diff options
| -rw-r--r-- | lib/smtp.c | 239 | ||||
| -rw-r--r-- | lib/smtp.h | 2 |
2 files changed, 240 insertions, 1 deletions
diff --git a/lib/smtp.c b/lib/smtp.c index 45dec6a49..d2cc3d090 100644 --- a/lib/smtp.c +++ b/lib/smtp.c @@ -22,6 +22,7 @@ * RFC3207 SMTP over TLS * RFC4954 SMTP Authentication * RFC2195 CRAM-MD5 authentication + * RFC2831 DIGEST-MD5 authentication * RFC4616 PLAIN authentication * ***************************************************************************/ @@ -82,6 +83,7 @@ #include "rawstr.h" #include "strtoofft.h" #include "curl_base64.h" +#include "curl_rand.h" #include "curl_md5.h" #include "curl_hmac.h" #include "curl_gethostname.h" @@ -279,6 +281,33 @@ static int smtp_endofresp(struct pingpong *pp, int *resp) return result; } +#ifndef CURL_DISABLE_CRYPTO_AUTH +/* Retrieves the value for a corresponding key from the challenge string + * returns TRUE if the key could be found, FALSE if it does not exists + */ +static bool smtp_digest_get_key_value(const unsigned char *chlg, + const char *key, + char *value, + size_t max_val_len, + char end_char) +{ + char *find_pos; + size_t i; + + find_pos = strstr((const char *) chlg, key); + if(!find_pos) + return FALSE; + + find_pos += strlen(key); + + for(i = 0; *find_pos && *find_pos != end_char && i < max_val_len - 1; ++i) + value[i] = *find_pos++; + value[i] = '\0'; + + return TRUE; +} +#endif + /* This is the ONLY way to change SMTP state! */ static void state(struct connectdata *conn, smtpstate newstate) @@ -297,6 +326,8 @@ static void state(struct connectdata *conn, "AUTHLOGIN", "AUTHPASSWD", "AUTHCRAM", + "AUTHDIGESTMD5", + "AUTHDIGESTMD5_RESP", "AUTHNTLM", "AUTHNTLM_TYPE2MSG", "AUTH", @@ -426,7 +457,12 @@ static CURLcode smtp_authenticate(struct connectdata *conn) /* Check supported authentication mechanisms by decreasing order of security. */ #ifndef CURL_DISABLE_CRYPTO_AUTH - if(smtpc->authmechs & SMTP_AUTH_CRAM_MD5) { + if(smtpc->authmechs & SMTP_AUTH_DIGEST_MD5) { + mech = "DIGEST-MD5"; + state1 = SMTP_AUTHDIGESTMD5; + smtpc->authused = SMTP_AUTH_DIGEST_MD5; + } + else if(smtpc->authmechs & SMTP_AUTH_CRAM_MD5) { mech = "CRAM-MD5"; state1 = SMTP_AUTHCRAMMD5; smtpc->authused = SMTP_AUTH_CRAM_MD5; @@ -816,6 +852,199 @@ static CURLcode smtp_state_authcram_resp(struct connectdata *conn, return result; } +/* for AUTH DIGEST-MD5 challenge responses */ +static CURLcode smtp_state_authdigest_resp(struct connectdata *conn, + int smtpcode, + smtpstate instate) +{ + static const char table16[] = "0123456789abcdef"; + + CURLcode result = CURLE_OK; + struct SessionHandle *data = conn->data; + char *chlg64 = data->state.buffer; + unsigned char *chlg; + size_t chlglen; + size_t len = 0; + size_t i; + char *rplyb64 = NULL; + MD5_context *ctxt; + unsigned char digest[MD5_DIGEST_LEN]; + char HA1_hex[2 * MD5_DIGEST_LEN + 1]; + char HA2_hex[2 * MD5_DIGEST_LEN + 1]; + char resp_hash_hex[2 * MD5_DIGEST_LEN + 1]; + + char nonce[64]; + char realm[128]; + char alg[64]; + char nonceCount[] = "00000001"; + char cnonce[] = "12345678"; /* will be changed */ + char method[] = "AUTHENTICATE"; + char qop[] = "auth"; + char uri[128] = "smtp/"; + char response[512]; + + (void)instate; /* no use for this yet */ + + if(smtpcode != 334) { + failf(data, "Access denied: %d", smtpcode); + return CURLE_LOGIN_DENIED; + } + + /* Get the challenge */ + for(chlg64 += 4; *chlg64 == ' ' || *chlg64 == '\t'; chlg64++) + ; + + chlg = (unsigned char *) NULL; + chlglen = 0; + + result = Curl_base64_decode(chlg64, &chlg, &chlglen); + + if(result) + return result; + + /* Retrieve nonce string from the challenge */ + if(!smtp_digest_get_key_value(chlg, "nonce=\"", nonce, + sizeof(nonce), '\"')) { + Curl_safefree(chlg); + return CURLE_LOGIN_DENIED; + } + + /* Retrieve realm string from the challenge */ + if(!smtp_digest_get_key_value(chlg, "realm=\"", realm, + sizeof(realm), '\"')) { + /* Challenge does not have a realm, set empty string [RFC2831] page 6 */ + strcpy(realm, ""); + } + + /* Retrieve algorithm string from the challenge */ + if(!smtp_digest_get_key_value(chlg, "algorithm=", alg, + sizeof(alg), ',')) { + Curl_safefree(chlg); + return CURLE_LOGIN_DENIED; + } + + Curl_safefree(chlg); + + /* We do not support other algorithms */ + if(strcmp(alg, "md5-sess") != 