| 1 |
#include <string.h> |
| 2 |
#include <errno.h> |
| 3 |
#include <unistd.h> |
| 4 |
#include <sys/time.h> |
| 5 |
#include <sys/types.h> |
| 6 |
#include <sys/socket.h> |
| 7 |
#include <netinet/in.h> |
| 8 |
#include <netdb.h> |
| 9 |
#include <fcntl.h> |
| 10 |
|
| 11 |
#include "config.h" |
| 12 |
#include "imapfilter.h" |
| 13 |
|
| 14 |
#ifdef SSL_TLS |
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#include <openssl/ssl.h> |
| 16 |
#include <openssl/err.h> |
| 17 |
#include <openssl/x509.h> |
| 18 |
#endif |
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|
| 20 |
|
| 21 |
long timeout = -1; /* Server non-response timeout in seconds. */ |
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|
| 23 |
int sockpri = -1; /* Main socket used mostly. */ |
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int sockaux = -1; /* Auxiliary socked used when another |
| 25 |
connection is needed. */ |
| 26 |
#ifdef SSL_TLS |
| 27 |
static SSL *sslpri = NULL; |
| 28 |
static SSL *sslaux = NULL; |
| 29 |
#endif |
| 30 |
|
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|
| 32 |
|
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/* |
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* Connect to mail server. |
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*/ |
| 36 |
int init_connection(int *sock, char *serv, unsigned short int port, |
| 37 |
unsigned int protocol) |
| 38 |
{ |
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struct sockaddr_in sa; |
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struct hostent *he; |
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#ifdef SSL_TLS |
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SSL **ssl = (sock == &sockpri ? &sslpri : &sslaux); |
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#else |
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if (protocol != SSL_DISABLED) { |
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error("imapfilter: SSL not supported by this build\n"); |
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return ERROR_SSL; |
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} |
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#endif |
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|
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memset((char *)&sa, 0, sizeof(struct sockaddr_in)); |
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|
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*sock = socket(PF_INET, SOCK_STREAM, 0); |
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|
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if (*sock < 0) { |
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error("imapfilter: create socket; %s\n", strerror(errno)); |
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return ERROR_NETWORK; |
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} |
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if (!(he = gethostbyname(serv))) { |
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error("imapfilter: get network host entry of %s; %s\n", serv, |
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strerror(errno)); |
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close_connection(sock); |
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return ERROR_NETWORK; |
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} |
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sa.sin_family = AF_INET; |
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sa.sin_port = htons(port); |
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sa.sin_addr = *(struct in_addr *) he->h_addr; |
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|
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xstrncpy(serv, he->h_name, SERVER_LEN - 1); |
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|
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if (connect(*sock, (struct sockaddr *) & sa, sizeof(struct sockaddr))) { |
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error("imapfilter: initiating connection to %s; %s\n", serv, |
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strerror(errno)); |
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close_connection(sock); |
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return ERROR_NETWORK; |
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} |
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log_info(LOG_SERVER, serv); |
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|
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#ifdef SSL_TLS |
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if (protocol != SSL_DISABLED) |
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if (!ssl_init(sock, protocol)) { |
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if (sock == &sockpri) |
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info("Connected to %s using %s.\n", serv, |
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SSL_get_cipher(*ssl)); |
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return 0; |
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} else |
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return ERROR_SSL; |
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else |
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*ssl = NULL; |
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#endif |
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|
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if (sock == &sockpri) |
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info("Connected to %s.\n", serv); |
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|
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return 0; |
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} |
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|
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|
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#ifdef SSL_TLS |
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/* |
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* Initialize Secure Socket Layer connection. |
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*/ |
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int ssl_init(int *sock, unsigned int protocol) |
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{ |
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int e; |
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unsigned int i, n = 0; |
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SSL_CTX *ctx; |
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SSL_METHOD *method = NULL; |
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X509 *cert; |
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char *c; |
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const EVP_MD *evp; |
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unsigned char digest[EVP_MAX_MD_SIZE]; |
