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-rw-r--r--src/backend/libpq/auth-scram.c36
-rw-r--r--src/common/scram-common.c51
-rw-r--r--src/include/common/scram-common.h15
-rw-r--r--src/interfaces/libpq/fe-auth-scram.c58
4 files changed, 89 insertions, 71 deletions
diff --git a/src/backend/libpq/auth-scram.c b/src/backend/libpq/auth-scram.c
index 16bea446e37..5c85af943cd 100644
--- a/src/backend/libpq/auth-scram.c
+++ b/src/backend/libpq/auth-scram.c
@@ -396,7 +396,8 @@ scram_build_verifier(const char *username, const char *password,
{
char *prep_password = NULL;
pg_saslprep_rc rc;
- char saltbuf[SCRAM_SALT_LEN];
+ char saltbuf[SCRAM_DEFAULT_SALT_LEN];
+ uint8 salted_password[SCRAM_KEY_LEN];
uint8 keybuf[SCRAM_KEY_LEN];
char *encoded_salt;
char *encoded_storedkey;
@@ -414,10 +415,10 @@ scram_build_verifier(const char *username, const char *password,
password = (const char *) prep_password;
if (iterations <= 0)
- iterations = SCRAM_ITERATIONS_DEFAULT;
+ iterations = SCRAM_DEFAULT_ITERATIONS;
/* Generate salt, and encode it in base64 */
- if (!pg_backend_random(saltbuf, SCRAM_SALT_LEN))
+ if (!pg_backend_random(saltbuf, SCRAM_DEFAULT_SALT_LEN))
{
ereport(LOG,
(errcode(ERRCODE_INTERNAL_ERROR),
@@ -425,13 +426,14 @@ scram_build_verifier(const char *username, const char *password,
return NULL;
}
- encoded_salt = palloc(pg_b64_enc_len(SCRAM_SALT_LEN) + 1);
- encoded_len = pg_b64_encode(saltbuf, SCRAM_SALT_LEN, encoded_salt);
+ encoded_salt = palloc(pg_b64_enc_len(SCRAM_DEFAULT_SALT_LEN) + 1);
+ encoded_len = pg_b64_encode(saltbuf, SCRAM_DEFAULT_SALT_LEN, encoded_salt);
encoded_salt[encoded_len] = '\0';
/* Calculate StoredKey, and encode it in base64 */
- scram_ClientOrServerKey(password, saltbuf, SCRAM_SALT_LEN,
- iterations, SCRAM_CLIENT_KEY_NAME, keybuf);
+ scram_SaltedPassword(password, saltbuf, SCRAM_DEFAULT_SALT_LEN,
+ iterations, salted_password);
+ scram_ClientKey(salted_password, keybuf);
scram_H(keybuf, SCRAM_KEY_LEN, keybuf); /* StoredKey */
encoded_storedkey = palloc(pg_b64_enc_len(SCRAM_KEY_LEN) + 1);
@@ -440,8 +442,7 @@ scram_build_verifier(const char *username, const char *password,
encoded_storedkey[encoded_len] = '\0';
/* And same for ServerKey */
- scram_ClientOrServerKey(password, saltbuf, SCRAM_SALT_LEN, iterations,
- SCRAM_SERVER_KEY_NAME, keybuf);
+ scram_ServerKey(salted_password, keybuf);
encoded_serverkey = palloc(pg_b64_enc_len(SCRAM_KEY_LEN) + 1);
encoded_len = pg_b64_encode((const char *) keybuf, SCRAM_KEY_LEN,
@@ -473,6 +474,7 @@ scram_verify_plain_password(const char *username, const char *password,
char *salt;
int saltlen;
int iterations;
+ uint8 salted_password[SCRAM_KEY_LEN];
uint8 stored_key[SCRAM_KEY_LEN];
uint8 server_key[SCRAM_KEY_LEN];
uint8 computed_key[SCRAM_KEY_LEN];
@@ -502,9 +504,9 @@ scram_verify_plain_password(const char *username, const char *password,
if (rc == SASLPREP_SUCCESS)
password = prep_password;
- /* Compute Server key based on the user-supplied plaintext password */
- scram_ClientOrServerKey(password, salt, saltlen, iterations,
- SCRAM_SERVER_KEY_NAME, computed_key);
+ /* Compute Server Key based on the user-supplied plaintext password */
+ scram_SaltedPassword(password, salt, saltlen, iterations, salted_password);
+ scram_ServerKey(salted_password, computed_key);
if (prep_password)
pfree(prep_password);
@@ -630,12 +632,12 @@ mock_scram_verifier(const char *username, int *iterations, char **salt,
/* Generate deterministic salt */
raw_salt = scram_MockSalt(username);
- encoded_salt = (char *) palloc(pg_b64_enc_len(SCRAM_SALT_LEN) + 1);
- encoded_len = pg_b64_encode(raw_salt, SCRAM_SALT_LEN, encoded_salt);
+ encoded_salt = (char *) palloc(pg_b64_enc_len(SCRAM_DEFAULT_SALT_LEN) + 1);
+ encoded_len = pg_b64_encode(raw_salt, SCRAM_DEFAULT_SALT_LEN, encoded_salt);
encoded_salt[encoded_len] = '\0';
*salt = encoded_salt;
- *iterations = SCRAM_ITERATIONS_DEFAULT;
+ *iterations = SCRAM_DEFAULT_ITERATIONS;
/* StoredKey and ServerKey are not used in a doomed authentication */
memset(stored_key, 0, SCRAM_KEY_LEN);
@@ -1179,7 +1181,7 @@ build_server_final_message(scram_state *state)
/*
* Determinisitcally generate salt for mock authentication, using a SHA256
* hash based on the username and a cluster-level secret key. Returns a
- * pointer to a static buffer of size SCRAM_SALT_LEN.
