From 951dfbb13a79bff82cef8096d2c93bc2d65a7525 Mon Sep 17 00:00:00 2001 From: "Mark J. Cox" Date: Thu, 28 Sep 2006 11:29:03 +0000 Subject: [PATCH] Introduce limits to prevent malicious keys being able to cause a denial of service. (CVE-2006-2940) [Steve Henson, Bodo Moeller] Fix ASN.1 parsing of certain invalid structures that can result in a denial of service. (CVE-2006-2937) [Steve Henson] Fix buffer overflow in SSL_get_shared_ciphers() function. (CVE-2006-3738) [Tavis Ormandy and Will Drewry, Google Security Team] Fix SSL client code which could crash if connecting to a malicious SSLv2 server. (CVE-2006-4343) [Tavis Ormandy and Will Drewry, Google Security Team] --- CHANGES | 14 +++++++++++++ NEWS | 6 ++++++ crypto/asn1/tasn_dec.c | 1 + crypto/dh/dh.h | 5 +++++ crypto/dh/dh_err.c | 1 + crypto/dh/dh_key.c | 6 ++++++ crypto/dsa/dsa.h | 6 ++++++ crypto/dsa/dsa_err.c | 2 ++ crypto/dsa/dsa_ossl.c | 12 +++++++++++ crypto/ec/ec.h | 7 +++++++ crypto/ec/ec_asn1.c | 46 ++++++++++++++++++++++++++++++++++++++++++ crypto/ec/ec_err.c | 3 +++ crypto/rsa/rsa.h | 12 +++++++++++ crypto/rsa/rsa_eay.c | 44 ++++++++++++++++++++++++++++++++++++++++ crypto/rsa/rsa_err.c | 1 + ssl/s2_clnt.c | 3 ++- ssl/s3_srvr.c | 2 +- ssl/ssl_lib.c | 2 +- 18 files changed, 170 insertions(+), 3 deletions(-) diff --git a/CHANGES b/CHANGES index 01642e13e0..4e2740be5e 100644 --- a/CHANGES +++ b/CHANGES @@ -4,6 +4,20 @@ Changes between 0.9.8c and 0.9.8d [xx XXX xxxx] + *) Introduce limits to prevent malicious keys being able to + cause a denial of service. (CVE-2006-2940) + [Steve Henson, Bodo Moeller] + + *) Fix ASN.1 parsing of certain invalid structures that can result + in a denial of service. (CVE-2006-2937) [Steve Henson] + + *) Fix buffer overflow in SSL_get_shared_ciphers() function. + (CVE-2006-3738) [Tavis Ormandy and Will Drewry, Google Security Team] + + *) Fix SSL client code which could crash if connecting to a + malicious SSLv2 server. (CVE-2006-4343) + [Tavis Ormandy and Will Drewry, Google Security Team] + *) Since 0.9.8b, ciphersuite strings naming explicit ciphersuites match only those. Before that, "AES256-SHA" would be interpreted as a pattern and match "AES128-SHA" too (since AES128-SHA got diff --git a/NEWS b/NEWS index 6bda70f39b..ad8033a81b 100644 --- a/NEWS +++ b/NEWS @@ -5,6 +5,12 @@ This file gives a brief overview of the major changes between each OpenSSL release. For more details please read the CHANGES file. + Major changes between OpenSSL 0.9.7c and OpenSSL 0.9.8d: + + o Introduce limits to prevent malicious key DoS (CVE-2006-2940) + o Fix security issues (CVE-2006-2937, CVE-2006-3737, CVE-2006-4343) + o Changes to ciphersuite selection algorithm + Major changes between OpenSSL 0.9.8b and OpenSSL 0.9.8c: o Fix Daniel Bleichenbacher forged signature attack, CVE-2006-4339 diff --git a/crypto/asn1/tasn_dec.c b/crypto/asn1/tasn_dec.c index 0294d8e766..ff2f77b9d8 100644 --- a/crypto/asn1/tasn_dec.c +++ b/crypto/asn1/tasn_dec.c @@ -832,6 +832,7 @@ static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, } else if (ret == -1) return -1; + ret = 