rpki-client: emit object hash identifier in filemode

[Job Snijders]

Hi all,

Since certificate mallebility no longer is a problem in the RPKI
ecosystem ... the SHA256 digest of a RPKI signed object input file is a
very stable identifier to associate to the decoded (validated) output
from filemode!

Example:

    $ rpki-client -j -f rZWj66_V88W5B41mgMEm-TNr_EU.roa
    {
            "file": "rZWj66_V88W5B41mgMEm-TNr_EU.roa",
            "hash_id": "SYWMTnEkWN5L+qD/TgYvMakQ1rSktXsgJrR1dLu8GTA=",
            "type": "roa",
            "ski": 
"AD:95:A3:EB:AF:D5:F3:C5:B9:07:8D:66:80:C1:26:F9:33:6B:FC:45",
            "cert_serial": "03",
            "aki": 
"38:E1:4F:92:FD:C7:CC:FB:FC:18:23:61:52:3A:E2:7D:69:7E:95:2F",
            "aia": 
"rsync://rpki.ripe.net/repository/DEFAULT/OOFPkv3HzPv8GCNhUjrifWl-lS8.cer",
            "valid_until": 1656633600,
            "vrps": [
                    { "prefix": "2a0e:b240::/29", "asid": 0, "maxlen": 29 }
            ],
            "validation": "OK"
    }

'hash_id' could be used as a proper primary key in relational databases.

OK?

Kind regards,

Job

Index: filemode.c
===================================================================
RCS file: /cvs/src/usr.sbin/rpki-client/filemode.c,v
retrieving revision 1.2
diff -u -p -r1.2 filemode.c
--- filemode.c  21 Apr 2022 12:59:03 -0000      1.2
+++ filemode.c  23 Apr 2022 19:02:19 -0000
@@ -265,6 +265,7 @@ proc_parser_file(char *file, unsigned ch
        struct gbr *gbr = NULL;
        struct tal *tal = NULL;
        char *aia = NULL, *aki = NULL;
+       char filehash[SHA256_DIGEST_LENGTH], *hash = NULL;
        enum rtype type;
        int is_ta = 0;
 
@@ -284,10 +285,20 @@ proc_parser_file(char *file, unsigned ch
                }
        }
 
-       if (outformats & FORMAT_JSON)
+
+       if (!EVP_Digest(buf, len, filehash, NULL, EVP_sha256(), NULL))
+               errx(1, "EVP_Digest failed in %s", __func__);
+
+       if (base64_encode(filehash, sizeof(filehash), &hash) == -1)
+               errx(1, "base64_encode failed in %s", __func__);
+
+       if (outformats & FORMAT_JSON) {
                printf("{\n\t\"file\": \"%s\",\n", file);
-       else
+               printf("\t\"hash_id\": \"%s\",\n", hash);
+       } else {
                printf("File: %s\n", file);
+               printf("Hash identifier: %s\n", hash);
+       }
 
        type = rtype_from_file_extension(file);