+ * pointer to a static buffer of size SCRAM_DEFAULT_SALT_LEN.
*/
static char *
scram_MockSalt(const char *username)
@@ -1194,7 +1196,7 @@ scram_MockSalt(const char *username)
* not larger the SHA256 digest length. If the salt is smaller, the caller
* will just ignore the extra data))
*/
- StaticAssertStmt(PG_SHA256_DIGEST_LENGTH >= SCRAM_SALT_LEN,
+ StaticAssertStmt(PG_SHA256_DIGEST_LENGTH >= SCRAM_DEFAULT_SALT_LEN,
"salt length greater than SHA256 digest length");
pg_sha256_init(&ctx);
diff --git a/src/common/scram-common.c b/src/common/scram-common.c
index df9f0eaa90d..a8ea44944c4 100644
--- a/src/common/scram-common.c
+++ b/src/common/scram-common.c
@@ -98,14 +98,16 @@ scram_HMAC_final(uint8 *result, scram_HMAC_ctx *ctx)
}
/*
- * Iterate hash calculation of HMAC entry using given salt.
- * scram_Hi() is essentially PBKDF2 (see RFC2898) with HMAC() as the
- * pseudorandom function.
+ * Calculate SaltedPassword.
+ *
+ * The password should already be normalized by SASLprep.
*/
-static void
-scram_Hi(const char *str, const char *salt, int saltlen, int iterations, uint8 *result)
+void
+scram_SaltedPassword(const char *password,
+ const char *salt, int saltlen, int iterations,
+ uint8 *result)
{
- int str_len = strlen(str);
+ int password_len = strlen(password);
uint32 one = htonl(1);
int i,
j;
@@ -113,8 +115,14 @@ scram_Hi(const char *str, const char *salt, int saltlen, int iterations, uint8 *
uint8 Ui_prev[SCRAM_KEY_LEN];
scram_HMAC_ctx hmac_ctx;
+ /*
+ * Iterate hash calculation of HMAC entry using given salt. This is
+ * essentially PBKDF2 (see RFC2898) with HMAC() as the pseudorandom
+ * function.
+ */
+
/* First iteration */
- scram_HMAC_init(&hmac_ctx, (uint8 *) str, str_len);
+ scram_HMAC_init(&hmac_ctx, (uint8 *) password, password_len);
scram_HMAC_update(&hmac_ctx, salt, saltlen);
scram_HMAC_update(&hmac_ctx, (char *) &one, sizeof(uint32));
scram_HMAC_final(Ui_prev, &hmac_ctx);
@@ -123,7 +131,7 @@ scram_Hi(const char *str, const char *salt, int saltlen, int iterations, uint8 *
/* Subsequent iterations */
for (i = 2; i <= iterations; i++)
{
- scram_HMAC_init(&hmac_ctx, (uint8 *) str, str_len);
+ scram_HMAC_init(&hmac_ctx, (uint8 *) password, password_len);
scram_HMAC_update(&hmac_ctx, (const char *) Ui_prev, SCRAM_KEY_LEN);
scram_HMAC_final(Ui, &hmac_ctx);
for (j = 0; j < SCRAM_KEY_LEN; j++)
@@ -148,20 +156,27 @@ scram_H(const uint8 *input, int len, uint8 *result)
}
/*
- * Calculate ClientKey or ServerKey.