0; /* SEQUENCE, SET and "OTHER" are left in encoded form */ if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) diff --git a/crypto/dh/dh.h b/crypto/dh/dh.h index 4d0c565316..ccdf35ae1c 100644 --- a/crypto/dh/dh.h +++ b/crypto/dh/dh.h @@ -73,6 +73,10 @@ #include #endif +#ifndef OPENSSL_DH_MAX_MODULUS_BITS +# define OPENSSL_DH_MAX_MODULUS_BITS 10000 +#endif + #define DH_FLAG_CACHE_MONT_P 0x01 #define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH * implementation now uses constant time @@ -221,6 +225,7 @@ void ERR_load_DH_strings(void); /* Reason codes. */ #define DH_R_BAD_GENERATOR 101 #define DH_R_INVALID_PUBKEY 102 +#define DH_R_MODULUS_TOO_LARGE 103 #define DH_R_NO_PRIVATE_VALUE 100 #ifdef __cplusplus diff --git a/crypto/dh/dh_err.c b/crypto/dh/dh_err.c index b14a94f36a..783bb4754c 100644 --- a/crypto/dh/dh_err.c +++ b/crypto/dh/dh_err.c @@ -84,6 +84,7 @@ static ERR_STRING_DATA DH_str_reasons[]= { {ERR_REASON(DH_R_BAD_GENERATOR) ,"bad generator"}, {ERR_REASON(DH_R_INVALID_PUBKEY) ,"invalid public key"}, +{ERR_REASON(DH_R_MODULUS_TOO_LARGE) ,"modulus too large"}, {ERR_REASON(DH_R_NO_PRIVATE_VALUE) ,"no private value"}, {0,NULL} }; diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c index 79984e13bc..cb5abdcf47 100644 --- a/crypto/dh/dh_key.c +++ b/crypto/dh/dh_key.c @@ -179,6 +179,12 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) int ret= -1; int check_result; + if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) + { + DHerr(DH_F_COMPUTE_KEY,DH_R_MODULUS_TOO_LARGE); + goto err; + } + ctx = BN_CTX_new(); if (ctx == NULL) goto err; BN_CTX_start(ctx); diff --git a/crypto/dsa/dsa.h b/crypto/dsa/dsa.h index b12db98b13..3a8fe5b56b 100644 --- a/crypto/dsa/dsa.h +++ b/crypto/dsa/dsa.h @@ -84,6 +84,10 @@ #endif #endif +#ifndef OPENSSL_DSA_MAX_MODULUS_BITS +# define OPENSSL_DSA_MAX_MODULUS_BITS 10000 +#endif + #define DSA_FLAG_CACHE_MONT_P 0x01 #define DSA_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DSA * implementation now uses constant time @@ -270,8 +274,10 @@ void ERR_load_DSA_strings(void); #define DSA_F_SIG_CB 114 /* Reason codes. */ +#define DSA_R_BAD_Q_VALUE 102 #define DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE 100 #define DSA_R_MISSING_PARAMETERS 101 +#define DSA_R_MODULUS_TOO_LARGE 103 #ifdef __cplusplus } diff --git a/crypto/dsa/dsa_err.c b/crypto/dsa/dsa_err.c index fd42053572..d7fac69154 100644 --- a/crypto/dsa/dsa_err.c +++ b/crypto/dsa/dsa_err.c @@ -89,8 +89,10 @@ static ERR_STRING_DATA DSA_str_functs[]= static ERR_STRING_DATA DSA_str_reasons[]= { +{ERR_REASON(DSA_R_BAD_Q_VALUE) ,"bad q value"}, {ERR_REASON(DSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE),"data too large for key size"}, {ERR_REASON(DSA_R_MISSING_PARAMETERS) ,"missing parameters"}, +{ERR_REASON(DSA_R_MODULUS_TOO_LARGE) ,"modulus too large"}, {0,NULL} }; diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c index 3fd8a35613..e6aad85825 100644 --- a/crypto/dsa/dsa_ossl.c +++ b/crypto/dsa/dsa_ossl.c @@ -304,6 +304,18 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig, return -1; } + if (BN_num_bits(dsa->q) != 160) + { + DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_BAD_Q_VALUE); + return -1; + } + + if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) + { + DSAerr(DSA_F_DSA_DO_VERIFY,DSA_R_MODULUS_TOO_LARGE); + return -1; + } + BN_init(&u1); BN_init(&u2); BN_init(&t1); diff --git a/crypto/ec/ec.h b/crypto/ec/ec.h index 919c736388..3c96fbd0d8 100644 --- a/crypto/ec/ec.h +++ b/crypto/ec/ec.h @@ -93,6 +93,10 @@ extern "C" { #endif +#ifndef OPENSSL_ECC_MAX_FIELD_BITS +# define OPENSSL_ECC_MAX_FIELD_BITS 661 +#endif + typedef enum { /* values as defined in X9.62 (ECDSA) and elsewhere */ POINT_CONVERSION_COMPRESSED = 2, @@ -482,6 +486,7 @@ void ERR_load_EC_strings(void); #define EC_R_D2I_ECPKPARAMETERS_FAILURE 117 #define EC_R_DISCRIMINANT_IS_ZERO 118 #define EC_R_EC_GROUP_NEW_BY_NAME_FAILURE 119 +#define EC_R_FIELD_TOO_LARGE 138 #define EC_R_GROUP2PKPARAMETERS_FAILURE 120 #define EC_R_I2D_ECPKPARAMETERS_FAILURE 121 #define EC_R_INCOMPATIBLE_OBJECTS 101 @@ -492,7 +497,9 @@ void ERR_load_EC_strings(void); #define EC_R_INVALID_FIELD 103 #define EC_R_INVALID_FORM 104 #define EC_R_INVALID_GROUP_ORDER 122 +#define EC_R_INVALID_PENTANOMIAL_BASIS 132 #define EC_R_INVALID_PRIVATE_KEY 123 +#define EC_R_INVALID_TRINOMIAL_BASIS 137 #define EC_R_MISSING_PARAMETERS 124 #define EC_R_MISSING_PRIVATE_KEY 125 #define EC_R_NOT_A_NIST_PRIME 135 diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c index dec913b8ad..66ef129293 100644 --- a/crypto/ec/ec_asn1.c +++ b/crypto/ec/ec_asn1.c @@ -741,6 +741,7 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) EC_GROUP *ret = NULL; BIGNUM *p = NULL, *a = NULL, *b = NULL; EC_POINT *point=NULL; + long field_bits; if (!params->fieldID || !params->fieldID->fieldType || !params->fieldID->p.ptr) @@ -779,6 +780,13 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) char_two = params->fieldID->p.char_two; + field_bits = char_two->m; + if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_FIELD_TOO_LARGE); + goto err; + } + if ((p = BN_new()) == NULL) { ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_MALLOC_FAILURE); @@ -799,6 +807,13 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) } tmp_long = ASN1_INTEGER_get(char_two->p.tpBasis); + + if (!(char_two->m > tmp_long && tmp_long > 0)) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_TRINOMIAL_BASIS); + goto err; + } + /* create the polynomial */ if (!BN_set_bit(p, (int)char_two->m)) goto err; @@ -817,6 +832,13 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR); goto err; } + + if (!(char_two->m > penta->k3 && penta->k3 > penta->k2 && penta->k2 > penta->k1 && penta->k1 > 0)) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_PENTANOMIAL_BASIS); + goto err; + } + /* create the polynomial */ if (!BN_set_bit(p, (int)char_two->m)) goto err; if (!BN_set_bit(p, (int)penta->k1)) goto err; @@ -853,6 +875,20 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_ASN1_LIB); goto err; } + + if (BN_is_negative(p) || BN_is_zero(p)) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_FIELD); + goto err; + } + + field_bits = BN_num_bits(p); + if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_FIELD_TOO_LARGE); + goto err; + } + /* create the EC_GROUP structure */ ret = EC_GROUP_new_curve_GFp(p, a, b, NULL); } @@ -910,6 +946,16 @@ static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params) ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_ASN1_LIB); goto err; } + if (BN_is_negative(a) || BN_is_zero(a)) + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_GROUP_ORDER); + goto err; + } + if (BN_num_bits(a) > (int)field_bits + 1) /* Hasse bound */ + { + ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_GROUP_ORDER); + goto err; + } /* extract the cofactor (optional) */ if (params->cofactor == NULL) diff --git a/crypto/ec/ec_err.c b/crypto/ec/ec_err.c index 38302b9b54..031c54d0b5 100644 --- a/crypto/ec/ec_err.c +++ b/crypto/ec/ec_err.c @@ -188,6 +188,7 @@ static ERR_STRING_DATA EC_str_reasons[]= {ERR_REASON(EC_R_D2I_ECPKPARAMETERS_FAILURE),"d2i ecpkparameters failure"}, {ERR_REASON(EC_R_DISCRIMINANT_IS_ZERO) ,"discriminant is zero"}, {ERR_REASON(EC_R_EC_GROUP_NEW_BY_NAME_FAILURE),"ec group new by name failure"}, +{ERR_REASON(EC_R_FIELD_TOO_LARGE) ,"field too large"}, {ERR_REASON(EC_R_GROUP2PKPARAMETERS_FAILURE),"group2pkparameters failure"}, {ERR_REASON(EC_R_I2D_ECPKPARAMETERS_FAILURE),"i2d ecpkparameters failure"}, {ERR_REASON(EC_R_INCOMPATIBLE_OBJECTS) ,"incompatible objects"}, @@ -198,7 +199,9 @@ static ERR_STRING_DATA EC_str_reasons[]= {ERR_REASON(EC_R_INVALID_FIELD) ,"invalid field"}, {ERR_REASON(EC_R_INVALID_FORM) ,"invalid form"}, {ERR_REASON(EC_R_INVALID_GROUP_ORDER) ,"invalid group order"}, +{ERR_REASON(EC_R_INVALID_PENTANOMIAL_BASIS),"invalid pentanomial basis"}, {ERR_REASON(EC_R_INVALID_PRIVATE_KEY) ,"invalid private key"}, +{ERR_REASON(EC_R_INVALID_TRINOMIAL_BASIS),"invalid trinomial basis"}, {ERR_REASON(EC_R_MISSING_PARAMETERS) ,"missing parameters"}, {ERR_REASON(EC_R_MISSING_PRIVATE_KEY) ,"missing private key"}, {ERR_REASON(EC_R_NOT_A_NIST_PRIME) ,"not a NIST prime"}, diff --git a/crypto/rsa/rsa.h b/crypto/rsa/rsa.h index d302254bb1..b19c556930 100644 --- a/crypto/rsa/rsa.h +++ b/crypto/rsa/rsa.h @@ -159,6 +159,17 @@ struct rsa_st BN_BLINDING *mt_blinding; }; +#ifndef OPENSSL_RSA_MAX_MODULUS_BITS +# define OPENSSL_RSA_MAX_MODULUS_BITS 16384 +#endif + +#ifndef OPENSSL_RSA_SMALL_MODULUS_BITS +# define OPENSSL_RSA_SMALL_MODULUS_BITS 3072 +#endif +#ifndef OPENSSL_RSA_MAX_PUBEXP_BITS +# define OPENSSL_RSA_MAX_PUBEXP_BITS 64 /* exponent limit enforced for "large" modulus only */ +#endif + #define RSA_3 0x3L #define RSA_F4 0x10001L @@ -407,6 +418,7 @@ void ERR_load_RSA_strings(void); #define RSA_R_IQMP_NOT_INVERSE_OF_Q 126 #define RSA_R_KEY_SIZE_TOO_SMALL 120 #define RSA_R_LAST_OCTET_INVALID 134 +#define RSA_R_MODULUS_TOO_LARGE 105 #define RSA_R_NO_PUBLIC_EXPONENT 140 #define RSA_R_NULL_BEFORE_BLOCK_MISSING 113 #define RSA_R_N_DOES_NOT_EQUAL_P_Q 127 diff --git a/crypto/rsa/rsa_eay.c b/crypto/rsa/rsa_eay.c index 69cabd2716..e7b7a9c4fc 100644 --- a/crypto/rsa/rsa_eay.c +++ b/crypto/rsa/rsa_eay.c @@ -168,6 +168,28 @@ static int RSA_eay_public_encrypt(int