mirror of
https://git.postgresql.org/git/postgresql.git
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991 lines
25 KiB
C
991 lines
25 KiB
C
/*-------------------------------------------------------------------------
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*
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* be-secure.c
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* functions related to setting up a secure connection to the frontend.
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* Secure connections are expected to provide confidentiality,
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* message integrity and endpoint authentication.
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*
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*
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* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/libpq/be-secure.c,v 1.64 2006/04/27 02:29:14 momjian Exp $
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*
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* Since the server static private key ($DataDir/server.key)
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* will normally be stored unencrypted so that the database
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* backend can restart automatically, it is important that
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* we select an algorithm that continues to provide confidentiality
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* even if the attacker has the server's private key. Empheral
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* DH (EDH) keys provide this, and in fact provide Perfect Forward
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* Secrecy (PFS) except for situations where the session can
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* be hijacked during a periodic handshake/renegotiation.
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* Even that backdoor can be closed if client certificates
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* are used (since the imposter will be unable to successfully
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* complete renegotiation).
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*
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* N.B., the static private key should still be protected to
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* the largest extent possible, to minimize the risk of
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* impersonations.
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*
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* Another benefit of EDH is that it allows the backend and
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* clients to use DSA keys. DSA keys can only provide digital
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* signatures, not encryption, and are often acceptable in
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* jurisdictions where RSA keys are unacceptable.
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*
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* The downside to EDH is that it makes it impossible to
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* use ssldump(1) if there's a problem establishing an SSL
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* session. In this case you'll need to temporarily disable
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* EDH by commenting out the callback.
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*
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* ...
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*
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* Because the risk of cryptanalysis increases as large
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* amounts of data are sent with the same session key, the
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* session keys are periodically renegotiated.
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*
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* PATCH LEVEL
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* milestone 1: fix basic coding errors
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* [*] existing SSL code pulled out of existing files.
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* [*] SSL_get_error() after SSL_read() and SSL_write(),
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* SSL_shutdown(), default to TLSv1.
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*
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* milestone 2: provide endpoint authentication (server)
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* [*] client verifies server cert
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* [*] client verifies server hostname
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*
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* milestone 3: improve confidentially, support perfect forward secrecy
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* [ ] use 'random' file, read from '/dev/urandom?'
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* [*] emphermal DH keys, default values
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* [*] periodic renegotiation
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* [*] private key permissions
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*
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* milestone 4: provide endpoint authentication (client)
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* [*] server verifies client certificates
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*
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* milestone 5: provide informational callbacks
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* [*] provide informational callbacks
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*
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* other changes
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* [ ] tcp-wrappers
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* [ ] more informative psql
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <sys/stat.h>
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#include <signal.h>
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#include <fcntl.h>
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#include <ctype.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#include <netdb.h>
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#include <netinet/in.h>
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#ifdef HAVE_NETINET_TCP_H
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#include <netinet/tcp.h>
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#include <arpa/inet.h>
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#endif
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#ifdef USE_SSL
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#include <openssl/ssl.h>
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#include <openssl/dh.h>
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#endif
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#include "libpq/libpq.h"
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#include "miscadmin.h"
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#include "tcop/tcopprot.h"
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#ifdef USE_SSL
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#define ROOT_CERT_FILE "root.crt"
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#define ROOT_CRL_FILE "root.crl"
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#define SERVER_CERT_FILE "server.crt"
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#define SERVER_PRIVATE_KEY_FILE "server.key"
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static DH *load_dh_file(int keylength);
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static DH *load_dh_buffer(const char *, size_t);
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static DH *tmp_dh_cb(SSL *s, int is_export, int keylength);
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static int verify_cb(int, X509_STORE_CTX *);
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static void info_cb(const SSL *ssl, int type, int args);
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static void initialize_SSL(void);
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static void destroy_SSL(void);
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static int open_server_SSL(Port *);
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static void close_SSL(Port *);
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static const char *SSLerrmessage(void);
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#endif
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#ifdef USE_SSL
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/*
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* How much data can be sent across a secure connection
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* (total in both directions) before we require renegotiation.