- *
- * The password should already be normalized by SASLprep.
+ * Calculate ClientKey.
*/
void
-scram_ClientOrServerKey(const char *password,
- const char *salt, int saltlen, int iterations,
- const char *keystr, uint8 *result)
+scram_ClientKey(const uint8 *salted_password, uint8 *result)
+{
+ scram_HMAC_ctx ctx;
+
+ scram_HMAC_init(&ctx, salted_password, SCRAM_KEY_LEN);
+ scram_HMAC_update(&ctx, "Client Key", strlen("Client Key"));
+ scram_HMAC_final(result, &ctx);
+}
+
+/*
+ * Calculate ServerKey.
+ */
+void
+scram_ServerKey(const uint8 *salted_password, uint8 *result)
{
- uint8 keybuf[SCRAM_KEY_LEN];
scram_HMAC_ctx ctx;
- scram_Hi(password, salt, saltlen, iterations, keybuf);
- scram_HMAC_init(&ctx, keybuf, SCRAM_KEY_LEN);
- scram_HMAC_update(&ctx, keystr, strlen(keystr));
+ scram_HMAC_init(&ctx, salted_password, SCRAM_KEY_LEN);
+ scram_HMAC_update(&ctx, "Server Key", strlen("Server Key"));
scram_HMAC_final(result, &ctx);
}
diff --git a/src/include/common/scram-common.h b/src/include/common/scram-common.h
index 6740069eee1..656d9e1e6b1 100644
--- a/src/include/common/scram-common.h
+++ b/src/include/common/scram-common.h
@@ -29,14 +29,10 @@
#define SCRAM_RAW_NONCE_LEN 10
/* length of salt when generating new verifiers */
-#define SCRAM_SALT_LEN 10
+#define SCRAM_DEFAULT_SALT_LEN 10
/* default number of iterations when generating verifier */
-#define SCRAM_ITERATIONS_DEFAULT 4096
-
-/* Base name of keys used for proof generation */
-#define SCRAM_SERVER_KEY_NAME "Server Key"
-#define SCRAM_CLIENT_KEY_NAME "Client Key"
+#define SCRAM_DEFAULT_ITERATIONS 4096
/*
* Context data for HMAC used in SCRAM authentication.
@@ -51,9 +47,10 @@ extern void scram_HMAC_init(scram_HMAC_ctx *ctx, const uint8 *key, int keylen);
extern void scram_HMAC_update(scram_HMAC_ctx *ctx, const char *str, int slen);
extern void scram_HMAC_final(uint8 *result, scram_HMAC_ctx *ctx);
+extern void scram_SaltedPassword(const char *password, const char *salt,
+ int saltlen, int iterations, uint8 *result);
extern void scram_H(const uint8 *str, int len, uint8 *result);
-extern void scram_ClientOrServerKey(const char *password, const char *salt,
- int saltlen, int iterations,
- const char *keystr, uint8 *result);
+extern void scram_ClientKey(const uint8 *salted_password, uint8 *result);
+extern void scram_ServerKey(const uint8 *salted_password, uint8 *result);
#endif /* SCRAM_COMMON_H */
diff --git a/src/interfaces/libpq/fe-auth-scram.c b/src/interfaces/libpq/fe-auth-scram.c
index c56e91e0e04..be271ce8ac0 100644
--- a/src/interfaces/libpq/fe-auth-scram.c
+++ b/src/interfaces/libpq/fe-auth-scram.c
@@ -46,6 +46,7 @@ typedef struct
char *password;
/* We construct these */
+ uint8 SaltedPassword[SCRAM_KEY_LEN];
char *client_nonce;
char *client_first_message_bare;
char *client_final_message_without_proof;
@@ -59,7 +60,7 @@ typedef struct
/* These come from the server-final message */
char *server_final_message;
- char ServerProof[SCRAM_KEY_LEN];
+ char ServerSignature[SCRAM_KEY_LEN];
} fe_scram_state;
static bool read_server_first_message(fe_scram_state *state, char *input,
@@ -70,7 +71,7 @@ static char *build_client_first_message(fe_scram_state *state,
PQExpBuffer errormessage);
static char *build_client_final_message(fe_scram_state *state,
PQExpBuffer errormessage);
-static bool verify_server_proof(fe_scram_state *state);
+static bool verify_server_signature(fe_scram_state *state);
static void calculate_client_proof(fe_scram_state *state,
const char *client_final_message_without_proof,
uint8 *result);
@@ -216,12 +217,12 @@ pg_fe_scram_exchange(void *opaq, char *input, int inputlen,
goto error;
/*
- * Verify server proof, to make sure we're talking to the genuine
- * server. XXX: A fake server could simply not require
+ * Verify server signature, to make sure we're talking to the
+ * genuine server. XXX: A fake server could simply not require
* authentication, though. There is currently no option in libpq
* to reject a connection, if SCRAM authentication did not happen.
