Improve error handling of cryptohash computations
authorMichael Paquier <michael@paquier.xyz>
Tue, 11 Jan 2022 00:55:16 +0000 (09:55 +0900)
committerMichael Paquier <michael@paquier.xyz>
Tue, 11 Jan 2022 00:55:16 +0000 (09:55 +0900)
The existing cryptohash facility was causing problems in some code paths
related to MD5 (frontend and backend) that relied on the fact that the
only type of error that could happen would be an OOM, as the MD5
implementation used in PostgreSQL ~13 (the in-core implementation is
used when compiling with or without OpenSSL in those older versions),
could fail only under this circumstance.

The new cryptohash facilities can fail for reasons other than OOMs, like
attempting MD5 when FIPS is enabled (upstream OpenSSL allows that up to
1.0.2, Fedora and Photon patch OpenSSL 1.1.1 to allow that), so this
would cause incorrect reports to show up.

This commit extends the cryptohash APIs so as callers of those routines
can fetch more context when an error happens, by using a new routine
called pg_cryptohash_error().  The error states are stored within each
implementation's internal context data, so as it is possible to extend
the logic depending on what's suited for an implementation.  The default
implementation requires few error states, but OpenSSL could report
various issues depending on its internal state so more is needed in
cryptohash_openssl.c, and the code is shaped so as we are always able to
grab the necessary information.

The core code is changed to adapt to the new error routine, painting
more "const" across the call stack where the static errors are stored,
particularly in authentication code paths on variables that provide
log details.  This way, any future changes would warn if attempting to
free these strings.  The MD5 authentication code was also a bit blurry
about the handling of "logdetail" (LOG sent to the postmaster), so
improve the comments related that, while on it.

The origin of the problem is 87ae969, that introduced the centralized
cryptohash facility.  Extra changes are done for pgcrypto in v14 for the
non-OpenSSL code path to cope with the improvements done by this
commit.

Reported-by: Michael Mühlbeyer
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/89B7F072-5BBE-4C92-903E-D83E865D9367@trivadis.com
Backpatch-through: 14

18 files changed:
contrib/passwordcheck/passwordcheck.c
contrib/uuid-ossp/uuid-ossp.c
src/backend/commands/user.c
src/backend/libpq/auth-sasl.c
src/backend/libpq/auth-scram.c
src/backend/libpq/auth.c
src/backend/libpq/crypt.c
src/backend/replication/backup_manifest.c
src/backend/utils/adt/cryptohashfuncs.c
src/common/cryptohash.c
src/common/cryptohash_openssl.c
src/common/md5_common.c
src/include/common/cryptohash.h
src/include/common/md5.h
src/include/libpq/crypt.h
src/include/libpq/sasl.h
src/interfaces/libpq/fe-auth.c
src/tools/pgindent/typedefs.list

index 1da323c0aa8bbadd6251d2d5429e32280ed1b70c..074836336d48499b5c7635ee93f90bce643d841a 100644 (file)
@@ -74,7 +74,7 @@ check_password(const char *username,
                 *
                 * We only check for username = password.
                 */
-               char       *logdetail;
+               const char *logdetail = NULL;
 
                if (plain_crypt_verify(username, shadow_pass, username, &logdetail) == STATUS_OK)
                        ereport(ERROR,
index 4859bd19334bcc9c8b768ec78190f0d47a68295d..7c0fb812fd759ecc63d66ef2beb27ea6e5c7d8eb 100644 (file)
@@ -319,14 +319,17 @@ uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
                                        pg_cryptohash_ctx *ctx = pg_cryptohash_create(PG_MD5);
 
                                        if (pg_cryptohash_init(ctx) < 0)
-                                               elog(ERROR, "could not initialize %s context", "MD5");
+                                               elog(ERROR, "could not initialize %s context: %s", "MD5",
+                                                        pg_cryptohash_error(ctx));
                                        if (pg_cryptohash_update(ctx, ns, sizeof(uu)) < 0 ||
                                                pg_cryptohash_update(ctx, (unsigned char *) ptr, len) < 0)
-                                               elog(ERROR, "could not update %s context", "MD5");
+                                               elog(ERROR, "could not update %s context: %s", "MD5",
+                                                        pg_cryptohash_error(ctx));
                                        /* we assume sizeof MD5 result is 16, same as UUID size */
                                        if (pg_cryptohash_final(ctx, (unsigned char *) &uu,
                                                                                        sizeof(uu)) < 0)
-                                               elog(ERROR, "could not finalize %s context", "MD5");
+                                               elog(ERROR, "could not finalize %s context: %s", "MD5",
+                                                        pg_cryptohash_error(ctx));
                                        pg_cryptohash_free(ctx);
                                }
                                else
@@ -335,12 +338,15 @@ uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
                                        unsigned char sha1result[SHA1_DIGEST_LENGTH];
 
