Sommelier DB

how to build

Execute following commands, you can install Sommelier DB command & C API.

# in this repository
$ git submodule update --init --recursive
$ configure --prefix=/path/to/install
$ make install
$ make

C API example.

#include <stdio.h>
#include "sommelier-db.h"
#include "rust_searchable_pke.h"

#define DBFILE "./sommelier_test.db"
#define MAX_SIZE_SQL 512
#define NUM_KEYWORDS 14
#define MAX_SIZE_KEYWORD_CIPHER_TEXT 2900000
#define MAX_SIZE_TRAPDOOR 22800
#define MAX_INT_SIZE 64
#define MAX_SIZE_CIPHER_TEXT_INSERT_SQL \
    MAX_SIZE_SQL + MAX_INT_SIZE + 2 * MAX_SIZE_KEYWORD_CIPHER_TEXT
#define MAX_SIZE_CIPHER_TEXT_SEARCH_SQL MAX_SIZE_SQL + MAX_SIZE_TRAPDOOR

int main(void)
{
    // Open a new database.
    sqlite3 *db = NULL;
    int err = sqlite3_open(DBFILE, &db);
    if (err)
    {
        fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
        sqlite3_close(db);
        return (1);
    }
    printf("create db - %s\n", DBFILE);

    // Create a user_table.
    const char create_sql[MAX_SIZE_SQL] = {
        "CREATE TABLE user_table (\
            UserID INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,\
            NameCT TEXT NOT NULL,\
            AgeCT TEXT NOT NULL\
        );",
    };
    int rc;
    char *zErrMsg = 0;
    rc = sqlite3_exec(db, create_sql, 0, 0, &zErrMsg);
    if (rc != SQLITE_OK)
    {
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    }

    char *region_name = "test_cipher";

    // Generate new keys.
    CPecdkSecretKey sk = pecdkGenSecretKey(NUM_KEYWORDS);
    CPecdkPublicKey pk = pecdkGenPublicKey(sk);

    // Here, name and age encryptions are generated for two users.
    char *name1 = "Tanaka Taro";
    unsigned int age1 = 21;
    CPecdkCiphertext ct_name1 = genCiphertextForPrefixSearch(pk, region_name, name1);
    CPecdkCiphertext ct_age1 = genCiphertextForRangeSearch(pk, region_name, 7, age1);
    char *name2 = "Tanaka Hanako";
    unsigned int age2 = 18;
    CPecdkCiphertext ct_name2 = genCiphertextForPrefixSearch(pk, region_name, name2);
    CPecdkCiphertext ct_age2 = genCiphertextForRangeSearch(pk, region_name, 7, age2);

    // Insert ciphertexts into the user_table.
    char insert_sql[MAX_SIZE_CIPHER_TEXT_INSERT_SQL] = "";
    sprintf(insert_sql,
            "INSERT INTO user_table (NameCT, AgeCT) values "
            "('%s', '%s');",
            ct_name1.ptr, ct_age1.ptr);
    rc = sqlite3_exec(db, insert_sql, 0, 0, &zErrMsg);
    if (rc != SQLITE_OK)
    {
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    }
    sprintf(insert_sql,
            "INSERT INTO user_table (NameCT, AgeCT) values "
            "('%s', '%s');",
            ct_name2.ptr, ct_age2.ptr);
    rc = sqlite3_exec(db, insert_sql, 0, 0, &zErrMsg);
    if (rc != SQLITE_OK)
    {
        fprintf(stderr, "SQL error: %s\n", zErrMsg);
        sqlite3_free(zErrMsg);
    }

    // Generate a trapdoor to search for the user whose name has a prefix "Tanaka ".
    CPecdkTrapdoor td_name = genTrapdoorForPrefixSearch(sk, region_name, "Tanaka ");
    char select_sql[MAX_SIZE_CIPHER_TEXT_SEARCH_SQL] = "";
    sprintf(select_sql,
            "SELECT UserID FROM user_table "
            "WHERE test_cipher(NameCT, '%s')=1;",
            td_name.ptr);

    sqlite3_stmt *stmt1 = NULL;
    int return_value = sqlite3_prepare_v2(db, select_sql, -1, &stmt1, 0);

    if (return_value)
    {
        printf("Selecting data from DB Failed (err_code=%d)\n", return_value);
        return -1;
    }

    int i = 0;
    while (1)
    {
        return_value = sqlite3_step(stmt1);

        if (return_value == SQLITE_ROW)
        {
            int id = (int)sqlite3_column_int(stmt1, 0);
            printf("%d-th user id for name search: %d\n", i, id);
        }
        else if (return_value == SQLITE_DONE)
        {
            break;
        }
        else
        {
            sqlite3_finalize(stmt1);
            printf("Some error encountered\n");
            return -1;
        }
        i++;
    }
    sqlite3_finalize(stmt1);

    // Generate a trapdoor to search for the user whose age is from 20 to 25.
    CPecdkTrapdoor td_age = genTrapdoorForRangeSearch(sk, region_name, 20, 25, 7);
    sprintf(select_sql,
            "SELECT UserID FROM user_table "
            "WHERE test_cipher(AgeCT, '%s')=1;",
            td_age.ptr);
    sqlite3_stmt *stmt2 = NULL;
    return_value = sqlite3_prepare_v2(db, select_sql, -1, &stmt2, 0);

    if (return_value)
    {
        printf("Selecting data from DB Failed (err_code=%d)\n", return_value);
        return -1;
    }

    i = 0;
    while (1)
    {
        return_value = sqlite3_step(stmt2);

        if (return_value == SQLITE_ROW)
        {
            int id = (int)sqlite3_column_int(stmt2, 0);
            printf("%d-th user id for age search: %d\n", i, id);
        }
        else if (return_value == SQLITE_DONE)
        {
            break;
        }
        else
        {
            sqlite3_finalize(stmt2);
            printf("Some error encountered\n");
            return -1;
        }
        i++;
    }
    sqlite3_finalize(stmt2);
}