From 9a0953ed768571d2c6077b9698be718cc9a8a367 Mon Sep 17 00:00:00 2001 From: Pauli Date: Wed, 5 Jul 2017 14:40:39 +1000 Subject: [PATCH] Avoid buffer overruns in the req command line utility. Clean up some of the formatting "return x" instead of "return (x)" mostly. Reviewed-by: Rich Salz (Merged from https://github.com/openssl/openssl/pull/3848) --- apps/req.c | 86 +++++++++++++++++++++++++++++++++--------------------- 1 file changed, 53 insertions(+), 33 deletions(-) diff --git a/apps/req.c b/apps/req.c index 9b6c48d4c4..d72a172e8d 100644 --- a/apps/req.c +++ b/apps/req.c @@ -64,6 +64,8 @@ static int add_DN_object(X509_NAME *n, char *text, const char *def, static int genpkey_cb(EVP_PKEY_CTX *ctx); static int req_check_len(int len, int n_min, int n_max); static int check_end(const char *str, const char *end); +static int join(char buf[], size_t buf_size, const char *name, + const char *tail, const char *desc); static EVP_PKEY_CTX *set_keygen_ctx(const char *gstr, int *pkey_type, long *pkeylen, char **palgnam, ENGINE *keygen_engine); @@ -836,7 +838,7 @@ int req_main(int argc, char **argv) OPENSSL_free(passin); if (passout != nofree_passout) OPENSSL_free(passout); - return (ret); + return ret; } static int make_REQ(X509_REQ *req, EVP_PKEY *pkey, char *subj, int multirdn, @@ -896,7 +898,7 @@ static int make_REQ(X509_REQ *req, EVP_PKEY *pkey, char *subj, int multirdn, ret = 1; err: - return (ret); + return ret; } /* @@ -984,30 +986,30 @@ static int prompt_info(X509_REQ *req, /* If OBJ not recognised ignore it */ if ((nid = OBJ_txt2nid(type)) == NID_undef) goto start; - if (strlen(v->name) + sizeof("_default") > sizeof(buf)) { - BIO_printf(bio_err, "Name '%s' too long\n", v->name); + if (!join(buf, sizeof(buf), v->name, "_default", "Name")) return 0; - } - sprintf(buf, "%s_default", v->name); - if ((def = NCONF_get_string(req_conf, dn_sect, buf)) == NULL) { ERR_clear_error(); def = ""; } - sprintf(buf, "%s_value", v->name); + if (!join(buf, sizeof(buf), v->name, "_value", "Name")) + return 0; if ((value = NCONF_get_string(req_conf, dn_sect, buf)) == NULL) { ERR_clear_error(); value = NULL; } - sprintf(buf, "%s_min", v->name); + if (!join(buf, sizeof(buf), v->name, "_min", "Name")) + return 0; if (!NCONF_get_number(req_conf, dn_sect, buf, &n_min)) { ERR_clear_error(); n_min = -1; } - sprintf(buf, "%s_max", v->name); + + if (!join(buf, sizeof(buf), v->name, "_max", "Name")) + return 0; if (!NCONF_get_number(req_conf, dn_sect, buf, &n_max)) { ERR_clear_error(); n_max = -1; @@ -1044,32 +1046,31 @@ static int prompt_info(X509_REQ *req, if ((nid = OBJ_txt2nid(type)) == NID_undef) goto start2; - if (strlen(type) + sizeof("_default") > sizeof(buf)) { - BIO_printf(bio_err, "Name '%s' too long\n", v->name); + if (!join(buf, sizeof(buf), type, "_default", "Name")) return 0; - } - sprintf(buf, "%s_default", type); - if ((def = NCONF_get_string(req_conf, attr_sect, buf)) == NULL) { ERR_clear_error(); def = ""; } - sprintf(buf, "%s_value", type); + if (!join(buf, sizeof(buf), type, "_value", "Name")) + return 0; if ((value = NCONF_get_string(req_conf, attr_sect, buf)) == NULL) { ERR_clear_error(); value = NULL; } - sprintf(buf, "%s_min", type); + if (!join(buf, sizeof(buf), type,"_min", "Name")) + return 0; if (!NCONF_get_number(req_conf, attr_sect, buf, &n_min)) { ERR_clear_error(); n_min = -1; } - sprintf(buf, "%s_max", type); + if (!join(buf, sizeof(buf), type, "_max", "Name")) + return 0; if (!NCONF_get_number(req_conf, attr_sect, buf, &n_max)) { ERR_clear_error(); n_max = -1; @@ -1168,8 +1169,8 @@ static int add_DN_object(X509_NAME *n, char *text, const char *def, BIO_printf(bio_err, "%s [%s]:", text, def); (void)BIO_flush(bio_err); if (value != NULL) { - strcpy(buf, value); - strcat(buf, "\n"); + if (!join(buf, sizeof(buf), value, "\n", "DN value")) + return 0; BIO_printf(bio_err, "%s\n", value); } else { buf[0] = '\0'; @@ -1187,8 +1188,8 @@ static int add_DN_object(X509_NAME *n, char *text, const char *def, if (buf[0] == '\n') { if ((def == NULL) || (def[0] == '\0')) return 1; - strcpy(buf, def); - strcat(buf, "\n"); + if (!join(buf, sizeof(buf), def, "\n", "DN default")) + return 0; } else if ((buf[0] == '.') && (buf[1] == '\n')) { return 1; } @@ -1213,7 +1214,7 @@ static int add_DN_object(X509_NAME *n, char *text, const char *def, goto err; ret = 1; err: - return (ret); + return ret; } static int add_attribute_object(X509_REQ *req, char *text, const char *def, @@ -1228,8 +1229,8 @@ static int add_attribute_object(X509_REQ *req, char *text, const char *def, BIO_printf(bio_err, "%s [%s]:", text, def); (void)BIO_flush(bio_err); if (value != NULL) { - strcpy(buf, value); - strcat(buf, "\n"); + if (!join(buf, sizeof(buf), value, "\n", "Attribute value")) + return 0; BIO_printf(bio_err, "%s\n", value); } else { buf[0] = '\0'; @@ -1247,8 +1248,8 @@ static int add_attribute_object(X509_REQ *req, char *text, const char *def, if (buf[0] == '\n') { if ((def == NULL) || (def[0] == '\0')) return 1; - strcpy(buf, def); - strcat(buf, "\n"); + if (!join(buf, sizeof(buf), def, "\n", "Attribute default")) + return 0; } else if ((buf[0] == '.') && (buf[1] == '\n')) { return 1; } @@ -1275,9 +1276,9 @@ static int add_attribute_object(X509_REQ *req, char *text, const char *def, goto err; } - return (1); + return 1; err: - return (0); + return 0; } static int req_check_len(int len, int n_min, int n_max) @@ -1286,22 +1287,23 @@ static int req_check_len(int len, int n_min, int n_max) BIO_printf(bio_err, "string is too short, it needs to be at least %d bytes long\n", n_min); - return (0); + return 0; } if ((n_max >= 0) && (len > n_max)) { BIO_printf(bio_err, "string is too long, it needs to be no more than %d bytes long\n", n_max); - return (0); + return 0; } - return (1); + return 1; } /* Check if the end of a string matches 'end' */ static int check_end(const char *str, const char *end) { - int elen, slen; + size_t elen, slen; const char *tmp; + elen = strlen(end); slen = strlen(str); if (elen > slen) @@ -1310,6 +1312,24 @@ static int check_end(const char *str, const char *end) return strcmp(tmp, end); } +/* + * Merge the two strings together into the result buffer checking for + * overflow and producing an error message is there is. + */ +static int join(char buf[], size_t buf_size, const char *name, + const char *tail, const char *desc) +{ + const size_t name_len = strlen(name), tail_len = strlen(tail); + + if (name_len + tail_len + 1 > buf_size) { + BIO_printf(bio_err, "%s '%s' too long\n", desc, name); + return 0; + } + memcpy(buf, name, name_len); + memcpy(buf + name_len, tail, tail_len + 1); + return 1; +} + static EVP_PKEY_CTX *set_keygen_ctx(const char *gstr, int *pkey_type, long *pkeylen, char **palgnam, ENGINE *keygen_engine) -- 2.34.1