-int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
- const unsigned char *key, const unsigned char *iv, int enc)
- {
- if (enc == -1)
- enc = ctx->encrypt;
- else
- {
- if (enc)
- enc = 1;
- ctx->encrypt = enc;
- }
- /* Whether it's nice or not, "Inits" can be used on "Final"'d contexts
- * so this context may already have an ENGINE! Try to avoid releasing
- * the previous handle, re-querying for an ENGINE, and having a
- * reinitialisation, when it may all be unecessary. */
- if (ctx->engine && ctx->cipher && (!cipher ||
- (cipher && (cipher->nid == ctx->cipher->nid))))
- goto skip_to_init;
- if (cipher)
- {
- /* Ensure a context left lying around from last time is cleared
- * (the previous check attempted to avoid this if the same
- * ENGINE and EVP_CIPHER could be used). */
- EVP_CIPHER_CTX_cleanup(ctx);
-
- /* Restore encrypt field: it is zeroed by cleanup */
- ctx->encrypt = enc;
- if(impl)
- {
- if (!ENGINE_init(impl))
- {
- EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
- return 0;
- }
- }
- else
- /* Ask if an ENGINE is reserved for this job */
- impl = ENGINE_get_cipher_engine(cipher->nid);
- if(impl)
- {
- /* There's an ENGINE for this job ... (apparently) */
- const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
- if(!c)
- {
- /* One positive side-effect of US's export
- * control history, is that we should at least
- * be able to avoid using US mispellings of
- * "initialisation"? */
- EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
- return 0;
- }
- /* We'll use the ENGINE's private cipher definition */
- cipher = c;
- /* Store the ENGINE functional reference so we know
- * 'cipher' came from an ENGINE and we need to release
- * it when done. */
- ctx->engine = impl;
- }
- else
- ctx->engine = NULL;
-
- ctx->cipher=cipher;
- ctx->cipher_data=OPENSSL_malloc(ctx->cipher->ctx_size);
- ctx->key_len = cipher->key_len;
- ctx->flags = 0;
- if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT)
- {
- if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL))
- {
- EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
- return 0;
- }
- }
- }
- else if(!ctx->cipher)
- {
- EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
- return 0;
- }
-skip_to_init:
- /* we assume block size is a power of 2 in *cryptUpdate */
- assert(ctx->cipher->block_size == 1
- || ctx->cipher->block_size == 8
- || ctx->cipher->block_size == 16);
-
- if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
- switch(EVP_CIPHER_CTX_mode(ctx)) {
-
- case EVP_CIPH_STREAM_CIPHER:
- case EVP_CIPH_ECB_MODE:
- break;
-
- case EVP_CIPH_CFB_MODE:
- case EVP_CIPH_OFB_MODE:
-
- ctx->num = 0;
-
- case EVP_CIPH_CBC_MODE:
-
- if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
- memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
- break;
-
- default:
- return 0;
- break;
- }
- }
-
- if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
- if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
- }
- ctx->buf_len=0;
- ctx->final_used=0;
- ctx->block_mask=ctx->cipher->block_size-1;
- return 1;
- }
-