diff options
author | Arne Schwabe <arne@rfc2549.org> | 2015-02-12 22:22:25 +0100 |
---|---|---|
committer | Arne Schwabe <arne@rfc2549.org> | 2015-02-12 22:22:25 +0100 |
commit | 9f0928c6593f937a17b7974b04051c57e3874b20 (patch) | |
tree | 1aaffa07a5c177fef2c1386f1850a688045bec2e /main/openssl/crypto/evp/evp_enc.c | |
parent | 68d26e1b1b5b411adce714c88532fc8889289f34 (diff) |
Update OpenSSL to AOSP -master
Diffstat (limited to 'main/openssl/crypto/evp/evp_enc.c')
-rw-r--r-- | main/openssl/crypto/evp/evp_enc.c | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/main/openssl/crypto/evp/evp_enc.c b/main/openssl/crypto/evp/evp_enc.c index 7b1842a5..2e863ac5 100644 --- a/main/openssl/crypto/evp/evp_enc.c +++ b/main/openssl/crypto/evp/evp_enc.c @@ -67,7 +67,6 @@ #ifdef OPENSSL_FIPS #include <openssl/fips.h> #endif -#include "constant_time_locl.h" #include "evp_locl.h" #ifdef OPENSSL_FIPS @@ -501,21 +500,21 @@ int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) { - unsigned int i, b; - unsigned char pad, padding_good; + int i,n; + unsigned int b; *outl=0; if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) { - int ret = M_do_cipher(ctx, out, NULL, 0); - if (ret < 0) + i = M_do_cipher(ctx, out, NULL, 0); + if (i < 0) return 0; else - *outl = ret; + *outl = i; return 1; } - b=(unsigned int)(ctx->cipher->block_size); + b=ctx->cipher->block_size; if (ctx->flags & EVP_CIPH_NO_PADDING) { if(ctx->buf_len) @@ -534,34 +533,33 @@ int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) return(0); } OPENSSL_assert(b <= sizeof ctx->final); - pad=ctx->final[b-1]; - - padding_good = (unsigned char)(~constant_time_is_zero_8(pad)); - padding_good &= constant_time_ge_8(b, pad); - - for (i = 1; i < b; ++i) - { - unsigned char is_pad_index = constant_time_lt_8(i, pad); - unsigned char pad_byte_good = constant_time_eq_8(ctx->final[b-i-1], pad); - padding_good &= constant_time_select_8(is_pad_index, pad_byte_good, 0xff); - } /* - * At least 1 byte is always padding, so we always write b - 1 - * bytes to avoid a timing leak. The caller is required to have |b| - * bytes space in |out| by the API contract. + * The following assumes that the ciphertext has been authenticated. + * Otherwise it provides a padding oracle. */ - for (i = 0; i < b - 1; ++i) - out[i] = ctx->final[i] & padding_good; - /* Safe cast: for a good padding, EVP_MAX_IV_LENGTH >= b >= pad */ - *outl = padding_good & ((unsigned char)(b - pad)); - return padding_good & 1; + 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; - } + *outl=0; + return(1); } void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx) |