pgwire, ccl: add support for LDAP server authentication

informs #125087
fixes #124307
fixes #125076
fixes #125080
Epic CRDB-33829

Release note(enterprise, security): We will be adding a new authentication
mechanism `authLDAP` to connect to AD servers over LDAPs. Example hba conf entry
for this auth method:
```
 # TYPE    DATABASE      USER           ADDRESS             METHOD             OPTIONS
 # Allow all users to connect to using LDAP authentication with search and bind
   host    all           all            all                 ldap               ldapserver=ldap.example.com ldapport=636 "ldapbasedn=ou=users,dc=example,dc=com" "ldapbinddn=cn=readonly,dc=example,dc=com" ldapbindpasswd=readonly_password ldapsearchattribute=uid "ldapsearchfilter=(memberof=cn=cockroachdb_users,ou=groups,dc=example,dc=com)"
 # Fallback to password authentication for the root user
   host    all           root           0.0.0.0/0          password
```
Example to use for azure AD server:
```
SET cluster setting server.host_based_authentication.configuration = 'host    all           all            all                 ldap ldapserver=azure.dev ldapport=636 "ldapbasedn=OU=AADDC Users,DC=azure,DC=dev" "ldapbinddn=CN=Some User,OU=AADDC Users,DC=azure,DC=dev" ldapbindpasswd=my_pwd ldapsearchattribute=sAMAccountName "ldapsearchfilter=(memberOf=CN=azure-dev-domain-sync-users,OU=AADDC Users,DC=crlcloud,DC=dev)"
host    all           root           0.0.0.0/0          password';
```

We also add the following cluster settings:
1. `server.ldap_authentication.domain_ca` to allow operators to set a custom CA
for their domain (i.e. `example.com`).
2. `server.ldap_authentication.client.tls_certificate` and
`server.ldap_authentication.client.tls_key` to allow operators to set the client
certificate and key for establishing mTLS connection with LDAP server.

Post configuration users should be able to authenticate to LDAP server if:
1. The distinguished name corresponding to their sql username exists (we search
for the sql username using `ldapbinddn` and `ldapbindpasswd` in the `ldapbasedn`
domain with filter set to `ldapsearchfilter` and `ldapsearchattribute` key
having value sql username in db connection string) and we retrieve the DN.
2. Their bind attempt is successful with LDAP server using the retrieved DN and
provided ldap password in db connection string.

Example DB client sql login commands. Note `LDAP_SEARCH_VAL` and `SQL_USERNAME`
are same. In case of azure `LDAP_SEARCH_VAL` will be value for `sAMAccountName`:
1.
```
cockroach sql --url "postgresql://{LDAP_SEARCH_VAL}:{LDAP_PASSWORD}@{CLUSTER_HOST}:26257" --certs-dir={CLUSTER_CERT_DIR}
```
2.
```
export PGPASSWORD='LDAP_PASSWORD'
cockroach sql --certs-dir=certs --url "postgresql://{LDAP_SEARCH_VAL}@{CLUSTER_HOST}:26257"
```

.github/CODEOWNERS

@@ -381,6 +381,7 @@
 /pkg/ccl/jwtauthccl/         @cockroachdb/cloud-identity
 #!/pkg/ccl/kvccl/              @cockroachdb/kv-noreview
 /pkg/ccl/kvccl/kvtenantccl/  @cockroachdb/server-prs
+/pkg/ccl/ldapccl/            @cockroachdb/prodsec
 #!/pkg/ccl/upgradeccl/       @cockroachdb/release-eng-prs @cockroachdb/upgrade-prs
 #!/pkg/ccl/logictestccl/       @cockroachdb/sql-queries-noreview
 #!/pkg/ccl/sqlitelogictestccl/ @cockroachdb/sql-queries-noreview

