/* ARM assembly Raspberry PI  */
/*  program yahoosearch.s   */
/* access RosettaCode.org and data extract       */
/* use openssl  for access to port 443 */
/* test openssl : package libssl-dev  */

/* REMARK 1 : this program use routines in a include file
   see task Include a file language arm assembly
   for the routine affichageMess conversion10
   see at end of this program the instruction include */

/*******************************************/
/* Constantes                              */
/*******************************************/
.equ STDOUT, 1           @ Linux output console
.equ EXIT,   1           @ Linux syscall
.equ WRITE,  4           @ Linux syscall
.equ BRK,    0x2d        @ Linux syscall
.equ CHARPOS,     '@'

.equ EXIT,          1
.equ TAILLEBUFFER,  500

.equ SSL_OP_NO_SSLv3,        0x02000000
.equ SSL_OP_NO_COMPRESSION,  0x00020000
.equ SSL_MODE_AUTO_RETRY,    0x00000004
.equ SSL_CTRL_MODE,          33

.equ BIO_C_SET_CONNECT,      100
.equ BIO_C_DO_STATE_MACHINE, 101
.equ BIO_C_SET_SSL,          109
.equ BIO_C_GET_SSL,          110

.equ LGBUFFERREQ,       512001
.equ LGBUFFER2,         128001

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessDebutPgm:       .asciz "Début du programme. \n"
szRetourLigne:        .asciz "\n"
szMessFinOK:          .asciz "Fin normale du programme. \n"
szMessErreur:         .asciz "Erreur  !!!"
szMessExtractArea:    .asciz "Extraction = "
szNomSite1:           .asciz "search.yahoo.com:443"   @ host name and port
szLibStart:           .asciz ">Rosetta Code"          @ search string
szNomrepCertif:       .asciz "/pi/certificats"
szRequete1:           .asciz "GET /search?p=\"Rosettacode.org\"&b=1 HTTP/1.1 \r\nHost: search.yahoo.com\r\nConnection: keep-alive\r\nContent-Type: text/plain\r\n\r\n"
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss
.align 4
sBufferreq:           .skip LGBUFFERREQ
szExtractArea:        .skip TAILLEBUFFER
stNewSSL:             .skip 200
/*********************************/
/*  code section                 */
/*********************************/
.text
.global main
main:
    ldr r0,iAdrszMessDebutPgm
    bl affichageMess                             @ start message

    /* connexion host port 443 and send query */
    bl envoiRequete
    cmp r0,#-1
    beq 99f                                       @ error ?

    bl analyseReponse

    ldr r0,iAdrszMessFinOK                        @ end message
    bl affichageMess
    mov r0, #0                                    @ return code ok
    b 100f
99:
    ldr r0,iAdrszMessErreur                       @ error
    bl affichageMess
    mov r0, #1                                    @ return code error
    b 100f
100:
    mov r7,#EXIT                                  @ program end
    svc #0                                        @ system call
iAdrszMessDebutPgm:          .int szMessDebutPgm
iAdrszMessFinOK:             .int szMessFinOK
iAdrszMessErreur:            .int szMessErreur

