OpenSSL SSL_write: SSL_ERROR_SYSCALL, errno 0

[gold22]

I did this

Upload of files to an FTP storage via SSL is broken in 8.10.1.

Run code from the file
upload-test.txt

Upload fails with the error code 55

Curl version: 8.10.1
*   Trying 10.69.43.144:21...
* Connected to 10.69.43.144 (10.69.43.144) port 21
< 220 ProFTPD Server (ProFTPD) [10.69.43.144]
> AUTH SSL
< 234 AUTH SSL successful
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384 / X25519 / RSASSA-PSS
* Server certificate:
*  subject: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  start date: Sep 29 09:27:53 2024 GMT
*  expire date: Sep 29 09:27:53 2025 GMT
*  issuer: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
*   Certificate level 0: Public key type RSA (2048/112 Bits/secBits), signed using sha256WithRSAEncryption
* Connected to 10.69.43.144 (10.69.43.144) port 21
> USER ftpuser
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
< 331 Password required for ftpuser
> PASS ftppassword
< 230 User ftpuser logged in
> PBSZ 0
< 200 PBSZ 0 successful
> PROT P
< 200 Protection set to Private
> PWD
< 257 "/" is the current directory
* Entry path is '/'
* Request has same path as previous transfer
> EPSV
* Connect data stream passively
< 229 Entering Extended Passive Mode (|||49206|)
* Connecting to 10.69.43.144 (10.69.43.144) port 49206
*   Trying 10.69.43.144:49206...
* SSL reusing session ID
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
> TYPE I
< 200 Type set to I
> STOR test.out
< 150 Opening BINARY mode data connection for test.out
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384 / X25519 / UNDEF
* Server certificate:
*  subject: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  start date: Sep 29 09:27:53 2024 GMT
*  expire date: Sep 29 09:27:53 2025 GMT
*  issuer: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* Connected 2nd connection to 10.69.43.144 port 49206
* OpenSSL SSL_write: SSL_ERROR_SYSCALL, errno 0
* closing connection #0
upload failed, code 55 (Failed sending data to the peer).

I expected the following

Upload succeeds

curl/libcurl version

libcurl 8.10.1

operating system

Ubuntu 24.04 x86_64
Microsoft Windows Server 2022 x86_64

[icing]

Thanks for the report. Could you add a trace with -v --trace-config all for this situation?

[gold22]

I cannot reproduce it with the curl utility, it is reproduced with code example upload-test.txt. The example uses the curl multi interface.

[icing]

I see. In that case, could you add the following line to the sample code, right after curl_global_init()?

curl_global_trace("all");

That will give more tracing at what is happening at the network level while talking to your server.

[gold22]

