Route PMBToken calls through TRUST_TOKEN_METHOD.
Change-Id: I8b87484ea94cf1f931fa66216aab4654abe26bd3
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41068
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
diff --git a/crypto/trust_token/internal.h b/crypto/trust_token/internal.h
index 56c750a..f542c9a 100644
--- a/crypto/trust_token/internal.h
+++ b/crypto/trust_token/internal.h
@@ -72,72 +72,88 @@
DEFINE_STACK_OF(PMBTOKEN_PRETOKEN)
-// pmbtoken_generate_key generates a fresh keypair and writes their serialized
-// forms into |out_private| and |out_public|. It returns one on success and zero
-// on failure.
+// The following functions implement the corresponding |TRUST_TOKENS_METHOD|
+// functions for |TRUST_TOKENS_experiment_v0|'s PMBTokens construction.
int pmbtoken_generate_key(CBB *out_private, CBB *out_public);
-
-// pmbtoken_client_key_from_bytes decodes a client key from |in| and sets |key|
-// to the resulting key. It returns one on success and zero
-// on failure.
int pmbtoken_client_key_from_bytes(PMBTOKEN_CLIENT_KEY *key, const uint8_t *in,
size_t len);
-
-// pmbtoken_issuer_key_from_bytes decodes a issuer key from |in| and sets |key|
-// to the resulting key. It returns one on success and zero
-// on failure.
int pmbtoken_issuer_key_from_bytes(PMBTOKEN_ISSUER_KEY *key, const uint8_t *in,
size_t len);
-
-// pmbtoken_blind generates a new issuance request for |count| tokens. On
-// success, it returns a newly-allocated |STACK_OF(PMBTOKEN_PRETOKEN)| and
-// writes a request to the issuer to |cbb|. On failure, it returns NULL. The
-// |STACK_OF(PMBTOKEN_PRETOKEN)|s should be passed to |pmbtoken_unblind| when
-// the server responds.
-//
-// This function implements the AT.Usr0 operation.
-STACK_OF(PMBTOKEN_PRETOKEN) *pmbtoken_blind(CBB *cbb, size_t count);
-
-// pmbtoken_sign parses a request for |num_requested| tokens from |cbs| and
-// issues |num_to_issue| tokens with |key| and a private metadata value of
-// |private_metadata|. It then writes the response to |cbb|. It returns one on
-// success and zero on failure.
-//
-// This function implements the AT.Sig operation.
+STACK_OF(PMBTOKEN_PRETOKEN) * pmbtoken_blind(CBB *cbb, size_t count);
int pmbtoken_sign(const PMBTOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
size_t num_requested, size_t num_to_issue,
uint8_t private_metadata);
-
-// pmbtoken_unblind processes an issuance response for |count| tokens from |cbs|
-// and unblinds the signed tokens. |pretokens| are the pre-tokens returned from
-// the corresponding |pmbtoken_blind| call. On success, the function returns a
-// newly-allocated |STACK_OF(TRUST_TOKEN)| containing the resulting tokens. Each
-// token's serialization will have |key_id| prepended. Otherwise, it returns
-// NULL.
-//
-// This function implements the AT.Usr1 operation.
STACK_OF(TRUST_TOKEN) *
pmbtoken_unblind(const PMBTOKEN_CLIENT_KEY *key,
- const STACK_OF(PMBTOKEN_PRETOKEN) *pretokens, CBS *cbs,
+ const STACK_OF(PMBTOKEN_PRETOKEN) * pretokens, CBS *cbs,
size_t count, uint32_t key_id);
-
-// pmbtoken_read parses a PMBToken from |token| and verifies it using |key|. On
-// success, it returns one and stores the nonce and private metadata bit in
-// |out_nonce| and |*out_private_metadata|. Otherwise, it returns zero. Note
-// that, unlike the output of |pmbtoken_unblind|, |token| does not have a
-// four-byte key ID prepended.
int pmbtoken_read(const PMBTOKEN_ISSUER_KEY *key,
uint8_t out_nonce[PMBTOKEN_NONCE_SIZE],
uint8_t *out_private_metadata, const uint8_t *token,
size_t token_len);
-
// Trust Tokens internals.
struct trust_token_method_st {
- // TODO(davidben): Add functions here to swap out the PMBTokens mechanism.
- char empty;
+ // generate_key generates a fresh keypair and writes their serialized
+ // forms into |out_private| and |out_public|. It returns one on success and
+ // zero on failure.
+ int (*generate_key)(CBB *out_private, CBB *out_public);
+
+ // client_key_from_bytes decodes a client key from |in| and sets |key|
+ // to the resulting key. It returns one on success and zero
+ // on failure.
+ int (*client_key_from_bytes)(PMBTOKEN_CLIENT_KEY *key, const uint8_t *in,
+ size_t len);
+
+ // issuer_key_from_bytes decodes a issuer key from |in| and sets |key|
+ // to the resulting key. It returns one on success and zero
+ // on failure.
+ int (*issuer_key_from_bytes)(PMBTOKEN_ISSUER_KEY *key, const uint8_t *in,
+ size_t len);
+
+ // blind generates a new issuance request for |count| tokens. On
+ // success, it returns a newly-allocated |STACK_OF(PMBTOKEN_PRETOKEN)| and
+ // writes a request to the issuer to |cbb|. On failure, it returns NULL. The
+ // |STACK_OF(PMBTOKEN_PRETOKEN)|s should be passed to |pmbtoken_unblind| when
+ // the server responds.
