initial commit

pow.go

@@ -0,0 +1,102 @@
+package deepseek
+
+import (
+	"context"
+	"deepseek/pow"
+	"encoding/base64"
+	"encoding/json"
+	"log"
+)
+
+// CreatePowChallengeReq is the request body used to obtain a PoW challenge.
+type CreatePowChallengeReq struct {
+	TargetPath string `json:"target_path"`
+}
+
+// CreatePowChallengeRes contains a server-issued PoW challenge.
+type CreatePowChallengeRes struct {
+	Challenge PowChallenge `json:"challenge"`
+}
+
+// PowChallenge describes a signed DeepSeek proof-of-work challenge.
+type PowChallenge struct {
+	Algorithm   string `json:"algorithm"`
+	Challenge   string `json:"challenge"`
+	Salt        string `json:"salt"`
+	Signature   string `json:"signature"`
+	Difficulty  uint64 `json:"difficulty"`
+	ExpireAt    uint64 `json:"expire_at"`
+	ExpireAfter int    `json:"expire_after"`
+	TargetPath  string `json:"target_path"`
+}
+
+func (c PowChallenge) solve() (uint64, error) {
+	answer, err := pow.Challenge{
+		Algorithm:  c.Algorithm,
+		Challenge:  c.Challenge,
+		Salt:       c.Salt,
+		Difficulty: c.Difficulty,
+		ExpireAt:   c.ExpireAt,
+	}.Solve()
+	if err != nil {
+		return 0, err
+	}
+
+	log.Printf("PoW answer: %d", answer)
+	return answer, nil
+}
+
+// ToBase64 solves c and returns the URL-safe base64-encoded JSON response sent
+// in the x-ds-pow-response header.
+func (c PowChallenge) ToBase64() ([]byte, error) {
+	type s struct {
+		Algorithm  string `json:"algorithm"`
+		Challenge  string `json:"challenge"`
+		Salt       string `json:"salt"`
+		Answer     uint64 `json:"answer"`
+		Signature  string `json:"signature"`
+		TargetPath string `json:"target_path"`
+	}
+
+	answer, err := c.solve()
+	if err != nil {
+		return nil, err
+	}
+	data, err := json.Marshal(s{
+		Algorithm:  c.Algorithm,
+		Challenge:  c.Challenge,
+		Salt:       c.Salt,
+		Answer:     answer,
+		Signature:  c.Signature,
+		TargetPath: c.TargetPath,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return []byte(base64.URLEncoding.EncodeToString(data)), nil
+}
+
+// CreatePowChallenge requests a PoW challenge using a background context.
+func (api *Client) CreatePowChallenge() (CreatePowChallengeRes, error) {
+	return api.CreatePowChallengeWithContext(context.Background())
+}
+
+// CreatePowChallengeWithContext requests a PoW challenge and honors ctx
+// cancellation.
+func (api *Client) CreatePowChallengeWithContext(ctx context.Context) (CreatePowChallengeRes, error) {
+	var zero CreatePowChallengeRes
+
+	body := CreatePowChallengeReq{TargetPath: "/api/v0/chat/completion"}
+	req := NewRequest[CreatePowChallengeRes]("POST", "chat/create_pow_challenge", body)
+	resp, err := req.DoWithContext(ctx, api)
+	if err != nil {
+		return zero, err
+	}
+	defer resp.Body.Close()
+	response, err := req.unmarshallBizResponse(resp)
+	if err != nil {
+		return zero, err
+	}
+	return response.Data.Data, nil
+}