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*/
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#define RENEGOTIATION_LIMIT (512 * 1024 * 1024)
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static SSL_CTX *SSL_context = NULL;
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#endif
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/* ------------------------------------------------------------ */
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/* Hardcoded values */
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/* ------------------------------------------------------------ */
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/*
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* Hardcoded DH parameters, used in empheral DH keying.
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* As discussed above, EDH protects the confidentiality of
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* sessions even if the static private key is compromised,
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* so we are *highly* motivated to ensure that we can use
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* EDH even if the DBA... or an attacker... deletes the
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* $DataDir/dh*.pem files.
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*
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* We could refuse SSL connections unless a good DH parameter
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* file exists, but some clients may quietly renegotiate an
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* unsecured connection without fully informing the user.
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* Very uncool.
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*
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* Alternately, the backend could attempt to load these files
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* on startup if SSL is enabled - and refuse to start if any
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* do not exist - but this would tend to piss off DBAs.
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*
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* If you want to create your own hardcoded DH parameters
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* for fun and profit, review "Assigned Number for SKIP
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* Protocols" (http://www.skip-vpn.org/spec/numbers.html)
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* for suggestions.
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*/
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#ifdef USE_SSL
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static const char file_dh512[] =
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"-----BEGIN DH PARAMETERS-----\n\
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MEYCQQD1Kv884bEpQBgRjXyEpwpy1obEAxnIByl6ypUM2Zafq9AKUJsCRtMIPWak\n\
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XUGfnHy9iUsiGSa6q6Jew1XpKgVfAgEC\n\
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-----END DH PARAMETERS-----\n";
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static const char file_dh1024[] =
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"-----BEGIN DH PARAMETERS-----\n\
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MIGHAoGBAPSI/VhOSdvNILSd5JEHNmszbDgNRR0PfIizHHxbLY7288kjwEPwpVsY\n\
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jY67VYy4XTjTNP18F1dDox0YbN4zISy1Kv884bEpQBgRjXyEpwpy1obEAxnIByl6\n\
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ypUM2Zafq9AKUJsCRtMIPWakXUGfnHy9iUsiGSa6q6Jew1XpL3jHAgEC\n\
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-----END DH PARAMETERS-----\n";
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static const char file_dh2048[] =
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"-----BEGIN DH PARAMETERS-----\n\
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MIIBCAKCAQEA9kJXtwh/CBdyorrWqULzBej5UxE5T7bxbrlLOCDaAadWoxTpj0BV\n\
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89AHxstDqZSt90xkhkn4DIO9ZekX1KHTUPj1WV/cdlJPPT2N286Z4VeSWc39uK50\n\
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T8X8dryDxUcwYc58yWb/Ffm7/ZFexwGq01uejaClcjrUGvC/RgBYK+X0iP1YTknb\n\
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zSC0neSRBzZrM2w4DUUdD3yIsxx8Wy2O9vPJI8BD8KVbGI2Ou1WMuF040zT9fBdX\n\
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Q6MdGGzeMyEstSr/POGxKUAYEY18hKcKctaGxAMZyAcpesqVDNmWn6vQClCbAkbT\n\
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CD1mpF1Bn5x8vYlLIhkmuquiXsNV6TILOwIBAg==\n\
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-----END DH PARAMETERS-----\n";
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static const char file_dh4096[] =
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"-----BEGIN DH PARAMETERS-----\n\
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MIICCAKCAgEA+hRyUsFN4VpJ1O8JLcCo/VWr19k3BCgJ4uk+d+KhehjdRqNDNyOQ\n\
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l/MOyQNQfWXPeGKmOmIig6Ev/nm6Nf9Z2B1h3R4hExf+zTiHnvVPeRBhjdQi81rt\n\
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Xeoh6TNrSBIKIHfUJWBh3va0TxxjQIs6IZOLeVNRLMqzeylWqMf49HsIXqbcokUS\n\
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Vt1BkvLdW48j8PPv5DsKRN3tloTxqDJGo9tKvj1Fuk74A+Xda1kNhB7KFlqMyN98\n\
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VETEJ6c7KpfOo30mnK30wqw3S8OtaIR/maYX72tGOno2ehFDkq3pnPtEbD2CScxc\n\
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alJC+EL7RPk5c/tgeTvCngvc1KZn92Y//EI7G9tPZtylj2b56sHtMftIoYJ9+ODM\n\
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sccD5Piz/rejE3Ome8EOOceUSCYAhXn8b3qvxVI1ddd1pED6FHRhFvLrZxFvBEM9\n\
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ERRMp5QqOaHJkM+Dxv8Cj6MqrCbfC4u+ZErxodzuusgDgvZiLF22uxMZbobFWyte\n\
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OvOzKGtwcTqO/1wV5gKkzu1ZVswVUQd5Gg8lJicwqRWyyNRczDDoG9jVDxmogKTH\n\
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AaqLulO7R8Ifa1SwF2DteSGVtgWEN8gDpN3RBmmPTDngyF2DHb5qmpnznwtFKdTL\n\
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KWbuHn491xNO25CQWMtem80uKw+pTnisBRF/454n1Jnhub144YRBoN8CAQI=\n\
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-----END DH PARAMETERS-----\n";
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#endif
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/* ------------------------------------------------------------ */
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/* Procedures common to all secure sessions */
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/* ------------------------------------------------------------ */
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/*
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* Initialize global context
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*/
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int
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secure_initialize(void)
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{
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#ifdef USE_SSL
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initialize_SSL();
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#endif
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return 0;
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}
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/*
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* Destroy global context
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*/
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void
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secure_destroy(void)
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{
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#ifdef USE_SSL
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destroy_SSL();
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#endif
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}
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/*
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* Attempt to negotiate secure session.
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*/
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int
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secure_open_server(Port *port)
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{
