Mercurial > dropbear
view libtomcrypt/src/misc/base64/base64_encode.c @ 1938:77bc00dcc19f default tip main master
Bump version to 2022.82
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Fri, 01 Apr 2022 14:43:27 +0800 |
parents | 6dba84798cd5 |
children |
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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_encode.c Compliant base64 encoder 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 char * const codes_base64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; #endif /* LTC_BASE64 */ #if defined(LTC_BASE64_URL) static const char * const codes_base64url = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; #endif /* LTC_BASE64_URL */ static int _base64_encode_internal(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen, const char *codes, int pad) { unsigned long i, len2, leven; unsigned char *p; LTC_ARGCHK(in != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); /* valid output size ? */ len2 = 4 * ((inlen + 2) / 3); if (*outlen < len2 + 1) { *outlen = len2 + 1; return CRYPT_BUFFER_OVERFLOW; } p = out; leven = 3*(inlen / 3); for (i = 0; i < leven; i += 3) { *p++ = codes[(in[0] >> 2) & 0x3F]; *p++ = codes[(((in[0] & 3) << 4) + (in[1] >> 4)) & 0x3F]; *p++ = codes[(((in[1] & 0xf) << 2) + (in[2] >> 6)) & 0x3F]; *p++ = codes[in[2] & 0x3F]; in += 3; } /* Pad it if necessary... */ if (i < inlen) { unsigned a = in[0]; unsigned b = (i+1 < inlen) ? in[1] : 0; *p++ = codes[(a >> 2) & 0x3F]; *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F]; if (pad) { *p++ = (i+1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '='; *p++ = '='; } else { if (i+1 < inlen) *p++ = codes[(((b & 0xf) << 2)) & 0x3F]; } } /* append a NULL byte */ *p = '\0'; /* return ok */ *outlen = (unsigned long)(p - out); return CRYPT_OK; } #if defined(LTC_BASE64) /** base64 Encode a buffer (NUL terminated) @param in The input buffer to encode @param inlen The length of the input buffer @param out [out] The destination of the base64 encoded data @param outlen [in/out] The max size and resulting size @return CRYPT_OK if successful */ int base64_encode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_encode_internal(in, inlen, out, outlen, codes_base64, 1); } #endif /* LTC_BASE64 */ #if defined(LTC_BASE64_URL) /** base64 (URL Safe, RFC 4648 section 5) Encode a buffer (NUL terminated) @param in The input buffer to encode @param inlen The length of the input buffer @param out [out] The destination of the base64 encoded data @param outlen [in/out] The max size and resulting size @return CRYPT_OK if successful */ int base64url_encode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_encode_internal(in, inlen, out, outlen, codes_base64url, 0); } int base64url_strict_encode(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen) { return _base64_encode_internal(in, inlen, out, outlen, codes_base64url, 1); } #endif /* LTC_BASE64_URL */ #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */