chore: initial snapshot for gitea/github upload

llm-gateway-competitors/sub2api-tar/backend/internal/service/bedrock_signer.go

@@ -0,0 +1,67 @@
+package service
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	v4 "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
+)
+
+// BedrockSigner 使用 AWS SigV4 对 Bedrock 请求签名
+type BedrockSigner struct {
+	credentials aws.Credentials
+	region      string
+	signer      *v4.Signer
+}
+
+// NewBedrockSigner 创建 BedrockSigner
+func NewBedrockSigner(accessKeyID, secretAccessKey, sessionToken, region string) *BedrockSigner {
+	return &BedrockSigner{
+		credentials: aws.Credentials{
+			AccessKeyID:     accessKeyID,
+			SecretAccessKey: secretAccessKey,
+			SessionToken:    sessionToken,
+		},
+		region: region,
+		signer: v4.NewSigner(),
+	}
+}
+
+// NewBedrockSignerFromAccount 从 Account 凭证创建 BedrockSigner
+func NewBedrockSignerFromAccount(account *Account) (*BedrockSigner, error) {
+	accessKeyID := account.GetCredential("aws_access_key_id")
+	if accessKeyID == "" {
+		return nil, fmt.Errorf("aws_access_key_id not found in credentials")
+	}
+	secretAccessKey := account.GetCredential("aws_secret_access_key")
+	if secretAccessKey == "" {
+		return nil, fmt.Errorf("aws_secret_access_key not found in credentials")
+	}
+	region := account.GetCredential("aws_region")
+	if region == "" {
+		region = defaultBedrockRegion
+	}
+	sessionToken := account.GetCredential("aws_session_token") // 可选
+
+	return NewBedrockSigner(accessKeyID, secretAccessKey, sessionToken, region), nil
+}
+
+// SignRequest 对 HTTP 请求进行 SigV4 签名
+// 重要约束：调用此方法前，req 应只包含 AWS 相关的 header（如 Content-Type、Accept）。
+// 非 AWS header（如 anthropic-beta）会参与签名计算，如果 Bedrock 服务端不识别这些 header，
+// 签名验证可能失败。litellm 通过 _filter_headers_for_aws_signature 实现头过滤，
+// 当前实现中 buildUpstreamRequestBedrock 仅设置了 Content-Type 和 Accept，因此是安全的。
+func (s *BedrockSigner) SignRequest(ctx context.Context, req *http.Request, body []byte) error {
+	payloadHash := sha256Hash(body)
+	return s.signer.SignHTTP(ctx, s.credentials, req, payloadHash, "bedrock", s.region, time.Now())
+}
+
+func sha256Hash(data []byte) string {
+	h := sha256.Sum256(data)
+	return hex.EncodeToString(h[:])
+}