- {
- int i,n;
- unsigned int b;
- *outl=0;
-
- if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER)
- {
- i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
- if (i < 0)
- return 0;
- else
- *outl = i;
- return 1;
- }
-
- b=ctx->cipher->block_size;
- if (ctx->flags & EVP_CIPH_NO_PADDING)
- {
- if(ctx->buf_len)
- {
- EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
- return 0;
- }
- *outl = 0;
- return 1;
- }
- if (b > 1)
- {
- if (ctx->buf_len || !ctx->final_used)
- {
- EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
- return(0);
- }
- OPENSSL_assert(b <= sizeof ctx->final);
- n=ctx->final[b-1];
- if (n == 0 || n > (int)b)
- {
- EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_BAD_DECRYPT);
- return(0);
- }
- for (i=0; i<n; i++)
- {
- if (ctx->final[--b] != n)
- {
- EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_BAD_DECRYPT);
- return(0);
- }
- }
- n=ctx->cipher->block_size-n;
- for (i=0; i<n; i++)
- out[i]=ctx->final[i];
- *outl=n;
- }
- else
- *outl=0;
- return(1);
- }
-
-void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
- {
- if (ctx)
- {
- EVP_CIPHER_CTX_cleanup(ctx);
- OPENSSL_free(ctx);
- }
- }
-
-int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
- {
- if (c->cipher != NULL)
- {
- if(c->cipher->cleanup && !c->cipher->cleanup(c))
- return 0;
- /* Cleanse cipher context data */
- if (c->cipher_data)
- OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
- }
- if (c->cipher_data)
- OPENSSL_free(c->cipher_data);
-#ifndef OPENSSL_NO_ENGINE
- if (c->engine)
- /* The EVP_CIPHER we used belongs to an ENGINE, release the
- * functional reference we held for this reason. */
- ENGINE_finish(c->engine);
-#endif
- memset(c,0,sizeof(EVP_CIPHER_CTX));
- return 1;
- }
+{
+ int i, n;
+ unsigned int b;
+ *outl = 0;
+
+ if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
+ i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
+ if (i < 0)
+ return 0;
+ else
+ *outl = i;
+ return 1;
+ }
+
+ b = ctx->cipher->block_size;
+ if (ctx->flags & EVP_CIPH_NO_PADDING) {
+ if (ctx->buf_len) {
+ EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
+ EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
+ return 0;
+ }
+ *outl = 0;
+ return 1;
+ }
+ if (b > 1) {
+ if (ctx->buf_len || !ctx->final_used) {
+ EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
+ return (0);
+ }
+ OPENSSL_assert(b <= sizeof ctx->final);
+
+ /*
+ * The following assumes that the ciphertext has been authenticated.
+ * Otherwise it provides a padding oracle.
+ */
+ n = ctx->final[b - 1];
+ if (n == 0 || n > (int)b) {
+ EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
+ return (0);
+ }
+ for (i = 0; i < n; i++) {
+ if (ctx->final[--b] != n) {
+ EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
+ return (0);
+ }
+ }
+ n = ctx->cipher->block_size - n;
+ for (i = 0; i < n; i++)
+ out[i] = ctx->final[i];
+ *outl = n;
+ } else
+ *outl = 0;
+ return (1);
+}