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int r = 0;
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#ifdef USE_SSL
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r = open_server_SSL(port);
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#endif
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return r;
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}
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/*
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* Close secure session.
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*/
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void
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secure_close(Port *port)
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{
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#ifdef USE_SSL
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if (port->ssl)
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close_SSL(port);
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#endif
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}
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/*
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* Read data from a secure connection.
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*/
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ssize_t
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secure_read(Port *port, void *ptr, size_t len)
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{
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ssize_t n;
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#ifdef USE_SSL
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if (port->ssl)
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{
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int err;
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rloop:
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n = SSL_read(port->ssl, ptr, len);
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err = SSL_get_error(port->ssl, n);
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switch (err)
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{
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case SSL_ERROR_NONE:
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port->count += n;
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break;
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case SSL_ERROR_WANT_READ:
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case SSL_ERROR_WANT_WRITE:
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#ifdef WIN32
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pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
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(err == SSL_ERROR_WANT_READ) ?
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FD_READ | FD_CLOSE : FD_WRITE | FD_CLOSE);
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#endif
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goto rloop;
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case SSL_ERROR_SYSCALL:
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if (n == -1)
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ereport(COMMERROR,
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(errcode_for_socket_access(),
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errmsg("SSL SYSCALL error: %m")));
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else
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{
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL SYSCALL error: EOF detected")));
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errno = ECONNRESET;
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n = -1;
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}
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break;
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case SSL_ERROR_SSL:
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL error: %s", SSLerrmessage())));
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/* fall through */
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case SSL_ERROR_ZERO_RETURN:
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errno = ECONNRESET;
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n = -1;
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break;
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default:
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("unrecognized SSL error code: %d",
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err)));
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n = -1;
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break;
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}
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}
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else
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#endif
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{
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prepare_for_client_read();
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n = recv(port->sock, ptr, len, 0);
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client_read_ended();
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}
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return n;
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}
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/*
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* Write data to a secure connection.
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*/
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ssize_t
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secure_write(Port *port, void *ptr, size_t len)
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{
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ssize_t n;
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#ifdef USE_SSL
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if (port->ssl)
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{
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int err;
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if (port->count > RENEGOTIATION_LIMIT)
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{
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SSL_set_session_id_context(port->ssl, (void *) &SSL_context,
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sizeof(SSL_context));
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if (SSL_renegotiate(port->ssl) <= 0)
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL renegotiation failure")));
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if (SSL_do_handshake(port->ssl) <= 0)
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL renegotiation failure")));
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if (port->ssl->state != SSL_ST_OK)
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL failed to send renegotiation request")));
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port->ssl->state |= SSL_ST_ACCEPT;
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SSL_do_handshake(port->ssl);
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if (port->ssl->state != SSL_ST_OK)
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL renegotiation failure")));
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port->count = 0;
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}
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wloop:
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n = SSL_write(port->ssl, ptr, len);
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err = SSL_get_error(port->ssl, n);
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switch (err)
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{
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case SSL_ERROR_NONE:
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port->count += n;
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break;
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case SSL_ERROR_WANT_READ:
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case SSL_ERROR_WANT_WRITE:
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#ifdef WIN32
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pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
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(err == SSL_ERROR_WANT_READ) ?