                                        if (pg_cryptohash_init(ctx) < 0)
-                                               elog(ERROR, "could not initialize %s context", "SHA1");
+                                               elog(ERROR, "could not initialize %s context: %s", "SHA1",
+                                                        pg_cryptohash_error(ctx));
                                        if (pg_cryptohash_update(ctx, ns, sizeof(uu)) < 0 ||
                                                pg_cryptohash_update(ctx, (unsigned char *) ptr, len) < 0)
-                                               elog(ERROR, "could not update %s context", "SHA1");
+                                               elog(ERROR, "could not update %s context: %s", "SHA1",
+                                                        pg_cryptohash_error(ctx));
                                        if (pg_cryptohash_final(ctx, sha1result, sizeof(sha1result)) < 0)
-                                               elog(ERROR, "could not finalize %s context", "SHA1");
+                                               elog(ERROR, "could not finalize %s context: %s", "SHA1",
+                                                        pg_cryptohash_error(ctx));
                                        pg_cryptohash_free(ctx);
 
                                        memcpy(&uu, sha1result, sizeof(uu));
index c79c8d247f017fbf6e2da2eb9d107193388b2bd4..3b512a84b3a087b11b8293a5c699eaf1b70a465c 100644 (file)
@@ -355,7 +355,7 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
        if (password)
        {
                char       *shadow_pass;
-               char       *logdetail;
+               const char *logdetail = NULL;
 
                /*
                 * Don't allow an empty password. Libpq treats an empty password the
@@ -775,7 +775,7 @@ AlterRole(ParseState *pstate, AlterRoleStmt *stmt)
        if (password)
        {
                char       *shadow_pass;
-               char       *logdetail;
+               const char *logdetail = NULL;
 
                /* Like in CREATE USER, don't allow an empty password. */
                if (password[0] == '\0' ||
index 6cc776edebf0980a42c0914aaab1b32c8b8e358e..a1d7dbb6d588bc1a9a6205eec897cecb456a5936 100644 (file)
@@ -50,7 +50,7 @@
  */
 int
 CheckSASLAuth(const pg_be_sasl_mech *mech, Port *port, char *shadow_pass,
-                         char **logdetail)
+                         const char **logdetail)
 {
        StringInfoData sasl_mechs;
        int                     mtype;
index fdfc3d5067d256ee43859cfad6c7cbee71bc41ea..7c9dee70ce71ebd31972ebb86677ec0709a98888 100644 (file)
@@ -111,7 +111,8 @@ static void scram_get_mechanisms(Port *port, StringInfo buf);
 static void *scram_init(Port *port, const char *selected_mech,
                                                const char *shadow_pass);
 static int     scram_exchange(void *opaq, const char *input, int inputlen,
-                                                  char **output, int *outputlen, char **logdetail);
+                                                  char **output, int *outputlen,
+                                                  const char **logdetail);
 
 /* Mechanism declaration */
 const pg_be_sasl_mech pg_be_scram_mech = {
@@ -335,7 +336,7 @@ scram_init(Port *port, const char *selected_mech, const char *shadow_pass)
  */
 static int
 scram_exchange(void *opaq, const char *input, int inputlen,
-                          char **output, int *outputlen, char **logdetail)
+                          char **output, int *outputlen, const char **logdetail)
 {
        scram_state *state = (scram_state *) opaq;
        int                     result;
index b0d6988aff64e502f0d5c1fdc2307536342cf71a..9a266beb5dd20afa7daa55ce404bbdf73dada6fa 100644 (file)
@@ -45,7 +45,7 @@
  * Global authentication functions
  *----------------------------------------------------------------
  */
-static void auth_failed(Port *port, int status, char *logdetail);
+static void auth_failed(Port *port, int status, const char *logdetail);
 static char *recv_password_packet(Port *port);
 static void set_authn_id(Port *port, const char *id);
 
@@ -54,10 +54,11 @@ static void set_authn_id(Port *port, const char *id);
  * Password-based authentication methods (password, md5, and scram-sha-256)
  *----------------------------------------------------------------
  */
-static int     CheckPasswordAuth(Port *port, char **logdetail);
-static int     CheckPWChallengeAuth(Port *port, char **logdetail);
+static int     CheckPasswordAuth(Port *port, const char **logdetail);
+static int     CheckPWChallengeAuth(Port *port, const char **logdetail);
 
-static int     CheckMD5Auth(Port *port, char *shadow_pass, char **logdetail);
+static int     CheckMD5Auth(Port *port, char *shadow_pass,
+                                                const char **logdetail);
 
 
 /*----------------------------------------------------------------
@@ -247,7 +248,7 @@ ClientAuthentication_hook_type ClientAuthentication_hook = NULL;
  * particular, if logdetail isn't NULL, we send that string to the log.
  */
 static void
-auth_failed(Port *port, int status, char *logdetail)
+auth_failed(Port *port, int status, const char *logdetail)
 {
        const char *errstr;
        char       *cdetail;
@@ -383,7 +384,7 @@ void
 ClientAuthentication(Port *port)
 {
        int                     status = STATUS_ERROR;
-       char       *logdetail = NULL;
+       const char *logdetail = NULL;
 
