Uma solução simples, é utilizar o próprio browser pra solicitar usuário e senha.
código fonte:
/* Web Server - HTTP Autentication Baseado na versão de exemplo do Arduino. ATENÇÃO: esse código é apenas para exemplo e não deve ser encarado como solução completa para segurança de informações de qualquer aplicação. modified 25 feb 2015 by Fabiano A. Arndt (fabianoallex) */ /* descrição Original: Web Server A simple web server that shows the value of the analog input pins. using an Arduino Wiznet Ethernet shield. Circuit: * Ethernet shield attached to pins 10, 11, 12, 13 * Analog inputs attached to pins A0 through A5 (optional) created 18 Dec 2009 by David A. Mellis modified 9 Apr 2012 by Tom Igoe */ /********************************************************************************** ************************************BIBLIOTECAS************************************ **********************************************************************************/ #include <SPI.h> #include <Ethernet.h> /********************************************************************************** ********************************FIM BIBLIOTECAS************************************ **********************************************************************************/ /********************************************************************************** *************************ROTINAS USUARIO E SENHA*********************************** ***********************************************************************************/ boolean validar_usuario(char * linebuf) { /* nesse exemplo o usuario e senha estão definidos dentro do código fonte. mas o usuário e senha poderiam ser autenticados de diversas maneiras, lendo os dados de um servidor web, arquivo texto, etc, bastando apenas atribuir o valor lido para a variável usuario_senha. */ char usuario_senha[] = "admin:admin"; int t = strlen(usuario_senha); int tamanhoEnc = (((t-1) / 3) + 1) * 4; //tamanho da string codificada char out[tamanhoEnc]; base64_encode(out, usuario_senha, t+1 ); //---desconta é usado pra eliminar os caracteres '=' int desconta = 0; if ((t%3) == 1) { desconta = 2; } if ((t%3) == 2) { desconta = 1; } char out2[tamanhoEnc-desconta]; byte i; for (i=0; i<(tamanhoEnc-desconta);i++){ out2[i] = out[i]; } out2[i] = '\0'; return ( strstr(linebuf, out2)>0 ); } /********************************************************************************** *************************FIM ROTINA USUARIO E SENHA******************************** ***********************************************************************************/ /********************************************************************************** ***********************************PAGINAS HTML************************************ ***********************************************************************************/ EthernetServer * server; void iniciar_ethernet(){ byte ip[4] = {192,168,200,188}; //byte gateway[4] = {192,168,1,1}; //byte subnet[4] = {255,255,255,0}; byte mac[6] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED}; int porta = 80; server = new EthernetServer(porta); //Ethernet.begin(mac, ip, gateway, subnet); //caso necessario gateway utilizar essa linha Ethernet.begin(mac, ip); server->begin(); } void html_autenticar(EthernetClient &client) { client.print(F("HTTP/1.1 401 Authorization Required\n" "WWW-Authenticate: Basic realm=\"Area Restrita\"\n" "Content-Type: text/html\n" "Connnection: close\n\n" "<!DOCTYPE HTML>\n" "<HTML><HEAD><TITLE>Error</TITLE>\n" "</HEAD><BODY><H1>401 Acesso nao autorizado</H1></BODY></HTML>\n")); } void html_autenticado(EthernetClient &client){ client.println(F("HTTP/1.1 200 OK\n" "Content-Type: text/html\n" "Connection: keep-alive\n\n" "<!DOCTYPE HTML>" "<html>")); for (int analogChannel = 0; analogChannel < 6; analogChannel++) { int sensorReading = analogRead(analogChannel); client.print(F("analog input ")); client.print(analogChannel); client.print(F(" is ")); client.print(sensorReading); client.println(F("<br>")); } client.println(F("</html>")); } void exec_ethernet(){ EthernetClient client = server->available(); if (client) { char linebuf[80]; memset(linebuf, 0, sizeof(linebuf)); int charCount = 0; boolean autenticado = false; boolean currentLineIsBlank = true; boolean conteudo = false; while (client.connected()) { if (client.available()) { char c = client.read(); linebuf[charCount] = c; if (charCount<sizeof(linebuf)-1) { charCount++; } Serial.write(c); if (c == '\n' && currentLineIsBlank) { autenticado ? html_autenticado(client) : html_autenticar(client); break; } if (c == '\n') { currentLineIsBlank = true; if (strstr(linebuf, "Authorization: Basic")>0 ) { if ( validar_usuario(linebuf) ) { autenticado = true; } } memset(linebuf, 0, sizeof(linebuf)); charCount = 0; } else if (c != '\r') { currentLineIsBlank = false; // you've gotten a character on the current line } } } delay(1); // give the web browser time to receive the data client.stop(); // close the connection: } } /********************************************************************************** **************************************** FIM PAGINAS HTML************************** ***********************************************************************************/ /********************************************************************************** *************************BASE 64 CODE/DECODE DO USUARIO E SENHA******************** ***********************************************************************************/ void a3_to_a4(unsigned char * a4, unsigned char * a3); void a4_to_a3(unsigned char * a3, unsigned char * a4); unsigned char b64_lookup(char c); int base64_encode(char *output, char *input, int inputLen) { const char b64_alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; int i=0, j=0, encLen=0; unsigned char a3[3], a4[4]; while(inputLen--) { a3[i++] = *(input++); if(i == 3) { a3_to_a4(a4, a3); for(i=0; i<4; i++) { output[encLen++] = b64_alphabet[a4[i]]; } i = 0; } } if (i) { for(j = i; j < 3; j++) { a3[j] = '\0'; } a3_to_a4(a4, a3); for(j = 0; j < i + 1; j++) { output[encLen++] = b64_alphabet[a4[j]]; } while((i++ < 3)) { output[encLen++] = '='; } } output[encLen] = '\0'; return encLen; } /* int base64_decode(char * output, char * input, int inputLen) { int i = 0, j = 0; int decLen = 0; unsigned char a3[3]; unsigned char a4[4]; while (inputLen--) { if (*input == '=') { break; } a4[i++] = *(input++); if (i == 4) { for (i = 0; i <4; i++) { a4[i] = b64_lookup(a4[i]); } a4_to_a3(a3,a4); for (i = 0; i < 3; i++) { output[decLen++] = a3[i]; } i = 0; } } if (i) { for (j=i; j<4; j++) { a4[j] = '\0'; } for (j=0; j<4; j++) { a4[j] = b64_lookup(a4[j]);} a4_to_a3(a3,a4); for (j=0; j<i-1; j++) { output[decLen++] = a3[j]; } } output[decLen] = '\0'; return decLen; } */ //int base64_enc_len(int plainLen) { // int n = plainLen; // return (n + 2 - ((n + 2) % 3)) / 3 * 4; //} //int base64_dec_len(char * input, int inputLen) { // int i = 0; // int numEq = 0; // for(i = inputLen - 1; input[i] == '='; i--) { numEq++; } // return ((6 * inputLen) / 8) - numEq; //} void a3_to_a4(unsigned char * a4, unsigned char * a3) { a4[0] = (a3[0] & 0xfc) >> 2; a4[1] = ((a3[0] & 0x03) << 4) + ((a3[1] & 0xf0) >> 4); a4[2] = ((a3[1] & 0x0f) << 2) + ((a3[2] & 0xc0) >> 6); a4[3] = (a3[2] & 0x3f); } //void a4_to_a3(unsigned char * a3, unsigned char * a4) { // a3[0] = (a4[0] << 2) + ((a4[1] & 0x30) >> 4); // a3[1] = ((a4[1] & 0xf) << 4) + ((a4[2] & 0x3c) >> 2); // a3[2] = ((a4[2] & 0x3) << 6) + a4[3]; //} unsigned char b64_lookup(char c) { if(c >='A' && c <='Z') return c - 'A'; if(c >='a' && c <='z') return c - 71; if(c >='0' && c <='9') return c + 4; if(c == '+') return 62; if(c == '/') return 63; return -1; } /********************************************************************************** *************************FIM BASE 64 CODE/DECODE DO USUARIO E SENHA**************** ***********************************************************************************/ /********************************************************************************** **************************************** VOID / LOOP ****************************** ***********************************************************************************/ void setup() { Serial.begin(9600); iniciar_ethernet(); } void loop() { exec_ethernet(); } /********************************************************************************** *************************************FIM VOID / LOOP******************************* ***********************************************************************************/