Mercurial > dropbear
view libtomcrypt/src/misc/base64/base64_decode.c @ 1594:c69df5d5db94
ciphers/hashes/kex algorithms won't have string lengths, also use
dictionary for fuzzer-preauth_nomaths
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Mon, 05 Mar 2018 21:02:26 +0800 |
parents | 6dba84798cd5 |
children | d885a77b98e0 |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. */ #include "tomcrypt.h" /** @file base64_decode.c Compliant base64 code donated by Wayne Scott ([email protected]) base64 URL Safe variant (RFC 4648 section 5) by Karel Miko */ #if defined(LTC_BASE64) || defined (LTC_BASE64_URL) #if defined(LTC_BASE64) static const unsigned char map_base64[256] = { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, 254, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255, 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 }; #endif /* LTC_BASE64 */ static const unsigned char map_base64url[] = { #if defined(LTC_BASE64_URL) 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, 255, 254, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 63, 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255 #endif /* LTC_BASE64_URL */ }; enum { relaxed = 0, strict = 1 }; static int _base64_decode_internal(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen, const unsigned char *map, int is_strict) { unsigned long t, x, y, z; unsigned char c; int g; LTC_ARGCHK(in != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); g = 0; /* '=' counter */ for (x = y = z = t = 0; x < inlen; x++) { c = map[in[x]&0xFF]; if (c == 254) { g++; continue; } else if (is_strict && g > 0) { /* we only allow '=' to be at the end */ return CRYPT_INVALID_PACKET; } if (c == 255) { if (is_strict) return CRYPT_INVALID_PACKET; else continue; } t = (t<<6)|c; if (++y == 4) { if (z + 3 > *outlen) return CRYPT_BUFFER_OVERFLOW; out[z++] = (unsigned char)((t>>16)&255); out[z++] = (unsigned char)((t>>8)&255); out[z++] = (unsigned char)(t&255); y = t = 0; } } if (y != 0) { if (y == 1) return CRYPT_INVALID_PACKET; if ((y + g) != 4 && is_strict && map != map_base64url) return CRYPT_INVALID_PACKET; t = t << (6 * (4 - y)); if (z + y - 1 > *outlen) return CRYPT_BUFFER_OVERFLOW; if (y >= 2) out[z++] = (unsigned char) ((t >> 16) & 255); if (y == 3) out[z++] = (unsigned char) ((t >> 8) & 255); } *outlen = z; return CRYPT_OK; } #if defined(LTC_BASE64) /** Relaxed base64 decode a block of memory @param in The base64 data to decode @param inlen The length of the base64 data @param out [out] The destination of the binary decoded data @param outlen [in/out] The max size and resulting size of the decoded data @return CRYPT_OK if successful */ int base64_decode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_decode_internal(in, inlen, out, outlen, map_base64, relaxed); } /** Strict base64 decode a block of memory @param in The base64 data to decode @param inlen The length of the base64 data @param out [out] The destination of the binary decoded data @param outlen [in/out] The max size and resulting size of the decoded data @return CRYPT_OK if successful */ int base64_strict_decode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_decode_internal(in, inlen, out, outlen, map_base64, strict); } #endif /* LTC_BASE64 */ #if defined(LTC_BASE64_URL) /** Relaxed base64 (URL Safe, RFC 4648 section 5) decode a block of memory @param in The base64 data to decode @param inlen The length of the base64 data @param out [out] The destination of the binary decoded data @param outlen [in/out] The max size and resulting size of the decoded data @return CRYPT_OK if successful */ int base64url_decode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_decode_internal(in, inlen, out, outlen, map_base64url, relaxed); } /** Strict base64 (URL Safe, RFC 4648 section 5) decode a block of memory @param in The base64 data to decode @param inlen The length of the base64 data @param out [out] The destination of the binary decoded data @param outlen [in/out] The max size and resulting size of the decoded data @return CRYPT_OK if successful */ int base64url_strict_decode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_decode_internal(in, inlen, out, outlen, map_base64url, strict); } #endif /* LTC_BASE64_URL */ #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */