If a proposal string cannot be matched to a token using strcmp (e.g. if
you want to register a whole class of algorithms containing their ID,
like my_alg_2342), you can use the provided function to register a
parser that transforms the given string into a proposal token.
Signed-off-by: Thomas Egerer <[email protected]>
---
Hello strongswan-developers,
I was wondering if I could get this patch upstream. It is particularly
helpful to deal with private proposal strings. They are comprised of a
prefix followed by their private ID. Since none of the given mechanisms
(static keywords, nor keyword registration) allows my to parse a whole
class of algorithm names like described, I would rather use a user
provided parser. What do you think? Any suggestions on how to get this
upstream are appreciated.
Cheers,
Thomas
.../crypto/proposal/proposal_keywords.c | 47 +++++++++++++++++++++-
.../crypto/proposal/proposal_keywords.h | 11 +++++
2 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/src/libstrongswan/crypto/proposal/proposal_keywords.c b/src/libstrongswan/crypto/proposal/proposal_keywords.c
index 4db504e..14d4c4f 100644
--- a/src/libstrongswan/crypto/proposal/proposal_keywords.c
+++ b/src/libstrongswan/crypto/proposal/proposal_keywords.c
@@ -56,6 +56,11 @@ struct private_proposal_keywords_t {
linked_list_t * tokens;
/**
+ * registered algname parsers, as algname_parser_t
+ */
+ linked_list_t *parsers;
+
+ /**
* rwlock to lock access to modules
*/
rwlock_t *lock;
@@ -85,11 +90,40 @@ static const proposal_token_t* find_token(private_proposal_keywords_t *this,
return found;
}
+/**
+ * Parse the given algorithm into a token with user defined parser functions.
+ */
+static const proposal_token_t* parse_token(private_proposal_keywords_t *this,
+ const char *str)
+{
+ algname_parser_t parser;
+ enumerator_t *enumerator;
+ proposal_token_t *found = NULL;
+
+ this->lock->read_lock(this->lock);
+ enumerator = this->parsers->create_enumerator(this->parsers);
+ while (enumerator->enumerate(enumerator, &parser))
+ {
+ found = parser(str);
+ if (found)
+ {
+ break;
+ }
+ }
+ enumerator->destroy(enumerator);
+ this->lock->unlock(this->lock);
+ return found;
+}
+
METHOD(proposal_keywords_t, get_token, const proposal_token_t*,
private_proposal_keywords_t *this, const char *str)
{
const proposal_token_t *token = proposal_get_token_static(str, strlen(str));
- return token ?: find_token(this, str);
+ if (!token)
+ {
+ token = find_token(this, str);
+ }
+ return token ?: parse_token(this, str);
}
METHOD(proposal_keywords_t, register_token, void,
@@ -110,6 +144,14 @@ METHOD(proposal_keywords_t, register_token, void,
this->lock->unlock(this->lock);
}
+METHOD(proposal_keywords_t, register_algname_parser, void,
+ private_proposal_keywords_t *this, algname_parser_t parser)
+{
+ this->lock->write_lock(this->lock);
+ this->tokens->insert_first(this->parsers, parser);
+ this->lock->unlock(this->lock);
+}
+
METHOD(proposal_keywords_t, destroy, void,
private_proposal_keywords_t *this)
{
@@ -121,6 +163,7 @@ METHOD(proposal_keywords_t, destroy, void,
free(token);
}
this->tokens->destroy(this->tokens);
+ this->parsers->destroy(this->parsers);
this->lock->destroy(this->lock);
free(this);
}
@@ -136,9 +179,11 @@ proposal_keywords_t *proposal_keywords_create()
.public = {
.get_token = _get_token,
.register_token = _register_token,
+ .register_algname_parser = _register_algname_parser,
.destroy = _destroy,
},
.tokens = linked_list_create(),
+ .parsers = linked_list_create(),
.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
);
diff --git a/src/libstrongswan/crypto/proposal/proposal_keywords.h b/src/libstrongswan/crypto/proposal/proposal_keywords.h
index d6107ab..278a0bf 100644
--- a/src/libstrongswan/crypto/proposal/proposal_keywords.h
+++ b/src/libstrongswan/crypto/proposal/proposal_keywords.h
@@ -46,6 +46,8 @@
typedef struct proposal_token_t proposal_token_t;
typedef struct proposal_keywords_t proposal_keywords_t;
+typedef proposal_token_t*(*algname_parser_t)(const char *algname);
+
#include <library.h>
#include <crypto/transform.h>
@@ -102,6 +104,15 @@ struct proposal_keywords_t {
u_int16_t keysize);
/**
+ * Register an algorithm name parser. It is meant to parse an
+ * algorithm name into a proposal token in a generic, user defined way.
+ *
+ * @param parser a pointer to the parser function
+ */
+ void (*register_algname_parser)(proposal_keywords_t *this,
+ algname_parser_t parser);
+
+ /**
* Destroy a proposal_keywords_t instance.
*/
void (*destroy)(proposal_keywords_t *this);
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