/*********************************************************/
/*   connexion host port 443 and send query            */
/*********************************************************/
envoiRequete:
    push {r2-r8,lr}                 @ save registers
    @*************************************
    @ openSsl functions use              *
    @*************************************
                                    @init ssl
    bl OPENSSL_init_crypto
    bl ERR_load_BIO_strings
    mov r2, #0
    mov r1, #0
    mov r0, #2
    bl OPENSSL_init_crypto
    mov r2, #0
    mov r1, #0
    mov r0, #0
    bl OPENSSL_init_ssl
    cmp r0,#0
    blt erreur
    bl TLS_client_method
    bl SSL_CTX_new
    cmp r0,#0
    ble erreur
    mov r6,r0                       @ save ctx
    ldr r1,iFlag
    bl SSL_CTX_set_options
    mov r0,r6
    mov r1,#0
    ldr r2,iAdrszNomrepCertif
    bl SSL_CTX_load_verify_locations
    cmp r0,#0
    ble erreur
    mov r0,r6
    bl BIO_new_ssl_connect
    cmp r0,#0
    ble erreur
    mov r5,r0                       @ save bio
    mov r1,#BIO_C_GET_SSL
    mov r2,#0
    ldr r3,iAdrstNewSSL
    bl BIO_ctrl
    ldr r0,iAdrstNewSSL
    ldr r0,[r0]
    mov r1,#SSL_CTRL_MODE
    mov r2,#SSL_MODE_AUTO_RETRY
    mov r3,#0
    bl SSL_ctrl
    mov r0,r5                       @ bio
    mov r1,#BIO_C_SET_CONNECT
    mov r2,#0
    ldr r3,iAdrszNomSite1
    bl BIO_ctrl
    mov r0,r5                       @ bio
    mov r1,#BIO_C_DO_STATE_MACHINE
    mov r2,#0
    mov r3,#0
    bl  BIO_ctrl
                                    @ compute query length
    mov r2,#0
    ldr r1,iAdrszRequete1           @ query
1:
    ldrb r0,[r1,r2]
    cmp r0,#0
    addne r2,#1
    bne 1b
                                    @ send query
    mov r0,r5                       @ bio
                                    @ r1 = address query
                                    @ r2 = length query
    mov r3,#0
    bl BIO_write                    @ send query
    cmp r0,#0
    blt erreur
    ldr r7,iAdrsBufferreq           @ buffer address
2:                                  @ begin loop to read datas
    mov r0,r5                       @ bio
    mov r1,r7                       @ buffer address
    mov r2,#LGBUFFERREQ - 1
    mov r3,#0
    bl BIO_read
    cmp r0,#0
    ble 4f                          @ error ou pb server
    add r7,r0
    sub r2,r7,#6
    ldr r2,[r2]
    ldr r3,iCharEnd
    cmp r2,r3                       @ text end ?
    beq 4f
    mov r1,#0xFFFFFF                @ delay loop
3:
    subs r1,#1
    bgt 3b
    b 2b                            @ loop read other chunk
4:                                  @ read end
    //ldr r0,iAdrsBufferreq           @ to display buffer response of the query
    //bl affichageMess
    mov r0, r5                      @ close bio
    bl BIO_free_all
    mov r0,#0
    b 100f
erreur:                             @ error display
    ldr r1,iAdrszMessErreur
    bl   afficheerreur
    mov r0,#-1                      @ error code
    b 100f
100:
    pop {r2-r8,lr}                  @ restaur registers
    bx lr
iAdrszRequete1:             .int szRequete1
iAdrsBufferreq:             .int sBufferreq
iFlag:                      .int SSL_OP_NO_SSLv3 | SSL_OP_NO_COMPRESSION
iAdrstNewSSL:               .int stNewSSL
iAdrszNomSite1:             .int szNomSite1
iAdrszNomrepCertif:         .int szNomrepCertif
iCharEnd:                   .int 0x0A0D300A
/*********************************************************/
/*   response analyze                                    */
/*********************************************************/
analyseReponse:
    push {r1-r4,lr}                           @ save registers
    ldr r0,iAdrsBufferreq                     @ buffer address
    ldr r1,iAdrszLibStart                     @ key text address
    mov r2,#2                                 @ occurence key text
    mov r3,#-11                               @ offset
    ldr r4,iAdrszExtractArea                  @ address result area
    bl extChaine
    cmp r0,#-1
    beq 99f
    ldr r0,iAdrszMessExtractArea
    bl affichageMess
    ldr r0,iAdrszExtractArea                  @ résult display
    bl affichageMess
    ldr r0,iAdrszRetourLigne
    bl affichageMess
    b 100f
99:
    ldr r0,iAdrszMessErreur                   @ error
    bl affichageMess
    mov r0, #-1                               @ error return code
    b 100f
100:
    pop {r1-r4,lr}                            @ restaur registers
    bx lr
iAdrszLibStart:                 .int szLibStart
iAdrszExtractArea:              .int szExtractArea
iAdrszMessExtractArea:          .int szMessExtractArea
iAdrszRetourLigne:              .int szRetourLigne
/*********************************************************/
/*   Text Extraction behind text key                     */
/*********************************************************/
/* r0  buffer address   */
/* r1  key text to search */
/* r2  number occurences to key text */
/* r3  offset */
/* r4  result address */
extChaine:
    push {r2-r8,lr}      @ save registers
    mov r5,r0            @ save buffer address
    mov r6,r1            @ save key text
                         @ compute text length
    mov r7,#0
1:                       @ loop
    ldrb r0,[r5,r7]      @ load a byte
    cmp r0,#0            @ end ?
    addne r7,#1          @ no -> loop
    bne 1b
    add r7,r5            @ compute text end