Curl version: 8.10.1
* [READ] client_reset, clear readers
* [FTP] [STOP] setup connection -> 0
* [SETUP] added
* [HAPPY-EYEBALLS] created ipv4 (timeout 299998ms)
* [HAPPY-EYEBALLS] ipv4 starting (timeout=299998ms)
*   Trying 10.69.43.144:21...
* [TCP] cf_socket_open() -> 0, fd=5
* [TCP] local address 10.69.45.55 port 44096...
* [HAPPY-EYEBALLS] ipv4 connect -> 0, connected=0
* [TCP] adjust_pollset, !connected, POLLOUT fd=5
* [HAPPY-EYEBALLS] adjust_pollset -> 1 socks
* [TCP] connected
* [HAPPY-EYEBALLS] ipv4 connect -> 0, connected=1
* [HAPPY-EYEBALLS] Connected to 10.69.43.144 (10.69.43.144) port 21
* Connected to 10.69.43.144 (10.69.43.144) port 21
* [FTP] [STOP] -> [WAIT220]
* [TCP] recv(len=900) -> 45, err=0
< 220 ProFTPD Server (ProFTPD) [10.69.43.144]
* [WRITE] download_write header(type=2, blen=45) -> 0
* [WRITE] client_write(type=2, len=45) -> 0
* [TCP] send(len=10) -> 10, err=0
> AUTH SSL
* [FTP] [WAIT220] -> [AUTH]
* [TCP] recv(len=900) -> 25, err=0
< 234 AUTH SSL successful
* [WRITE] download_write header(type=2, blen=25) -> 0
* [WRITE] client_write(type=2, len=25) -> 0
* [SSL] added
* [SSL] cf_connect()
* [SSL] No cached session ID for ftp://10.69.43.144:21
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* [TCP] send(len=517) -> 517, err=0
* [SSL] ossl_bio_cf_out_write(len=517) -> 517, err=0
* [TCP] recv(len=5) -> -1, err=81
* [SSL] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL] populate_x509_store, path=/etc/ssl/certs/ca-certificates.crt, blob=0
* [SSL] SSL_connect() -> err=-1, detail=2
* [SSL] SSL_connect() -> want recv
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=122) -> 122, err=0
* [SSL] ossl_bio_cf_in_read(len=122) -> 122, err=0
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=1) -> 1, err=0
* [SSL] ossl_bio_cf_in_read(len=1) -> 1, err=0
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=23) -> 23, err=0
* [SSL] ossl_bio_cf_in_read(len=23) -> 23, err=0
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=924) -> 924, err=0
* [SSL] ossl_bio_cf_in_read(len=924) -> 924, err=0
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=281) -> 281, err=0
* [SSL] ossl_bio_cf_in_read(len=281) -> 281, err=0
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=69) -> 69, err=0
* [SSL] ossl_bio_cf_in_read(len=69) -> 69, err=0
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* [TCP] send(len=80) -> 80, err=0
* [SSL] ossl_bio_cf_out_write(len=80) -> 80, err=0
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384 / X25519 / RSASSA-PSS
* Server certificate:
*  subject: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  start date: Sep 29 09:27:53 2024 GMT
*  expire date: Sep 29 09:27:53 2025 GMT
*  issuer: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
*   Certificate level 0: Public key type RSA (2048/112 Bits/secBits), signed using sha256WithRSAEncryption
* [SSL] cf_connect() -> 0, done=1
* Connected to 10.69.43.144 (10.69.43.144) port 21
* [TCP] send(len=36) -> 36, err=0
* [SSL] ossl_bio_cf_out_write(len=36) -> 36, err=0
> USER ftpuser
* [FTP] [AUTH] -> [USER]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=282) -> 282, err=0
* [SSL] ossl_bio_cf_in_read(len=282) -> 282, err=0
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* [SSL] No cached session ID for ftp://10.69.43.144:21
* [SSL] Added Session ID to cache for ftp://10.69.43.144:21 [server]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=282) -> 282, err=0
* [SSL] ossl_bio_cf_in_read(len=282) -> 282, err=0
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* [SSL] Found cached session ID for ftp://10.69.43.144:21
* [SSL] Added Session ID to cache for ftp://10.69.43.144:21 [server]
* [TCP] recv(len=5) -> -1, err=81
* [SSL] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL] cf_recv(len=900) -> -1, 81
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=52) -> 52, err=0
* [SSL] ossl_bio_cf_in_read(len=52) -> 52, err=0
* [SSL] cf_recv(len=900) -> 35, 0
< 331 Password required for ftpuser
