Setup project skeletonHEADmaster

1 files changed, 400 insertions, 0 deletions

diff --git a/ep_passwd.c b/ep_passwd.c
new file mode 100644
index 0000000..c3dab9a
--- /dev/null
+++ b/ep_passwd.c
@@ -0,0 +1,400 @@
+/*
+ * nanobbs, a tiny forums software.
+ * Copyright (C) 2025-2026  Xavier Del Campo Romero
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#define _POSIX_C_SOURCE 200809L
+
+#include "endpoints.h"
+#include "auth.h"
+#include "db.h"
+#include "defs.h"
+#include "form.h"
+#include <dynstr.h>
+#include <libweb/form.h>
+#include <libweb/http.h>
+#include <libweb/html.h>
+#include <sodium.h>
+#include <sqlite3.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct passwd
+{
+    bool valid;
+    sqlite3 *db;
+    sqlite3_stmt *stmt;
+    char *username, *old, *new;
+};
+
+static void free_passwd(struct passwd *const p)
+{
+    int error;
+
+    if (!p)
+        return;
+
+    sqlite3_finalize(p->stmt);
+
+    if ((error = sqlite3_close(p->db) != SQLITE_OK))
+        fprintf(stderr, "%s: sqlite3_close: %s\n", __func__,
+            sqlite3_errstr(error));
+
+    free(p->username);
+    free(p->old);
+    free(p->new);
+    free(p);
+}
+
+static int row(struct passwd *const p)
+{
+    char *const hashpwd = db_str(p->db, p->stmt, "password");
+
+    if (!hashpwd)
+    {
+        fprintf(stderr, "%s: missing password\n", __func__);
+        return -1;
+    }
+    else if (!crypto_pwhash_str_verify(hashpwd, p->old, strlen(p->old)))
+        p->valid = true;
+
+    free(hashpwd);
+    return 0;
+}
+
+static int finalize_update(struct passwd *const p,
+    struct http_response *const r)
+{
+    *r = (const struct http_response){.status = HTTP_STATUS_SEE_OTHER};
+
+    if (http_response_add_header(r, "Location", "/"))
+    {
+        fprintf(stderr, "%s: http_response_add_header failed\n", __func__);
+        return -1;
+    }
+
+    free_passwd(p);
+    return 0;
+}
+
+static int update(const struct http_payload *const pl,
+    struct http_response *const r, void *const user, void *const args)
+{
+    struct passwd *const p = args;
+    sqlite3_stmt *const stmt = p->stmt;
+    const int error = sqlite3_step(stmt);
+
+    switch (error)
+    {
+        case SQLITE_BUSY:
+            break;
+
+        case SQLITE_DONE:
+            if (finalize_update(p, r))
+                goto failure;
+
+            break;
+
+        default:
+            fprintf(stderr, "%s: sqlite3_step: %s\n", __func__,
+                sqlite3_errstr(error));
+            sqlite3_reset(stmt);
+            goto failure;
+    }
+
+    return 0;
+
+failure:
+    free_passwd(p);
+    return -1;
+}
+
+static int prepare_change(struct passwd *const p, struct http_response *const r)
+{
+    int ret = -1, error;
+    struct dynstr d;
+    sqlite3_stmt *stmt = NULL;
+    char hashpwd[crypto_pwhash_STRBYTES];
+
+    dynstr_init(&d);
+
+    if (crypto_pwhash_str(hashpwd, p->new, strlen(p->new),
+        crypto_pwhash_OPSLIMIT_INTERACTIVE, crypto_pwhash_MEMLIMIT_INTERACTIVE))
+    {
+        fprintf(stderr, "%s: crypto_pwhash_str failed\n", __func__);
+        goto end;
+    }
+    else if (dynstr_append(&d,
+        "UPDATE users SET password='%s' WHERE name = '%s';", hashpwd,
+        p->username))
+    {
+        fprintf(stderr, "%s: dynstr_append failed\n", __func__);
+        goto end;
+    }
+    else if ((error = sqlite3_prepare_v2(p->db, d.str, d.len, &stmt, NULL))
+        != SQLITE_OK)
+    {
+        fprintf(stderr, "%s: sqlite3_prepare_v2 \"%s\": %s\n", __func__,
+            d.str, sqlite3_errstr(error));
+        goto end;
+    }
+
+    p->stmt = stmt;
+
+    *r = (const struct http_response)
+    {
+        .step.payload = update,
+        .args = p
+    };
+
+    ret = 0;
+
+end:
+    dynstr_free(&d);
+    return ret;
+}
+
+static int finalize(struct passwd *const p, struct http_response *const r)
+{
+    const int error = sqlite3_finalize(p->stmt);
+
+    p->stmt = NULL;
+
+    if (error != SQLITE_OK)
+    {
+        fprintf(stderr, "%s: sqlite3_finalize: %s\n", __func__,
+            sqlite3_errstr(error));
+        return -1;
+    }
+    else if (!p->valid)
+    {
+        const int ret = form_unauthorized("Invalid current password", r);
+
+        free_passwd(p);
+        return ret;
+    }
+    else if (prepare_change(p, r))
+    {
+        fprintf(stderr, "%s: prepare_change failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int run_query(const struct http_payload *const pl,
+    struct http_response *const r, void *const user, void *const args)
+{
+    struct passwd *const p = args;
+    sqlite3_stmt *const stmt = p->stmt;
+    const int error = sqlite3_step(stmt);
+
+    switch (error)
+    {
+        case SQLITE_BUSY:
+            break;
+
+        case SQLITE_DONE:
+            if (finalize(p, r))
+                goto failure;
+
+            break;
+
+        case SQLITE_ROW:
+            if (row(p))
+                goto failure;
+
+            break;
+
+        default:
+            fprintf(stderr, "%s: sqlite3_step: %s\n", __func__,
+                sqlite3_errstr(error));
+            sqlite3_reset(stmt);
+            goto failure;
+    }
+
+    return 0;
+
+failure:
+    free_passwd(p);
+    return -1;
+}
+
+static int passwd(const struct cfg *const cfg, const char *const username,
+    const char *const old, const char *const new, sqlite3 *const db,
+    struct http_response *const r)
+{
+    int ret = -1, error;
+    struct dynstr d;
+    sqlite3_stmt *stmt = NULL;
+    char *userdup = NULL, *olddup = NULL, *newdup = NULL;
+    struct passwd *p = NULL;
+
+    dynstr_init(&d);
+
+    if (!(userdup = strdup(username))
+        || !(olddup = strdup(old))
+        || !(newdup = strdup(new)))
+    {
+        fprintf(stderr, "%s: strdup(3): %s\n", __func__, strerror(errno));
+        goto end;
+    }
+    else if (dynstr_append(&d,
+        "SELECT password from users WHERE name = '%s'", username))
+    {
+        fprintf(stderr, "%s: dynstr_append failed\n", __func__);
+        goto end;
+    }
+    else if ((error = sqlite3_prepare_v2(db, d.str, d.len, &stmt,
+        NULL)) != SQLITE_OK)
+    {
+        fprintf(stderr, "%s: sqlite3_prepare_v2 \"%s\": %s\n", __func__,
+            d.str, sqlite3_errstr(error));
+        goto end;
+    }
+    else if (!(p = malloc(sizeof *p)))
+    {
+        fprintf(stderr, "%s: malloc(3): %s\n", __func__, strerror(errno));
+        goto end;
+    }
+
+    *p = (const struct passwd)
+    {
+        .username = userdup,
+        .old = olddup,
+        .new = newdup,
+        .stmt = stmt,
+        .db = db
+    };
+
+    *r = (const struct http_response)
+    {
+        .step.payload = run_query,
+        .args = p
+    };
+
+    ret = 0;
+
+end:
+
+    if (ret)
+    {
+        free(p);
+        free(userdup);
+        free(olddup);
+        free(newdup);
+        sqlite3_finalize(stmt);
+    }
+
+    dynstr_free(&d);
+    return ret;
+}
+
+static int setup(const struct http_payload *const p,
+    struct http_response *const r, void *const user, sqlite3 *const db,
+    const struct auth_user *const u)
+{
+    int ret = -1, error;
+    struct form *f = NULL;
+    const char *old, *new, *cnew;
+    const struct cfg *const cfg = user;
+
+    *r = (const struct http_response){0};
+
+    if (!u)
+    {
+        ret = form_unauthorized("Authentication required", r);
+        goto failure;
+    }
+    else if ((error = form_alloc(p->u.post.data, &f)))
+    {
+        if ((ret = error) < 0)
+            fprintf(stderr, "%s: form_alloc failed\n", __func__);
+        else
+            ret = form_badreq("Invalid request", r);
+
+        goto failure;
+    }
+    else if (!(old = form_value(f, "old")))
+    {
+        ret = form_badreq("Missing old password", r);
+        goto failure;
+    }
+    else if (!(new = form_value(f, "new")))
+    {
+        ret = form_badreq("Missing new password", r);
+        goto failure;
+    }
+    else if (!(cnew = form_value(f, "cnew")))
+    {
+        ret = form_badreq("Missing confirmation password", r);
+        goto failure;
+    }
+    else if (strcmp(new, cnew))
+    {
+        ret = form_badreq("New password mismatch", r);
+        goto failure;
+    }
+    else if (strlen(new) < MINPWDLEN)
+    {
+        ret = form_shortpwd(r);
+        goto failure;
+    }
+    else if ((ret = passwd(cfg, u->username, old, new, db, r)))
+    {
+        fprintf(stderr, "%s: passwd failed\n", __func__);
+        goto failure;
+    }
+
+    form_free(f);
+    return 0;
+
+failure:
+
+    if ((error = sqlite3_close(db)) != SQLITE_OK)
+        fprintf(stderr, "%s: sqlite3_close: %s\n", __func__,
+            sqlite3_errstr(error));
+
+    form_free(f);
+    return ret;
+}
+
+int ep_passwd(const struct http_payload *const p,
+    struct http_response *const r, void *const user)
+{
+    const int n = auth_validate(p, r, user, setup);
+
+    if (n < 0)
+        fprintf(stderr, "%s: auth_validate failed\n", __func__);
+    else if (n)
+    {
+        const struct cfg *const cfg = user;
+        sqlite3 *db;
+
+        if (db_open(cfg->dir, &db))
+        {
+            fprintf(stderr, "%s: db_open failed\n", __func__);
+            return -1;
+        }
+
+        return setup(p, r, user, db, NULL);
+    }
+
+    return n;
+}