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-rw-r--r--crypto/evp/evp_enc.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/crypto/evp/evp_enc.c b/crypto/evp/evp_enc.c
index b9b6490fe069..0843caf4f0a4 100644
--- a/crypto/evp/evp_enc.c
+++ b/crypto/evp/evp_enc.c
@@ -8,6 +8,7 @@
*/
#include <stdio.h>
+#include <limits.h>
#include <assert.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
@@ -355,6 +356,19 @@ static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
return 1;
} else {
j = bl - i;
+
+ /*
+ * Once we've processed the first j bytes from in, the amount of
+ * data left that is a multiple of the block length is:
+ * (inl - j) & ~(bl - 1)
+ * We must ensure that this amount of data, plus the one block that
+ * we process from ctx->buf does not exceed INT_MAX
+ */
+ if (((inl - j) & ~(bl - 1)) > INT_MAX - bl) {
+ EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE,
+ EVP_R_OUTPUT_WOULD_OVERFLOW);
+ return 0;
+ }
memcpy(&(ctx->buf[i]), in, j);
inl -= j;
in += j;
@@ -502,6 +516,19 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
return 0;
}
+ /*
+ * final_used is only ever set if buf_len is 0. Therefore the maximum
+ * length output we will ever see from evp_EncryptDecryptUpdate is
+ * the maximum multiple of the block length that is <= inl, or just:
+ * inl & ~(b - 1)
+ * Since final_used has been set then the final output length is:
+ * (inl & ~(b - 1)) + b
+ * This must never exceed INT_MAX
+ */
+ if ((inl & ~(b - 1)) > INT_MAX - b) {
+ EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_OUTPUT_WOULD_OVERFLOW);
+ return 0;
+ }
memcpy(out, ctx->final, b);
out += b;
fix_len = 1;