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SSL **ssl = (sock == &sockpri ? &sslpri : &sslaux); |
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|
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SSL_library_init(); |
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|
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switch (protocol) { |
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case SSL_SSL_V2: |
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method = SSLv2_client_method(); |
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break; |
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case SSL_SSL_V3: |
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method = SSLv3_client_method(); |
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break; |
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case SSL_TLS_V1: |
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method = TLSv1_client_method(); |
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break; |
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} |
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|
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if (!(ctx = SSL_CTX_new(method))) |
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return ERROR_SSL; |
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|
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if (!(*ssl = SSL_new(ctx))) |
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return ERROR_SSL; |
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|
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SSL_set_fd(*ssl, *sock); |
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|
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e = SSL_connect(*ssl); |
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|
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if (e <= 0) { |
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SSL_get_error(*ssl, e); |
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error("imapfilter: initiating SSL connection; %s", |
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ERR_error_string(ERR_get_error(), NULL)); |
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return ERROR_SSL; |
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} |
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/* Get server's certificate. */ |
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if (!(cert = SSL_get_peer_certificate(*ssl))) |
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return ERROR_SSL; |
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|
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if (!(c = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0))) |
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return ERROR_SSL; |
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verbose("Server certificate subject: %s\n", c); |
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xfree(c); |
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|
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if (!(c = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0))) |
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return ERROR_SSL; |
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verbose("Server certificate issuer: %s\n", c); |
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xfree(c); |
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|
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if (!(evp = EVP_md5())) |
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return ERROR_SSL; |
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if (!(X509_digest(cert, evp, digest, &n))) |
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return ERROR_SSL; |
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|
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verbose("Server key fingerprint: "); |
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for (i = 0; i < n; i++) |
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verbose(i != n - 1 ? "%02X:" : "%02X\n", digest[i]); |
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|
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X509_free(cert); |
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SSL_CTX_free(ctx); |
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|
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return 0; |
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} |
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|
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#endif /* SSL_TLS */ |
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|
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|
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/* |
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* Disconnect from mail server. |
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*/ |
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int close_connection(int *sock) |
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{ |
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#ifdef SSL_TLS |
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SSL **ssl = (sock == &sockpri ? &sslpri : &sslaux); |
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|
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if (*ssl) { |
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SSL_shutdown(*ssl); |
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SSL_free(*ssl); |
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*ssl = NULL; |
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} |
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#endif |
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|
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if (*sock >= 0 && close(*sock)) { |
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error("imapfilter: closing socket; %s\n", strerror(errno)); |
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return ERROR_NETWORK; |
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} else { |
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*sock = -1; |
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return 0; |
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} |
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} |
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|
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|
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/* |
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* Read data from socket. |
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*/ |
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int socket_read(int *sock, char *buf) |
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{ |
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int f, e, s; |