*/
- if (verify_server_proof(state))
+ if (verify_server_signature(state))
*success = true;
else
{
@@ -486,12 +487,11 @@ read_server_first_message(fe_scram_state *state, char *input,
* Read the final exchange message coming from the server.
*/
static bool
-read_server_final_message(fe_scram_state *state,
- char *input,
+read_server_final_message(fe_scram_state *state, char *input,
PQExpBuffer errormessage)
{
- char *encoded_server_proof;
- int server_proof_len;
+ char *encoded_server_signature;
+ int server_signature_len;
state->server_final_message = strdup(input);
if (!state->server_final_message)
@@ -513,8 +513,8 @@ read_server_final_message(fe_scram_state *state,
}
/* Parse the message. */
- encoded_server_proof = read_attr_value(&input, 'v', errormessage);
- if (encoded_server_proof == NULL)
+ encoded_server_signature = read_attr_value(&input, 'v', errormessage);
+ if (encoded_server_signature == NULL)
{
/* read_attr_value() has generated an error message */
return false;
@@ -524,13 +524,13 @@ read_server_final_message(fe_scram_state *state,
printfPQExpBuffer(errormessage,
libpq_gettext("malformed SCRAM message (garbage at end of server-final-message)\n"));
- server_proof_len = pg_b64_decode(encoded_server_proof,
- strlen(encoded_server_proof),
- state->ServerProof);
- if (server_proof_len != SCRAM_KEY_LEN)
+ server_signature_len = pg_b64_decode(encoded_server_signature,
+ strlen(encoded_server_signature),
+ state->ServerSignature);
+ if (server_signature_len != SCRAM_KEY_LEN)
{
printfPQExpBuffer(errormessage,
- libpq_gettext("malformed SCRAM message (invalid server proof)\n"));
+ libpq_gettext("malformed SCRAM message (invalid server signature)\n"));
return false;
}
@@ -552,8 +552,14 @@ calculate_client_proof(fe_scram_state *state,
int i;
scram_HMAC_ctx ctx;
- scram_ClientOrServerKey(state->password, state->salt, state->saltlen,
- state->iterations, SCRAM_CLIENT_KEY_NAME, ClientKey);
+ /*
+ * Calculate SaltedPassword, and store it in 'state' so that we can reuse
+ * it later in verify_server_signature.
+ */
+ scram_SaltedPassword(state->password, state->salt, state->saltlen,
+ state->iterations, state->SaltedPassword);
+
+ scram_ClientKey(state->SaltedPassword, ClientKey);
scram_H(ClientKey, SCRAM_KEY_LEN, StoredKey);
scram_HMAC_init(&ctx, StoredKey, SCRAM_KEY_LEN);
@@ -575,19 +581,17 @@ calculate_client_proof(fe_scram_state *state,
}
/*
- * Validate the server proof, received as part of the final exchange message
- * received from the server.
+ * Validate the server signature, received as part of the final exchange
+ * message received from the server.
*/
static bool
-verify_server_proof(fe_scram_state *state)
+verify_server_signature(fe_scram_state *state)
{
- uint8 ServerSignature[SCRAM_KEY_LEN];
+ uint8 expected_ServerSignature[SCRAM_KEY_LEN];
uint8 ServerKey[SCRAM_KEY_LEN];
scram_HMAC_ctx ctx;
- scram_ClientOrServerKey(state->password, state->salt, state->saltlen,
- state->iterations, SCRAM_SERVER_KEY_NAME,
- ServerKey);
+ scram_ServerKey(state->SaltedPassword, ServerKey);
/* calculate ServerSignature */
scram_HMAC_init(&ctx, ServerKey, SCRAM_KEY_LEN);
@@ -602,9 +606,9 @@ verify_server_proof(fe_scram_state *state)
scram_HMAC_update(&ctx,
state->client_final_message_without_proof,
strlen(state->client_final_message_without_proof));
- scram_HMAC_final(ServerSignature, &ctx);
+ scram_HMAC_final(expected_ServerSignature, &ctx);
- if (memcmp(ServerSignature, state->ServerProof, SCRAM_KEY_LEN) != 0)
+ if (memcmp(expected_ServerSignature, state->ServerSignature, SCRAM_KEY_LEN) != 0)
return false;
return true;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-02 19:31:26 +0000