docs/generated/settings/settings-for-tenants.txt

@@ -90,6 +90,9 @@ server.hsts.enabled	boolean	false	if true, HSTS headers will be sent along with
 server.http.base_path	string	/	path to redirect the user to upon succcessful login	application
 server.identity_map.configuration	string		system-identity to database-username mappings	application
 server.jwt_authentication.issuer_custom_ca	string		sets the custom root CA for verifying certificates while fetching JWKS from the JWT issuer	application
+server.ldap_authentication.client.tls_certificate	string		sets the client certificate PEM for establishing mTLS connection with LDAP server	application
+server.ldap_authentication.client.tls_key	string		sets the client key PEM for establishing mTLS connection with LDAP server	application
+server.ldap_authentication.domain.custom_ca	string		sets the PEM encoded custom root CA for verifying domain certificates when establishing connection with LDAP server	application
 server.log_gc.max_deletions_per_cycle	integer	1000	the maximum number of entries to delete on each purge of log-like system tables	application
 server.log_gc.period	duration	1h0m0s	the period at which log-like system tables are checked for old entries	application
 server.max_connections_per_gateway	integer	-1	the maximum number of SQL connections per gateway allowed at a given time (note: this will only limit future connection attempts and will not affect already established connections). Negative values result in unlimited number of connections. Superusers are not affected by this limit.	application

docs/generated/settings/settings.html

@@ -118,6 +118,9 @@
 <tr><td><div id="setting-server-http-base-path" class="anchored"><code>server.http.base_path</code></div></td><td>string</td><td><code>/</code></td><td>path to redirect the user to upon succcessful login</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-identity-map-configuration" class="anchored"><code>server.identity_map.configuration</code></div></td><td>string</td><td><code></code></td><td>system-identity to database-username mappings</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-jwt-authentication-issuer-custom-ca" class="anchored"><code>server.jwt_authentication.issuer_custom_ca</code></div></td><td>string</td><td><code></code></td><td>sets the custom root CA for verifying certificates while fetching JWKS from the JWT issuer</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-server-ldap-authentication-client-tls-certificate" class="anchored"><code>server.ldap_authentication.client.tls_certificate</code></div></td><td>string</td><td><code></code></td><td>sets the client certificate PEM for establishing mTLS connection with LDAP server</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-server-ldap-authentication-client-tls-key" class="anchored"><code>server.ldap_authentication.client.tls_key</code></div></td><td>string</td><td><code></code></td><td>sets the client key PEM for establishing mTLS connection with LDAP server</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
+<tr><td><div id="setting-server-ldap-authentication-domain-custom-ca" class="anchored"><code>server.ldap_authentication.domain.custom_ca</code></div></td><td>string</td><td><code></code></td><td>sets the PEM encoded custom root CA for verifying domain certificates when establishing connection with LDAP server</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-log-gc-max-deletions-per-cycle" class="anchored"><code>server.log_gc.max_deletions_per_cycle</code></div></td><td>integer</td><td><code>1000</code></td><td>the maximum number of entries to delete on each purge of log-like system tables</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-log-gc-period" class="anchored"><code>server.log_gc.period</code></div></td><td>duration</td><td><code>1h0m0s</code></td><td>the period at which log-like system tables are checked for old entries</td><td>Serverless/Dedicated/Self-Hosted</td></tr>
 <tr><td><div id="setting-server-max-connections-per-gateway" class="anchored"><code>server.max_connections_per_gateway</code></div></td><td>integer</td><td><code>-1</code></td><td>the maximum number of SQL connections per gateway allowed at a given time (note: this will only limit future connection attempts and will not affect already established connections). Negative values result in unlimited number of connections. Superusers are not affected by this limit.</td><td>Serverless/Dedicated/Self-Hosted</td></tr>