        /*
         * Get the authentication method to use for this frontend/database
@@ -769,7 +770,7 @@ recv_password_packet(Port *port)
  * Plaintext password authentication.
  */
 static int
-CheckPasswordAuth(Port *port, char **logdetail)
+CheckPasswordAuth(Port *port, const char **logdetail)
 {
        char       *passwd;
        int                     result;
@@ -804,7 +805,7 @@ CheckPasswordAuth(Port *port, char **logdetail)
  * MD5 and SCRAM authentication.
  */
 static int
-CheckPWChallengeAuth(Port *port, char **logdetail)
+CheckPWChallengeAuth(Port *port, const char **logdetail)
 {
        int                     auth_result;
        char       *shadow_pass;
@@ -866,7 +867,7 @@ CheckPWChallengeAuth(Port *port, char **logdetail)
 }
 
 static int
-CheckMD5Auth(Port *port, char *shadow_pass, char **logdetail)
+CheckMD5Auth(Port *port, char *shadow_pass, const char **logdetail)
 {
        char            md5Salt[4];             /* Password salt */
        char       *passwd;
@@ -3085,6 +3086,8 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
        md5trailer = packet->vector;
        for (i = 0; i < encryptedpasswordlen; i += RADIUS_VECTOR_LENGTH)
        {
+               const char *errstr = NULL;
+
                memcpy(cryptvector + strlen(secret), md5trailer, RADIUS_VECTOR_LENGTH);
 
                /*
@@ -3093,10 +3096,12 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
                 */
                md5trailer = encryptedpassword + i;
 
-               if (!pg_md5_binary(cryptvector, strlen(secret) + RADIUS_VECTOR_LENGTH, encryptedpassword + i))
+               if (!pg_md5_binary(cryptvector, strlen(secret) + RADIUS_VECTOR_LENGTH,
+                                                  encryptedpassword + i, &errstr))
                {
                        ereport(LOG,
-                                       (errmsg("could not perform MD5 encryption of password")));
+                                       (errmsg("could not perform MD5 encryption of password: %s",
+                                                       errstr)));
                        pfree(cryptvector);
                        pg_freeaddrinfo_all(hint.ai_family, serveraddrs);
                        return STATUS_ERROR;
@@ -3181,6 +3186,7 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
                struct timeval timeout;
                struct timeval now;
                int64           timeoutval;
+               const char *errstr = NULL;
 
                gettimeofday(&now, NULL);
                timeoutval = (endtime.tv_sec * 1000000 + endtime.tv_usec) - (now.tv_sec * 1000000 + now.tv_usec);
@@ -3299,10 +3305,11 @@ PerformRadiusTransaction(const char *server, const char *secret, const char *por
 
                if (!pg_md5_binary(cryptvector,
                                                   packetlength + strlen(secret),
-                                                  encryptedpassword))
+                                                  encryptedpassword, &errstr))
                {
                        ereport(LOG,
-                                       (errmsg("could not perform MD5 encryption of received packet")));
+                                       (errmsg("could not perform MD5 encryption of received packet: %s",
+                                                       errstr)));
                        pfree(cryptvector);
                        continue;
                }
index 7ebcdd71236c6c28f960f3f030641aea10e17113..1ff8b0507d4a856ef6cdbebc2903508c9611bb00 100644 (file)
@@ -34,7 +34,7 @@
  * sent to the client, to avoid giving away user information!
  */
 char *
-get_role_password(const char *role, char **logdetail)
+get_role_password(const char *role, const char **logdetail)
 {
        TimestampTz vuntil = 0;
        HeapTuple       roleTup;
@@ -116,6 +116,7 @@ encrypt_password(PasswordType target_type, const char *role,
 {
        PasswordType guessed_type = get_password_type(password);
        char       *encrypted_password;
+       const char *errstr = NULL;
 
        if (guessed_type != PASSWORD_TYPE_PLAINTEXT)
        {
@@ -132,8 +133,8 @@ encrypt_password(PasswordType target_type, const char *role,
                        encrypted_password = palloc(MD5_PASSWD_LEN + 1);
 
                        if (!pg_md5_encrypt(password, role, strlen(role),
-                                                               encrypted_password))
-                               elog(ERROR, "password encryption failed");
+                                                               encrypted_password, &errstr))
+                               elog(ERROR, "password encryption failed: %s", errstr);
                        return encrypted_password;
 
                case PASSWORD_TYPE_SCRAM_SHA_256:
@@ -159,17 +160,18 @@ encrypt_password(PasswordType target_type, const char *role,
  * 'client_pass' is the response given by the remote user to the MD5 challenge.
  * 'md5_salt' is the salt used in the MD5 authentication challenge.
  *
- * In the error case, optionally store a palloc'd string at *logdetail
- * that will be sent to the postmaster log (but not the client).
+ * In the error case, save a string at *logdetail that will be sent to the
+ * postmaster log (but not the client).
  */
 int
 md5_crypt_verify(const char *role, const char *shadow_pass,
                                 const char *client_pass,
                                 const char *md5_salt, int md5_salt_len,
-                                char **logdetail)
+                                const char **logdetail)
 {
        int                     retval;
        char            crypt_pwd[MD5_PASSWD_LEN + 1];
+       const char *errstr = NULL;
 