0) + return CURLE_LOGIN_DENIED; + + /* Generate 64 bits of random data */ + for(i = 0; i < 8; i++) + cnonce[i] = table16[Curl_rand()%16]; + + /* So far so good, now calculate A1 and H(A1) according to RFC 2831 */ + ctxt = Curl_MD5_init(Curl_DIGEST_MD5); + Curl_MD5_update(ctxt, (const unsigned char *) conn->user, + strlen(conn->user)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) realm, strlen(realm)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) conn->passwd, + strlen(conn->passwd)); + Curl_MD5_final(ctxt, digest); + + ctxt = Curl_MD5_init(Curl_DIGEST_MD5); + Curl_MD5_update(ctxt, (const unsigned char *) digest, MD5_DIGEST_LEN); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) nonce, strlen(nonce)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) cnonce, strlen(cnonce)); + Curl_MD5_final(ctxt, digest); + + /* Convert calculated 16 octet hex into 32 bytes string */ + for(i = 0; i < MD5_DIGEST_LEN; i++) + snprintf(&HA1_hex[2 * i], 3, "%02x", digest[i]); + + /* Orepare URL string, append realm to the protocol */ + strcat(uri, realm); + + /* Calculate H(A2) */ + ctxt = Curl_MD5_init(Curl_DIGEST_MD5); + Curl_MD5_update(ctxt, (const unsigned char *) method, strlen(method)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) uri, strlen(uri)); + Curl_MD5_final(ctxt, digest); + + for(i = 0; i < MD5_DIGEST_LEN; i++) + snprintf(&HA2_hex[2 * i], 3, "%02x", digest[i]); + + /* Now calculate the response hash */ + ctxt = Curl_MD5_init(Curl_DIGEST_MD5); + Curl_MD5_update(ctxt, (const unsigned char *) HA1_hex, 2 * MD5_DIGEST_LEN); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) nonce, strlen(nonce)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + + Curl_MD5_update(ctxt, (const unsigned char *) nonceCount, + strlen(nonceCount)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) cnonce, strlen(cnonce)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + Curl_MD5_update(ctxt, (const unsigned char *) qop, strlen(qop)); + Curl_MD5_update(ctxt, (const unsigned char *) ":", 1); + + Curl_MD5_update(ctxt, (const unsigned char *) HA2_hex, 2 * MD5_DIGEST_LEN); + Curl_MD5_final(ctxt, digest); + + for(i = 0; i < MD5_DIGEST_LEN; i++) + snprintf(&resp_hash_hex[2 * i], 3, "%02x", digest[i]); + + strcpy(response, "username=\""); + strcat(response, conn->user); + strcat(response, "\",realm=\""); + strcat(response, realm); + strcat(response, "\",nonce=\""); + strcat(response, nonce); + strcat(response, "\",cnonce=\""); + strcat(response, cnonce); + strcat(response, "\",nc="); + strcat(response, nonceCount); + strcat(response, ",digest-uri=\""); + strcat(response, uri); + strcat(response, "\",response="); + strcat(response, resp_hash_hex); + + /* Encode it to base64 and send it */ + result = Curl_base64_encode(data, response, 0, &rplyb64, &len); + + if(!result) { + if(rplyb64) { + result = Curl_pp_sendf(&conn->proto.smtpc.pp, "%s", rplyb64); + + if(!result) + state(conn, SMTP_AUTHDIGESTMD5_RESP); + } + Curl_safefree(rplyb64); + } + + return result; +} + +/* For AUTH DIGEST-MD5 challenge-response responses */ +static CURLcode smtp_state_authdigest_resp_resp(struct connectdata *conn, + int smtpcode, + smtpstate instate) +{ + CURLcode result = CURLE_OK; + struct SessionHandle *data = conn->data; + + (void)instate; /* no use for this yet */ + + if(smtpcode != 334) { + failf(data, "Authentication failed: %d", smtpcode); + result = CURLE_LOGIN_DENIED; + } + else { + result = Curl_pp_sendf(&conn->proto.smtpc.pp, ""); + + if(!result) + state(conn, SMTP_AUTH); + } + + return result; +} + #endif #ifdef USE_NTLM @@ -1170,6 +1399,14 @@ static CURLcode smtp_statemach_act(struct connectdata *conn) case SMTP_AUTHCRAMMD5: result = smtp_state_authcram_resp(conn, smtpcode, smtpc->state); break; + + case SMTP_AUTHDIGESTMD5: + result = smtp_state_authdigest_resp(conn, smtpcode, smtpc->state); + break; + + case SMTP_AUTHDIGESTMD5_RESP: + result = smtp_state_authdigest_resp_resp(conn, smtpcode, smtpc->state); + break; #endif #ifdef USE_NTLM diff --git a/lib/smtp.h b/lib/smtp.h index 8164037db..502f65cbe 100644 --- a/lib/smtp.h +++ b/lib/smtp.h @@ -40,6 +40,8 @@ typedef enum { SMTP_AUTHLOGIN, SMTP_AUTHPASSWD, SMTP_AUTHCRAMMD5, + SMTP_AUTHDIGESTMD5, + SMTP_AUTHDIGESTMD5_RESP, SMTP_AUTHNTLM, SMTP_AUTHNTLM_TYPE2MSG, SMTP_AUTH, |