flen, const unsigned char *from, unsigned char *buf=NULL; BN_CTX *ctx=NULL; + if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE); + return -1; + } + + if (BN_ucmp(rsa->n, rsa->e) <= 0) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); + return -1; + } + + /* for large moduli, enforce exponent limit */ + if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) + { + if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); + return -1; + } + } + if ((ctx=BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); @@ -597,6 +619,28 @@ static int RSA_eay_public_decrypt(int flen, const unsigned char *from, unsigned char *buf=NULL; BN_CTX *ctx=NULL; + if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); + return -1; + } + + if (BN_ucmp(rsa->n, rsa->e) <= 0) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); + return -1; + } + + /* for large moduli, enforce exponent limit */ + if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) + { + if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) + { + RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); + return -1; + } + } + if((ctx = BN_CTX_new()) == NULL) goto err; BN_CTX_start(ctx); f = BN_CTX_get(ctx); diff --git a/crypto/rsa/rsa_err.c b/crypto/rsa/rsa_err.c index f82b2d6ad9..da7a4fb4c2 100644 --- a/crypto/rsa/rsa_err.c +++ b/crypto/rsa/rsa_err.c @@ -137,6 +137,7 @@ static ERR_STRING_DATA RSA_str_reasons[]= {ERR_REASON(RSA_R_IQMP_NOT_INVERSE_OF_Q) ,"iqmp not inverse of q"}, {ERR_REASON(RSA_R_KEY_SIZE_TOO_SMALL) ,"key size too small"}, {ERR_REASON(RSA_R_LAST_OCTET_INVALID) ,"last octet invalid"}, +{ERR_REASON(RSA_R_MODULUS_TOO_LARGE) ,"modulus too large"}, {ERR_REASON(RSA_R_NO_PUBLIC_EXPONENT) ,"no public exponent"}, {ERR_REASON(RSA_R_NULL_BEFORE_BLOCK_MISSING),"null before block missing"}, {ERR_REASON(RSA_R_N_DOES_NOT_EQUAL_P_Q) ,"n does not equal p q"}, diff --git a/ssl/s2_clnt.c b/ssl/s2_clnt.c index efb52485a7..ce60de630a 100644 --- a/ssl/s2_clnt.c +++ b/ssl/s2_clnt.c @@ -520,7 +520,8 @@ static int get_server_hello(SSL *s) CRYPTO_add(&s->session->peer->references, 1, CRYPTO_LOCK_X509); } - if (s->session->peer != s->session->sess_cert->peer_key->x509) + if (s->session->sess_cert == NULL + || s->session->peer != s->session->sess_cert->peer_key->x509) /* can't happen */ { ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR); diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c index a8c5df822c..098eea13ce 100644 --- a/ssl/s3_srvr.c +++ b/ssl/s3_srvr.c @@ -2003,7 +2003,7 @@ int ssl3_get_client_key_exchange(SSL *s) if (kssl_ctx->client_princ) { - int len = strlen(kssl_ctx->client_princ); + size_t len = strlen(kssl_ctx->client_princ); if ( len < SSL_MAX_KRB5_PRINCIPAL_LENGTH ) { s->session->krb5_client_princ_len = len; diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index 28c90fc68e..4971b34375 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -1219,7 +1219,7 @@ char *SSL_get_shared_ciphers(const SSL *s,char *buf,int len) c=sk_SSL_CIPHER_value(sk,i); for (cp=c->name; *cp; ) { - if (len-- == 0) + if (len-- <= 0) { *p='\0'; return(buf); -- 2.40.0