diff options
Diffstat (limited to 'src/crypto_openssl.c')
| -rw-r--r-- | src/crypto_openssl.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/crypto_openssl.c b/src/crypto_openssl.c new file mode 100644 index 0000000..6035b7c --- /dev/null +++ b/src/crypto_openssl.c @@ -0,0 +1,251 @@ +/* +** SQLCipher +** http://sqlcipher.net +** +** Copyright (c) 2008 - 2013, ZETETIC LLC +** All rights reserved. +** +** Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in the +** documentation and/or other materials provided with the distribution. +** * Neither the name of the ZETETIC LLC nor the +** names of its contributors may be used to endorse or promote products +** derived from this software without specific prior written permission. +** +** THIS SOFTWARE IS PROVIDED BY ZETETIC LLC ''AS IS'' AND ANY +** EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +** DISCLAIMED. IN NO EVENT SHALL ZETETIC LLC BE LIABLE FOR ANY +** DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +** (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +** SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +** +*/ +/* BEGIN SQLCIPHER */ +#ifdef SQLITE_HAS_CODEC +#ifdef SQLCIPHER_CRYPTO_OPENSSL +#include "sqliteInt.h" +#include "crypto.h" +#include "sqlcipher.h" +#include <openssl/rand.h> +#include <openssl/evp.h> +#include <openssl/hmac.h> + +typedef struct { + EVP_CIPHER *evp_cipher; +} openssl_ctx; + + +static unsigned int openssl_external_init = 0; +static unsigned int openssl_init_count = 0; +static sqlite3_mutex* openssl_rand_mutex = NULL; + +static int sqlcipher_openssl_add_random(void *ctx, void *buffer, int length) { +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + sqlite3_mutex_enter(openssl_rand_mutex); +#endif + RAND_add(buffer, length, 0); +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + sqlite3_mutex_leave(openssl_rand_mutex); +#endif + return SQLITE_OK; +} + +/* activate and initialize sqlcipher. Most importantly, this will automatically + intialize OpenSSL's EVP system if it hasn't already be externally. Note that + this function may be called multiple times as new codecs are intiialized. + Thus it performs some basic counting to ensure that only the last and final + sqlcipher_openssl_deactivate() will free the EVP structures. +*/ +static int sqlcipher_openssl_activate(void *ctx) { + /* initialize openssl and increment the internal init counter + but only if it hasn't been initalized outside of SQLCipher by this program + e.g. on startup */ + sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)); + + if(openssl_init_count == 0 && EVP_get_cipherbyname(CIPHER) != NULL) { + /* if openssl has not yet been initialized by this library, but + a call to get_cipherbyname works, then the openssl library + has been initialized externally already. */ + openssl_external_init = 1; + } + + if(openssl_init_count == 0 && openssl_external_init == 0) { + /* if the library was not externally initialized, then should be now */ + OpenSSL_add_all_algorithms(); + } + +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + if(openssl_rand_mutex == NULL) { + /* allocate a mutex to guard against concurrent calls to RAND_bytes() */ + openssl_rand_mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST); + } +#endif + + openssl_init_count++; + sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)); + return SQLITE_OK; +} + +/* deactivate SQLCipher, most imporantly decremeting the activation count and + freeing the EVP structures on the final deactivation to ensure that + OpenSSL memory is cleaned up */ +static int sqlcipher_openssl_deactivate(void *ctx) { + sqlite3_mutex_enter(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)); + openssl_init_count--; + + if(openssl_init_count == 0) { + if(openssl_external_init == 0) { + /* if OpenSSL hasn't be initialized externally, and the counter reaches zero + after it's decremented, release EVP memory + Note: this code will only be reached if OpensSSL_add_all_algorithms() + is called by SQLCipher internally. This should prevent SQLCipher from + "cleaning up" openssl when it was initialized externally by the program */ + EVP_cleanup(); + } +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + sqlite3_mutex_free(openssl_rand_mutex); + openssl_rand_mutex = NULL; +#endif + } + sqlite3_mutex_leave(sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER)); + return SQLITE_OK; +} + +static const char* sqlcipher_openssl_get_provider_name(void *ctx) { + return "openssl"; +} + +/* generate a defined number of random