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FD_READ | FD_CLOSE : FD_WRITE | FD_CLOSE);
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#endif
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goto wloop;
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case SSL_ERROR_SYSCALL:
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if (n == -1)
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ereport(COMMERROR,
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(errcode_for_socket_access(),
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errmsg("SSL SYSCALL error: %m")));
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else
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{
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL SYSCALL error: EOF detected")));
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errno = ECONNRESET;
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n = -1;
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}
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break;
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case SSL_ERROR_SSL:
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("SSL error: %s", SSLerrmessage())));
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/* fall through */
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case SSL_ERROR_ZERO_RETURN:
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errno = ECONNRESET;
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n = -1;
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break;
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default:
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ereport(COMMERROR,
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(errcode(ERRCODE_PROTOCOL_VIOLATION),
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errmsg("unrecognized SSL error code: %d",
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err)));
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n = -1;
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break;
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}
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}
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else
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#endif
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n = send(port->sock, ptr, len, 0);
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return n;
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}
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/* ------------------------------------------------------------ */
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/* SSL specific code */
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/* ------------------------------------------------------------ */
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#ifdef USE_SSL
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/*
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* Private substitute BIO: this wraps the SSL library's standard socket BIO
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* so that we can enable and disable interrupts just while calling recv().
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* We cannot have interrupts occurring while the bulk of openssl runs,
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* because it uses malloc() and possibly other non-reentrant libc facilities.
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*
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* As of openssl 0.9.7, we can use the reasonably clean method of interposing
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* a wrapper around the standard socket BIO's sock_read() method. This relies
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* on the fact that sock_read() doesn't call anything non-reentrant, in fact
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* not much of anything at all except recv(). If this ever changes we'd
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* probably need to duplicate the code of sock_read() in order to push the
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* interrupt enable/disable down yet another level.
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*/
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static bool my_bio_initialized = false;
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static BIO_METHOD my_bio_methods;
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static int (*std_sock_read) (BIO *h, char *buf, int size);
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static int
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my_sock_read(BIO *h, char *buf, int size)
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{
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int res;
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prepare_for_client_read();
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res = std_sock_read(h, buf, size);
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client_read_ended();
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return res;
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}
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static BIO_METHOD *
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my_BIO_s_socket(void)
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{
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if (!my_bio_initialized)
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{
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memcpy(&my_bio_methods, BIO_s_socket(), sizeof(BIO_METHOD));
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std_sock_read = my_bio_methods.bread;
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my_bio_methods.bread = my_sock_read;
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my_bio_initialized = true;
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}
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return &my_bio_methods;
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}
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/* This should exactly match openssl's SSL_set_fd except for using my BIO */
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static int
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my_SSL_set_fd(SSL *s, int fd)
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{
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int ret = 0;
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BIO *bio = NULL;
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bio = BIO_new(my_BIO_s_socket());
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if (bio == NULL)
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{
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SSLerr(SSL_F_SSL_SET_FD, ERR_R_BUF_LIB);
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goto err;
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}
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BIO_set_fd(bio, fd, BIO_NOCLOSE);
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SSL_set_bio(s, bio, bio);
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ret = 1;
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err:
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return ret;
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}
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/*
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* Load precomputed DH parameters.
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*
|
|
* To prevent "downgrade" attacks, we perform a number of checks
|
|
* to verify that the DBA-generated DH parameters file contains
|
|
* what we expect it to contain.