    mov r8,#0
2:                       @ compute length text key
    ldrb r0,[r6,r8]
    cmp r0,#0
    addne r8,#1
    bne 2b

3:                       @ loop to search nième(r2)  key text
    mov r0,r5
    mov r1,r6
    bl rechercheSousChaine
    cmp r0,#0
    blt 100f
    subs r2,#1
    addgt r5,r0
    addgt r5,r8
    bgt 3b
    add r0,r5           @ add address text to index
    add r3,r0           @ add offset
    sub r3,#1
                        @ and add length key text
    add r3,r8
    cmp r3,r7           @ > at text end
    movge r0,#-1        @ yes -> error
    bge 100f
    mov r0,#0
4:                      @ character loop copy
    ldrb r2,[r3,r0]
    strb r2,[r4,r0]
    cmp r2,#0           @ text end ?
    moveq r0,#0         @ return zero
    beq 100f
    cmp r0,#48          @ extraction length
    beq 5f
    add r0,#1
    b 4b                @ and loop
5:
    mov r2,#0           @ store final zéro
    strb r2,[r4,r0]
    add r0,#1
    add r0,r3           @ r0 return the last position of extraction
                        @ it is possible o search another text
100:
   	pop {r2-r8,lr}      @ restaur registers
    bx lr

/******************************************************************/
/*   search substring in string                                   */
/******************************************************************/
/* r0 contains address string */
/* r1 contains address substring */
/* r0 return start index substring or -1 if not find */
rechercheSousChaine:
    push {r1-r6,lr}                       @ save registers
    mov r2,#0                             @ index position string
    mov r3,#0                             @ index position substring
    mov r6,#-1                            @ search index
    ldrb r4,[r1,r3]                       @ load first byte substring
    cmp r4,#0                             @ zero final ?
    moveq r0,#-1                          @ error
    beq 100f
1:
    ldrb r5,[r0,r2]                       @ load string byte
    cmp r5,#0                             @ zero final ?
    moveq r0,#-1                          @ yes -> not find
    beq 100f
    cmp r5,r4                             @ compare character two strings
    beq 2f
    mov r6,#-1                            @ not equal - > raz index
    mov r3,#0                             @ and raz byte counter
    ldrb r4,[r1,r3]                       @ and load byte
    add r2,#1                             @ and increment byte counter
    b 1b                                  @ and loop
2:                                        @ characters equal
    cmp r6,#-1                            @ first character equal ?
    moveq r6,r2                           @ yes -> start index in r6
    add r3,#1                             @ increment substring counter
    ldrb r4,[r1,r3]                       @ and load next byte
    cmp r4,#0                             @ zero final ?
    beq 3f                                @ yes -> search end
    add r2,#1                             @ else increment string index
    b 1b                                  @ and loop
3:
    mov r0,r6                             @ return start index substring in the string
100:
    pop {r1-r6,lr}                        @ restaur registres
    bx lr

/***************************************************/
/*      ROUTINES INCLUDE                 */
/***************************************************/
.include "../affichage.inc"