diff --git a/SoObjects/SOGo/GNUmakefile b/SoObjects/SOGo/GNUmakefile
index 158d40732..b965a681f 100644
--- a/SoObjects/SOGo/GNUmakefile
+++ b/SoObjects/SOGo/GNUmakefile
@@ -143,9 +143,13 @@ SOGo_RESOURCE_FILES = \
 	DAVReportMap.plist
 
 ifeq ($(saml2_config), yes)
-	SOGo_HEADER_FILES += SOGoSAML2Session.h
-	SOGo_OBJC_FILES += SOGoSAML2Session.m
+	SOGo_HEADER_FILES += SOGoSAML2Session.h SOGoSAML2Exceptions.h
+	SOGo_OBJC_FILES += SOGoSAML2Session.m SOGoSAML2Exceptions.m
 	SOGo_RESOURCE_FILES += SOGoSAML2Metadata.xml
+
+SOGoSAML2Exceptions.h SOGoSAML2Exceptions.m: gen-saml2-exceptions.py
+	$(ECHO_CREATING) ./gen-saml2-exceptions.py $(LASSO_CFLAGS) $(END_ECHO)
+
 endif
 
 ifeq ($(ldap_config),yes)
diff --git a/SoObjects/SOGo/gen-saml2-exceptions.py b/SoObjects/SOGo/gen-saml2-exceptions.py
new file mode 100755
index 000000000..3738f6750
--- /dev/null
+++ b/SoObjects/SOGo/gen-saml2-exceptions.py
@@ -0,0 +1,158 @@
+#!/usr/bin/python
+
+include_dirs = []
+
+output = "-"
+
+import os
+import sys
+
+m_template = """/* %(module)s.m (auto-generated) */
+
+#include <objc/objc.h>
+#include <stdint.h>
+
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+#import "%(module)s.h"
+
+%(exception_init)s
+
+static NSMutableDictionary *exceptionTable = nil;
+
+@implementation NSException (SOGoSAML2Extension)
+
+static void
+InitExceptionTable ()
+{
+  exceptionTable = [NSMutableDictionary new];
+  %(exception_table_init)s
+}
+
++ (void) raiseSAML2Exception: (lasso_error_t) lassoError
+{
+  NSString *exceptionName, *reason;
+
+  if (!exceptionTable)
+    InitExceptionTable ();
+
+  exceptionName = [exceptionTable objectForKey: [NSNumber numberWithInt: lassoError]];
+  if (!exceptionName)
+    exceptionName = NSGenericException;
+
+  reason = [NSString stringWithUTF8String: lasso_strerror (lassoError)];
+  if (!reason)
+    reason = @"unspecified";
+
+  [self raise: exceptionName format: @"%%@", reason];
+}
+
+@end
+"""
+
+h_template = """/* %(module)s.h (auto-generated) */
+
+#ifndef %(h_exclusion)s
+#define %(h_exclusion)s 1
+
+#include <lasso/errors.h>
+#import <Foundation/NSException.h>
+
+@class NSString;
+
+%(exception_decls)s
+
+@interface NSException (SOGoSAML2Extension)
+
++ (void) raiseSAML2Exception: (lasso_error_t) lassoError;
+
+@end
+
+#endif /* %(h_exclusion)s */
+"""
+
+def ParseErrorsHLine(line):
+    result = None
+    if line.startswith("#define LASSO_"):
+        next_space = line.find(" ", 19)
+        result = line[8:next_space]
+
+    return result
+
+def ParseIncludeDirs(args):
+    dirs = ["/usr/include", "/usr/local/include"]
+    ignore = True
+    for arg in args:
+        if ignore:
+            if arg == "-I":
+                ignore = False
+            elif arg.startswith("-I"):
+                dirs.append(arg[2:])
+        else:
+            dirs.append(arg)
+            ignore = True
+
+    return dirs
+
+def FindHFile(args, filename):
+    found = None
+
+    include_dirs = ParseIncludeDirs(args)
+    for dirname in include_dirs:
+        full_filename = "%s/%s" % (dirname, filename)
+        if os.path.exists(full_filename):
+            found = full_filename
+
+    if found is None:
+        raise Exception, "'%s' not found in include dirs" % filename
+
+    return found
+
+def ErrorCodeToName(name):
+    parts = name.split("_")
+    cap_parts = [part.capitalize() for part in parts]
+
+    return "".join(cap_parts)
+
+if __name__ == "__main__":
+    errors_filename = FindHFile(sys.argv, os.path.join("lasso", "errors.h"))
+
+    inf = open(errors_filename)
+    error_codes = {}
+    line = inf.readline()
+    while line != "":
+        error_code = ParseErrorsHLine(line)
+        if error_code:
+            error_codes[error_code] = ErrorCodeToName(error_code)
+        line = inf.readline()
+    inf.close()
+
+    exception_decls = []
+    exception_init = []
+    exception_table_init = []
+
+    exc_table_format \
+        = ("  [exceptionTable setObject: %s\n"
+           "                     forKey: [NSNumber numberWithInt: %s]];")
+    for error_code in error_codes:
+        name = error_codes[error_code];
+        exception_init.append("NSString * const %s = @\"%s\";" % (name, name))
+        exception_decls.append("extern NSString * const %s;" % name)
+        exception_table_init.append(exc_table_format % (name, error_code))
+
+    module = "SOGoSAML2Exceptions"
+    outvars = {"module": module,
+               "h_exclusion": "%s_H" % module.upper(),
+               "exception_decls": "\n".join(exception_decls),
+               "exception_init": "\n".join(exception_init),
+               "exception_table_init": "\n".join(exception_table_init)}
+
+    outf = open("%s.m" % module, "w+")
+    outf.write(m_template % outvars)
+    outf.close()
+
+    outf = open("%s.h" % module, "w+")
+    outf.write(h_template % outvars)
+    outf.close()