diff options
| -rw-r--r-- | CHANGES | 27 | ||||
| -rw-r--r-- | FAQ | 2 | ||||
| -rw-r--r-- | NEWS | 17 | ||||
| -rw-r--r-- | README | 4 | ||||
| -rw-r--r-- | crypto/opensslv.h | 6 | ||||
| -rw-r--r-- | crypto/rand/md_rand.c | 50 | ||||
| -rw-r--r-- | doc/crypto/rand.pod | 13 |
7 files changed, 84 insertions, 35 deletions
@@ -2,7 +2,32 @@ OpenSSL CHANGES _______________ - Changes between 0.9.6a and 0.9.6b [XX xxx XXXX] + Changes between 0.9.6a and 0.9.6b [9 Jul 2001] + + *) Change ssleay_rand_bytes (crypto/rand/md_rand.c) + to avoid a SSLeay/OpenSSL PRNG weakness pointed out by + Markku-Juhani O. Saarinen <markku-juhani.saarinen@nokia.com>: + PRNG state recovery was possible based on the output of + one PRNG request appropriately sized to gain knowledge on + 'md' followed by enough consecutive 1-byte PRNG requests + to traverse all of 'state'. + + 1. When updating 'md_local' (the current thread's copy of 'md') + during PRNG output generation, hash all of the previous + 'md_local' value, not just the half used for PRNG output. + + 2. Make the number of bytes from 'state' included into the hash + independent from the number of PRNG bytes requested. + + The first measure alone would be sufficient to avoid + Markku-Juhani's attack. (Actually it had never occurred + to me that the half of 'md_local' used for chaining was the + half from which PRNG output bytes were taken -- I had always + assumed that the secret half would be used.) The second + measure makes sure that additional data from 'state' is never + mixed into 'md_local' in small portions; this heuristically + further strengthens the PRNG. + [Bodo Moeller] *) Fix crypto/bn/asm/mips3.s. [Andy Polyakov] @@ -57,7 +57,7 @@ OpenSSL - Frequently Asked Questions * Which is the current version of OpenSSL? The current version is available from <URL: http://www.openssl.org>. -OpenSSL 0.9.6a was released on April 5th, 2001. +OpenSSL 0.9.6b was released on July 9th, 2001. In addition to the current stable release, you can also access daily snapshots of the OpenSSL development version at <URL: @@ -5,6 +5,23 @@ This file gives a brief overview of the major changes between each OpenSSL release. For more details please read the CHANGES file. + Changes between OpenSSL 0.9.6a and OpenSSL 0.9.6b: + + o Security fix: PRNG improvements. + o Security fix: RSA OAEP check. + o Security fix: Reinsert and fix countermeasure to Bleichbacher's + attack. + o MIPS bug fix in BIGNUM. + o Bug fix in "openssl enc". + o Bug fix in X.509 printing routine. + o Bug fix in DSA verification routine and DSA S/MIME verification. + o Bug fix to make PRNG thread-safe. + o Bug fix in RAND_file_name(). + o Bug fix in compatibility mode trust settings. + o Bug fix in blowfish EVP. + o Increase default size for BIO buffering filter. + o Compatibility fixes in some scripts. + Major changes between OpenSSL 0.9.6 and OpenSSL 0.9.6a: o Security fix: change behavior of OpenSSL to avoid using @@ -1,7 +1,7 @@ - OpenSSL 0.9.6b-dev [engine] XX xxx XXXX + OpenSSL 0.9.6b [engine] 9 Jul 2001 - Copyright (c) 1998-2000 The OpenSSL Project + Copyright (c) 1998-2001 The OpenSSL Project Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson All rights reserved. diff --git a/crypto/opensslv.h b/crypto/opensslv.h index da3d185341..4b25018e49 100644 --- a/crypto/opensslv.h +++ b/crypto/opensslv.h @@ -2,7 +2,7 @@ #define HEADER_OPENSSLV_H /* Numeric release version identifier: - * MMNNFFPPS: major minor fix patch status + * MNNFFPPS: major minor fix patch status * The status nibble has one of the values 0 for development, 1 to e for betas * 1 to 14, and f for release. The patch level is exactly that. * For example: @@ -25,8 +25,8 @@ * (Prior to 0.9.5a beta1, a different scheme was used: MMNNFFRBB for * major minor fix final patch/beta) */ -#define OPENSSL_VERSION_NUMBER 0x00906020L -#define OPENSSL_VERSION_TEXT "OpenSSL 0.9.6b-dev [engine] XX xxx XXXX" +#define OPENSSL_VERSION_NUMBER 0x0090602fL +#define OPENSSL_VERSION_TEXT "OpenSSL 0.9.6b [engine] 9 Jul 2001" #define OPENSSL_VERSION_PTEXT " part of " OPENSSL_VERSION_TEXT diff --git a/crypto/rand/md_rand.c b/crypto/rand/md_rand.c index 534899bbce..04b9d695b0 100644 --- a/crypto/rand/md_rand.c +++ b/crypto/rand/md_rand.c @@ -313,6 +313,7 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) { static volatile int stirred_pool = 0; int i,j,k,st_num,st_idx; + int num_ceil; int ok; long md_c[2]; unsigned char local_md[MD_DIGEST_LENGTH]; @@ -333,19 +334,24 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) } #endif + if (num <= 0) + return 1; + + /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ + num_ceil = (1 + (num-1)/(MD_DIGEST_LENGTH/2)) * (MD_DIGEST_LENGTH/2); + /* * (Based on the