+ //
+ // This function implements the AT.Usr0 operation.
+ STACK_OF(PMBTOKEN_PRETOKEN) *(*blind)(CBB *cbb, size_t count);
+
+ // sign parses a request for |num_requested| tokens from |cbs| and
+ // issues |num_to_issue| tokens with |key| and a private metadata value of
+ // |private_metadata|. It then writes the response to |cbb|. It returns one on
+ // success and zero on failure.
+ //
+ // This function implements the AT.Sig operation.
+ int (*sign)(const PMBTOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
+ size_t num_requested, size_t num_to_issue,
+ uint8_t private_metadata);
+
+ // unblind processes an issuance response for |count| tokens from |cbs|
+ // and unblinds the signed tokens. |pretokens| are the pre-tokens returned
+ // from the corresponding |blind| call. On success, the function returns a
+ // newly-allocated |STACK_OF(TRUST_TOKEN)| containing the resulting tokens.
+ // Each token's serialization will have |key_id| prepended. Otherwise, it
+ // returns NULL.
+ //
+ // This function implements the AT.Usr1 operation.
+ STACK_OF(TRUST_TOKEN) *
+ (*unblind)(const PMBTOKEN_CLIENT_KEY *key,
+ const STACK_OF(PMBTOKEN_PRETOKEN) * pretokens, CBS *cbs,
+ size_t count, uint32_t key_id);
+
+ // read parses a PMBToken from |token| and verifies it using |key|. On
+ // success, it returns one and stores the nonce and private metadata bit in
+ // |out_nonce| and |*out_private_metadata|. Otherwise, it returns zero. Note
+ // that, unlike the output of |unblind|, |token| does not have a
+ // four-byte key ID prepended.
+ int (*read)(const PMBTOKEN_ISSUER_KEY *key,
+ uint8_t out_nonce[PMBTOKEN_NONCE_SIZE],
+ uint8_t *out_private_metadata, const uint8_t *token,
+ size_t token_len);
};
// Structure representing a single Trust Token public key with the specified ID.
diff --git a/crypto/trust_token/trust_token.c b/crypto/trust_token/trust_token.c
index f34b41b..a18fb20 100644
--- a/crypto/trust_token/trust_token.c
+++ b/crypto/trust_token/trust_token.c
@@ -28,7 +28,15 @@
// construction.
const TRUST_TOKEN_METHOD *TRUST_TOKEN_experiment_v0(void) {
- static const TRUST_TOKEN_METHOD kMethod = {0};
+ static const TRUST_TOKEN_METHOD kMethod = {
+ pmbtoken_generate_key,
+ pmbtoken_client_key_from_bytes,
+ pmbtoken_issuer_key_from_bytes,
+ pmbtoken_blind,
+ pmbtoken_sign,
+ pmbtoken_unblind,
+ pmbtoken_read,
+ };
return &kMethod;
}
@@ -75,7 +83,7 @@
goto err;
}
- if (!pmbtoken_generate_key(&priv_cbb, &pub_cbb)) {
+ if (!method->generate_key(&priv_cbb, &pub_cbb)) {
goto err;
}
@@ -133,8 +141,8 @@
CBS_init(&cbs, key, key_len);
uint32_t key_id;
if (!CBS_get_u32(&cbs, &key_id) ||
- !pmbtoken_client_key_from_bytes(&key_s->key, CBS_data(&cbs),
- CBS_len(&cbs))) {
+ !ctx->method->client_key_from_bytes(&key_s->key, CBS_data(&cbs),
+ CBS_len(&cbs))) {
OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
return 0;
}
@@ -166,7 +174,7 @@
goto err;
}
- pretokens = pmbtoken_blind(&request, count);
+ pretokens = ctx->method->blind(&request, count);
if (pretokens == NULL) {
goto err;
}
@@ -223,7 +231,7 @@
}
STACK_OF(TRUST_TOKEN) *tokens =
- pmbtoken_unblind(&key->key, ctx->pretokens, &in, count, key_id);
+ ctx->method->unblind(&key->key, ctx->pretokens, &in, count, key_id);
if (tokens == NULL) {
return NULL;
}
@@ -348,8 +356,8 @@
CBS_init(&cbs, key, key_len);
uint32_t key_id;
if (!CBS_get_u32(&cbs, &key_id) ||
- !pmbtoken_issuer_key_from_bytes(&key_s->key, CBS_data(&cbs),
- CBS_len(&cbs))) {
+ !ctx->method->issuer_key_from_bytes(&key_s->key, CBS_data(&cbs),
+ CBS_len(&cbs))) {
OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
return 0;
}
@@ -430,8 +438,8 @@
goto err;
}
- if (!pmbtoken_sign(&key->key, &response, &in, num_requested, num_to_issue,
- private_metadata)) {
+ if (!ctx->method->sign(&key->key, &response, &in, num_requested, num_to_issue,
+ private_metadata)) {
goto err;
}
@@ -530,8 +538,8 @@
trust_token_issuer_get_key(ctx, public_metadata);
uint8_t nonce[PMBTOKEN_NONCE_SIZE];
if (key == NULL ||
- !pmbtoken_read(&key->key, nonce, &private_metadata, CBS_data(&token_cbs),
- CBS_len(&token_cbs))) {
+ !ctx->method->read(&key->key, nonce, &private_metadata,
+ CBS_data(&token_cbs), CBS_len(&token_cbs))) {
OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_INVALID_TOKEN);
return 0;
}