        Assert(md5_salt_len > 0);
 
@@ -183,16 +185,13 @@ md5_crypt_verify(const char *role, const char *shadow_pass,
 
        /*
         * Compute the correct answer for the MD5 challenge.
-        *
-        * We do not bother setting logdetail for any pg_md5_encrypt failure
-        * below: the only possible error is out-of-memory, which is unlikely, and
-        * if it did happen adding a psprintf call would only make things worse.
         */
        /* stored password already encrypted, only do salt */
        if (!pg_md5_encrypt(shadow_pass + strlen("md5"),
                                                md5_salt, md5_salt_len,
-                                               crypt_pwd))
+                                               crypt_pwd, &errstr))
        {
+               *logdetail = errstr;
                return STATUS_ERROR;
        }
 
@@ -215,15 +214,16 @@ md5_crypt_verify(const char *role, const char *shadow_pass,
  * pg_authid.rolpassword.
  * 'client_pass' is the password given by the remote user.
  *
- * In the error case, optionally store a palloc'd string at *logdetail
- * that will be sent to the postmaster log (but not the client).
+ * In the error case, store a string at *logdetail that will be sent to the
+ * postmaster log (but not the client).
  */
 int
 plain_crypt_verify(const char *role, const char *shadow_pass,
                                   const char *client_pass,
-                                  char **logdetail)
+                                  const char **logdetail)
 {
        char            crypt_client_pass[MD5_PASSWD_LEN + 1];
+       const char *errstr = NULL;
 
        /*
         * Client sent password in plaintext.  If we have an MD5 hash stored, hash
@@ -251,14 +251,10 @@ plain_crypt_verify(const char *role, const char *shadow_pass,
                        if (!pg_md5_encrypt(client_pass,
                                                                role,
                                                                strlen(role),
-                                                               crypt_client_pass))
+                                                               crypt_client_pass,
+                                                               &errstr))
                        {
-                               /*
-                                * We do not bother setting logdetail for pg_md5_encrypt
-                                * failure: the only possible error is out-of-memory, which is
-                                * unlikely, and if it did happen adding a psprintf call would
-                                * only make things worse.
-                                */
+                               *logdetail = errstr;
                                return STATUS_ERROR;
                        }
                        if (strcmp(crypt_client_pass, shadow_pass) == 0)
index 1678b8926680cc3a3720f8fecff23136c1b673d1..7e22f9e48cf6fbf2aaf654331e1f4dc9dec2cf0f 100644 (file)
@@ -68,7 +68,8 @@ InitializeBackupManifest(backup_manifest_info *manifest,
                manifest->buffile = BufFileCreateTemp(false);
                manifest->manifest_ctx = pg_cryptohash_create(PG_SHA256);
                if (pg_cryptohash_init(manifest->manifest_ctx) < 0)
-                       elog(ERROR, "failed to initialize checksum of backup manifest");
+                       elog(ERROR, "failed to initialize checksum of backup manifest: %s",
+                                pg_cryptohash_error(manifest->manifest_ctx));
        }
 
        manifest->manifest_size = UINT64CONST(0);
@@ -311,7 +312,7 @@ AddWALInfoToBackupManifest(backup_manifest_info *manifest, XLogRecPtr startptr,
  * Finalize the backup manifest, and send it to the client.
  */
 void
-SendBackupManifest(backup_manifest_info *manifest, bbsink *sink)
+SendBackupManifest(backup_manifest_info *manifest, bbsink * sink)
 {
        uint8           checksumbuf[PG_SHA256_DIGEST_LENGTH];
        char            checksumstringbuf[PG_SHA256_DIGEST_STRING_LENGTH];
@@ -334,7 +335,8 @@ SendBackupManifest(backup_manifest_info *manifest, bbsink *sink)
        manifest->still_checksumming = false;
        if (pg_cryptohash_final(manifest->manifest_ctx, checksumbuf,
                                                        sizeof(checksumbuf)) < 0)
-               elog(ERROR, "failed to finalize checksum of backup manifest");
+               elog(ERROR, "failed to finalize checksum of backup manifest: %s",
+                        pg_cryptohash_error(manifest->manifest_ctx));
        AppendStringToManifest(manifest, "\"Manifest-Checksum\": \"");
 
        hex_encode((char *) checksumbuf, sizeof checksumbuf, checksumstringbuf);
@@ -391,7 +393,8 @@ AppendStringToManifest(backup_manifest_info *manifest, char *s)
        if (manifest->still_checksumming)
        {
                if (pg_cryptohash_update(manifest->manifest_ctx, (uint8 *) s, len) < 0)
-                       elog(ERROR, "failed to update checksum of backup manifest");
+                       elog(ERROR, "failed to update checksum of backup manifest: %s",
+                                pg_cryptohash_error(manifest->manifest_ctx));
        }
        BufFileWrite(manifest->buffile, s, len);
        manifest->manifest_size += len;
index 7e43c0e01db9116bdfad32c84a26b19d0be70f26..03d84ea2172943ffd6b37f08d15c76be237917d7 100644 (file)
@@ -35,15 +35,17 @@ md5_text(PG_FUNCTION_ARGS)
        text       *in_text = PG_GETARG_TEXT_PP(0);
        size_t          len;
        char            hexsum[MD5_HASH_LEN + 1];
+       const char *errstr = NULL;
 
