인코딩 string encodeBase64(const unsigned char *buf, size_t blen) { auto plen = 4 * ((blen + 2) / 3); auto obuf = make_unique<unsigned char[]>(plen + 1); EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new(); EVP_EncodeInit(ctx); int olen = plen; EVP_EncodeUpdate(ctx, obuf.get(), &olen, buf, blen); int flen = 0; EVP_EncodeFinal(ctx, obuf.get() + olen, &flen); olen += flen; EVP_ENCODE_CTX_free(ctx); return string((char *)obuf.get(), olen); } 디코딩 pair<unique_ptr<unsigned char[]>, size_t> decodeBase64(const string &buf) { auto plen = 3 * buf.size() / 4; auto obuf = make_unique<unsigned char[]>(plen + 1); EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new(); EVP_DecodeInit(ctx); int olen = plen; EVP_DecodeUpdate(ctx, obuf.get(), &olen, (unsigned char *)buf.c_str(), buf.size()); int flen = 0; EVP_DecodeFinal(ctx, obuf.get() + olen, &flen); olen += flen; EVP_ENCODE_CTX_free(ctx); ret