a scoring model

src/Yavsc.Org/Services/TrustTokenService.cs

@@ -0,0 +1,75 @@
+// Yavsc.Services.Kyc/TrustTokenService.cs
+namespace Yavsc.Services.Kyc
+{
+    using System;
+    using System.Security.Cryptography;
+    using System.Text;
+    using System.Threading.Tasks;
+    using Microsoft.EntityFrameworkCore;
+    using Microsoft.Extensions.Options;
+    using Yavsc.Models;
+    using Yavsc.Models.Kyc;
+
+    public class TrustTokenService : ITrustTokenService
+    {
+        private readonly ApplicationDbContext _db;
+        private readonly byte[] _hmacKey;
+
+        public TrustTokenService(ApplicationDbContext db, IOptions<KycOptions> options)
+        {
+            _db = db;
+            // La clé est chargée depuis la config, jamais hardcodée
+            _hmacKey = Encoding.UTF8.GetBytes(options.Value.HmacSecret
+                ?? throw new InvalidOperationException("KycOptions:HmacSecret manquant"));
+        }
+
+        public async Task<TrustToken> GetOrCreateFromTrustedPartyAsync(string externalToken)
+        {
+            if (string.IsNullOrWhiteSpace(externalToken))
+                throw new ArgumentException("Token externe invalide", nameof(externalToken));
+
+            // Le token tiers arrive déjà pseudonymisé — on le stocke tel quel
+            return await GetOrCreateAsync(externalToken, "trusted_party");
+        }
+
+        public async Task<TrustToken> GetOrCreateFromEmailAsync(string confirmedEmail)
+        {
+            if (string.IsNullOrWhiteSpace(confirmedEmail))
+                throw new ArgumentException("Email invalide", nameof(confirmedEmail));
+
+            // HMAC-SHA256(email normalisé, clé_secrète) → pseudonyme stable, irréversible
+            var tokenHash = ComputeHmac(confirmedEmail.Trim().ToLowerInvariant());
+            return await GetOrCreateAsync(tokenHash, "confirmed_email");
+        }
+
+        // ── Privé ────────────────────────────────────────────────────────────
+
+        private async Task<TrustToken> GetOrCreateAsync(string tokenHash, string source)
+        {
+            // Idempotent : même entité → même token
+            var existing = await _db.TrustTokens
+                .FirstOrDefaultAsync(t => t.TokenHash == tokenHash);
+
+            if (existing != null)
+                return existing;
+
+            var token = new TrustToken
+            {
+                TokenHash  = tokenHash,
+                TokenSource = source,
+                CreatedAt  = DateTime.UtcNow
+            };
+
+            _db.TrustTokens.Add(token);
+            await _db.SaveChangesAsync();
+            return token;
+        }
+
+        private string ComputeHmac(string input)
+        {
+            using var hmac = new HMACSHA256(_hmacKey);
+            var hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(input));
+            return Convert.ToHexString(hash).ToLowerInvariant(); // 64 chars, stockable
+        }
+    }
+}