bytes */ +static int sqlcipher_openssl_random (void *ctx, void *buffer, int length) { + int rc = 0; + /* concurrent calls to RAND_bytes can cause a crash under some openssl versions when a + naive application doesn't use CRYPTO_set_locking_callback and + CRYPTO_THREADID_set_callback to ensure openssl thread safety. + This is simple workaround to prevent this common crash + but a more proper solution is that applications setup platform-appropriate + thread saftey in openssl externally */ +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + sqlite3_mutex_enter(openssl_rand_mutex); +#endif + rc = RAND_bytes((unsigned char *)buffer, length); +#ifndef SQLCIPHER_OPENSSL_NO_MUTEX_RAND + sqlite3_mutex_leave(openssl_rand_mutex); +#endif + return (rc == 1) ? SQLITE_OK : SQLITE_ERROR; +} + +static int sqlcipher_openssl_hmac(void *ctx, unsigned char *hmac_key, int key_sz, unsigned char *in, int in_sz, unsigned char *in2, int in2_sz, unsigned char *out) { + HMAC_CTX hctx; + unsigned int outlen; + HMAC_CTX_init(&hctx); + HMAC_Init_ex(&hctx, hmac_key, key_sz, EVP_sha1(), NULL); + HMAC_Update(&hctx, in, in_sz); + HMAC_Update(&hctx, in2, in2_sz); + HMAC_Final(&hctx, out, &outlen); + HMAC_CTX_cleanup(&hctx); + return SQLITE_OK; +} + +static int sqlcipher_openssl_kdf(void *ctx, const char *pass, int pass_sz, unsigned char* salt, int salt_sz, int workfactor, int key_sz, unsigned char *key) { + PKCS5_PBKDF2_HMAC_SHA1(pass, pass_sz, salt, salt_sz, workfactor, key_sz, key); + return SQLITE_OK; +} + +static int sqlcipher_openssl_cipher(void *ctx, int mode, unsigned char *key, int key_sz, unsigned char *iv, unsigned char *in, int in_sz, unsigned char *out) { + EVP_CIPHER_CTX ectx; + int tmp_csz, csz; + + EVP_CipherInit(&ectx, ((openssl_ctx *)ctx)->evp_cipher, NULL, NULL, mode); + EVP_CIPHER_CTX_set_padding(&ectx, 0); // no padding + EVP_CipherInit(&ectx, NULL, key, iv, mode); + EVP_CipherUpdate(&ectx, out, &tmp_csz, in, in_sz); + csz = tmp_csz; + out += tmp_csz; + EVP_CipherFinal(&ectx, out, &tmp_csz); + csz += tmp_csz; + EVP_CIPHER_CTX_cleanup(&ectx); + assert(in_sz == csz); + return SQLITE_OK; +} + +static int sqlcipher_openssl_set_cipher(void *ctx, const char *cipher_name) { + openssl_ctx *o_ctx = (openssl_ctx *)ctx; + o_ctx->evp_cipher = (EVP_CIPHER *) EVP_get_cipherbyname(cipher_name); + return SQLITE_OK; +} + +static const char* sqlcipher_openssl_get_cipher(void *ctx) { + return EVP_CIPHER_name(((openssl_ctx *)ctx)->evp_cipher); +} + +static int sqlcipher_openssl_get_key_sz(void *ctx) { + return EVP_CIPHER_key_length(((openssl_ctx *)ctx)->evp_cipher); +} + +static int sqlcipher_openssl_get_iv_sz(void *ctx) { + return EVP_CIPHER_iv_length(((openssl_ctx *)ctx)->evp_cipher); +} + +static int sqlcipher_openssl_get_block_sz(void *ctx) { + return EVP_CIPHER_block_size(((openssl_ctx *)ctx)->evp_cipher); +} + +static int sqlcipher_openssl_get_hmac_sz(void *ctx) { + return EVP_MD_size(EVP_sha1()); +} + +static int sqlcipher_openssl_ctx_copy(void *target_ctx, void *source_ctx) { + memcpy(target_ctx, source_ctx, sizeof(openssl_ctx)); + return SQLITE_OK; +} + +static int sqlcipher_openssl_ctx_cmp(void *c1, void *c2) { + return ((openssl_ctx *)c1)->evp_cipher == ((openssl_ctx *)c2)->evp_cipher; +} + +static int sqlcipher_openssl_ctx_init(void **ctx) { + *ctx = sqlcipher_malloc(sizeof(openssl_ctx)); + if(*ctx == NULL) return SQLITE_NOMEM; + sqlcipher_openssl_activate(*ctx); + return SQLITE_OK; +} + +static int sqlcipher_openssl_ctx_free(void **ctx) { + sqlcipher_openssl_deactivate(*ctx); + sqlcipher_free(*ctx, sizeof(openssl_ctx)); + return SQLITE_OK; +} + +int sqlcipher_openssl_setup(sqlcipher_provider *p) { + p->activate = sqlcipher_openssl_activate; + p->deactivate = sqlcipher_openssl_deactivate; + p->get_provider_name = sqlcipher_openssl_get_provider_name; + p->random = sqlcipher_openssl_random; + p->hmac = sqlcipher_openssl_hmac; + p->kdf = sqlcipher_openssl_kdf; + p->cipher = sqlcipher_openssl_cipher; + p->set_cipher = sqlcipher_openssl_set_cipher; + p->get_cipher = sqlcipher_openssl_get_cipher; + p->get_key_sz = sqlcipher_openssl_get_key_sz; + p->get_iv_sz = sqlcipher_openssl_get_iv_sz; + p->get_block_sz = sqlcipher_openssl_get_block_sz; + p->get_hmac_sz = sqlcipher_openssl_get_hmac_sz; + p->ctx_copy = sqlcipher_openssl_ctx_copy; + p->ctx_cmp = sqlcipher_openssl_ctx_cmp; + p->ctx_init = sqlcipher_openssl_ctx_init; + p->ctx_free = sqlcipher_openssl_ctx_free; + p->add_random = sqlcipher_openssl_add_random; + return SQLITE_OK; +} + +#endif +#endif +/* END SQLCIPHER */ |