        /* Calculate the length of the buffer using varlena metadata */
        len = VARSIZE_ANY_EXHDR(in_text);
 
        /* get the hash result */
-       if (pg_md5_hash(VARDATA_ANY(in_text), len, hexsum) == false)
+       if (pg_md5_hash(VARDATA_ANY(in_text), len, hexsum, &errstr) == false)
                ereport(ERROR,
-                               (errcode(ERRCODE_OUT_OF_MEMORY),
-                                errmsg("out of memory")));
+                               (errcode(ERRCODE_INTERNAL_ERROR),
+                                errmsg("could not compute %s hash: %s", "MD5",
+                                               errstr)));
 
        /* convert to text and return it */
        PG_RETURN_TEXT_P(cstring_to_text(hexsum));
@@ -58,12 +60,14 @@ md5_bytea(PG_FUNCTION_ARGS)
        bytea      *in = PG_GETARG_BYTEA_PP(0);
        size_t          len;
        char            hexsum[MD5_HASH_LEN + 1];
+       const char *errstr = NULL;
 
        len = VARSIZE_ANY_EXHDR(in);
-       if (pg_md5_hash(VARDATA_ANY(in), len, hexsum) == false)
+       if (pg_md5_hash(VARDATA_ANY(in), len, hexsum, &errstr) == false)
                ereport(ERROR,
-                               (errcode(ERRCODE_OUT_OF_MEMORY),
-                                errmsg("out of memory")));
+                               (errcode(ERRCODE_INTERNAL_ERROR),
+                                errmsg("could not compute %s hash: %s", "MD5",
+                                               errstr)));
 
        PG_RETURN_TEXT_P(cstring_to_text(hexsum));
 }
@@ -111,12 +115,15 @@ cryptohash_internal(pg_cryptohash_type type, bytea *input)
 
        ctx = pg_cryptohash_create(type);
        if (pg_cryptohash_init(ctx) < 0)
-               elog(ERROR, "could not initialize %s context", typestr);
+               elog(ERROR, "could not initialize %s context: %s", typestr,
+                        pg_cryptohash_error(ctx));
        if (pg_cryptohash_update(ctx, data, len) < 0)
-               elog(ERROR, "could not update %s context", typestr);
+               elog(ERROR, "could not update %s context: %s", typestr,
+                        pg_cryptohash_error(ctx));
        if (pg_cryptohash_final(ctx, (unsigned char *) VARDATA(result),
                                                        digest_len) < 0)
-               elog(ERROR, "could not finalize %s context", typestr);
+               elog(ERROR, "could not finalize %s context: %s", typestr,
+                        pg_cryptohash_error(ctx));
        pg_cryptohash_free(ctx);
 
        SET_VARSIZE(result, digest_len + VARHDRSZ);
index b13815dd98e8833a47546e7e52c79d242a75dff1..ddf35d28b222ba1f91404e10ceb43a0526e1e844 100644 (file)
 #define FREE(ptr) free(ptr)
 #endif
 
+/* Set of error states */
+typedef enum pg_cryptohash_errno
+{
+       PG_CRYPTOHASH_ERROR_NONE = 0,
+       PG_CRYPTOHASH_ERROR_DEST_LEN
+} pg_cryptohash_errno;
+
 /* Internal pg_cryptohash_ctx structure */
 struct pg_cryptohash_ctx
 {
        pg_cryptohash_type type;
+       pg_cryptohash_errno error;
 
        union
        {
@@ -76,9 +84,10 @@ pg_cryptohash_create(pg_cryptohash_type type)
        ctx = ALLOC(sizeof(pg_cryptohash_ctx));
        if (ctx == NULL)
                return NULL;
+
        memset(ctx, 0, sizeof(pg_cryptohash_ctx));
        ctx->type = type;
-
+       ctx->error = PG_CRYPTOHASH_ERROR_NONE;
        return ctx;
 }
 