|
|
*/
|
|
static DH *
|
|
load_dh_file(int keylength)
|
|
{
|
|
FILE *fp;
|
|
char fnbuf[MAXPGPATH];
|
|
DH *dh = NULL;
|
|
int codes;
|
|
|
|
/* attempt to open file. It's not an error if it doesn't exist. */
|
|
snprintf(fnbuf, sizeof(fnbuf), "dh%d.pem", keylength);
|
|
if ((fp = fopen(fnbuf, "r")) == NULL)
|
|
return NULL;
|
|
|
|
/* flock(fileno(fp), LOCK_SH); */
|
|
dh = PEM_read_DHparams(fp, NULL, NULL, NULL);
|
|
/* flock(fileno(fp), LOCK_UN); */
|
|
fclose(fp);
|
|
|
|
/* is the prime the correct size? */
|
|
if (dh != NULL && 8 * DH_size(dh) < keylength)
|
|
{
|
|
elog(LOG, "DH errors (%s): %d bits expected, %d bits found",
|
|
fnbuf, keylength, 8 * DH_size(dh));
|
|
dh = NULL;
|
|
}
|
|
|
|
/* make sure the DH parameters are usable */
|
|
if (dh != NULL)
|
|
{
|
|
if (DH_check(dh, &codes))
|
|
{
|
|
elog(LOG, "DH_check error (%s): %s", fnbuf, SSLerrmessage());
|
|
return NULL;
|
|
}
|
|
if (codes & DH_CHECK_P_NOT_PRIME)
|
|
{
|
|
elog(LOG, "DH error (%s): p is not prime", fnbuf);
|
|
return NULL;
|
|
}
|
|
if ((codes & DH_NOT_SUITABLE_GENERATOR) &&
|
|
(codes & DH_CHECK_P_NOT_SAFE_PRIME))
|
|
{
|
|
elog(LOG,
|
|
"DH error (%s): neither suitable generator or safe prime",
|
|
fnbuf);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return dh;
|
|
}
|
|
|
|
/*
|
|
* Load hardcoded DH parameters.
|
|
*
|
|
* To prevent problems if the DH parameters files don't even
|
|
* exist, we can load DH parameters hardcoded into this file.
|
|
*/
|
|
static DH *
|
|
load_dh_buffer(const char *buffer, size_t len)
|
|
{
|
|
BIO *bio;
|
|
DH *dh = NULL;
|
|
|
|
bio = BIO_new_mem_buf((char *) buffer, len);
|
|
if (bio == NULL)
|
|
return NULL;
|
|
dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
|
|
if (dh == NULL)
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("DH load buffer: %s",
|
|
SSLerrmessage())));
|
|
BIO_free(bio);
|
|
|
|
return dh;
|
|
}
|
|
|
|
/*
|
|
* Generate an empheral DH key. Because this can take a long
|
|
* time to compute, we can use precomputed parameters of the
|
|
* common key sizes.
|
|
*
|
|
* Since few sites will bother to precompute these parameter
|
|
* files, we also provide a fallback to the parameters provided
|
|
* by the OpenSSL project.
|
|
*
|
|
* These values can be static (once loaded or computed) since
|
|
* the OpenSSL library can efficiently generate random keys from
|
|
* the information provided.
|
|
*/
|
|
static DH *
|
|
tmp_dh_cb(SSL *s, int is_export, int keylength)
|
|
{
|
|
DH *r = NULL;
|
|
static DH *dh = NULL;
|
|
static DH *dh512 = NULL;
|
|
static DH *dh1024 = NULL;
|
|
static DH *dh2048 = NULL;
|
|
static DH *dh4096 = NULL;
|
|
|
|
switch (keylength)
|
|
{
|
|
case 512:
|
|
if (dh512 == NULL)
|
|
dh512 = load_dh_file(keylength);
|
|
if (dh512 == NULL)
|
|
dh512 = load_dh_buffer(file_dh512, sizeof file_dh512);
|
|
r = dh512;
|
|
break;
|
|
|
|
case 1024:
|
|
if (dh1024 == NULL)
|
|
dh1024 = load_dh_file(keylength);
|
|
if (dh1024 == NULL)
|
|
dh1024 = load_dh_buffer(file_dh1024, sizeof file_dh1024);
|
|
r = dh1024;
|
|
break;
|
|
|
|
case 2048:
|
|
if (dh2048 == NULL)
|
|
dh2048 = load_dh_file(keylength);
|
|
if (dh2048 == NULL)
|
|
dh2048 = load_dh_buffer(file_dh2048, sizeof file_dh2048);
|
|
r = dh2048;
|
|
break;
|
|
|
|
case 4096:
|
|
if (dh4096 == NULL)
|
|
dh4096 = load_dh_file(keylength);
|
|
if (dh4096 == NULL)
|
|
dh4096 = load_dh_buffer(file_dh4096, sizeof file_dh4096);
|
|
r = dh4096;
|
|
break;
|
|
|
|
default:
|
|
if (dh == NULL)
|
|
dh = load_dh_file(keylength);
|
|
r = dh;
|
|
}
|
|
|
|
/* this may take a long time, but it may be necessary... */
|
|
if (r == NULL || 8 * DH_size(r) < keylength)
|
|
{
|
|
ereport(DEBUG2,
|
|
(errmsg_internal("DH: generating parameters (%d bits)....",
|
|
keylength)));
|
|
r = DH_generate_parameters(keylength, DH_GENERATOR_2, NULL, NULL);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
/*
|
|
* Certificate verification callback
|
|
*
|
|
* This callback allows us to log intermediate problems during
|
|
* verification, but for now we'll see if the final error message
|
|
* contains enough information.
