Prevent read_openpgp_stream from returning empty packets

[onak.git] / parsekey.c

diff --git a/parsekey.c b/parsekey.c
index aedbd14d8361a395b71d18abe7ee92eec4298c0d..b8bb5b0b44dbb64bf42b0952376c5f66c24bcff9 100644 (file)
--- a/parsekey.c
+++ b/parsekey.c
@@ -191,7 +191,7 @@ onak_status_t read_openpgp_stream(int (*getchar_func)(void *ctx, size_t count,
                                int maxnum)
 {
        unsigned char                    curchar = 0;
-       struct openpgp_packet_list      *curpacket = NULL;
+       struct openpgp_packet_list      *curpacket = NULL, **packetend = NULL;
        onak_status_t                    rc = ONAK_E_OK;
        int                              keys = 0;
        bool                             inpacket = false;
@@ -216,10 +216,12 @@ onak_status_t read_openpgp_stream(int (*getchar_func)(void *ctx, size_t count,
                        inpacket = true;
                        if (curpacket != NULL) {
                                curpacket->next = malloc(sizeof (*curpacket));
+                               packetend = &curpacket->next;
                                curpacket = curpacket->next;
                        } else {
                                *packets = curpacket =
                                        malloc(sizeof (*curpacket));
+                               packetend = packets;
                        }
                        memset(curpacket, 0, sizeof(*curpacket));
                        curpacket->packet =
@@ -245,7 +247,9 @@ onak_status_t read_openpgp_stream(int (*getchar_func)(void *ctx, size_t count,
                                        curpacket->packet->length += 192;
                                } else if (curpacket->packet->length > 223 &&
                                        curpacket->packet->length < 255) {
-                                       return ONAK_E_UNSUPPORTED_FEATURE;
+                                       free(curpacket->packet);
+                                       curpacket->packet = NULL;
+                                       rc = ONAK_E_UNSUPPORTED_FEATURE;
                                } else if (curpacket->packet->length == 255) {
                                        /*
                                         * 5 byte length; ie 255 followed by 3
@@ -292,8 +296,8 @@ onak_status_t read_openpgp_stream(int (*getchar_func)(void *ctx, size_t count,
                                        break;
                                case 3:
                                        rc = ONAK_E_UNSUPPORTED_FEATURE;
-                                       curpacket->packet->length = 0;
-                                       curpacket->packet->data = NULL;
+                                       free(curpacket->packet);
+                                       curpacket->packet = NULL;
                                        break;
                                }
                        }
@@ -320,6 +324,12 @@ onak_status_t read_openpgp_stream(int (*getchar_func)(void *ctx, size_t count,
                }
        }
 
+       /* Trim the last packet if it doesn't actually exist */
+       if (packetend != NULL && (*packetend)->packet == NULL) {
+               free(*packetend);
+               *packetend = NULL;
+       }
+
        return (rc);
 }