From da23637e8e04387689ef8747e8229a0c325a25fc Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Thu, 16 Apr 2015 00:00:40 +0100 Subject: [PATCH] Limit depth of nested sequences when generating ASN.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Reported by Hanno Böck PR#3800 Reviewed-by: Rich Salz (cherry picked from commit c4137b5e828d8fab0b244defb79257619dad8fc7) --- crypto/asn1/asn1_gen.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/crypto/asn1/asn1_gen.c b/crypto/asn1/asn1_gen.c index 33d3096c72..65749239b1 100644 --- a/crypto/asn1/asn1_gen.c +++ b/crypto/asn1/asn1_gen.c @@ -74,6 +74,8 @@ #define ASN1_GEN_STR(str,val) {str, sizeof(str) - 1, val} #define ASN1_FLAG_EXP_MAX 20 +/* Maximum number of nested sequences */ +#define ASN1_GEN_SEQ_MAX_DEPTH 50 /* Input formats */ @@ -110,13 +112,16 @@ typedef struct { int exp_count; } tag_exp_arg; +static ASN1_TYPE *generate_v3(char *str, X509V3_CTX *cnf, int depth, + int *perr); static int bitstr_cb(const char *elem, int len, void *bitstr); static int asn1_cb(const char *elem, int len, void *bitstr); static int append_exp(tag_exp_arg *arg, int exp_tag, int exp_class, int exp_constructed, int exp_pad, int imp_ok); static int parse_tagging(const char *vstart, int vlen, int *ptag, int *pclass); -static ASN1_TYPE *asn1_multi(int utype, const char *section, X509V3_CTX *cnf); +static ASN1_TYPE *asn1_multi(int utype, const char *section, X509V3_CTX *cnf, + int depth, int *perr); static ASN1_TYPE *asn1_str2type(const char *str, int format, int utype); static int asn1_str2tag(const char *tagstr, int len); @@ -132,6 +137,16 @@ ASN1_TYPE *ASN1_generate_nconf(char *str, CONF *nconf) } ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf) +{ + int err = 0; + ASN1_TYPE *ret = generate_v3(str, cnf, 0, &err); + if (err) + ASN1err(ASN1_F_ASN1_GENERATE_V3, err); + return ret; +} + +static ASN1_TYPE *generate_v3(char *str, X509V3_CTX *cnf, int depth, + int *perr) { ASN1_TYPE *ret; tag_exp_arg asn1_tags; @@ -160,11 +175,14 @@ ASN1_TYPE *ASN1_generate_v3(char *str, X509V3_CTX *cnf) if ((asn1_tags.utype == V_ASN1_SEQUENCE) || (asn1_tags.utype == V_ASN1_SET)) { if (!cnf) { - ASN1err(ASN1_F_ASN1_GENERATE_V3, - ASN1_R_SEQUENCE_OR_SET_NEEDS_CONFIG); + *perr = ASN1_R_SEQUENCE_OR_SET_NEEDS_CONFIG; + return NULL; + } + if (depth >= ASN1_GEN_SEQ_MAX_DEPTH) { + *perr = ASN1_R_ILLEGAL_NESTED_TAGGING; return NULL; } - ret = asn1_multi(asn1_tags.utype, asn1_tags.str, cnf); + ret = asn1_multi(asn1_tags.utype, asn1_tags.str, cnf, depth, perr); } else ret = asn1_str2type(asn1_tags.str, asn1_tags.format, asn1_tags.utype); @@ -355,7 +373,7 @@ static int asn1_cb(const char *elem, int len, void *bitstr) break; case ASN1_GEN_FLAG_FORMAT: - if(!vstart) { + if (!vstart) { ASN1err(ASN1_F_ASN1_CB, ASN1_R_UNKNOWN_FORMAT); return -1; } @@ -437,7 +455,8 @@ static int parse_tagging(const char *vstart, int vlen, int *ptag, int *pclass) /* Handle multiple types: SET and SEQUENCE */ -static ASN1_TYPE *asn1_multi(int utype, const char *section, X509V3_CTX *cnf) +static ASN1_TYPE *asn1_multi(int utype, const char *section, X509V3_CTX *cnf, + int depth, int *perr) { ASN1_TYPE *ret = NULL; STACK_OF(ASN1_TYPE) *sk = NULL; @@ -456,7 +475,8 @@ static ASN1_TYPE *asn1_multi(int utype, const char *section, X509V3_CTX *cnf) goto bad; for (i = 0; i < sk_CONF_VALUE_num(sect); i++) { ASN1_TYPE *typ = - ASN1_generate_v3(sk_CONF_VALUE_value(sect, i)->value, cnf); + generate_v3(sk_CONF_VALUE_value(sect, i)->value, cnf, + depth + 1, perr); if (!typ) goto bad; if (!sk_ASN1_TYPE_push(sk, typ)) -- 2.34.1