|
|
*
|
|
* This callback also allows us to override the default acceptance
|
|
* criteria (e.g., accepting self-signed or expired certs), but
|
|
* for now we accept the default checks.
|
|
*/
|
|
static int
|
|
verify_cb(int ok, X509_STORE_CTX *ctx)
|
|
{
|
|
return ok;
|
|
}
|
|
|
|
/*
|
|
* This callback is used to copy SSL information messages
|
|
* into the PostgreSQL log.
|
|
*/
|
|
static void
|
|
info_cb(const SSL *ssl, int type, int args)
|
|
{
|
|
switch (type)
|
|
{
|
|
case SSL_CB_HANDSHAKE_START:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: handshake start")));
|
|
break;
|
|
case SSL_CB_HANDSHAKE_DONE:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: handshake done")));
|
|
break;
|
|
case SSL_CB_ACCEPT_LOOP:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: accept loop")));
|
|
break;
|
|
case SSL_CB_ACCEPT_EXIT:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: accept exit (%d)", args)));
|
|
break;
|
|
case SSL_CB_CONNECT_LOOP:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: connect loop")));
|
|
break;
|
|
case SSL_CB_CONNECT_EXIT:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: connect exit (%d)", args)));
|
|
break;
|
|
case SSL_CB_READ_ALERT:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: read alert (0x%04x)", args)));
|
|
break;
|
|
case SSL_CB_WRITE_ALERT:
|
|
ereport(DEBUG4,
|
|
(errmsg_internal("SSL: write alert (0x%04x)", args)));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Initialize global SSL context.
|
|
*/
|
|
static void
|
|
initialize_SSL(void)
|
|
{
|
|
struct stat buf;
|
|
|
|
if (!SSL_context)
|
|
{
|
|
SSL_library_init();
|
|
SSL_load_error_strings();
|
|
SSL_context = SSL_CTX_new(SSLv23_method());
|
|
if (!SSL_context)
|
|
ereport(FATAL,
|
|
(errmsg("could not create SSL context: %s",
|
|
SSLerrmessage())));
|
|
|
|
/*
|
|
* Load and verify certificate and private key
|
|
*/
|
|
if (!SSL_CTX_use_certificate_file(SSL_context,
|
|
SERVER_CERT_FILE,
|
|
SSL_FILETYPE_PEM))
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CONFIG_FILE_ERROR),
|
|
errmsg("could not load server certificate file \"%s\": %s",
|
|
SERVER_CERT_FILE, SSLerrmessage())));
|
|
|
|
if (stat(SERVER_PRIVATE_KEY_FILE, &buf) == -1)
|
|
ereport(FATAL,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not access private key file \"%s\": %m",
|
|
SERVER_PRIVATE_KEY_FILE)));
|
|
|
|
/*
|
|
* Require no public access to key file.