* [WRITE] download_write header(type=2, blen=35) -> 0
* [WRITE] client_write(type=2, len=35) -> 0
* [TCP] send(len=39) -> 39, err=0
* [SSL] ossl_bio_cf_out_write(len=39) -> 39, err=0
> PASS ftppassword
* [FTP] [USER] -> [PASS]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=45) -> 45, err=0
* [SSL] ossl_bio_cf_in_read(len=45) -> 45, err=0
* [SSL] cf_recv(len=900) -> 28, 0
< 230 User ftpuser logged in
* [WRITE] download_write header(type=2, blen=28) -> 0
* [WRITE] client_write(type=2, len=28) -> 0
* [TCP] send(len=30) -> 30, err=0
* [SSL] ossl_bio_cf_out_write(len=30) -> 30, err=0
> PBSZ 0
* [FTP] [PASS] -> [PBSZ]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=40) -> 40, err=0
* [SSL] ossl_bio_cf_in_read(len=40) -> 40, err=0
* [SSL] cf_recv(len=900) -> 23, 0
< 200 PBSZ 0 successful
* [WRITE] download_write header(type=2, blen=23) -> 0
* [WRITE] client_write(type=2, len=23) -> 0
* [TCP] send(len=30) -> 30, err=0
* [SSL] ossl_bio_cf_out_write(len=30) -> 30, err=0
> PROT P
* [FTP] [PBSZ] -> [PROT]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=48) -> 48, err=0
* [SSL] ossl_bio_cf_in_read(len=48) -> 48, err=0
* [SSL] cf_recv(len=900) -> 31, 0
< 200 Protection set to Private
* [WRITE] download_write header(type=2, blen=31) -> 0
* [WRITE] client_write(type=2, len=31) -> 0
* [TCP] send(len=27) -> 27, err=0
* [SSL] ossl_bio_cf_out_write(len=27) -> 27, err=0
> PWD
* [FTP] [PROT] -> [PWD]
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=51) -> 51, err=0
* [SSL] ossl_bio_cf_in_read(len=51) -> 51, err=0
* [SSL] cf_recv(len=900) -> 34, 0
< 257 "/" is the current directory
* [WRITE] download_write header(type=2, blen=34) -> 0
* [WRITE] client_write(type=2, len=34) -> 0
* Entry path is '/'
* [FTP] [PWD] -> [STOP]
* [FTP] [STOP] protocol connect phase DONE
* Request has same path as previous transfer
* [FTP] [STOP] DO phase starts
* [TCP] send(len=28) -> 28, err=0
* [SSL] ossl_bio_cf_out_write(len=28) -> 28, err=0
> EPSV
* [FTP] [STOP] -> [PASV]
* Connect data stream passively
* [FTP] [PASV] perform, awaiting DATA connect
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=65) -> 65, err=0
* [SSL] ossl_bio_cf_in_read(len=65) -> 65, err=0
* [SSL] cf_recv(len=900) -> 48, 0
< 229 Entering Extended Passive Mode (|||58419|)
* [WRITE] download_write header(type=2, blen=48) -> 0
* [WRITE] client_write(type=2, len=48) -> 0
* [SETUP-1] added
* Connecting to 10.69.43.144 (10.69.43.144) port 58419
* [FTP] [PASV] -> [STOP]
* [FTP] [STOP] DO phase is complete2
* [HAPPY-EYEBALLS-1] created ipv4 (timeout 299668ms)
* [HAPPY-EYEBALLS-1] ipv4 starting (timeout=299668ms)
*   Trying 10.69.43.144:58419...
* [TCP-1] cf_socket_open() -> 0, fd=6
* [TCP-1] local address 10.69.45.55 port 60618...
* [HAPPY-EYEBALLS-1] ipv4 connect -> 0, connected=0
* [FTP] [STOP] ftp_domore_getsock()
* [TCP-1] adjust_pollset, !connected, POLLOUT fd=6
* [HAPPY-EYEBALLS-1] adjust_pollset -> 2 socks
* [TCP-1] connected
* [HAPPY-EYEBALLS-1] ipv4 connect -> 0, connected=1
* [HAPPY-EYEBALLS-1] Connected to 10.69.43.144 (10.69.43.144) port 58419
* [SSL-1] cf_connect()
* [SSL-1] Found cached session ID for ftp://10.69.43.144:21
* SSL reusing session ID
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* [TCP-1] send(len=596) -> 596, err=0
* [SSL-1] ossl_bio_cf_out_write(len=596) -> 596, err=0
* [TCP-1] recv(len=5) -> -1, err=81
* [SSL-1] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL-1] populate_x509_store, path=/etc/ssl/certs/ca-certificates.crt, blob=0
* [SSL-1] SSL_connect() -> err=-1, detail=2
* [SSL-1] SSL_connect() -> want recv
* [SSL-1] cf_connect() -> 0, done=0
* [TCP] send(len=30) -> 30, err=0
* [SSL] ossl_bio_cf_out_write(len=30) -> 30, err=0
> TYPE I
* [FTP] [STOP] -> [STOR_TYPE]
* [FTP] [STOR_TYPE] ftp_domore_getsock()
* [SSL-1] adjust_pollset, POLLIN fd=6
* [TCP-1] adjust_pollset, !active, POLLIN fd=6
* [SSL-1] cf_connect()
* [TCP-1] recv(len=5) -> -1, err=81
* [SSL-1] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL-1] SSL_connect() -> err=-1, detail=2
* [SSL-1] SSL_connect() -> want recv
* [SSL-1] cf_connect() -> 0, done=0
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=36) -> 36, err=0
* [SSL] ossl_bio_cf_in_read(len=36) -> 36, err=0
* [SSL] cf_recv(len=900) -> 19, 0
< 200 Type set to I
* [WRITE] download_write header(type=2, blen=19) -> 0
* [WRITE] client_write(type=2, len=19) -> 0
* [TCP] send(len=37) -> 37, err=0
* [SSL] ossl_bio_cf_out_write(len=37) -> 37, err=0
> STOR test.out
* [FTP] [STOR_TYPE] -> [STOR]
* [FTP] [STOR] ftp_domore_getsock()
* [SSL-1] adjust_pollset, POLLIN fd=6
* [TCP-1] adjust_pollset, !active, POLLIN fd=6
* [SSL-1] cf_connect()
* [TCP-1] recv(len=5) -> -1, err=81
* [SSL-1] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL-1] SSL_connect() -> err=-1, detail=2
* [SSL-1] SSL_connect() -> want recv
* [SSL-1] cf_connect() -> 0, done=0
* [TCP] recv(len=5) -> 5, err=0
* [SSL] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP] recv(len=71) -> 71, err=0
* [SSL] ossl_bio_cf_in_read(len=71) -> 71, err=0
* [SSL] cf_recv(len=900) -> 54, 0
< 150 Opening BINARY mode data connection for test.out
* [WRITE] download_write header(type=2, blen=54) -> 0
* [WRITE] client_write(type=2, len=54) -> 0
* [FTP] InitiateTransfer()
* [SSL-1] cf_connect()
* [TCP-1] recv(len=5) -> -1, err=81
* [SSL-1] ossl_bio_cf_in_read(len=5) -> -1, err=81
* [SSL-1] SSL_connect() -> err=-1, detail=2
* [SSL-1] SSL_connect() -> want recv
* [TCP-1] recv(len=5) -> 5, err=0
* [SSL-1] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP-1] recv(len=128) -> 128, err=0
* [SSL-1] ossl_bio_cf_in_read(len=128) -> 128, err=0
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* [TCP-1] recv(len=5) -> 5, err=0
* [SSL-1] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP-1] recv(len=1) -> 1, err=0
* [SSL-1] ossl_bio_cf_in_read(len=1) -> 1, err=0
* [TCP-1] recv(len=5) -> 5, err=0
* [SSL-1] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP-1] recv(len=23) -> 23, err=0
* [SSL-1] ossl_bio_cf_in_read(len=23) -> 23, err=0
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* [TCP-1] recv(len=5) -> 5, err=0
* [SSL-1] ossl_bio_cf_in_read(len=5) -> 5, err=0
* [TCP-1] recv(len=69) -> 69, err=0
* [SSL-1] ossl_bio_cf_in_read(len=69) -> 69, err=0
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* [TCP-1] send(len=80) -> 80, err=0
* [SSL-1] ossl_bio_cf_out_write(len=80) -> 80, err=0
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384 / X25519 / UNDEF
* Server certificate:
*  subject: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  start date: Sep 29 09:27:53 2024 GMT
*  expire date: Sep 29 09:27:53 2025 GMT
*  issuer: C=CH; L=XX; O=XX; CN=XX; emailAddress=xx@xx.xx
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* [SSL-1] cf_connect() -> 0, done=1
* Connected 2nd connection to 10.69.43.144 port 58419
* [FTP] [STOR] -> [STOP]
* [READ] add fread reader, len=-1 -> 0
* [READ] cr_in_read(len=65536, total=-1, read=26) -> 0, nread=26, eos=0
* [READ] client_read(len=65536) -> 0, nread=26, eos=0
* [TCP-1] send(len=48) -> 48, err=0
* [SSL-1] ossl_bio_cf_out_write(len=48) -> 48, err=0
* [READ] cr_in_read(len=65536, total=-1, read=26) -> 0, nread=0, eos=1
* [READ] client_read(len=65536) -> 0, nread=0, eos=1
* OpenSSL SSL_write: SSL_ERROR_SYSCALL, errno 0
* [FTP] [STOP] closing DATA connection
* [SETUP-1] close
* [HAPPY-EYEBALLS-1] close
* [TCP-1] cf_socket_close(6)
* [TCP-1] destroy
* [HAPPY-EYEBALLS-1] destroy
* [SETUP-1] destroy
* [FTP] [STOP] done, result=55
* [WRITE] cw-out done
* closing connection #0
* [SETUP] close
* [HAPPY-EYEBALLS] close
* [TCP] cf_socket_close(5)
* [TCP] destroy
* [HAPPY-EYEBALLS] destroy
* [SETUP] destroy
upload failed, code 55 (Failed sending data to the peer).

[icing]

Thanks. I made #15102 with a test case and a fix for this.

[MonkeybreadSoftware]

Thank you. I also had a client complaining about this, so I applied your patch, rebuild curl and send to the client. Bug fixed.
Great work!