@@ -174,32 +183,50 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
        {
                case PG_MD5:
                        if (len < MD5_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_md5_final(&ctx->data.md5, dest);
                        break;
                case PG_SHA1:
                        if (len < SHA1_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_sha1_final(&ctx->data.sha1, dest);
                        break;
                case PG_SHA224:
                        if (len < PG_SHA224_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_sha224_final(&ctx->data.sha224, dest);
                        break;
                case PG_SHA256:
                        if (len < PG_SHA256_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_sha256_final(&ctx->data.sha256, dest);
                        break;
                case PG_SHA384:
                        if (len < PG_SHA384_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_sha384_final(&ctx->data.sha384, dest);
                        break;
                case PG_SHA512:
                        if (len < PG_SHA512_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        pg_sha512_final(&ctx->data.sha512, dest);
                        break;
        }
@@ -221,3 +248,31 @@ pg_cryptohash_free(pg_cryptohash_ctx *ctx)
        explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
        FREE(ctx);
 }
+
+/*
+ * pg_cryptohash_error
+ *
+ * Returns a static string providing errors about an error that
+ * happened during a computation.
+ */
+const char *
+pg_cryptohash_error(pg_cryptohash_ctx *ctx)
+{
+       /*
+        * This implementation would never fail because of an out-of-memory error,
+        * except when creating the context.
+        */
+       if (ctx == NULL)
+               return _("out of memory");
+
+       switch (ctx->error)
+       {
+               case PG_CRYPTOHASH_ERROR_NONE:
+                       return _("success");
+               case PG_CRYPTOHASH_ERROR_DEST_LEN:
+                       return _("destination buffer too small");
+       }
+
+       Assert(false);
+       return _("success");
+}
index f7b390ed54dc149846eb239919e8e8033279e2db..2e835b066b40726e6481bd9fb44c1f2e63dc6c09 100644 (file)
@@ -21,6 +21,7 @@
 #include "postgres_fe.h"
 #endif
 
+#include <openssl/err.h>
 #include <openssl/evp.h>
 
 #include "common/cryptohash.h"
 #define FREE(ptr) free(ptr)
 #endif
 
+/* Set of error states */
+typedef enum pg_cryptohash_errno
+{
+       PG_CRYPTOHASH_ERROR_NONE = 0,
+       PG_CRYPTOHASH_ERROR_DEST_LEN,
+       PG_CRYPTOHASH_ERROR_OPENSSL
+} pg_cryptohash_errno;
+
 /*
  * Internal pg_cryptohash_ctx structure.
  *
@@ -55,6 +64,8 @@
 struct pg_cryptohash_ctx
 {
        pg_cryptohash_type type;
+       pg_cryptohash_errno error;
+       const char *errreason;
 
        EVP_MD_CTX *evpctx;
 
@@ -63,6 +74,19 @@ struct pg_cryptohash_ctx
 #endif
 };
 
+static const char *
+SSLerrmessage(unsigned long ecode)
+{
+       if (ecode == 0)
+               return NULL;
+
+       /*
+        * This may return NULL, but we would fall back to a default error path if
+        * that were the case.
+        */
+       return ERR_reason_error_string(ecode);
+}
+
 /*
  * pg_cryptohash_create
  *
@@ -88,6 +112,8 @@ pg_cryptohash_create(pg_cryptohash_type type)
                return NULL;
        memset(ctx, 0, sizeof(pg_cryptohash_ctx));
        ctx->type = type;
+       ctx->error = PG_CRYPTOHASH_ERROR_NONE;
+       ctx->errreason = NULL;
 
        /*
         * Initialization takes care of assigning the correct type for OpenSSL.
@@ -153,7 +179,11 @@ pg_cryptohash_init(pg_cryptohash_ctx *ctx)
 
        /* OpenSSL internals return 1 on success, 0 on failure */
        if (status <= 0)
+       {
+               ctx->errreason = SSLerrmessage(ERR_get_error());
+               ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
                return -1;
+       }
        return 0;
 }
 
@@ -174,7 +204,11 @@ pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len)
 
        /* OpenSSL internals return 1 on success, 0 on failure */
        if (status <= 0)
+       {
+               ctx->errreason = SSLerrmessage(ERR_get_error());
+               ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
                return -1;
+       }
        return 0;
 }
 
@@ -195,27 +229,45 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
        {
                case PG_MD5:
                        if (len < MD5_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
                case PG_SHA1:
                        if (len < SHA1_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
                case PG_SHA224:
                        if (len < PG_SHA224_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
                case PG_SHA256:
                        if (len < PG_SHA256_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
                case PG_SHA384:
                        if (len < PG_SHA384_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
                case PG_SHA512:
                        if (len < PG_SHA512_DIGEST_LENGTH)
+                       {
+                               ctx->error = PG_CRYPTOHASH_ERROR_DEST_LEN;
                                return -1;
+                       }
                        break;
        }
 
@@ -223,7 +275,11 @@ pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
 
        /* OpenSSL internals return 1 on success, 0 on failure */
        if (status <= 0)
+       {
+               ctx->errreason = SSLerrmessage(ERR_get_error());
+               ctx->error = PG_CRYPTOHASH_ERROR_OPENSSL;
                return -1;
+       }
        return 0;
 }
 
