diff --git a/CHANGES b/CHANGES index 90fd18b0e1..2d5f6b8622 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,10 @@ Changes between 0.9.6a and 0.9.6b [XX xxx XXXX] + *) Verify that incoming data obeys the block size in + ssl3_enc (ssl/s3_enc.c) and tls1_enc (ssl/t1_enc.c). + [Bodo Moeller] + *) Fix OAEP check. [Ulf Möller, Bodo Möller] diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c index 455a6f3d06..8709da9175 100644 --- a/ssl/s3_enc.c +++ b/ssl/s3_enc.c @@ -366,7 +366,6 @@ int ssl3_enc(SSL *s, int send) /* COMPRESS */ - /* This should be using (bs-1) and bs instead of 7 and 8 */ if ((bs != 1) && send) { i=bs-((int)l%bs); @@ -376,12 +375,24 @@ int ssl3_enc(SSL *s, int send) rec->length+=i; rec->input[l-1]=(i-1); } - + + if (!send) + { + if (l == 0 || l%bs != 0) + { + SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); + ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPT_ERROR); + return(0); + } + } + EVP_Cipher(ds,rec->data,rec->input,l); if ((bs != 1) && !send) { i=rec->data[l-1]+1; + /* SSL 3.0 bounds the number of padding bytes by the block size; + * padding bytes (except that last) are arbitrary */ if (i > bs) { SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c index 18e98602bc..a0758e9261 100644 --- a/ssl/t1_enc.c +++ b/ssl/t1_enc.c @@ -447,11 +447,21 @@ int tls1_enc(SSL *s, int send) rec->length+=i; } + if (!send) + { + if (l == 0 || l%bs != 0) + { + SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); + ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPT_ERROR); + return(0); + } + } + EVP_Cipher(ds,rec->data,rec->input,l); if ((bs != 1) && !send) { - ii=i=rec->data[l-1]; + ii=i=rec->data[l-1]; /* padding_length */ i++; if (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG) { @@ -462,6 +472,8 @@ int tls1_enc(SSL *s, int send) if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) i--; } + /* TLS 1.0 does not bound the number of padding bytes by the block size. + * All of them must have value 'padding_length'. */ if (i > (int)rec->length) { SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);