|
|
*
|
|
* XXX temporarily suppress check when on Windows, because there may
|
|
* not be proper support for Unix-y file permissions. Need to think
|
|
* of a reasonable check to apply on Windows. (See also the data
|
|
* directory permission check in postmaster.c)
|
|
*/
|
|
#if !defined(WIN32) && !defined(__CYGWIN__)
|
|
if (!S_ISREG(buf.st_mode) || (buf.st_mode & (S_IRWXG | S_IRWXO)) ||
|
|
buf.st_uid != geteuid())
|
|
ereport(FATAL,
|
|
(errcode(ERRCODE_CONFIG_FILE_ERROR),
|
|
errmsg("unsafe permissions on private key file \"%s\"",
|
|
SERVER_PRIVATE_KEY_FILE),
|
|
errdetail("File must be owned by the database user and must have no permissions for \"group\" or \"other\".")));
|
|
#endif
|
|
|
|
if (!SSL_CTX_use_PrivateKey_file(SSL_context,
|
|
SERVER_PRIVATE_KEY_FILE,
|
|
SSL_FILETYPE_PEM))
|
|
ereport(FATAL,
|
|
(errmsg("could not load private key file \"%s\": %s",
|
|
SERVER_PRIVATE_KEY_FILE, SSLerrmessage())));
|
|
|
|
if (!SSL_CTX_check_private_key(SSL_context))
|
|
ereport(FATAL,
|
|
(errmsg("check of private key failed: %s",
|
|
SSLerrmessage())));
|
|
}
|
|
|
|
/* set up empheral DH keys */
|
|
SSL_CTX_set_tmp_dh_callback(SSL_context, tmp_dh_cb);
|
|
SSL_CTX_set_options(SSL_context, SSL_OP_SINGLE_DH_USE | SSL_OP_NO_SSLv2);
|
|
|
|
/* setup the allowed cipher list */
|
|
if (SSL_CTX_set_cipher_list(SSL_context, "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH") != 1)
|
|
elog(FATAL, "could not set the cipher list (no valid ciphers available)");
|
|
|
|
/*
|
|
* Require and check client certificates only if we have a root.crt file.
|
|
*/
|
|
if (!SSL_CTX_load_verify_locations(SSL_context, ROOT_CERT_FILE, NULL))
|
|
{
|
|
/* Not fatal - we do not require client certificates */
|
|
ereport(LOG,
|
|
(errmsg("could not load root certificate file \"%s\": %s",
|
|
ROOT_CERT_FILE, SSLerrmessage()),
|
|
errdetail("Will not verify client certificates.")));
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Check the Certificate Revocation List (CRL) if file exists.
|
|
* http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci803160,00.html
|
|
*/
|
|
X509_STORE *cvstore = SSL_CTX_get_cert_store(SSL_context);
|
|
|
|
if (cvstore)
|
|
{
|
|
if (X509_STORE_load_locations(cvstore, ROOT_CRL_FILE, NULL) != 0)
|
|
/* setting the flags to check against the complete CRL chain */
|
|
X509_STORE_set_flags(cvstore,
|
|
X509_V_FLAG_CRL_CHECK|X509_V_FLAG_CRL_CHECK_ALL);
|
|
else
|
|
{
|
|
/* Not fatal - we do not require CRL */
|
|
ereport(LOG,
|
|
(errmsg("SSL Certificate Revocation List (CRL) file \"%s\" not found, skipping: %s",
|
|
ROOT_CRL_FILE, SSLerrmessage()),
|
|
errdetail("Will not check certificates against CRL.")));
|
|
}
|
|
}
|
|
|
|
SSL_CTX_set_verify(SSL_context,
|
|
(SSL_VERIFY_PEER |
|
|
SSL_VERIFY_FAIL_IF_NO_PEER_CERT |
|
|
SSL_VERIFY_CLIENT_ONCE),
|
|
verify_cb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Destroy global SSL context.
|
|
*/
|
|
static void
|
|
destroy_SSL(void)
|
|
{
|
|
if (SSL_context)
|
|
{
|
|
SSL_CTX_free(SSL_context);
|
|
SSL_context = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Attempt to negotiate SSL connection.