@@ -248,3 +304,40 @@ pg_cryptohash_free(pg_cryptohash_ctx *ctx)
        explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
        FREE(ctx);
 }
+
+/*
+ * pg_cryptohash_error
+ *
+ * Returns a static string providing errors about an error that
+ * happened during a computation.
+ */
+const char *
+pg_cryptohash_error(pg_cryptohash_ctx *ctx)
+{
+       /*
+        * This implementation would never fail because of an out-of-memory error,
+        * except when creating the context.
+        */
+       if (ctx == NULL)
+               return _("out of memory");
+
+       /*
+        * If a reason is provided, rely on it, else fallback to any error code
+        * set.
+        */
+       if (ctx->errreason)
+               return ctx->errreason;
+
+       switch (ctx->error)
+       {
+               case PG_CRYPTOHASH_ERROR_NONE:
+                       return _("success");
+               case PG_CRYPTOHASH_ERROR_DEST_LEN:
+                       return _("destination buffer too small");
+               case PG_CRYPTOHASH_ERROR_OPENSSL:
+                       return _("OpenSSL failure");
+       }
+
+       Assert(false);                          /* cannot be reached */
+       return _("success");
+}
index 65b0be4b6613ca89b0df6dba3aab9ab42fbb6959..edc935eeb8d40ed4e12074c43b8ae82a9d7944b2 100644 (file)
@@ -67,7 +67,7 @@ bytesToHex(uint8 b[16], char *s)
  */
 
 bool
-pg_md5_hash(const void *buff, size_t len, char *hexsum)
+pg_md5_hash(const void *buff, size_t len, char *hexsum, const char **errstr)
 {
        uint8           sum[MD5_DIGEST_LENGTH];
        pg_cryptohash_ctx *ctx;
@@ -80,6 +80,7 @@ pg_md5_hash(const void *buff, size_t len, char *hexsum)
                pg_cryptohash_update(ctx, buff, len) < 0 ||
                pg_cryptohash_final(ctx, sum, sizeof(sum)) < 0)
        {
+               *errstr = pg_cryptohash_error(ctx);
                pg_cryptohash_free(ctx);
                return false;
        }
@@ -90,18 +91,23 @@ pg_md5_hash(const void *buff, size_t len, char *hexsum)
 }
 
 bool
-pg_md5_binary(const void *buff, size_t len, void *outbuf)
+pg_md5_binary(const void *buff, size_t len, void *outbuf, const char **errstr)
 {
        pg_cryptohash_ctx *ctx;
 
+       *errstr = NULL;
        ctx = pg_cryptohash_create(PG_MD5);
        if (ctx == NULL)
+       {
+               *errstr = pg_cryptohash_error(NULL);    /* returns OOM */
                return false;
+       }
 
        if (pg_cryptohash_init(ctx) < 0 ||
                pg_cryptohash_update(ctx, buff, len) < 0 ||
                pg_cryptohash_final(ctx, outbuf, MD5_DIGEST_LENGTH) < 0)
        {
+               *errstr = pg_cryptohash_error(ctx);
                pg_cryptohash_free(ctx);
                return false;
        }
@@ -118,11 +124,12 @@ pg_md5_binary(const void *buff, size_t len, void *outbuf)
  * Output format is "md5" followed by a 32-hex-digit MD5 checksum.
  * Hence, the output buffer "buf" must be at least 36 bytes long.
  *
- * Returns true if okay, false on error (out of memory).
+ * Returns true if okay, false on error with *errstr providing some
+ * error context.
  */
 bool
 pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
-                          char *buf)
+                          char *buf, const char **errstr)
 {
        size_t          passwd_len = strlen(passwd);
 
@@ -131,7 +138,10 @@ pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
        bool            ret;
 
        if (!crypt_buf)
+       {
+               *errstr = _("out of memory");
                return false;
+       }
 
        /*
         * Place salt at the end because it may be known by users trying to crack
@@ -141,7 +151,7 @@ pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
        memcpy(crypt_buf + passwd_len, salt, salt_len);
 
        strcpy(buf, "md5");
-       ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3);
+       ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3, errstr);
 
        free(crypt_buf);
 
index ea1300d5d4bceb486b9de34ad77d862c50155582..8e339c83ad148f8acd0b469441c51d4753e9ffc9 100644 (file)
@@ -34,5 +34,6 @@ extern int    pg_cryptohash_init(pg_cryptohash_ctx *ctx);
 extern int     pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len);
 extern int     pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len);
 extern void pg_cryptohash_free(pg_cryptohash_ctx *ctx);
+extern const char *pg_cryptohash_error(pg_cryptohash_ctx *ctx);
 
 #endif                                                 /* PG_CRYPTOHASH_H */
index bbd2ec0165d8acae39268fd7f03f3582bcba4df3..942ca4242c7b89db070bb62d0bf65f569cd66c7b 100644 (file)
 #define MD5_PASSWD_LEN 35
 
 /* Utilities common to all the MD5 implementations, as of md5_common.c */
-extern bool pg_md5_hash(const void *buff, size_t len, char *hexsum);
-extern bool pg_md5_binary(const void *buff, size_t len, void *outbuf);
+extern bool pg_md5_hash(const void *buff, size_t len, char *hexsum,
+                                               const char **errstr);
+extern bool pg_md5_binary(const void *buff, size_t len, void *outbuf,
+                                                 const char **errstr);
 extern bool pg_md5_encrypt(const char *passwd, const char *salt,
-                                                  size_t salt_len, char *buf);
+                                                  size_t salt_len, char *buf,
+                                                  const char **errstr);
 
