7'] = 59,
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['8'] = 60, ['9'] = 61, ['+'] = 62, ['/'] = 63,
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};
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/*
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* Encode data in RFC 3548 base 64 representation. The target buffer must
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* Encode data in RFC 4648 base 64 representation. The target buffer must
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* have room for base64_enclen(len) characters and a terminating NUL.
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*/
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int
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@ -64,10 +83,10 @@ base64_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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bits |= (uint32_t)in[2];
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ilen -= 3;
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in += 3;
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out[0] = b64[bits >> 18 & 0x3f];
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out[1] = b64[bits >> 12 & 0x3f];
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out[2] = b64[bits >> 6 & 0x3f];
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out[3] = b64[bits & 0x3f];
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out[0] = b64enc[bits >> 18 & 0x3f];
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out[1] = b64enc[bits >> 12 & 0x3f];
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out[2] = b64enc[bits >> 6 & 0x3f];
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out[3] = b64enc[bits & 0x3f];
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*olen += 4;
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out += 4;
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}
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@ -79,9 +98,9 @@ base64_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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case 1:
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bits |= (uint32_t)in[0] << 16;
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}
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out[0] = b64[bits >> 18 & 0x3f];
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out[1] = b64[bits >> 12 & 0x3f];
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out[2] = ilen > 1 ? b64[bits >> 6 & 0x3f] : '=';
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out[0] = b64enc[bits >> 18 & 0x3f];
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out[1] = b64enc[bits >> 12 & 0x3f];
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out[2] = ilen > 1 ? b64enc[bits >> 6 & 0x3f] : '=';
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out[3] = '=';
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*olen += 4;
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out += 4;
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@ -92,10 +111,15 @@ base64_enc(const uint8_t *in, size_t ilen, char *out, size_t *olen)
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}
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/*
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* Decode data in RFC 2548 base 64 representation, stopping at the
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* Decode data in RFC 4648 base 64 representation, stopping at the
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* terminating NUL, the first invalid (non-base64, non-whitespace)
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* character or after len characters, whichever comes first.
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*
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* Padding is handled sloppily: any padding character following the data
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* is silently consumed. This not only simplifies the code but ensures
|
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* compatibility with implementations which do not emit or understand
|
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* padding.
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*
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* The olen argument is used by the caller to pass the size of the buffer
|
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* and by base64_dec() to return the amount of data successfully decoded.
|
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* If the buffer is too small, base64_dec() discards the excess data, but
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@ -105,83 +129,40 @@ int
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base64_dec(const char *in, size_t ilen, uint8_t *out, size_t *olen)
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{
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size_t len;
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uint32_t bits;
|
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int shift;
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int bits, shift, padding;
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for (len = 0, bits = 0, shift = 24; ilen && *in; --ilen, ++in) {
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n') {
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for (bits = shift = padding = len = 0; ilen && *in; --ilen, ++in) {
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n' ||
|
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(padding && *in == '=')) {
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/* consume */
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continue;
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} else if (*in >= 'A' && *in <= 'Z') {
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shift -= 6;
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bits |= (uint32_t)(*in - 'A') << shift;
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} else if (*in >= 'a' && *in <= 'z') {
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shift -= 6;
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bits |= (uint32_t)(*in - 'a' + 26) << shift;
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} else if (*in >= '0' && *in <= '9') {
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shift -= 6;
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bits |= (uint32_t)(*in - '0' + 52) << shift;
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} else if (*in == '+') {
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shift -= 6;
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bits |= (uint32_t)62 << shift;
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} else if (*in == '/') {
|
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shift -= 6;
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bits |= (uint32_t)63 << shift;
|
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} else if (*in == '=') {
|
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/* handled below */
|
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break;
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} else if (!padding && b64dec[(int)*in]) {
|
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/* shift into accumulator */
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shift += 6;
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bits = bits << 6 | b64dec[(int)*in];
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} else if (!padding && shift && *in == '=') {
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/* final byte */
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shift = 0;
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padding = 1;
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} else {
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goto bad;
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/* error */
|
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*olen = 0;
|
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errno = EINVAL;
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return (-1);
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}
|
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if (shift == 0) {
|
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if ((len += 3) <= *olen) {
|
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*out++ = (bits >> 16) & 0xff;
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*out++ = (bits >> 8) & 0xff;
|
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*out++ = bits & 0xff;
|
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}
|
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bits = 0;
|
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shift = 24;
|
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if (shift >= 8) {
|
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/* output accumulated byte */
|
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shift -= 8;
|
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if (len++ < *olen)
|
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*out++ = (bits >> shift) & 0xff;
|
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}
|
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}
|
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if (ilen && *in == '=' && (shift == 12 || shift == 6)) {
|
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/*
|
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* Padding:
|
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*
|
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* 00 8 AA== 12
|
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* 00 00 16 AAA= 6
|
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*
|
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* XXX We should check that the last few bits before the
|
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* padding starts are zero.
|
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*/
|
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switch (shift) {
|
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case 6:
|
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if (++len <= *olen)
|
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*out++ = (bits >> 16) & 0xff;
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bits <<= 8;
|
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case 12:
|
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if (++len <= *olen)
|
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*out++ = (bits >> 16) & 0xff;
|
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bits <<= 8;
|
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break;
|
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default:
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goto bad;
|
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}
|
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/* consume remaining padding and whitespace */
|
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for (; ilen && *in; --ilen, ++in) {
|
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if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n')
|
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continue;
|
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else if (*in == '=' && shift)
|
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shift -= 6;
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else
|
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goto bad;
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}
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}
|
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if (ilen)
|
||||
goto bad;
|
||||
/* report decoded length */
|
||||
*olen = len;
|
||||
if (len > *olen)
|
||||
if (len > *olen) {
|
||||
/* overflow */
|
||||
errno = ENOSPC;
|
||||
return (-1);
|
||||
}
|
||||
return (0);
|
||||
bad:
|
||||
*olen = 0;
|
||||
return (-1);
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue