MINOR: cfgcond: implements openssl_version_atleast and openssl_version_before

Implements a way of checking the running openssl version:

If the OpenSSL support was not compiled within HAProxy it will returns a
error, so it's recommanded to do a SSL feature check before:

	$ ./haproxy -cc 'feature(OPENSSL) && openssl_version_atleast(0.9.8zh) && openssl_version_before(3.0.0)'

This will allow to select the SSL reg-tests more carefully.

include/haproxy/cfgcond-t.h

@@ -50,6 +50,8 @@ enum cond_predicate {
 	CFG_PRED_STRNEQ,          // "strneq"
 	CFG_PRED_VERSION_ATLEAST, // "version_atleast"
 	CFG_PRED_VERSION_BEFORE,  // "version_before"
+	CFG_PRED_OSSL_VERSION_ATLEAST, // "openssl_version_atleast"
+	CFG_PRED_OSSL_VERSION_BEFORE,  // "openssl_version_before"
 };
 
 /* types for condition terms */

include/haproxy/tools.h

@@ -1093,4 +1093,8 @@ static inline void update_char_fingerprint(uint8_t *fp, char prev, char curr)
 	fp[32 * from + to]++;
 }
 
+
+/* compare the current OpenSSL version to a string */
+int openssl_compare_current_version(const char *version);
+
 #endif /* _HAPROXY_TOOLS_H */

src/cfgcond.c

@@ -18,12 +18,14 @@
 
 /* supported condition predicates */
 const struct cond_pred_kw cond_predicates[] = {
-	{ "defined",          CFG_PRED_DEFINED,         ARG1(1, STR)         },
-	{ "feature",          CFG_PRED_FEATURE,         ARG1(1, STR)         },
-	{ "streq",            CFG_PRED_STREQ,           ARG2(2, STR, STR)    },
-	{ "strneq",           CFG_PRED_STRNEQ,          ARG2(2, STR, STR)    },
-	{ "version_atleast",  CFG_PRED_VERSION_ATLEAST, ARG1(1, STR)         },
-	{ "version_before",   CFG_PRED_VERSION_BEFORE,  ARG1(1, STR)         },
+	{ "defined",                  CFG_PRED_DEFINED,              ARG1(1, STR)         },
+	{ "feature",                  CFG_PRED_FEATURE,              ARG1(1, STR)         },
+	{ "streq",                    CFG_PRED_STREQ,                ARG2(2, STR, STR)    },
+	{ "strneq",                   CFG_PRED_STRNEQ,               ARG2(2, STR, STR)    },
+	{ "version_atleast",          CFG_PRED_VERSION_ATLEAST,      ARG1(1, STR)         },
+	{ "version_before",           CFG_PRED_VERSION_BEFORE,       ARG1(1, STR)         },
+	{ "openssl_version_atleast",  CFG_PRED_OSSL_VERSION_ATLEAST, ARG1(1, STR)         },
+	{ "openssl_version_before",   CFG_PRED_OSSL_VERSION_BEFORE,  ARG1(1, STR)         },
 	{ NULL, CFG_PRED_NONE, 0 }
 };
 
@@ -230,6 +232,24 @@ int cfg_eval_cond_term(const struct cfg_cond_term *term, char **err)
 			ret = compare_current_version(term->args[0].data.str.area) > 0;
 			break;
 
+		case CFG_PRED_OSSL_VERSION_ATLEAST: { // checks if the current openssl version is at least this one
+			int opensslret = openssl_compare_current_version(term->args[0].data.str.area);
+
+			if (opensslret < -1) /* can't parse the string or no openssl available */
+				ret = -1;
+			else
+				ret = opensslret <= 0;
+			break;
+		}
+		case CFG_PRED_OSSL_VERSION_BEFORE: { // checks if the current openssl version is older than this one
+			int opensslret = openssl_compare_current_version(term->args[0].data.str.area);
+
+			if (opensslret < -1) /* can't parse the string or no openssl available */
+				ret = -1;
+			else
+				ret = opensslret > 0;
+			break;
+		}
 		default:
 			memprintf(err, "internal error: unhandled conditional expression predicate '%s'", term->pred->word);
 			break;

src/tools.c

@@ -62,6 +62,7 @@ extern void *__elf_aux_vector;
 #include <haproxy/resolvers.h>
 #include <haproxy/sock.h>
 #include <haproxy/ssl_sock.h>
+#include <haproxy/ssl_utils.h>
 #include <haproxy/stream_interface.h>
 #include <haproxy/task.h>
 #include <haproxy/tools.h>
@@ -5592,6 +5593,38 @@ int word_fingerprint_distance(const uint8_t *fp1, const uint8_t *fp2)
 	return dist;
 }
 
+/*
+ * This function compares the loaded openssl version with a string <version>
+ * This function use the same return code as compare_current_version:
+ *
+ *  -1 : the version in argument is older than the current openssl version
+ *   0 : the version in argument is the same as the current openssl version
+ *   1 : the version in argument is newer than the current openssl version
+ *
+ * Or some errors:
+ *  -2 : openssl is not available on this process
+ *  -3 : the version in argument is not parsable
+ */
+int openssl_compare_current_version(const char *version)
+{
+#ifdef USE_OPENSSL
+	int numversion;
+
+	numversion = openssl_version_parser(version);
+	if (numversion == 0)
+		return -3;
+
+	if (numversion < OPENSSL_VERSION_NUMBER)
+		return -1;
+	else if (numversion > OPENSSL_VERSION_NUMBER)
+		return 1;
+	else
+		return 0;
+#else
+	return -2;
+#endif
+}
+
 static int init_tools_per_thread()
 {
 	/* Let's make each thread start from a different position */