pkg/BUILD.bazel

@@ -51,6 +51,7 @@ ALL_TESTS = [
     "//pkg/ccl/kvccl/kvfollowerreadsccl:kvfollowerreadsccl_test",
     "//pkg/ccl/kvccl/kvtenantccl/upgradeccl:upgradeccl_test",
     "//pkg/ccl/kvccl/kvtenantccl/upgradeinterlockccl:upgradeinterlockccl_test",
+    "//pkg/ccl/ldapccl:ldapccl_test",
     "//pkg/ccl/logictestccl/tests/3node-tenant-multiregion:3node-tenant-multiregion_test",
     "//pkg/ccl/logictestccl/tests/3node-tenant:3node-tenant_test",
     "//pkg/ccl/logictestccl/tests/5node:5node_test",
@@ -898,6 +899,8 @@ GO_TARGETS = [
     "//pkg/ccl/kvccl/kvtenantccl/upgradeinterlockccl:upgradeinterlockccl_test",
     "//pkg/ccl/kvccl/kvtenantccl:kvtenantccl",
     "//pkg/ccl/kvccl:kvccl",
+    "//pkg/ccl/ldapccl:ldapccl",
+    "//pkg/ccl/ldapccl:ldapccl_test",
     "//pkg/ccl/logictestccl/tests/3node-tenant-multiregion:3node-tenant-multiregion_test",
     "//pkg/ccl/logictestccl/tests/3node-tenant:3node-tenant_test",
     "//pkg/ccl/logictestccl/tests/5node:5node_test",

pkg/ccl/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "//pkg/ccl/jwtauthccl",
         "//pkg/ccl/kvccl",
         "//pkg/ccl/kvccl/kvtenantccl",
+        "//pkg/ccl/ldapccl",
         "//pkg/ccl/multiregionccl",
         "//pkg/ccl/multitenantccl",
         "//pkg/ccl/oidcccl",

pkg/ccl/ccl_init.go

@@ -25,6 +25,7 @@ import (
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/jwtauthccl"
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/kvccl"
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/kvccl/kvtenantccl"
+	_ "github.com/cockroachdb/cockroach/pkg/ccl/ldapccl"
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/multiregionccl"
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/multitenantccl"
 	_ "github.com/cockroachdb/cockroach/pkg/ccl/oidcccl"

pkg/ccl/ldapccl/BUILD.bazel

@@ -0,0 +1,64 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "ldapccl",
+    srcs = [
+        "authentication_ldap.go",
+        "ldap_util.go",
+        "settings.go",
+    ],
+    importpath = "github.com/cockroachdb/cockroach/pkg/ccl/ldapccl",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/ccl/utilccl",
+        "//pkg/clusterversion",
+        "//pkg/security",
+        "//pkg/security/username",
+        "//pkg/server/telemetry",
+        "//pkg/settings",
+        "//pkg/settings/cluster",
+        "//pkg/sql/pgwire",
+        "//pkg/sql/pgwire/hba",
+        "//pkg/sql/pgwire/identmap",
+        "//pkg/sql/pgwire/pgcode",
+        "//pkg/sql/pgwire/pgerror",
+        "//pkg/util/log",
+        "//pkg/util/syncutil",
+        "//pkg/util/uuid",
+        "@com_github_cockroachdb_errors//:errors",
+        "@com_github_cockroachdb_redact//:redact",
+        "@com_github_go_ldap_ldap_v3//:ldap",
+    ],
+)
+
+go_test(
+    name = "ldapccl_test",
+    size = "small",
+    srcs = [
+        "authentication_ldap_test.go",
+        "main_test.go",
+        "settings_test.go",
+    ],
+    data = glob(["testdata/**"]),
+    embed = [":ldapccl"],
+    deps = [
+        "//pkg/base",
+        "//pkg/ccl",
+        "//pkg/security/certnames",
+        "//pkg/security/securityassets",
+        "//pkg/security/securitytest",
+        "//pkg/security/username",
+        "//pkg/server",
+        "//pkg/sql/pgwire/hba",
+        "//pkg/testutils",
+        "//pkg/testutils/serverutils",
+        "//pkg/testutils/testcluster",
+        "//pkg/util/leaktest",
+        "//pkg/util/log",
+        "//pkg/util/randutil",
+        "@com_github_cockroachdb_errors//:errors",
+        "@com_github_cockroachdb_redact//:redact",
+        "@com_github_go_ldap_ldap_v3//:ldap",
+        "@com_github_stretchr_testify//require",
+    ],
+)