/*- * Copyright (c) 2013-2014 The University of Oslo * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Author: Dag-Erling Smørgrav * Sponsor: the University of Oslo * * $Cryb$ */ #include "cryb/impl.h" #include #include #include #include static const char b64enc[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz" "0123456789+/"; static const char b64dec[256] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, }; /* * Encode data in RFC 4648 base 64 representation. The target buffer must * have room for base64_enclen(len) characters and a terminating NUL. */ int base64_encode(const uint8_t *in, size_t ilen, char *out, size_t *olen) { uint32_t bits; if (*olen <= base64_enclen(ilen)) { *olen = base64_enclen(ilen) + 1; errno = ENOSPC; return (-1); } *olen = base64_enclen(ilen) + 1; while (ilen >= 3) { bits = 0; bits |= (uint32_t)*in++ << 16; bits |= (uint32_t)*in++ << 8; bits |= (uint32_t)*in++; ilen -= 3; *out++ = b64enc[bits >> 18 & 0x3f]; *out++ = b64enc[bits >> 12 & 0x3f]; *out++ = b64enc[bits >> 6 & 0x3f]; *out++ = b64enc[bits & 0x3f]; } if (ilen > 0) { bits = 0; switch (ilen) { case 2: bits |= (uint32_t)in[1] << 8; case 1: bits |= (uint32_t)in[0] << 16; CRYB_NO_DEFAULT_CASE } *out++ = b64enc[bits >> 18 & 0x3f]; *out++ = b64enc[bits >> 12 & 0x3f]; *out++ = ilen > 1 ? b64enc[bits >> 6 & 0x3f] : '='; *out++ = '='; } *out++ = '\0'; return (0); } /* * Decode data in RFC 4648 base 64 representation, stopping at the * terminating NUL, the first invalid (non-base64, non-whitespace) * character or after len characters, whichever comes first. * * Padding is handled sloppily: any padding character following the data * is silently consumed. This not only simplifies the code but ensures * compatibility with implementations which do not emit or understand * padding. * * The olen argument is used by the caller to pass the size of the buffer * and by base64_decode() to return the amount of data successfully * decoded. If the buffer is too small, base64_decode() discards the * excess data, but returns the total amount. */ int base64_decode(const char *in, size_t ilen, uint8_t *out, size_t *olen) { size_t len; int bits, shift, padding; for (bits = shift = padding = len = 0; ilen && *in; --ilen, ++in) { if (*in == ' ' || *in == '\t' || *in == '\r' || *in == '\n' || (padding && *in == '=')) { /* consume */ continue; } else if (!padding && b64dec[(uint8_t)*in] >= 0) { /* shift into accumulator */ shift += 6; bits = bits << 6 | b64dec[(uint8_t)*in]; } else if (!padding && *in == '=' && (shift == 2 || shift == 4)) { /* final byte */ padding = 1; } else { /* error */ *olen = 0; errno = EINVAL; return (-1); } if (shift >= 8) { /* output accumulated byte */ shift -= 8; if (len++ < *olen) *out++ = (bits >> shift) & 0xff; } } /* non-zero bits in last byte before padding */ if (shift && (bits & ~(~0 << shift)) != 0) { errno = EINVAL; return (-1); } /* report decoded length */ if (len > *olen) { /* overflow */ *olen = len; errno = ENOSPC; return (-1); } *olen = len; return (0); }