|
|
*/
|
|
static int
|
|
open_server_SSL(Port *port)
|
|
{
|
|
int r;
|
|
int err;
|
|
|
|
Assert(!port->ssl);
|
|
Assert(!port->peer);
|
|
|
|
if (!(port->ssl = SSL_new(SSL_context)))
|
|
{
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("could not initialize SSL connection: %s",
|
|
SSLerrmessage())));
|
|
close_SSL(port);
|
|
return -1;
|
|
}
|
|
if (!my_SSL_set_fd(port->ssl, port->sock))
|
|
{
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("could not set SSL socket: %s",
|
|
SSLerrmessage())));
|
|
close_SSL(port);
|
|
return -1;
|
|
}
|
|
|
|
aloop:
|
|
r = SSL_accept(port->ssl);
|
|
if (r <= 0)
|
|
{
|
|
err = SSL_get_error(port->ssl, r);
|
|
switch (err)
|
|
{
|
|
case SSL_ERROR_WANT_READ:
|
|
case SSL_ERROR_WANT_WRITE:
|
|
#ifdef WIN32
|
|
pgwin32_waitforsinglesocket(SSL_get_fd(port->ssl),
|
|
(err == SSL_ERROR_WANT_READ) ?
|
|
FD_READ | FD_CLOSE | FD_ACCEPT : FD_WRITE | FD_CLOSE);
|
|
#endif
|
|
goto aloop;
|
|
case SSL_ERROR_SYSCALL:
|
|
if (r < 0)
|
|
ereport(COMMERROR,
|
|
(errcode_for_socket_access(),
|
|
errmsg("could not accept SSL connection: %m")));
|
|
else
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("could not accept SSL connection: EOF detected")));
|
|
break;
|
|
case SSL_ERROR_SSL:
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("could not accept SSL connection: %s",
|
|
SSLerrmessage())));
|
|
break;
|
|
case SSL_ERROR_ZERO_RETURN:
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("could not accept SSL connection: EOF detected")));
|
|
break;
|
|
default:
|
|
ereport(COMMERROR,
|
|
(errcode(ERRCODE_PROTOCOL_VIOLATION),
|
|
errmsg("unrecognized SSL error code: %d",
|
|
err)));
|
|
break;
|
|
}
|
|
close_SSL(port);
|
|
return -1;
|
|
}
|
|
|
|
port->count = 0;
|
|
|
|
/* get client certificate, if available. */
|
|
port->peer = SSL_get_peer_certificate(port->ssl);
|
|
if (port->peer == NULL)
|
|
{
|
|
strncpy(port->peer_dn, "(anonymous)", sizeof(port->peer_dn));
|
|
strncpy(port->peer_cn, "(anonymous)", sizeof(port->peer_cn));
|
|
}
|
|
else
|
|
{
|
|
X509_NAME_oneline(X509_get_subject_name(port->peer),
|
|
port->peer_dn, sizeof(port->peer_dn));
|
|
port->peer_dn[sizeof(port->peer_dn) - 1] = '\0';
|
|
X509_NAME_get_text_by_NID(X509_get_subject_name(port->peer),
|
|
NID_commonName, port->peer_cn, sizeof(port->peer_cn));
|
|
port->peer_cn[sizeof(port->peer_cn) - 1] = '\0';
|
|
}
|
|
ereport(DEBUG2,
|
|
(errmsg("SSL connection from \"%s\"", port->peer_cn)));
|
|
|
|
/* set up debugging/info callback */
|
|
SSL_CTX_set_info_callback(SSL_context, info_cb);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Close SSL connection.
|
|
*/
|
|
static void
|
|
close_SSL(Port *port)
|
|
{
|
|
if (port->ssl)
|
|
{
|
|
SSL_shutdown(port->ssl);
|
|
SSL_free(port->ssl);
|
|
port->ssl = NULL;
|
|
}
|
|
|
|
if (port->peer)
|
|
{
|
|
X509_free(port->peer);
|
|
port->peer = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Obtain reason string for last SSL error
|
|
*
|
|
* Some caution is needed here since ERR_reason_error_string will
|
|
* return NULL if it doesn't recognize the error code. We don't
|
|
* want to return NULL ever.
|
|
*/
|
|
static const char *
|
|
SSLerrmessage(void)
|
|
{
|
|
unsigned long errcode;
|
|
const char *errreason;
|
|
static char errbuf[32];
|
|
|
|
errcode = ERR_get_error();
|
|
if (errcode == 0)
|
|
return "No SSL error reported";
|
|
errreason = ERR_reason_error_string(errcode);
|
|
if (errreason != NULL)
|
|
return errreason;
|
|
snprintf(errbuf, sizeof(errbuf), "SSL error code %lu", errcode);
|
|
return errbuf;
|
|
}
|
|
|
|
#endif /* USE_SSL */
|