 #endif                                                 /* PG_MD5_H */
index ee60772e9433e03ab512b113dfb72461dd89996e..3238cf66d3ae6406d07401031e1b563e1ee186a9 100644 (file)
@@ -35,12 +35,13 @@ extern PasswordType get_password_type(const char *shadow_pass);
 extern char *encrypt_password(PasswordType target_type, const char *role,
                                                          const char *password);
 
-extern char *get_role_password(const char *role, char **logdetail);
+extern char *get_role_password(const char *role, const char **logdetail);
 
 extern int     md5_crypt_verify(const char *role, const char *shadow_pass,
                                                         const char *client_pass, const char *md5_salt,
-                                                        int md5_salt_len, char **logdetail);
+                                                        int md5_salt_len, const char **logdetail);
 extern int     plain_crypt_verify(const char *role, const char *shadow_pass,
-                                                          const char *client_pass, char **logdetail);
+                                                          const char *client_pass,
+                                                          const char **logdetail);
 
 #endif
index 7ba3f5f5bc716fc3b3c91349b9642f4409850692..71cc0dc25142690ca54d605f1d1eb787267bc709 100644 (file)
@@ -126,11 +126,11 @@ typedef struct pg_be_sasl_mech
        int                     (*exchange) (void *state,
                                                         const char *input, int inputlen,
                                                         char **output, int *outputlen,
-                                                        char **logdetail);
+                                                        const char **logdetail);
 } pg_be_sasl_mech;
 
 /* Common implementation for auth.c */
 extern int     CheckSASLAuth(const pg_be_sasl_mech *mech, Port *port,
-                                                 char *shadow_pass, char **logdetail);
+                                                 char *shadow_pass, const char **logdetail);
 
 #endif                                                 /* PG_SASL_H */
index 8d2e4e5db4354671ea8500b5ac546a62ff75705e..2e6b2e8f04e92241f525e01fdd831ca92cabeff6 100644 (file)
@@ -790,6 +790,7 @@ pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
                case AUTH_REQ_MD5:
                        {
                                char       *crypt_pwd2;
+                               const char *errstr = NULL;
 
                                /* Allocate enough space for two MD5 hashes */
                                crypt_pwd = malloc(2 * (MD5_PASSWD_LEN + 1));
@@ -802,14 +803,21 @@ pg_password_sendauth(PGconn *conn, const char *password, AuthRequest areq)
 
                                crypt_pwd2 = crypt_pwd + MD5_PASSWD_LEN + 1;
                                if (!pg_md5_encrypt(password, conn->pguser,
-                                                                       strlen(conn->pguser), crypt_pwd2))
+                                                                       strlen(conn->pguser), crypt_pwd2,
+                                                                       &errstr))
                                {
+                                       appendPQExpBuffer(&conn->errorMessage,
+                                                                         libpq_gettext("could not encrypt password: %s\n"),
+                                                                         errstr);
                                        free(crypt_pwd);
                                        return STATUS_ERROR;
                                }
                                if (!pg_md5_encrypt(crypt_pwd2 + strlen("md5"), md5Salt,
-                                                                       4, crypt_pwd))
+                                                                       4, crypt_pwd, &errstr))
                                {
+                                       appendPQExpBuffer(&conn->errorMessage,
+                                                                         libpq_gettext("could not encrypt password: %s\n"),
+                                                                         errstr);
                                        free(crypt_pwd);
                                        return STATUS_ERROR;
                                }
@@ -1175,12 +1183,13 @@ char *
 PQencryptPassword(const char *passwd, const char *user)
 {
        char       *crypt_pwd;
+       const char *errstr = NULL;
 
        crypt_pwd = malloc(MD5_PASSWD_LEN + 1);
        if (!crypt_pwd)
                return NULL;
 
-       if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd))
+       if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd, &errstr))
        {
                free(crypt_pwd);
                return NULL;
@@ -1287,8 +1296,13 @@ PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user,
                crypt_pwd = malloc(MD5_PASSWD_LEN + 1);
                if (crypt_pwd)
                {
-                       if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd))
+                       const char *errstr = NULL;
+
+                       if (!pg_md5_encrypt(passwd, user, strlen(user), crypt_pwd, &errstr))
                        {
+                               appendPQExpBuffer(&conn->errorMessage,
+                                                                 libpq_gettext("could not encrypt password: %s\n"),
+                                                                 errstr);
                                free(crypt_pwd);
                                crypt_pwd = NULL;
                        }
index f09360547265821ff71350eda443536710b8ae37..5015fa7db000a385f6f40b3564b504afc43dc2ac 100644 (file)
@@ -3350,6 +3350,7 @@ pg_conv_map
 pg_crc32
 pg_crc32c
 pg_cryptohash_ctx
+pg_cryptohash_errno
 pg_cryptohash_type
 pg_ctype_cache
 pg_enc