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fd_set fds; |
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struct timeval tv; |
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struct timeval *tvp = NULL; |
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#ifdef SSL_TLS |
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SSL **ssl = (sock == &sockpri ? &sslpri : &sslaux); |
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#endif |
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|
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e = 0; |
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s = 1; |
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|
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memset(buf, 0, RESPONSE_BUF); |
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|
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if (timeout >= 0) { |
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tv.tv_sec = timeout; |
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tv.tv_usec = 0; |
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tvp = &tv; |
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} |
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f = fcntl(*sock, F_GETFL, 0); |
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fcntl(*sock, F_SETFL, f | O_NONBLOCK); |
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|
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FD_ZERO(&fds); |
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FD_SET(*sock, &fds); |
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|
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#ifdef SSL_TLS |
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if (*ssl) { |
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|
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for (;;) { |
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if (SSL_pending(*ssl) || |
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((s = select(*sock + 1, &fds, NULL, NULL, tvp)) > 0 && |
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FD_ISSET(*sock, &fds))) |
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e = SSL_read(*ssl, buf, RESPONSE_BUF - 1); |
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|
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if (e > 0) |
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break; |
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|
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switch (SSL_get_error(*ssl, e)) { |
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case SSL_ERROR_WANT_READ: |
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case SSL_ERROR_WANT_WRITE: |
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continue; |
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case SSL_ERROR_ZERO_RETURN: |
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return ERROR_NETWORK; |
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case SSL_ERROR_SYSCALL: |
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case SSL_ERROR_SSL: |
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fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
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ERR_error_string(ERR_get_error(), NULL)); |
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default: |
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fatal(ERROR_NETWORK, |
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"imapfilter: undefined ssl error while reading data\n"); |
| 255 |
} |
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} |
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} else |
| 258 |
#endif |
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{ |
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if ((s = select(*sock + 1, &fds, NULL, NULL, tvp)) > 0 && |
| 261 |
FD_ISSET(*sock, &fds)) |
| 262 |
e = read(*sock, buf, RESPONSE_BUF - 1); |
| 263 |
|
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if (e == -1) |
| 265 |
fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
| 266 |
strerror(errno)); |
| 267 |
else if (e == 0) |
| 268 |
return ERROR_NETWORK; |
| 269 |
} |
| 270 |
|
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fcntl(*sock, F_SETFL, f); |
| 272 |
|
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if (s == -1) |
| 274 |
fatal(ERROR_NETWORK, "imapfilter: waiting to read from socket; %s\n", |
| 275 |
strerror(errno)); |
| 276 |
else if (s == 0) |
| 277 |
fatal(ERROR_NETWORK, |
| 278 |
"imapfilter: timeout period expired while waiting to read " |
| 279 |
"data\n"); |
| 280 |
|
| 281 |
return 0; |
| 282 |
} |
| 283 |
|
| 284 |
|
| 285 |
/* |
| 286 |
* Write data to socket. |
| 287 |
*/ |
| 288 |
int socket_write(int *sock, char *data) |
| 289 |
{ |
| 290 |
int f, e, s; |
| 291 |
fd_set fds; |
| 292 |
struct timeval tv; |
| 293 |
struct timeval *tvp = NULL; |
| 294 |
#ifdef SSL_TLS |
| 295 |
SSL **ssl = (sock == &sockpri ? &sslpri : &sslaux); |
| 296 |
#endif |
| 297 |
|
| 298 |
e = 0; |
| 299 |
s = 1; |
| 300 |
|
| 301 |
if (timeout >= 0) { |
| 302 |
tv.tv_sec = timeout; |
| 303 |
tv.tv_usec = 0; |
| 304 |
tvp = &tv; |
| 305 |
} |
| 306 |
f = fcntl(*sock, F_GETFL, 0); |
| 307 |
fcntl(*sock, F_SETFL, f | O_NONBLOCK); |
| 308 |
|
| 309 |
FD_ZERO(&fds); |
| 310 |
FD_SET(*sock, &fds); |
| 311 |
|
| 312 |
#ifdef SSL_TLS |
| 313 |
if (*ssl) { |
| 314 |
for (;;) { |
| 315 |
if ((s = select(*sock + 1, NULL, &fds, NULL, tvp) > 0 && |
| 316 |
FD_ISSET(*sock, &fds))) |
| 317 |
e = SSL_write(*ssl, data, strlen(data)); |
| 318 |
|
| 319 |
if (e > 0) |
| 320 |
break; |
| 321 |
|
| 322 |
switch (SSL_get_error(*ssl, e)) { |
| 323 |
case SSL_ERROR_WANT_READ: |
| 324 |
case SSL_ERROR_WANT_WRITE: |
| 325 |
continue; |
| 326 |
case SSL_ERROR_ZERO_RETURN: |
| 327 |
return ERROR_NETWORK; |
| 328 |
case SSL_ERROR_SYSCALL: |
| 329 |
case SSL_ERROR_SSL: |
| 330 |
fatal(ERROR_NETWORK, "imapfilter: writing data; %s", |
| 331 |
ERR_error_string(ERR_get_error(), NULL)); |
| 332 |
default: |
| 333 |
fatal(ERROR_NETWORK, |
| 334 |
"imapfilter: undefined ssl error while writing data\n"); |
| 335 |
} |
| 336 |
} |
| 337 |
} else |
| 338 |
#endif |
| 339 |
{ |
| 340 |
if ((s = select(*sock + 1, NULL, &fds, NULL, tvp)) > 0 && |
| 341 |
FD_ISSET(*sock, &fds)) |
| 342 |
e = write(*sock, data, strlen(data)); |
| 343 |
|
| 344 |
if (e == -1) |
| 345 |
fatal(ERROR_NETWORK, "imapfilter: writing data; %s", |
| 346 |
strerror(errno)); |
| 347 |
} |
| 348 |
|
| 349 |
fcntl(*sock, F_SETFL, f); |
| 350 |
|
| 351 |
if (s == -1) |
| 352 |
fatal(ERROR_NETWORK, "imapfilter: waiting to write to socket; %s\n", |
| 353 |
strerror(errno)); |
| 354 |
else if (s == 0) |
| 355 |
fatal(ERROR_NETWORK, |
| 356 |
"imapfilter: timeout period expired while waiting to write " |
| 357 |
"data\n"); |
| 358 |
|
| 359 |
return 0; |
| 360 |
} |
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