rand(3) manpage:) * * For each group of 10 bytes (or less), we do the following: * - * Input into the hash function the top 10 bytes from the - * local 'md' (which is initialized from the global 'md' - * before any bytes are generated), the bytes that are - * to be overwritten by the random bytes, and bytes from the - * 'state' (incrementing looping index). From this digest output - * (which is kept in 'md'), the top (up to) 10 bytes are - * returned to the caller and the bottom (up to) 10 bytes are xored - * into the 'state'. + * Input into the hash function the local 'md' (which is initialized from + * the global 'md' before any bytes are generated), the bytes that are to + * be overwritten by the random bytes, and bytes from the 'state' + * (incrementing looping index). From this digest output (which is kept + * in 'md'), the top (up to) 10 bytes are returned to the caller and the + * bottom 10 bytes are xored into the 'state'. + * * Finally, after we have finished 'num' random bytes for the * caller, 'count' (which is incremented) and the local and global 'md' * are fed into the hash function and the results are kept in the @@ -389,11 +395,11 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) if (do_stir_pool) { - /* Our output function chains only half of 'md', so we better - * make sure that the required entropy gets 'evenly distributed' - * through 'state', our randomness pool. The input function - * (ssleay_rand_add) chains all of 'md', which makes it more - * suitable for this purpose. + /* In the output function only half of 'md' remains secret, + * so we better make sure that the required entropy gets + * 'evenly distributed' through 'state', our randomness pool. + * The input function (ssleay_rand_add) chains all of 'md', + * which makes it more suitable for this purpose. */ int n = STATE_SIZE; /* so that the complete pool gets accessed */ @@ -418,11 +424,11 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) md_c[1] = md_count[1]; memcpy(local_md, md, sizeof md); - state_index+=num; + state_index+=num_ceil; if (state_index > state_num) state_index %= state_num; - /* state[st_idx], ..., state[(st_idx + num - 1) % st_num] + /* state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] * are now ours (but other threads may use them too) */ md_count[0] += 1; @@ -434,6 +440,7 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) while (num > 0) { + /* num_ceil -= MD_DIGEST_LENGTH/2 */ j=(num >= MD_DIGEST_LENGTH/2)?MD_DIGEST_LENGTH/2:num; num-=j; MD_Init(&m); @@ -444,27 +451,28 @@ static int ssleay_rand_bytes(unsigned char *buf, int num) curr_pid = 0; } #endif - MD_Update(&m,&(local_md[MD_DIGEST_LENGTH/2]),MD_DIGEST_LENGTH/2); + MD_Update(&m,local_md,MD_DIGEST_LENGTH); MD_Update(&m,(unsigned char *)&(md_c[0]),sizeof(md_c)); #ifndef PURIFY MD_Update(&m,buf,j); /* purify complains */ #endif - k=(st_idx+j)-st_num; + k=(st_idx+MD_DIGEST_LENGTH/2)-st_num; if (k > 0) { - MD_Update(&m,&(state[st_idx]),j-k); + MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2-k); MD_Update(&m,&(state[0]),k); } else - MD_Update(&m,&(state[st_idx]),j); + MD_Update(&m,&(state[st_idx]),MD_DIGEST_LENGTH/2); MD_Final(local_md,&m); - for (i=0; i<j; i++) + for (i=0; i<MD_DIGEST_LENGTH/2; i++) { state[st_idx++]^=local_md[i]; /* may compete with other threads */ - *(buf++)=local_md[i+MD_DIGEST_LENGTH/2]; if (st_idx >= st_num) st_idx=0; + if (i < j) + *(buf++)=local_md[i+MD_DIGEST_LENGTH/2]; } } diff --git a/doc/crypto/rand.pod b/doc/crypto/rand.pod index 9545f0e109..96901f109e 100644 --- a/doc/crypto/rand.pod +++ b/doc/crypto/rand.pod @@ -127,13 +127,12 @@ function and xor). When bytes are extracted from the RNG, the following process is used. For each group of 10 bytes (or less), we do the following: -Input into the hash function the top 10 bytes from the local 'md' -(which is initialized from the global 'md' before any bytes are -generated), the bytes that are to be overwritten by the random bytes, -and bytes from the 'state' (incrementing looping index). From this -digest output (which is kept in 'md'), the top (up to) 10 bytes are -returned to the caller and the bottom (up to) 10 bytes are xored into -the 'state'. +Input into the hash function the local 'md' (which is initialized from +the global 'md' before any bytes are generated), the bytes that are to +be overwritten by the random bytes, and bytes from the 'state' +(incrementing looping index). From this digest output (which is kept +in 'md'), the top (up to) 10 bytes are returned to the caller and the +bottom 10 bytes are xored into the 'state'. Finally, after we have finished 'num' random bytes for the caller, 'count' (which is incremented) and the local and global 'md' are fed |